Preparing \ Cutting Refrigerant Pipe

 Take your time when preparing tubing for soldering, protect the pipe at all times.
 Measure the length of the pipe needed and place a mark at the desired length.

Note: When cutting pipe, you should be mindful of your surroundings. It is a best practice to first clean
the area of the pipe to be cut so that this reduces the risk of containments entering the piping during
the following steps.

 When placing your cutting wheel on the pipe leave ample space between the wheel and the
rollers/guides. This will allow the guide to lay flat onto the pipe.
 Slowly tighten the wheel until you have reached the pipe. Do not overtighten, there should be a
small amount of pressure applied only.
 Begin cutting, for every one rotation around the pipe you can expect to turn the wheel 1/8 of a
turn. “This may feel like a never-ending process however it is critical to ensure you have a
proper bond when fitted”
 Continue until you have successfully cut through 100%, do not add pressure or bend the piping.
 Now that you have your pipe cut to the desired length you will need to remove any burrs
formed while cutting. Use an approved deburring tool, you will rotate this tool with a slight
pressure applied until you have successfully removed the burr (lip) from the inside of the pipe.

Note: When deburring the pipe, it is best to point the end being cleaned down to allow any materials to
fall out of instead of into the pipe. This may not be possible on a repair, it these cases placing the system
underneath a continuous nitrogen purge is a best practice to reduce the likelihood of containments from
entering the piping

Oxy-Acetylene Torch

 Place regulators on their respected bottles (Red=Acetylene & Green=Oxygen) Do Not

Overtighten.
 Open Gas and oxygen bottles with torch handles closed.
 Now slightly open acetylene valve and adjust regulator to (Red Hose) to 5-7 psig. Now Close it.
 Now slightly open oxygen valve and adjust regulator to (Green Hose) to 9-11 psig. Now Close it
 Your torch is now prepared to light. Use only an approved striker for lighting the torch.
 Place piping under a nitrogen purge of no greater than 2psig to prevent oxidation forming inside
of the piping.
 Slightly open the acetylene and purge any air trapped, now use an approved striker to light the
torch, adjust the oxygen to obtain a steady Blue “Neutral” flame.

Note: Be cautious when lighting a torch indoors as you may release soot into the home. A best practice
for this is to add a small amount of oxygen before lighting the torch, this will take practice but when
done properly no to very little soot is produced

 When brazing is complete first shut off the acetylene at the torch handle and then the oxygen.
 Close the cylinders and purge gasses from the hoses
 Prepare your torch for storage & transit (But do not put it away just yet)
Test your work performed by placing equipment under a Nitrogen pressure test to determine if the
system is leak free. You can utilize the HVAC School App with their free Nitrogen Pressure test calculator
of with your Measure Quick App.

Evacuation

While you were monitoring the Nitrogen pressure test this allows you an excellent opportunity to clean
up your worksite and bring materials & tools that are no longer needed to the van. When finished
placing materials back in their respected areas now you should grab your vacuum kit and prepare it for
the next steps.

 Once confirmed that system is leak free, remove the nitrogen from the refrigerant lines, monitor
this and stop the removal once the system has a minimal amount of pressure 3-10 psig.
 The Schrader cores should have been removed during the brazing and nitrogen pressure testing
stages however if they are still located inside of the service valves than proceed with removal
using your core removal tools.
 Prepare the evacuation hose or hoses by attaching to the vacuum pump. Release remaining
nitrogen from the system and attach the opposing end of the vacuum hose to your core removal
tool /tools, your micron gauge should be located on the smaller liquid line and capable of being
isolated from the vacuum for moisture/decay testing.
 Turn on the Vacuum pump and slowly open both your vapor and liquid line core removal tools
to allow the pump to pull from both sides.
 Once the vacuum has reached at or below 1500-1000 microns you may isolate and determine if
there is a large decay (Rise) in your microns. A fast rise with a slow plateau normally indicates
moisture is present in the system. At this point sweeping the system with nitrogen may greatly
reduce the time required to evacuate the equipment. This may take multiple nitrogen sweeps
(Purge) before you can reach a satisfactory micron level.
 Once the system passes the initial decay test restart the vacuum and allow to operate until the
system reaches at or below 500 microns. Once again repeating your decay test and sweeping
with nitrogen as necessary to obtain desired micron levels.
 At this point assuming that the system is holding at or below 500 microns you are now prepared
to move forward with the repairs. It is worth noting that if there are additional tasks that can be
completed now is a great time to allow the vacuum to continue to run, reaching a much deeper
vacuum while you accomplish other tasks that are preventing you from moving forward
(Electrical wiring, site cleanup, etc.)

Initial Charging

 If a repair was made and refrigerant was captured then weigh it back into the system, calculate
the additional line set length and multiply that measurement by a minimum of 0.6 to determine
 the amount of additional refrigerant in Ounces over the factory holding charge required for the
approximate total system refrigerant charge
 Release the refrigerant ensuring you weigh it back in from the recovery cylinder back into the
system. You may reintroduce the refrigerant through both the liquid and vapor ports, ensure a
filter is inline between your charging hose and the recovery cylinder to help protect against any
moisture or other containment’s that may be present in your recovery cylinder.
OR
If this is a new system then you will measure the actual distance of the refrigerant piping so that
you can add the necessary additional refrigerant before releasing the factory holding charge into
the vapor line only. After weighing in the additional. 6oz per foot over 15ft of refrigerant piping
you must then allow the system to equalize before operating the HVAC equipment. The reason
for releasing the factory holding charge into the vapor line only is that this will ensure that if
there is a pressure differential the oil can not be pushed out of the compressor into the
condensing circuit, but instead into the vapor circuit so that any oil loss to the piping has a more
direct pathway back into the compressor

 Close your vacuum rated Schrader core tools and remove your hoses.
 Prepare to reinstall your Schrader cores, Put a small amount of Nylog sealant on the threads of
the Schrader core and insert it into your core removal tool. Do not thread 100% closed yet.
 Bleed a slight release of refrigerant by opening the core valve to remove any air from the fittings
while tightening the tool to seal/stop the leakage. Now insert the cores, ensure you DO NOT
OVERTIGHTEN.
 Remove core tools and place back into their respected storage (Clean & Dry) containers.

Start Up

1. Before turning the system on First do one last visual inspection, give wires a tug, prime
the trap, make sure everything is properly installed and secured before turning on the
equipment.
2. Place both Vapor and Liquid line pressure & temperature probes in their respected
locations, ensure you have a clean connection to piping for improved accuracy.
3. First test to ensure you have proper incoming voltage, turn the power on to the
equipment with the Thermostat in the OFF position, place your electric meter on the
equipment to be tested.
4. Insert both return and supply static pressure probes.
5. Insert both return and supply psychrometers.
6. Open Measure quick and ensure all tools are connected.
7. Begin by first testing the Fan function (Does it turn on and off with a call)
8. Now operate the electric heater, check temperature rise and amperage to ensure all
equipment is functioning properly. You can expect to see a 50° temperature rise if
airflow is setup correctly for approximately63 CFM per KW of electric heat. This may
require adjusting fan flows for optimum heating performance. Confirm external static
pressure is within manufactures tolerances of .2-.5” w.c.
 9. Now begin the cooling cycle, allow ample time for the evaporator to become saturated.
This may take up to 20 minutes of continuous operation (utilize this time by confirming
operating amperages, triple checking work, looking for tools that may have been
misplaced, or simply putting your tools neatly back in their places)
10. Once the system has reached a steady state record your information and determine if
additional adjustments are necessary to obtain manufactures ratings. Follow standard
charging & airflow adjustment procedures to obtain desired results. Most commonly in
our market we are looking for an approximate 300-400 CFM per ton of airflow.

 Attach all measurements to the customer file

 Raise the indoor thermostat set point and ensure the system cycles off properly. Gather all
remaining tools, confirm system is draining properly and store tools away in their proper
locations.
 Take pictures of the completed work
 Instruct client on how to operate and maintain their new equipment
 Ask client what temperature they would like the home at and set this for them
 Request payment for work performed, continue to clean any remaining mess that was made
(even if it wasn’t made by you or our team)

Your Done! Thank them for the opportunity, Ask if there are any questions they may have, remind
them to leave a quick review (good or bad) on google/social media, etc. And tell them you look
forward to seeing them this Spring/Fall for their Preventative Maintenance visit.