CHAPTER 34

ICE RINKS
Applications .................................................................................................................................. 34.1
Refrigeration Requirements ......................................................................................................... 34.1
Ice Rink Conditions ...................................................................................................................... 34.4
Equipment Selection ..................................................................................................................... 34.5
Rink Floor Design ........................................................................................................................ 34.8
Building, Maintaining, and Planing Ice Surfaces ...................................................................... 34.10
Imitation Ice-Skating Surfaces ................................................................................................... 34.11

A NY level sheet of ice made by refrigeration (the term arti-

ficial ice is sometimes used) is referred to in this chapter as an
ice rink regardless of use and whether it is located indoors or out-
Speed Skating. Indoor speed skating has traditionally been per-
formed on hockey-sized rinks. The Olympic-sized outdoor speed
skating track is a 400 m oval, 10 m wide with 112 m straightaways
doors. Bobsled-luge tracks are not referred to as rinks but are refer- and curves with an inner radius of 25 m. Most speed skating ovals
enced under this chapter. were originally constructed outdoors; however, some have now
The freezing of an ice sheet is usually accomplished by the cir- been constructed indoors.
culation of a heat transfer fluid through a network of pipes or tubes Recreational Skating. Recreational skating can be done on any
located below the surface of the ice. The heat transfer fluid is pre- size or shape rink, as long as it can be efficiently resurfaced. Gen-
dominantly a secondary coolant such as glycol, methanol, or cal- erally, 2.3 to 2.8 m2 is allowed for each person actually skating. This
cium chloride (see Chapter 21 of the 2001 ASHRAE Handbook— ratio may vary for large numbers of beginner skaters. A 26 by 61 m
Fundamentals). hockey rink with 8.5 m radius corners has an area of 1517 m2 and
R-22 and R-717 are most frequently used for chilling secondary will accommodate a mixed group of about 650 skaters.
coolants for ice rinks. R-12 and R-502 have also been used; how- Public Arenas, Auditoriums, and Coliseums. Public arenas,
ever, due to the phaseout of the CFC refrigerants, they should no auditoriums, field houses, etc., are designed primarily for spectator
longer be considered for use. R-22 will also be phased out, so for events. They are used for ice sports, ice shows, and recreational
new rink equipment selection, R-22 and CFC replacements should skating, as well as for non-ice events, such as basketball, boxing,
be evaluated according to status and availability. tennis, conventions, exhibits, circuses, rodeos, tractor events, and
In some rinks, R-22, and R-717 to a lesser degree, have been stock shows. The refrigeration system can be designed so that, with
applied as a direct coolant for freezing ice. The direct refrigerant adequate personnel, the ice surface can be produced within 12 to
rinks operate at higher compressor suction pressures and tempera- 16 h. However, general practice is to leave the ice sheet in place and
tures, thus achieving an increased COP, compared to secondary to hold other events on an insulated floor placed on the ice. This
coolants. The primary refrigerant charge is greatly increased with approach saves significant time, labor, and energy.
this method of freezing. Because of emissions regulations, the pro- Bobsled-Luge Tracks. The bobsled-luge track usually incorpo-
jected R-22 phaseout, building codes, and fire regulations, R-22 and rates steel piping embedded in the track fed by an ammonia liquid
R-717 should not be used to freeze ice directly in indoor rinks. recirculation system. Approximately 85 000 to 90 000 m of piping is
required for an Olympic-sized track. The total refrigerated surface is
APPLICATIONS 8000 to 9300 m2. Refrigeration plant capacities in the range of
4000 to 5000 kW are required, depending on the ambient design
Most ice surfaces are used for a variety of sports, although some conditions, wind, and sun loads. The ammonia charge can exceed
are constructed for specific purposes and are of specific dimensions. 90 000 kg. Because the elevation changes are significant, care must
Usual rink sizes include the following: be exercised in placing the liquid recirculators, selecting the ammo-
Hockey. The accepted North American hockey rink size is 26 by nia pumps, and circuiting the floor piping.
61 m. Radius corners of 8.5 m are recommended by professional
and amateur rules. The Olympic and international hockey rink size REFRIGERATION REQUIREMENTS
is 30 by 60 m, with 6 m radius corners. Many rinks are considered
The heat load factors considered in the following section include
adequate with dimensions of 26 by 56.4 m, 24.4 by 54.9 m, and 21.3
type of service, length of season, usage, type of enclosure, radiant
by 51.8 m. In substandard size rinks, a corner radius of not less than
load from roof and lights, and geographic location of the rink with
4.5 m should be provided to permit the use of mechanical resurfac-
associated wet- and dry-bulb temperatures. In the case of outdoor
ing equipment.
rinks, the sun effect and weather conditions (wind velocity and rain)
Curling. Regulation surface for this sport is 4.3 by 45 m; how- must also be considered.
ever, the width of the ice sheet is often increased to allow space for
A fairly accurate estimate of refrigeration requirements can be
installation of dividers between the sheets, particularly at the cir-
made based on data from a number of rink installations with the
cles. Most curling rinks are laid out with ice sheets measuring 4.5 by
pipes covered by not more than 25 mm of sand or concrete and not
46 m.
more than 40 mm of ice (a total of 65 mm sand or concrete and ice).
Figure Skating. School or compulsory figures are generally
The refrigeration load may be estimated by considering the
done on a “patch” measuring approximately 5 by 12 m. Freestyle
larger of (1) the refrigeration necessary to freeze the ice to required
and dance routines generally require an area of 18 by 36 m or more.
conditions in a specified time, or (2) the refrigeration necessary to
maintain the ice surface and temperature during the most severe
The preparation of this chapter is assigned to TC 10.2, Automatic Icemak- usage and operating conditions that coincide with the maximum
ing Plants and Skating Rinks. ambient environmental conditions.

Copyright © 2002 ASHRAE 34.1

34.2 2002 ASHRAE Refrigeration Handbook (SI)

In the time-to-freeze method, determine (1) the quantity of ice Table 1 Range of Refrigeration Capacities for Ice Rinks
required (rink surface area multiplied by thickness); (2) the heat Up to 7 months 8 months to
load to reduce the water from application temperature to 0°C, freeze (spring, fall, winter), year-round,
the water to ice, and reduce the ice to the required temperature; and Type of Facility m2/kW m2/kW
(3) the heat loads and system losses during the freezing period. The
Outdoors, unshaded 2.1 to 3.7 —
total requirement is divided by system efficiency and freezing
Outdoors, shaded 2.6 to 5.0 —
period to determine the required refrigeration load or rate of heat
Sports arena 2.9 to 4.2 2.6 to 3.7
removal.
Sports arena, accelerated ice making 2.1 to 3.6 2.0 to 3.2
Example 1. Calculate the refrigeration required to build 25 mm thick ice Ice recreation center 4.5 to 6.3 3.7 to 5.0
on a 1500 m2 rink in 24 hours. Curling rinks 5.3 to 10.0 4.0 to 5.3
Assume the following material properties and conditions: Ice shows 2.1 to 4.0 2.0 to 3.4

Temperature, °C Table 2 Ice Rink Heat Loads, Indoor Rinks

Specific Heat, Density or
Material kJ/(kg·K) Initial Final Mass
Approximate Maximum Reduction
150 mm concrete slab 0.67 2 −6 2400 kg/m3 Maximum of of Load Category
Supply water 4.18 11 0 1000 kg/m3 Load Sources Total Load,* Through Design
Ice 2.04 0 −4 — Category % and Operation, %
Ethylene glycol, 35% 3.5 5 −9 14 000 kg
Conductive loads:
Latent heat of freezing water = 334 kJ/kg
Building and pumping heat load = 170 kW of refrigeration Ice resurfacing 12 60
System losses = 15% System pump work 15 80
Mass of water = 1500 m2 × 0.025 m × 1000 kg/m3 = 37 500 kg Ground heat 4 80
Mass of concrete = 1500 m2 × 0.150 m × 2400 kg/m3 = 540 000 kg Header heat gain 2 40
Then: Skaters 4 0
Convective loads:
qR = (Sys. losses)(qF + qC + qSR + qHL)
Rink air temperature 13 50
where Rink humidity 15 80
qR = refrigeration requirement Radiant loads:
qF = water chilling and freezing Ceiling radiation 28 90
qC = concrete chilling load Lighting radiation 7 40
qSR = refrigeration to cool secondary coolant Total 100
qHL = building and pumping heat load *Load distribution for basic rink without insulation below rink floor.
37 500 kg { 4.18 ( 11 Ó 0 ) H 344 kJ ⁄ kg H 2.04 [ 0 Ó ( Ó 4 ) ] }
qF = ----------------------------------------------------------------------------------------------------------------------------------------
24 h × 3600 s/h Table 3 Ice Rink Heat Loads, Outdoor Rinks
= 168.5 kW Approximate Maximum Reduction
540 000 × 0.67 [ 2 Ó ( Ó 6 ) ] Maximum of of Load Category
qC = ------------------------------------------------------------- Z 33.6 kW
( 24 × 3600 ) Load Sources Total Load,* Through Design
Category % and Operation, %
14 000 × 3.5 [ 5 Ó ( Ó 9 ) ]
qSR = ------------------------------------------------------- Z 7.9 kW
( 24 × 3600 ) Conductive loads:
qR = 1.15(168.5 + 33.5 + 7.9 + 170) = 437 kW Ice resurfacing 9 50
System pump work 12 80
When no time restrictions for making ice apply, the estimated re- Ground heat 2 40
frigeration load is the amount of heat removal needed to offset the Header heat gain 1 30
usage loads plus the coincidental heat loads during the most severe Skaters 1 0
operating conditions. Table 1 lists approximate refrigeration re-
Convective loads:
quirements for various rinks with controlled and uncontrolled atmo-
Air velocity 0 to 15 10
spheric conditions. Table 1 should only be used to check the
Air temperature 0 to 15 0
calculated refrigeration requirements. Table 2 shows the distribu-
Humidity 0 to 15 0
tion of various load components for basic construction and the esti-
mated potential load reductions that may be obtained when energy- Radiant loads:
conserving design and operating techniques are used. Solar load 10 to 30 60
Total 100
Heat Loads *Load distribution for basic rink without insulation below rink floor.
Energy and operating costs for ice rinks are very significant, and
these costs should be analyzed during design. A good estimate of makes it more difficult to maintain a usable ice surface, can affect
required refrigeration can be calculated by summing the heat load the structural integrity of the building, and is dangerous to the users.
components at design operating conditions. The heat loads for ice The heat gain from the ground and perimeter is highest when the
rinks consist of conductive, convective, and radiant components. system is first placed in operation; however, it decreases as the tem-
Connelly (1976) collected the performance data summarized in perature of the mass beneath the rink decreases and permafrost
Tables 2 and 3. The amount of control over each load source is indi- accumulates. Ground heat gain is reduced substantially with insula-
cated as an approximate percentage of the maximum reduction pos- tion. Chapter 25 of the 2001 ASHRAE Handbook—Fundamentals
sible through effective design and operation. gives details on computing heat gain with insulation.
Conductive Loads. If a rink is uninsulated, heat gain from the Heat gain to the piping is normally about 2 to 4% of the total
ground below the rink and at the edges averages 2 to 4% of the total refrigeration load, depending on length of piping, surface area, and
heat load. Permafrost may accumulate and frost heaving, which is ambient temperatures. The ice and frost that naturally accumulate
detrimental to both the rink and the piping, may result. Heaving also on headers reduce the heat gain. Insulation can be applied to
Ice Rinks 34.3

reduce the heat gain to the piping and keep ice from accumulating. The effective heat load (including the latent heat effect of con-
However, insulating the headers while maintaining visual inspec- vective mass transfer) is given by the following equation:
tion of the joints (floor piping to the headers) is usually impracti-
cal. Headers may, with precautions and the use of steel headers and Qcv = h(ta – ti) + [K(Xa – Xi)(2852 kJ/kg)(18 kg/mol)]
piping, be imbedded within the rink floor. The imbedded headers
contribute to the ice freezing and eliminate the trench to rink floor where
piping penetrations. When the headers are imbedded in concrete, Qcv = convective heat load, W/m2
all the joints from the steel floor piping to the headers should, ide- K = mass heat transfer coefficient
ta = air temperature, °C
ally, be welded. It may be difficult to remove air from this type of
ti = ice temperature, °C
floor system. Xa = mole fraction of water vapor in air, kg mol/kg mol
A circuit loop should be placed around the rink perimeter to pre- Xi = mole fraction of water in saturated ice, kg mol/kg mol
vent soft ice from developing at the edges (see the section on Rink
Piping and Pipe Supports). A circuit loop is especially important if When the mole fraction of air is calculated using a relative
return bends are used and embedded in the concrete. If the return humidity of 80% and a dry bulb of 3.3°C, Xa is approximately
bends are embedded in the concrete, the pipe and the return bend 6.6 × 10–3, and Xi for saturated ice at 100% and a temperature of
should be steel with welded joints. −6.1°C is 3.6 × 10–3. On the basis of the Chilton/Colburn analogy,
Heat gain from coolant circulating pumps can represent up K ≈ 0.23 g/(s·m2) (DOE/TIC 1980).
to 15% of the refrigeration load. Some facilities operate continu- In locations with high ambient wet-bulb temperatures, dehumid-
ously. Energy consumption from pump operation can be reduced ification of the building interior should be considered. This process
by using pump cycling, two-speed motors, multiple pumps, multi- lowers the load on the icemaking plant and reduces condensation
ple motors driving a single pump, or variable-speed motors with and fog formation. Traditional air conditioners are inappropriate
the appropriate controls. High-efficiency pumps and motors because the large ice slab tends to maintain a lower than normal dry-
should be used. Proprietary variable motor speed controls are also bulb temperature.
available. The coolant flow should be sufficient at all times for Radiant Loads. Indoor ice rinks create a unique condition where
acceptable chiller operation and to maintain a balanced flow a large, relatively cold plane (the ice sheet) is maintained beneath an
through the piping grid. equally warm plane (the ceiling). The ceiling is warmed by conduc-
Equipment components should be selected for low energy tive heat flow from the outside and by normal stratification of arena
consumption; they may be selected to operate at or feature low air. Up to 35% of the heat load on the ice sheet comes from radiant
discharge pressure (oversized condenser), high suction pressure sources. On outdoor rinks radiant sources are the sun or a warm
(oversized chiller), multiple compressors, and an intelligent control cloud cover. Vertical hanging cloth suspended from east-west hori-
system. Computer control of the refrigeration system is zontal overhead wires has been used to reduce the winter sun load.
recommended. In indoor and covered rinks, lighting is a major source of radiant
Ice resurfacing represents a significant operating heat load. heat to the ice sheet. The actual quantity depends on the type of
Water is flooded onto the ice surface, normally at temperatures lighting and how the lighting is applied. The direct radiant heat com-
between 55 and 80°C, to restore the ice surface condition. The heat ponent of the lighting can be as much as 60% of the kilowatt rating
load resulting from the flood water application may be calculated as of the luminaires. A radiant heating system can be another source of
follows: radiant heat gain to the ice. If radiant heat is used to maintain the
comfort level in the promenade or spectator area, the radiant heaters
Qf = 1000Vf [4.2(tf – 0) + 334 + 2.0(0 – ti)] should be located and directed to avoid direct radiation to the ice
surface. The infrared components of the lighting can be estimated
from manufacturers’ data.
where
The infrared heat gain component from the ceiling and building
Qf = heat load per flood, kJ
Vf = flood water volume (typically 0.4 to 0.7 m3 for a 30 by 60 m
structure, which is warmer than the ice surface, can be calculated by
rink), m3 applying the Stefan-Boltzmann equation as follows:
tf = flood water temperature, °C 4 4
ti = ice temperature, °C q r Z A c f ci σ ( T c Ó T i )
Ac 1 Ó1
f ci Z ------- H  ---- Ó 1 H -----  ---- Ó 1
The resurfacing water temperature affects the load and time 1 1
required to freeze the flood water. Maintaining good water quality F ci  ε c  A i  ε i 
through proper treatment may permit the use of lower flood water
temperature and less volume. where
Convective Loads. The convective load from the air to the ice qr = radiant heat load, W
may be as much as 28% or more of the total heat load to the ice Ac = ceiling area,m2
(see Tables 2 and 3). The convective heat load is affected by air Ai = ice area,m2
temperature, relative humidity, and air velocity near the ice sur- ε = emissivity
fci = gray body configuration factor, ceiling to ice surface
face. Precautions should be taken to minimize the influence of air
Fci = angle factor, ceiling to ice interface (from Figure 1)
movement across the ice surface in the design of the rink heating T = temperature, K
and dehumidification air distribution system. The convection heat σ = Stefan-Boltzmann constant = 5.67 × 10−8 W/(m2 ·K4)
load may be estimated using the procedure from Appendix 5 in
“Energy Conservation in Ice Skating Rinks” (DOE 1980). The Example 2. An ice rink has the following conditions:
estimated convective heat transfer coefficient can be calculated as Ice dimension: 26 m × 60 m = 1560 m2
follows: Ice temperature: −4°C (269 K), εi = 0.95
Ceiling radiating area: 28 m × 60 m = 1680 mm2
h = 3.41 + 3.55V Ceiling mid-height: 7.6 m
Ceiling temperature: 16°C (289 K), εc = 0.90
where
h = convective heat transfer coefficient, W/(m2 ·K) x/d = 28/7.6 = 3.6
V = air velocity over the ice,m/s y/d = 60/7.6 = 7.9
34.4 2002 ASHRAE Refrigeration Handbook (SI)

From Figure 1, Fci = 0.68 Indoor rinks are operating successfully even in warm tropical cli-
mates. Relative humidity, temperature, and ceiling radiant losses
1 1 Ó1
1680 1
f ci Z ---------- H  ---------- Ó 1 H ------------  ---------- Ó 1 Z 0.610 must be controlled in these climates to prevent fog, ceiling dripping,
0.68  0.90  1560  0.95  and high operating cost.
Then
Steel frame, brick, concrete, and various forms of plastic have
been used to enclose ice skating rinks. Rinks have also been built
q r Z 1680 × 0.610 × 5.67 × 10 ( 289 Ó 269 ) ⁄ 1000
Ó8 4 4 under air-supported structures for seasonal use and are usually over
a multipurpose surface.
Z 101 kW Arena heating is frequently provided for skater and/or spectator
comfort. Where airflow may be directed to the ice surface, space
The ceiling radiant heat load can be reduced by lowering the tem-
heating should not be combined with a dehumidification system.
perature of the ceiling, keeping warm air away from the ceiling,
Both space heating and dehumidification have different objectives.
increasing the roof insulation, and, more significantly, lowering the
The dehumidification system removes moisture from the ice sur-
emissivity of the ceiling material to shield the ice from the building
face, whereas the space heating system provides comfort conditions
structure.
for spectators. Warm air movement over the ice surface is not desir-
Ceiling and roof materials and exposed structural members have
able; any air movement over the ice surface is detrimental to the
an emissivity that may be as high as 0.9. Special aluminum paint can
control of ice and space temperature. Heat recovery from the refrig-
lower the emissivity to between 0.5 and 0.2. Polished metal such as
eration system may be used for limited heating, supplementing the
polished aluminum or aluminum foil have an emissivity of 0.05.
heating system. Infrared heating has been used successfully for
Because a low-emissivity ceiling is cooled very little by radiant
spectator areas. Ice rink temperatures are usually maintained be-
loss, most of the time its temperature remains above the dew point
tween 5 and 15°C; however, for skater or spectator comfort, higher
of the rink air. Thus, condensation and dripping is substantially
temperatures are sometimes preferred. The relative humidity in the
reduced or eliminated.
arena depends on factors such as building construction, indoor tem-
Low-emissivity fabric or tiled ceilings are frequently incorpo-
perature, and outdoor wet bulb temperature.
rated into new and existing rinks to reduce radiation loads, decrease
condensation problems, and reduce the overall lighting required. The system should be designed to prevent fogging and surface
Radiant heat gain to the ice, especially in outdoor rinks, can be condensation. A maximum dew-point temperature of 7°C is usu-
further controlled by painting the ice about 25 mm below the surface ally sufficient to eliminate fogging; however, condensation can
with whitewash or slaked lime. Commercial paints with a low solar occur on the ceiling or roof structure due to radiation from the
absorptivity, which are generally water based, are also available. building structure to the ice. Low relative humidity is needed to
reduce this condition when a high-emissivity ceiling is exposed to
the ice surface. Ceiling emissivity and ceiling height are critcal
ICE RINK CONDITIONS factors in controlling roof and ceiling condensation. Low ceilings
Properly designed indoor rinks, as well as properly designed ren- and dark-colored structures promote condensation because these
ovated rinks, can be operated year-round without shutdown. How- features favor radiant heat flow toward the ice surface. The result
ever, some indoor rinks operate from 6 to 11 months and shut down is a low structure temperature that could be near the dew-point
for various reasons, including maintenance, rink construction, in- temperature of the space. Wire-suspended, low-emissivity ceiling
ability to control indoor conditions, or unprofitable operation during curtains are known to raise the inside surface temperature of the
part of the year. Outdoor, uncovered rinks generally operate from roof structure, thus eliminating the condition where condensation
early November to mid-March above 40° North latitude. However, could occur. Low-emissivity ceilings not only reduce the heat flow
if sufficient refrigeration capacity is provided, the ice can be main- between the roof and the ice surface, but also reflect light. This
tained for a longer period. reduces the lighting requirement and therefore reduces the cooling
load imposed to the refrigeration plant. The low-emissivity ceiling
Fig. 1 Angle Factor for Radiation between Parallel Rectan- must resist damage from hockey pucks and allow free air circula-
gles Fci tion around its perimeter. Providing too much roof insulation can
promote condensation by reducing the inside ceiling temperature.
Ventilation should be the minimum required for the building
occupancy so that the humidity introduced with outdoor air is kept
as low as is feasible; but enough outdoor air must enter to maintain
acceptable indoor air quality (see ASHRAE Standard 62). Makeup
air should always be conditioned before being introduced to the
arena space. Due to the high enthalpy difference between indoor
and outdoor air, exhaust air energy recovery using enthalpy wheels
will improve efficiency. Mechanical makeup air dehumidification
systems may be downsized up to 50% when using enthalpy wheels.
It is more energy-efficient to dehumidify makeup air separately
from the recirculated air, as the makeup air usually has a much
higher dew-point temperature. Self-contained, air-cooled, compres-
sor-equipped dehumidifying units, as well as dessiccant drier types
with gas or electric regeneration, are available to control humidity.
The owning and operating costs of various dehumidification and
defogging systems should be evaluated.
Carbon monoxide and nitrogen dioxide are pollutant emissions
from gasoline- or propane-fueled ice resurfacers. The concentra-
tion of these chemicals can reach dangerously high levels if they
are not controlled or eliminated. In some areas, regulations require
Fig. 1 Angle Factor for Radiation between Parallel sensors to detect and alarm at unsafe chemical concentrations.
Rectangles Fci Check health regulations for local requirements. Air circulation is
Ice Rinks 34.5

conducive to removing carbon monoxide produced by ice- systems are fed by direct expansion or liquid recirculation. The oper-
resurfacing equipment. Carbon monoxide is usually in the highest ating charge should be considered for this type of system. Local
concentration below the top of the boards and near the ice surface. codes may impose restrictions on the size and use of direct systems.
Gas-engine resurfacing machines should be equipped with cata- Care should be taken in designing common evaporators for
lytic exhaust convertors to reduce carbon monoxide emissions. multiple-rink facilities; the high load from one rink should not
Electric-powered resurfacing machines eliminate the need for impact on the ice temperature on the other rinks.
additional makeup air otherwise required to dilute and ventilate the
combustion products generated by internal combustion engines. Condensers and Heat Recovery
Each rink user group has its own preference for the type of ice Ice arenas and curling rinks typically reject heat to a water source
used. Hockey players and curlers prefer hard ice; figure skaters pre- or the atmosphere.
fer softer (i.e., warmer) ice so they can clearly see the tracings of Wells, lakes, or rivers can be good sources of condenser cooling
their skates; and recreational skaters prefer even softer ice, which water, if they are available. Capacity is easy to regulate and the low
minimizes the buildup of shavings and scrapings. coolant temperature maintains low condensing pressures, which
With approximately 7°C air temperature and one 25-mm saves energy. Condensers require high-quality water, though, which
ice thickness, ice at −6.5 to −5.5°C is satisfactory for hockey, −4 may need treatment to prevent scale formation, fouling, or corrosion
to −3°C for figure skating, and −3 to −2°C for recreational skating. in the condenser tubes. Water and sewage costs usually prohibit the
A 0.5 K higher ice temperature may be feasible when water with use of water for condensing on a “once-through” basis.
a low mineral content is used for resurfacing. To achieve these ice Cooling towers used in conjunction with water-cooled con-
temperatures, the coolant temperature is maintained about 3 to 6 K densers, evaporative condensers, or air-cooled condensers are
lower than the ice temperature. The temperature of the coolant alternatives to once-through water-cooled condensers. When
must be lowered to maintain the same ice conditions when there selecting a cooling tower or evaporative condenser, not only the
are higher wet-bulb temperatures or abnormally high loads, such maximum expected wet-bulb temperature during the skating sea-
as when television lighting is used. son should be considered, but also suitable controls to cover the
wide range in capacities and protection against freeze-up needed
EQUIPMENT SELECTION in cold weather. A water treatment specialist should also be con-
sulted.
Compressors Air-cooled condensers can be designed to produce reasonable
discharge pressures in northern climates, particularly where the rink
Two or more refrigeration compressors should be used in an ice
is used mostly in the spring, fall, and winter months. They can be
rink system. When two compressors are used, one compressor
economically sized and require no water, so the possibility of freez-
should be specified with ample capacity to maintain the ice sheet
eup is eliminated. This type of condenser, however, is not econom-
under normal load and operating conditions. When greater capacity
ical for year-round operation, and for seasonal operation it must
is required during the initial ice freezing or under high heat loads,
have wide-range capacity control.
the second compressor picks up the load. In multiple-compressor
One alternative to rejecting the heat to a water source or to the
installations, a multistage thermostat microprocessor control, pro-
atmosphere is to recover the waste heat and put it to use. This pro-
grammable logic controller (PLC), or computerized control system
cess harnesses all or a portion of this wasted heat and uses it to pre-
may be used to control the operation of the compressors. The mul-
heat a secondary fluid before the primary refrigerant enters the
tiple compressors serve as backups; they maintain the ice in the
condenser. Both reciprocating and screw compressors have the
event of compressor failure or a service requirement.
potential for heat reclaim. Abundant heating energy is available
Compressors and evaporators normally operate at a suction pres-
from discharge gas, by either desuperheating or condensing.
sure corresponding to a mean temperature difference of 4 to 6 K
In addition to the power saved by heating a secondary fluid with
between the coolant and primary refrigerant in systems operating
the refrigerant, the load to the condenser is reduced and reduction in
with secondary coolants, or between the ice and the refrigerant in
condenser fan and pump motor operation results in further electrical
direct refrigerant rinks.
savings. A lower operating head pressure reduces compressor motor
Most arenas with a single sheet of ice use two or three recipro-
power requirements and increases the operating life of the refriger-
cating compressors. With trends toward multiple ice sheets served
ation equipment. Condenser fouling is also reduced because of the
from a central plant, screw compressors are widely used. The devel-
lower discharge temperature.
opment of smaller, more economical screw compressors has led to
Superheat from discharge gas is reclaimed via a thermal contact
the use of screw compressors in applications that traditionally used
surface in which the superheated refrigerant transfers its energy to
reciprocating compressors.
the cooler fluid on the opposing side. When water is used as the fluid
to be heated, the water is often recirculated through a storage tank
Evaporators and used on demand.
Ideally, there should be one chiller (evaporator) for each ice sur- Heat of condensation is typically reclaimed through a designated
face. However, economics sometimes dictates one chiller serving condenser piped in parallel with the main condenser.
multiple ice surfaces. Whether to reclaim superheat or heat of condensation depends
Chillers for indirect systems normally are shell-and-tube (with on the amount of heat that may be used and the temperature level the
and without surface enhancement), immersed-tube, or plate-and- designer wishes to attain.
frame. Gravity-flooded or direct-expansion feed is usually used for To minimize the possibility of contamination of potable fluids by
the primary refrigerant. a rupture in the exchanger, a double wall of heat transfer surface
Flooded shell-and-tube chillers used for cooling glycol or cal- between the fluid and the refrigerant is required. Any leakage of pri-
cium chloride may be manufactured from carbon steel. Stainless mary refrigerant into the space between the inner and outer walls is
steel is recommended for constructing plate-and-frame chillers used vented to the atmosphere. Double wall-vented construction has
for cooling glycol. Titanium is recommended for plate-and-frame become the accepted standard for heat-recovery units heating pota-
chillers used for cooling calcium chloride. Aluminum is not recom- ble fluids and is required by law when used for this purpose.
mended for chillers cooling calcium chloride with ammonia. The exchanger material must be suitable for use with both the
The chiller for direct-cooled systems is composed of piping in- refrigerant and the process fluid and must meet code requirements.
stalled in the floor under the ice surface. Typically, direct halocarbons Standard materials that usually meet these requirements are 304 and
34.6 2002 ASHRAE Refrigeration Handbook (SI)

Fig. 2 Typical Waste Heat Recovery Piping The pipe grid must be maintained as close to level as possible,
regardless of the rink piping system used. When a pipe rink surface
is open with sand fill around and over the pipes, the pipe usually
rests on pressure-treated sleepers set level with the subbase; how-
ever, the sleepers can be omitted in a rink that is to be operated year-
round. The piping is then spaced with clips, plastic stripping, or
punched metal spacers.
In permanent concrete floors, the pipe or steel tubes are sup-
ported on notched iron supports or welded chair supports. The latter
must be used in the case of plastic pipe.

Headers and Expansion Tanks

Secondary coolant rinks using large-diameter pipe generally run
the piping lengthwise, with the supply and return headers across one
end and the return bends located on the opposite end. The supply
and return headers may be positioned in a header trench and the
return bends may be positioned in a return bend trench. This allows
regular inspection of the clamps and joints. However, to avoid hav-
ing header and return bend trenches, some facilities have success-
fully used straight headers running across the rink between the blue
Fig. 2 Typical Waste Heat Recovery Piping line and center ice, buried below the floor piping grid. The cooling
grid piping then crosses over the top of the headers to ensure con-
sistent slab temperatures. Curved headers buried at one of the rink
316 stainless steel and titanium. Some applications for using waste have also been used. Rinks using small-diameter tubing generally
heat are space heating, ice resurfacing, underfloor heating, building run crosswise, with the supply and return headers along one side.
makeup air, boiler water makeup and domestic hot water use. Direct refrigerant rinks generally run lengthwise, with the supply
Most installations in large plants show a payback period of 18 to header at one end and the return header at the opposite end in a bal-
30 months. Ice facilities with an 8 month operating season typically anced system. The header must be sized to ensure an even distribu-
have a 3 to 5 year payback. Paybacks depend on the degree of heat tion of coolant through every pipe. The systems are generally
reclaim, hours of operation, and the cost of the fuel source, and must designed with low coolant velocities, which do not need balancing
be analyzed on a project-by-project basis. valves. If at all possible, the return header should be placed at the
Figure 2 illustrates a desuperheater and a condenser piped for same elevation as the rink piping, with a minimum of two air vents
waste heat recovery. to eliminate the trapping of air.
The three-pipe reversed return header and distribution arrange-
Ice Temperature Control ment (Figure 3) is used occasionally. A properly sized two-pipe
Ice temperature may be controlled by (1) sensing the average header system (Figure 4) is frequently applied and gives nearly uni-
temperature of the secondary coolant, (2) infrared sensor(s) hung form circuit flow with no discernible differences in the ice surface
over the ice surface, (3) thermocouples or thermistors embedded temperature or conditions. To allow for thermal contraction and
underneath or in the ice, or (4) thermocouples or thermistors placed expansion, headers and main piping should be free to move without
in a well in the concrete floor under the ice surface. producing excessive stress.
Thermostats that sense the return coolant temperature or the dif- Polyvinyl chloride (PVC) distribution headers are becoming
ferential temperature between the supply and return coolant can be very popular because they have a very low maintenance requirement
used to control the refrigeration system. They may also be used in and accumulate less frost than steel headers. These headers should
controlling operation of the coolant pump. To be effective, a differ- be used with proper allowances for expansion and contraction. The
ential sensor should sense a small temperature difference. The coefficient of thermal expansion for steel is relatively low and very
return coolant temperature can be sensed by multistage sensors that close to that of concrete; the PVC pipe expansion coefficient is
sense a larger temperature difference. Another strategy varies cool- much higher. Schedule 80 wall thickness is used to provide a solid
ant flow by controlling the pump speed on a signal from an ice tem- connection to the pipe nipples leading to the floor piping. PVC pipe
perature sensor. Direct refrigerant systems can be controlled by can become brittle at low temperatures, so the pipe should not be
regulating compressor operation from an ice temperature sensor. used to support equipment weights nor should the nipples be placed
This method has been used with a direct refrigerant impulse pump- where they could be knocked or stood on. Pipe clamp connections
ing system. Compressor capacity and pump operation may be con- are not considered permanent joints and should ideally remain
trolled from the low-pressure receiver when refrigerant pumps are accessible for inspection and tightening. However, the use of
used to circulate the refrigerant. clamped return bends and header connections cast in the concrete
floor slab has been successful.
Rink Piping and Pipe Supports A closed secondary coolant system requires an expansion tank to
safely accommodate the expansion and contraction of the coolant
High-flow-rate secondary systems use standard mild steel pipe resulting from fluid temperature changes. The expansion tank must
20, 25, or 32 mm in diameter; thin-walled polyethylene plastic pipe be installed so that it cannot be isolated from the system.
25 mm in diameter; or UHMW (ultrahigh molecular mass) polyeth-
ylene plastic pipe 25 mm in diameter. These are placed at 90 or
100 mm centers on the rink floor. One proprietary low-flow-rate Coolant Equipment
secondary coolant system uses 6 mm tubing made of flexible plastic The coolant circulating pumps must be sized for the particular
with tube spacing averaging 20 mm or one dual tube every 40 mm. type of rink and system involved. Large-diameter pipe rinks re-
Direct refrigerant rinks generally use 16 to 22 mm steel tubing, quire 180 to 270 mL/s per kilowatt of refrigeration to maintain the
which is placed on 75 mm centers for outdoor rinks and 100 mm required 1 to 2 K temperature differential between incoming and
centers for indoor rinks. outgoing coolant. These operate at approximately 170 kPa (gage).
Ice Rinks 34.7

Fig. 3 Reversed Return System of Distribution When refrigeration on the ice surface is not required, a large vol-
ume of coolant in the accumulator may be cooled to approximately
–32°C and be ready to be pumped into the rink piping when needed.
The cold-coolant accumulator should store a sufficient volume to
cool the entire system coolant volume from 18 to –18°C. This cold-
coolant tank usually holds more than three times the volume of the
cooling system's charge.
The use of accumulators has been declining. Instead, ice-making
equipment is sized to handle the demand loads.

Energy Consumption
Energy consumption for an ice rink facility is unique. Mainte-
nance of internal conditions is affected by the cold ice sheet. Light-
ing, ventilation, heating, and dehumidification systems depend on
the use and occupancy of the facility. Energy consumed by the
refrigeration equipment is affected by construction, operation,
water quality, and various use factors. To reduce heat load and
Fig. 3 Reversed Return System of Distribution energy consumption,

• Install low-emissivity ceilings to reduce refrigeration and lighting

loads and to permit compressors to operate at a higher saturated
Fig. 4 Two-Pipe Header and Distribution suction temperature.
• Reclaim the refrigerant superheat to preheat shower water, heat
the ice resurfacing water, melt ice shavings, heat the subfloor, etc.
• Select a pumping system and controls to reduce or stop coolant
flow during part load conditions.
• Install an energy management system.
• Insulate the subfloor and header piping.
• Control the temperature and humidity in the arena to reduce
sensible and latent heat gain to the ice.
• Install high-efficiency luminaires.
• Use demineralized water or water with a very low mineral content
for the ice and resurfacing.
• Do not operate the underfloor heating system more than necessary
to prevent frost formation.
• Maintain the secondary coolant temperature no lower than
necessary to maintain the desired ice quality.
• Maintain high suction pressure and low discharge pressure.

Fig. 4 Two-Pipe Header and Distribution Dehumidifiers

To minimize the potential of rink fog or ceiling dripping, a prop-
erly designed dehumidification system should be installed. Operat-
Low-flow-rate dual tubing or mat rinks use about 40 mL/s per kilo- ing season, arena location, and utility costs should all be considered
watt. Differentials of 2 to 3 K are normal, but 6 to 7 K differentials when selecting a system.
can be experienced in high-load conditions. Temperature averag- Desiccant systems use adsorption or absorption to remove
ing is achieved in mat rinks by closely spacing adjoining counter- moisture from rink air. These systems can provide arena ventila-
flow tubes operating at approximately 280 to 350 kPa pressure. tion while delivering dew-point temperatures below freezing.
Desiccant systems come in many forms, from stand-alone dehu-
Ice Removal midifiers to total environmental control systems incorporating air
conditioning, heating, and energy recovery. Single desiccant
For auditoriums and sports arenas, the rink surface should have units, centrally located, have been used successfully to dehumid-
provision for deicing in less than 4 h. In this operation, the floor is ify multiple rinks.
heated to about 10°C so that the bond between the floor and ice is Self-contained mechanical refrigeration units rely on the
broken; the ice is then removed with power tractors. moisture removal capabilities of an evaporator to reduce the mois-
A standard heat exchanger can be used, with piping so arranged ture content of the air inside a rink. Either hot-gas or electric
that all the coolant can be pumped through the heater, with the coolant defrost is provided to remove the ice that forms on the evaporator
flowing in the tubes and the steam or hot water in the shell. Approx- surface. These units are typically manufactured with hermetic or
imately 630 to 1100 W per square metre of rink surface is needed to semihermetic compressors in the range of 3.5 to 5.5 kW. Multiple
heat the coolant in the system enough to warm the floor and break the units are selected to suit the size of the facility and moisture
ice bond. removal needs. Typically, a standard hockey rink requires two self-
contained units.
Storage Accumulators Some older facilities use the secondary coolant from the arena to
To reduce large cooling demands associated with frequently dehumidify the air. The temperature of the secondary coolant is too
producing ice in short time periods, some of the older, large-event low for dehumidification purposes and should be mixed by recircu-
facilities incorporate storage accumulators that act as a source of lation to suit the application. This method of dehumidification is not
low-temperature, large-volume secondary coolant. energy efficient.
34.8 2002 ASHRAE Refrigeration Handbook (SI)

RINK FLOOR DESIGN sand fill floor is used; a good system will ensure that the ice melted
after the skating season will completely drain away and the sand
Generally, five types of rink surface floors are used (Figure 5):
will dry out as quickly as possible.
• Open or sand fill, for plastic or metal piping or tubing
• Permanent, general-purpose, with piping or tubing embedded in Subfloor Heating for Freeze Protection
concrete on grade Subfloor heating, by electrical heating cables or a pipe or tubing
• All-purpose, with piping or tubing embedded in concrete with recirculating system using a warm antifreeze solution, is found in
floor slab insulated on grade most new rinks to prevent below-floor permafrost development and
• All-purpose floors, supported on piers or walls the resultant heaving. Pipes or tubing are on 300 to 600 mm centers
• All-purpose floor with reheat; for use when the water table and located under 50 to 100 mm of insulation. They are generally
moisture are severe problems or when the rink is to operate for installed in sand rinks, which are used year-round, although they
more than 6 months may be poured into a concrete base slab with insulation between the
base slab and the rink slab (see Figure 5).
The open sand fill floor is the least expensive type of rink floor.
The cooling pipes rest on wood sleepers over a bed of crushed stone Alternatively, the heating pipes may be laid directly in the sub-
or other fill. Clean, washed sand is filled in around the pipes. Curl- foundation below the rink pipe or insulation. However, an uninsu-
ing rink floors, as well as hockey and skating rinks, where first cost lated installation requires a greater depth between the heating pipes
is a factor and the building is not intended for other uses, are usually and the ice-making pipes to prevent an increased load.
constructed in this manner. Clay or cinders should never be used in Neither water nor warm air should be used for subfloor heating.
the bed or for fill around the pipes. Tubing rinks do not need sup- Water, if inadvertently allowed to freeze, cannot be readily melted
ports or sleepers; the tubes are laid on accurately leveled sand. out. In time, warm air ducts become filled with frost and ice because
Rinks using 25 mm plastic pipe or the mat type are usually cov- of high rink humidity and air duct leakage.
ered with sand to a depth of 13 to 25 mm to provide additional Usually, the same fluid used for the coolant in the ice-making
strength to the ice surface and to reduce cracking. Many portable system is used for subfloor heating; it can be heated to the necessary
outdoor rinks have used this arrangement for laying the plastic pipes temperature (4.4 to 5.6°C) in a heat exchanger warmed by compres-
or tubing mats on top of existing sodded areas, black top, or con- sor waste heat. Subfloor insulation should be of a rigid moisture-
crete. More permanent installations of outdoor semiportable rinks proof board, such as high-density polystyrene foam, and be com-
have used this same arrangement where recreational space is at a pletely enveloped in a polyethylene vapor retardant.
premium. Such an installation consists of steel pipes supported on
notched steel sleepers, which in turn are supported on concrete piers
Preparation of Rink Floor
down to solid ground. When building on natural ground, regardless of whether a sand
To obtain a better return on investment, most indoor rinks that fill or a permanent general-purpose floor is intended, proper prepa-
operate with an ice surface for only a portion of the year have a per- ration of the bed is important unless the rink is built on elevated sand
manent general-purpose concrete floor with subfloor insulation and and gravel subsoil. If the rink is to be built on clay, part clay, or rock
heat pipes so that the floor may be used for other purposes when the subsoil, water should be prevented from collecting in low areas.
skating season is over. The floor should withstand the average street Either the clay or rock should be excavated or the rink level should
load and is usually designed with 25 or 30 mm steel or plastic pipe be built up with crushed stone and gravel to a height of about
embedded in a steel-reinforced concrete slab 100 to 150 mm thick, 1200 mm, after which it should be well rolled. Water should not be
depending on the anticipated loading and coolant pipe diameter. used for settling the fill.
In sports arenas, where the ice is removed and the floor made For sand fill rinks, quickly draining the melted ice at the end of
ready for other sports and entertainment, the ice floor must be the skating season ensures rapid drying of the sand and rink piping
constructed to withstand the frequent change from hot to cold. and results in a longer life for the steel piping. Cinders should never
The refrigerating machinery must be of sufficient capacity to be used as fill in open sand fill rinks because of the possibility of sul-
freeze a sheet of ice 16 mm thick in 12 h. This type of floor is fur in the cinders, which, when damp, accelerates corrosion of steel
always insulated. piping.
Subfloor insulation must be installed when quick changeovers Care must be taken to ensure a level surface over the entire rink
are desired, when there is a high moisture content in the subsoil, with no more than ±3 mm in any 1 m2 area and ±6 mm overall.
when the floor is elevated, or when the rink is in continuous use for
more than 9 months. This subfloor insulation reduces the refrigera- Permanent General-Purpose Rink Floor
tion load on ice-making equipment and slows down, but does not When constructing a permanent general-purpose floor, the same
eliminate, the cooling of the subsoil on surfaces installed on grade. subsoil precaution must be taken as for a sand fill rink. The concrete
floor should withstand, at a minimum, the average road pavement
Drainage load.
The suitability of an ice rink’s subsoil has a great influence on the When local conditions make it advisable, the rink floor should be
rink’s success. Complete ice surfaces have had to be rebuilt because insulated. Insulation may be laid on a level concrete or sand base.
of poor drainage and the ultimate heaving of the ice surface. Thus, The concrete mixture should have a 28 day strength of 140 to 240
skating rinks should not be built on swampy or low-lying land kPa and be put in place in a quality manner (a concrete engineer is
unless adequate drainage is provided. recommended to specify concrete, its placement, and curing). Suit-
Moist subsoil will freeze in the ground to a depth of 1200 mm or able cross-reinforcing and pipe supports are necessary.
more. The frozen water will heave the ice surface when freezing Concrete floors with mat tubing are poured in two courses. A
takes place at a depth of 150 mm or more. Heaving creates an first course is poured and leveled; the mats are then rolled out and
uneven skating surface; moves and raises walls, piers, and header positioned. A 150 m by 150 mm wire mesh is laid on top of the mats;
trenches; cracks walls and piping; and necessitates the eventual then a second course, with grouting between it and the first, is
drainage and rebuilding of the rink floor. poured on top of the first course, mats, and wire. Water pressure
Not only should there be a complete drainage system around the should be kept in the tubing to spot any leaks or cuts that may
footings of the rink to prevent seepage, but there should also be one develop. Once started, the pouring of each course of the concrete
under the rink surface itself. This is particularly important when a floor should be continuous, with interruptions not to exceed 15 min.
Ice Rinks 34.9

Fig. 5 Ice Rink Floors General-purpose rink floors should not be defrosted too fre-
quently. When a rink constructed with a general-purpose floor is to
be used during the ice season for purposes that require an ice-free
floor, it is preferable to place an insulated portable-section wood
floor over the ice for each occasion.

All-Purpose Floors
If a rink floor as used in sports arenas is to withstand both the
expansion and contraction of frequent frosting and defrosting and
thermal shock because of the circulation of very-low-temperature
coolant, then extra precautions must be taken in its construction,
such as provisions for the free movement of the freezing slab with
respect to the subfloor.

Header Trench
A well-constructed header trench of sufficient size to house the
headers and connections and the subfloor heating system, if appli-
cable, is essential unless the steel distribution headers are cast into
the concrete slab as part of the rink. Provisions for movement of
pipes due to thermal expansion and contraction should be incorpo-
rated into the design. This trench should be equipped with remov-
able covers and be well drained to facilitate drying out. The headers
and piping in the trench are not usually insulated, which allows for
periodic inspection and painting of the piping. Provision must be
made for purging air from the rink piping and header system.

Snow Melt Pit

When the ice is resurfaced mechanically, a thin layer of ice is
removed and replaced by a thin layer of clean warm water. The thin
layer of removed ice appears as snow. The snow may be placed out-
doors and allowed to melt, but in many jurisdictions, the snow
cannot be placed outside and must be disposed of by other means. A
common method of disposal is to place the snow in a snow melting
pit.
The snow melting pit should be provided in the ice-resurfacer
holding area. For a single rink, the capacity of the pit should be suf-
ficient to hold and melt double the quantity of snow removed in one
resurfacing (approximately 1450 kg of snow or ice). In addition,
space must be allowed for water spraying, water reservoir, and
free-board. About 450 to 725 kg of snow can be generated every 45
min for each active rink in a facility.
The heat required to melt this snow can be obtained from a num-
ber of sources. By maintaining sufficient standing water in the pit,
the stored heat can be used to melt the snow as it is dumped. The
heat retained in the volume of standing water should be sufficient to
melt the entire load of snow as it is dumped. The temperature of the
water in the pit can be then restored over the next 45 min by several
heating sources:
• Cold domestic water supply
• Hot domestic water supply
• Waste heat from the refrigeration plant on a recirculated system
• Waste heat from the jacket-cooling water from ammonia
compressors
To minimize water consumption, it is recommended that a sup-
plementary heat source be used, such as the waste heat from the
refrigeration plant. Approximately 88 000 W of waste heat at a tem-
perature level of 21 to 27°C is recommended for one rink. The
standing water in the snow melt pit should not be circulated directly
through conventional heat exchangers.
One successful layout of a snow melt pit is shown in Figure 6.
Typical snow melt pit dimensions for a single rink would be 2.4 by
3 by 1.8 m. A large standpipe drain is required to handle the over-
flow of water during the snow dump. This drain should be
equipped with a removable screen (minimum 300 mm diameter
Fig. 5 Ice Rink Floors screen) to handle the large volume of trash scraped off the ice with
34.10 2002 ASHRAE Refrigeration Handbook (SI)

the snow. The standpipe drain also allows for a standing water rinks, the scraping is done manually with a wide hardened-steel
level to be maintained. For cleaning purposes, the pit can be scraper blade. The most satisfactory method of resurfacing the ice
pumped out with a portable sump pump when required. between sessions is to wheel a sprinkler tank filled with hot water
Spray headers are also recommended around the top of the pit over the ice. The sprinkler has an adjustable valve to control the
0.6 m above the water level to assist in snow melting if the water quantity of water, which is sprayed into a terry cloth bag that wipes
temperature is not high enough. Spray nozzles on 0.6 m centers the fine snow off the ice surface and fills the crevices cut by the
with a cone spray pattern are recommended. The spray header skaters. In this manner, the least amount of water is added, reduc-
should be located so the snow being dumped into the pit does not ing the ice buildup and refrigeration load.
impact the header. The spray headers can be supplied with warm By far the most common method is the use of automatic resur-
or cold domestic water. The snow melt pit should have a closable facing machines. Mounted on four-wheel drive chassis, the
lid to prevent moist air from infiltrating the refrigerated rink space. machines plane the ice, pick up the snow, and lay down a new ice
The snow melt pit is not intended for disposal of ice paint. Ice surface using hot or cold water. Hot water generally gives harder ice,
paint will clog the drain and is not permitted in most sewer systems. because air bubbles are removed, but energy costs have led many
The layer of painted ice is not affected when the ice resurfacer is rinks to alternate hot- and cold-water resurfacings. Rink corners
used for maintaining the ice surface. When the ice is being removed should be at least a 6.1 m (preferably 8.5 m) radius for effective use
at the end of the skating season, the entire ice surface is scraped up of this equipment. Smaller equipment is available for studio and
and should be disposed of in a temporary dump that allows the ice small rinks.
paint to be separated. The temporary dump can be constructed in a Because of inattentive ice making, improper sprinkling equip-
parking lot using a wood frame and plastic ground sheet. When the ment, or deep cutting of the ice during public skating, the ice may
ice has melted, the ice paint can be rolled up in the ground sheet and become uneven and excessively thick. There may be a fairly slight
disposed of in an environmentally friendly manner. variation in the ice thickness across the rink, but more serious is the
resulting variation in the condition of the ice. In any case, the low
BUILDING, MAINTAINING, AND spots on the ice must be built up, increasing the thickness and refrig-
PLANING ICE SURFACES eration requirements.
For example, under assumed conditions, where −8°C coolant
Regardless of the type of rink floor used, when the plant is first
would be cold enough to hold a 38 mm thickness of ice, calculations
placed in operation, the equipment should be operated long enough
show that −21°C coolant would be required if the ice were permitted
for a sharp frost to appear on the surface. Then the entire surface
to build up to 150 mm, with a corresponding decrease in effective
should be uniformly covered with a fine spray. This process should
refrigeration capacity and an increase in operating costs. In other
be repeated until a 13 mm thickness of ice is built, or until the sur-
words, every additional 25 mm of ice thickness required from the
face is level. After applying a layer of water-based white paint,
refrigeration system increases 8 to 15%, depending on system heat
another 10 mm thick layer of ice is built before painting the red and
load (DOE 1980).
blue lines. Red and blue lines are available in plasticized paper;
Because ice of 13 to 25 mm thickness is satisfactory for skating
however, they need to be covered with a minimum of 13 mm of ice
and is the most economical thickness to freeze and hold, the ice
to protect against damage. It is essential that sand floors be thor-
should be periodically planed to maintain this desired thickness.
oughly wet before freezing because dry sand has poor conductivity.
The surface should not be frozen any colder than required after this
buildup so as to allow the ice to temper before it is used for skating Pebbling
and also to deter cracking. Pebbling is a term used to describe the surface finish applied to
To maintain an ice surface, it is customary to scrape off the curling ice. The pebbles are actually water droplets frozen to the
snow after each skating session or hockey period. In all but the curling ice surface. The pebbles reduce the friction between the
smallest rinks, this is done by a motorized resurfacer. On small bottom of the curling rock and the ice surface. This makes the rock
Fig. 6 Snow Melt Pit

Fig. 6 Snow Melt Pit

Ice Rinks 34.11

glide easier and promotes the “curl” of the rock when a turn is REFERENCES
applied to the handle of the rock on release.
The temperature of the water used for pebbling is critical and var- ASHRAE. 1999. Ventilation for acceptable indoor air quality. ASHRAE
Standard 62-1999.
ies from facility to facility depending on ice surface temperature,
ASHRAE. 2001. 2001 ASHRAE Handbook—Fundamentals.
water quality, humidity, and application techniques. If the pebbling
Canadian Electrical Associates. 1992. Potential electricity savings in ice are-
water temperature is too warm, the pebbles will be too flat. If the nas and curling rinks through improved refrigeration plant. CEA No.
pebbling water temperature is too cold, the pebbles can break off 9129-858 Manbek Resource Consul Book.
when the rock passes over. Pebbles are applied manually from a Connelly, J.J. 1976. ASHRAE Seminar on Ice Rinks (February), Dallas, TX.
water can with a hose connected to a perforated sprinkler head. The DOE. 1980. Energy conservation in ice skating rinks. Prepared by B.K.
water can is carried by a shoulder strap and the sprinkler head is held Dietrich and T.J. McAvoy. U.S. Department of Energy.
in one hand. The person applying the pebbles usually walks back-
ward down the curling sheet, sprinkling the water in a rhythmic
side-to-side motion. BIBLIOGRAPHY
Water Quality Albern, W.F. and J.J. Seals. 1983. Heat recovery in an ice rink? They did it
The quality of the water affects energy consumption and ice at Cornell University. ASHRAE Journal 25(9):38-39.
quality. Water contaminants, such as minerals, organic matter, and ASHRAE. 1968. Ice skating rinks. Symposium at ASHRAE meeting in
Columbus, OH.
dissolved air, can affect both the freezing temperature and the ice
Banks. N.J. 1990. Desiccant dehumidifiers in ice arenas. ASHRAE Trans-
thickness necessary to provide satisfactory ice conditions. Propri-
actions 96(1):1269-1272.
etary treatment systems for arena flood water are available. When Blades, R.W. 1992. Modernizing and retrofitting ice skating rinks. ASHRAE
these treatments are properly applied, they reduce or eliminate the Journal 34(4):34-42.
effects of contaminants and improve ice conditions. Brauer, M., J.D. Spengler, K. Lee, and Y. Yanagisana. 1992. Air pollutant
exposures inside hockey rinks: Exposure assessment and reduction strat-
IMITATION ICE-SKATING SURFACES egies. Proceedings Second International Symposium on Safety in Ice
Hockey, Pittsburgh, PA.
A number of different imitation ice-skating surfaces have been
Matus, S.E. et al. 1988. Carbon monoxide poisoning at an indoor ice skating
marketed; these use semiporous plastic panels dressed with a syn- facility. Proceedings ASHRAE IAQ 88 Conference, pp. 275-283.
thetic lubricant. The coefficient of friction of ice is approximately Minnesota Department of Health. 1990. Indoor air quality unit: Regulating
0.03 at −3°C and is further reduced by the film of water produced by air quality in ice arenas.
pressure under the skate. In considering the use of imitation Rein, R.G. and C.M. Burrows. 1981. Basic concepts of frost heaving.
surfaces, the actual friction coefficients of these surfaces—both ASHRAE Transactions 87(2):1087-1097.
when freshly lubricated and after a period of usage—should be Strong, R.H. 1990. Refrigeration Theory and Safety Course for Arena
investigated. Operators.