CHAPTER 4: BASIC AIR CONDITIONING

4. Chilled Water A/C units

Air conditioning – consist of refrigeration circuit and chilled
 is used throughout the world to counter the water circuit.
negative effects caused by heat and humidity. – The chilled water A/C units are
 Without air conditioning, people tire easily and feel manufactured in small capacity, 3- 15 tons,
lethargic, resulting in low morale and productivity. while the large capacity units are made
from 50 to 500 tons of refrigeration.

a. The refrigeration circuit consist of simple

PRINCIPLES OF AIR CONDITIONING vapor refrigeration components and its system
controller
 ASHRAE (American Society of Heating, Refrigerating
& Air Conditioning Engineers) define air conditioning b. The chilled water circuit consist of package
as a process of treating air so as to control water chiller, chilled water circulating pump, air
simultaneously its temperature, humidity, handlers such as FCU and AHU, connecting
cleanliness & distribution to meet the condition of a chilled water piping and system controller.
given space.
 It is the process of conditioning the air in a space to
maintain a predetermined temperature-humidity 5. Combined Hot Water and Chilled Water System
relationship to meet comfort or technical – known as four-pipe water system normally
requirements. This warming and cooling of the air is consist of hot water lines and the heating
usually referred to as winter and summer air coils, cooled water lines and the cooling
conditioning. coils, circulating pumps, air handlers, and
controlling system.

TYPES OF AIR CONDITIONING SYSTEM COMMONLY

MANUFACTURED: PURPOSE OF AIR CONDITIONING
1. Window Type Air Conditioners 1. Health and Human Comfort
– small package type A/C units consist of  The human body is amazingly adaptable organism.
direct expansion refrigeration as cooling However, variation in outdoor temperature, humidity,
system, condenser fan, circulating fan, and and cleanliness when beyond the normal
control system. adaptability results to discomfort. In this regard, it is
– It is understood to serve one space or many necessary to provide modified air conditioner to
units serving larger space. maintain healthy and comfortable human
environment.
2. Split Type Air Conditioners
– consist of outdoor unit which are typically 2. Industrial Purpose and Special Air
condenser and compressor and the indoor Conditioning/Ventilation
unit that cools air before it is supplied to  Examples for air conditioning services for industrial
the condition space. services are:
– It is usually installed inside the condition i. Data processing area for computer
space. rooms
a. Single-split A/C units ii. Textile Processing
– consist of one indoor unit to match one iii. Drying & Storing Farm Crops
outdoor unit. iv. Nuclear Facilities
v. Industrial Exhaust System
b. Multi-split A/C units vi. Air Conditioning of wood and
– consist of two or more indoor units to paper products facilities
match one outdoor unit.
FACTORS INFLUENCING HUMAN COMFORT
3. Roof Top Package A/C 1. Human heat lost due to convection, evaporation, &
– larger package type A/C and are usually radiation in human bodies.
installed outside the condition space 2. Insulating factor – discomfort due to improper
typically on the roof top of the building clothing
where it served. 3. Physiological factors – due to activity, age, and
– Components are: health
a. Cooling/heating coil 4. Thermal comfort factor – due to varying air
b. Condenser coil
temperature and humidity
c. Compressor
5. Noise beyond acceptable limit
d. Circulating fan
e. Condenser fan for air cooled condenser
f. Air intake porch, grilles, and filter
g. Supply air porch CHAPTER 5: FIRE PROTECTION SYSTEM IN BUILDINGS
h. Package controller and control panel built
in the system
  The protection of building structures from the o by flames extending vertically from window
hazards of fire is one of the utmost concerns of the to window.
government. Hence, for a continued citizen
awareness of damages brought by fire to life and
property, the month of march was declared as fire 2. Noncombustible (Type II) Construction
prevention month in the Philippines.  also built of noncombustible steel or concrete walls,
 Planners and builders have their own contribution in floors, and structural framework; however, the roof
this campaign, by making their plans and covering is combustible, which can burn and spread
constructions conform to the fire code requirements. fire.
The owner on the other hand, is much more concern  The roof covering of a Type II building can be
of his investment protection. However, despite the constructed of a combustible built-up roof covering,
advancement in fire protection technology, fire is still a layered asphalt and felt paper covering, or an
common occurrence in buildings of all types. Records ethylene propylene diene monomer (EPDM) or
showed that the loss of life and damages to property polyvinylchloride (PVC) thermoplastic membrane.
is considerably enormous in every incident of fire. Combustible foams may be used as thermal
 Modern design and construction techniques, did not insulation.
escape the blame for allegedly having increased the  When a fire occurs inside a Type II building, flames
potential of fire, especially in tall buildings attributed can rise to the underside of the steel roof deck,
to one of the following: conduct heat through the metal, and ignite the
o (1) Light material construction methods do combustible roof covering. The asphalt, felt paper,
not offer inherent protection against fire and foam insulation may burn and spread fire along
unlike the cement plaster or concrete, the roof covering.
o (2) Non-integrally constructed floors and
walls provide fuse for fire and smoke, 3. Ordinary (Type III) Construction
o (3) False ceiling containing electrical and  built of noncombustible masonry bearing walls, but
other services, are hidden locations where the floors, structural framework, and roof can be
fire can start unnoticed, made of wood or another combustible material.
o (4) Punched-hole for installation of  The major recurring fire spread problem with Type III
telephone and other related services, construction is concealed spaces and penetration.
violates the design structural integrity, These small voids, cavities, and openings through
o (5) the central air conditioning system can which smoke and fire can spread are found behind
serve as passage for smoke the partition walls, floors, and ceilings.
o (6) The use of plastic materials for trim and  Wood studs, floor joists, and suspended ceilings
covering of interior structures create create concealed spaces. Penetrations are created by
potential ignition for fire and smoke, and small openings for utilities. These small openings
o (7) Furniture style and materials including around pipes and wires allow fire to spread into
the interior designs could pose a great concealed spaces.
flammability and could spread a fire quickly.  Flames can spread vertically several stories or
horizontally to adjoining occupancies through
concealed spaces.
TYPES OF BUILDING CONSTRUCTION IN REFERENCE WITH  Fire spreads inside concealed spaces of a Type III
FIRE PROTECTION building by convection, the transfer of heat by
motion of a liquid or gas. Heated fire gases and
There are five fundamental categories of building
flames in a concealed space can travel upwards
construction known as types of building construction.
several floors and break out in an attic space,
Each type of building construction has fire resistive engulfing the entire building envelope.
strengths and weaknesses—that is, some types burn much
more readily than others. The five building construction types 4. Heavy-Timber (Type IV) Construction
are arranged in the form of a scale based on the amount of  built of a structure that consists of large timbers. In
combustible material used in their construction. this type of construction, a wood column cannot be
less than 8 in thick in any dimension and a wood
beam cannot be less than 6 in thick.
1. Fire-Resistive (Type I) Construction  The floor and roof decking can be thick wood planks.
 with its concrete and protected steel walls, floors, Exposed timber beams, columns, and decks, if
and structural framework, was initially intended to ignited in a fire, create large radiated heat waves
confine a fire by its method of construction— that is; after the windows break during a blaze.
by containing the fire with noncombustible wall,  If a fire in a heavy-timber building is not
ceiling, and floor assemblies so it is confined to one extinguished by the initial firefighting attack, a
floor or one space on a floor. tremendous fire with flames shooting out of the
 However, fire does spread several floors in a modem windows will spread fire to adjoining buildings by
fire-resistive building through two paths: radiated heat.
o through ductwork in the central heating,  A fully involved type IV building requires large water
ventilating, and air conditioning (HVAC) supply sources to protect nearby buildings.
system and
 5. Wood-Frame (Type V) Construction o Provide structural and thermal integrity of
 the most combustible of the five types of building floor, wall, and ceiling assemblies during a
construction. fire for a specified time period
 A wood-frame building is the only one of the five  use materials and construction
types of construction that has combustible exterior assemblies that contain the fire in
walls. The interior framing and exterior walls are a small area and confine the fire in
typically constructed of slender repetitive wood the room or area for a specific
studs, joists, rafters, and trusses that burn very period of time
rapidly. o Compartmentalize a room or space to
 Flames can spread out a window and then along the control the fire spread
outside wood walls in addition to the interior fire  separating a building into
spread. compartments so that if there is a
 A Type five building is rapidly engulfed in flame and fire, the fire damage is confined to
is therefore reserved for small structures with small certain a room or certain section of
occupancies. the building only such as firewalls,
fire separation and firestop
o Provide exiting systems and evacuation
ELEMENTS OF FIRE PROTECTION SYSTEM IN BUILDINGS plans for occupants to safely and rapidly
evacuate the building
 provision of fire exit doors and fire
Classification of Fire according to Sources escape ladders/structures and
provision of emergency plan.
As provided by the Fire code of the Philippines (R.A.
9514 s. 2008), below are the classifications of fire according
to source: Active Fire Protection

 Class A Fires  include standpipe, sprinkler, and spray systems

o Fires involving ordinary combustible designed to extinguish the fire outright or control the
materials such as wood, cloth, rubber and fire by delaying its damaging effects. Types of
plastics. firefighting media include water, foams, inert gases,
 Class B Fires and chemical powders.
o Fires involving flammable liquids and gases.  extremely effective in containing and fighting a fire if
 Class C Fires they are designed and maintained so they work
o Fires involving energized electrical properly.
equipment.  These systems require regular inspection, testing,
 Class D Fire and maintenance. Poor maintenance leads to a false
o Fires involving combustible materials, such sense of security and lack of proper protection when
as sodium, magnesium, potassium, and the system is needed under an emergency situation.
other similar materials.
 Class K Fires  Stand Pipe Systems is an internal piping network
o Fires in cooking appliances that involve connected to fire-hose stations that are used to
combustible cooking media (vegetable or rapidly suppress a fire. Firefighters can use hoses
animal oils and fats). connected to the standpipe system or connect their
hoses to valve outlets near the fire.

o Wet Stand Pipes - This system always has

Classification of Fire Protection Methods water in the piping. The water in the
system is always under pressure. In some
Although heat alone can prove deadly to occupants, toxic cases, a fire pump may be used to increase
gases in smoke cause the majority of deaths and injuries. the water pressure. The wet pipe system is
About half of all fatalities from fires are from carbon the most commonly used standpipe system.
monoxide poisoning, and more than a third are from It is used in heated buildings where there is
cardiopulmonary complications. no danger of the water in the piping
freezing. Any part of the standpipe system
Fire is one of the greatest fears of any homeowner, that is exposed to freezing temperatures
business owner, or director of an institution. Although the should be insulated. It is very important
prime concern is always loss of lives in a fire, more than half that the water in the piping does not freeze.
of all businesses never reopen after the devastating effect of a Frozen water may prevent a standpipe
fire. system from working.

o Dry Stand Pipes – have no other special

1. Passive Fire Protection construction as compared to wet stand
 involves constructing walls, floors, ceilings, beams, pipes, the only difference is dry stand pipes
columns, and shaft enclosures so they can resist, does not contain standing water in the
control, and contain the damaging effects of a fire. piping that eliminates the possibility of
 It is intended to entail the following: fitting leaks and water freeze. Types of dry
stand pipes are
  Dry Standpipe with an Automatic (unlike the wet pipe or dry-pipe systems).
Dry Pipe Valve, The preaction sprinkler system is often
 Dry Standpipe with a Manual used where the use of sprinklers could
Control Valve, cause extensive material or equipment
 Dry Standpipe with No Permanent damage, such as in retail stores and
Water Supply. computer areas.

 Sprinkler System is fitted with automatic devices

o Deluge Automatic Sprinkler Systems - allow
designed to release water on a fire. These devices
all sprinkler heads to go off at the same
are called sprinkler heads. A rise to a predetermined
time. This system is very similar to the
temperature causes the sprinkler head to open.
preaction system, except all sprinkler
Water is then discharged in the form of spray. When
heads are open. Once a heat detecting
the sprinkler heads open, they are said to have fused.
device activates the valve, water will flow
The sprinkler heads are fitted at standard intervals
from all heads within the area. Deluge
on the piping. If more than one head opens, the area
systems are generally installed in hazardous
sprayed by each overlap that of the sprinkler head
areas where extremely rapid fire spread is
next to it. Types of automatic sprinkler systems are:
anticipated and that requires immediate
application of water.
o Wet-Pipe Automatic Sprinkler Systems -
have pressurized water in the pipe and
mains. Water is released when the sprinkler
 Alternative Fire Suppression Systems - Conventional
head is activated. Because of the potential
sprinklers demand high water supply rates and are
for freezing, this system is suitable for
associated with fixed large diameter pipe networks
buildings where the indoor ambient
around the area to be protected. The necessity for
temperature is not lower than about 40°F
large amounts of water has some inherent
(5°C). Wet-pipe sprinkler systems are the
disadvantages:
most common in use today. In wet systems
o it damages most of the building’s contents
exposed to freezing temperatures, pipes
and interior finishes;
containing an antifreeze solution of water–
o flammable oils tend to float on the water’s
glycerin or water– propylene glycol are
surface and continue to burn;
connected to a water supply.
o it conducts electricity; and
o if it vaporizes into steam, it may be harmful
o Dry-Pipe Automatic Sprinkler Systems -
to the firefighters.
have pipes filled with compressed air or
nitrogen. The pressure in these lines is
o Other methods may be considered when
slightly above the water pressure, and this
these disadvantages are of major concern.
pressure difference is what keeps the water
These alternative methods include the
out of the sprinkler lines. When a sprinkler
following.
head is activated, the air will begin to be
released and the air pressure will drop. As
air pressure drops, water will begin to
advance throughout the lines and flow o Water Mist Automatic Sprinkler Systems -
through the activated head(s). The dry-pipe rely upon a fine spray of water to suppress
type is typically used in unheated buildings a fire. Water mist systems must produce a
where there is danger that the water in the directional mist or fog of fine water drops
pipes would freeze and burst the pipes. through a nozzle. The optimum water
droplet size ranges from 0.003 to 0.005in
(80 to 200µm), although larger droplet sizes
can be used. The nozzle design must
o Preaction Automatic Sprinkler Systems -
produce a small droplet with an orifice
are similar to dry-pipe except that the
sufficiently large to avoid clogging from
water first fills the pipe as an alarm is set
suspended particulates that may be
off, providing an opportunity to extinguish
present in the water stream. The droplets
the fire manually before the sprinklers
must be small enough to penetrate all
open. Water is stopped at feeders (in the
areas behind obstructions, yet large
walls before the pipes supplying the
enough to penetrate to the surface of the
sprinkler heads) by a valve. This valve is
combusting fuel.
electronically activated by a heat detecting
device within the area, and a signal is sent
o Clean Agent Gas Fire Suppression Systems -
to the valve and the valve opens. Water will
discharge as a gas on the surface of
then flow to all heads, but will only
combusting materials. A typical system
discharge through the activated heads. If
consists of cylinders of a liquid agent
there is an accidental break of a sprinkler
under high pressure, heat/smoke detectors,
line, water will not immediately discharge
and discharge nozzles connected to a
because the valve is holding back the
network of pipes. Large amounts of heat
water flow and not the sprinkler heads
energy are absorbed from the surface of
 the burning material, lowering the surface A fire. So, an extinguisher rated 5- A will put out a fire five
temperature below the ignition point. times as large as one rated 1-A. For Class B extinguishers, the
Clean agent gases can be released in a numerical codes are even more complicated, and generally
building space without leaving residue. this type of information is of most use to professional
When released, they extinguish the fire firefighters.)
rapidly but do little harm to building
occupants, firefighters, interior contents,
o Class C Extinguishers - are suitable for use
and equipment.
on fires involving energized electrical
equipment and wiring where the dielectric
o Carbon Dioxide (CO2) Fire Suppression
conductivity of the extinguishing agent is of
Systems - discharge a CO2 gas that
importance. For example, water-solution
extinguishes fire by displacing oxygen or
extinguishers cannot be used on electrical
taking oxygen away from the fire. The
fires because water conducts electricity
principal problem with CO2 is that it must
and the operator could receive a shock
be used in fairly high concentrations and
from energized electrical equipment via
because high CO2 concentrations deplete
the water.
much of the oxygen in a space, this type of
system cannot be used with occupants or
o Class D Extinguishers - are suitable for use
other living beings present.
on fires in combustible metals such as
magnesium, titanium, zirconium, sodium,
o Foam Fire Suppression Systems - discharge
and potassium. No numeral is used for
a high volume of gas-filled bubbles that
Class D extinguishers; the relative
rapidly fill a space. Foam masses are lighter
effectiveness of these extinguishers for use
than water and flammable liquids, and
on specific combustible metal fires is
they may be either air or chemical gas
detailed on the extinguisher nameplate
bubbles. They float on the surface of
burning liquids to deplete oxygen and Note: Other types of fire extinguisher includes an
smother the fire.
 Air Pressurized Water (APW) Extinguisher,
 CO2 Fire Extinguisher,
 Portable Fire Extinguisher can be used to put out  Dry Chemical Fire Extinguisher which includes
most fires in their early stages. They are classified combination of classes, e.i., “BC”, “ABC” etc.
according to their ability to handle specific classes
and sizes of fires. Not all fuels are the same, and if a
fire extinguisher is used on the wrong type of fuel, FIRE DETECTION AND ALARM SYSTEM
it can make matters worse. Labels on extinguishers
indicate the class and relative size of fire that they  Fire alarm systems detect products of combustion,
can be expected to handle. Types of portable fire such as smoke (aerosol particulate), heat, and light,
extinguisher are as follows: and provide early occupant notification to allow the
safe egress of the occupants.
o Class A Extinguishers - are suitable for use
on fires in ordinary combustibles such as  In medium to large buildings and building complexes,
wood, paper, rubber, trash, and many an alarm system includes all or some of the
plastics, where a quenching-cooling effect following:
is required. The numeral indicates the o A system control unit
relative fire extinguishing effectiveness of o A primary or main electrical power supply
each unit. Class A extinguishers are rated o A secondary (stand-by) power supply,
from 1-A to 40-A. Extinguishers rated for usually batteries or an emergency
Class A hazards are water, foam, and generator
multipurpose dry chemical types. o Alarm-initiating devices such as automatic
fire detectors, manual pull stations, and/or
o Class B Extinguishers - are suitable for use sprinkler system flow devices, connected to
on fires in flammable liquids, gases, and initiating circuits of the system control unit
greases, where an oxygen-exclusion or o Alarm-indicating devices, such as bells or
flame-interruption effect is essential. Class lights, connected to initiating circuits of the
B extinguishers are rated from 1-B to 640-B. system control unit
(A discussion follows.) Extinguishers rated o Ancillary controls such as ventilation
for Class B hazards are foam, Halon shutdown functions, connected to output
alternative, and CO2 and multipurpose dry circuits of the system control unit
chemical. o Remote alarm indication to an external
response location, such as the fire
department
(Note: The numbers indicate the level of effectiveness in o Control circuits to activate a fire protection
extinguishing fires, with 10 rated 10 times more effective than system or smoke control system
1. A 1-A fire requires 1 1 ⁄4 gal (5 L) of water to extinguish. A
2-A fire needs 2 1 ⁄2 gal of water (10 L) or twice that of the 1-
 Fire detection includes all or some of the following:
o Smoke Detector - a sensing device that
identifies products of combustion in air.
o Fixed-temperature Heat Detectors - signal
an alarm after the temperature at the
detector reaches a set value.
o Rate of rise Heat Detectors – signals an
alarm when the temperature at the
detector increases at a rate exceeding a
preset value.
o Flame Detectors - optically sense high
levels of either infrared (IR) radiation or
ultraviolet (UV) radiation. Combination
UV/IR detectors are also commercially
available.
o Ionization Smoke Detectors – are designed
with a sensing chamber that has a
radioactive element.
o Photoelectric Smoke Detectors - use a light
scattering or light obscuration principle.
They contain a light emitting diode (LED)
that is adjusted to direct a narrow IR light
across the unit’s detection chamber.
o Air-Sampling Smoke Detectors - use a
similar approach to light obscuration
detectors, however, a laser or xenon tube is
typically used as a light source.