SWS Detail: Air-to-Air Split System- 5.0108.1; Subtopic 5.0103 Refrigerant Loop; 5.8801 Equipment Removal; Subtopic 5-8801.1 Decommissioning
Author: Jesse
Carefully remove the refrigerant following EPA guidelines.
Remove the old evaporator coil and condenser
Check the condition and compatibility of the existing lineset.
Replace the filter dryer.
Replace/repair if damaged, kinked, or if not compatible with new equipment.
Review the Manual J and Manual S for the house you are working on to verify equipment is sized correctly
Pick a coil that will allow for a maximum SEER rating for the condenser that is being installed. This information can be found at https://www.ahridirectory.org
Install the new coil and condensate drains to manufacturer specs.
Make sure the duct work allows for air to move across the entire coil.
Make sure the pad is level and is installed far enough away from walls or fences to allow for proper air flow and circulation.
Install the new condenser in accordance with the manufacturer specs.
A liquid line filter dryer shall be used when installing the line set.
Trickle nitrogen through the system as you braze. This will keep copper oxide from forming inside the line set and also help dry out the line set to speed up the vacuum process.
Be sure to remove both valve cores during this process so pressure does not build and they are not melted as you braze.
A recommended tool for this is a HVAC Nitrogen Regulator such as the VN-500 with a Braze setting.
Pressure test the line set to 300-500 psi.
A HVAC Nitrogen Regulator will have a "Test" setting that will usually pressurize to 250 psi or 500 psi depending on the model.
Leave nitrogen in line set for a minimum of 15 minutes and check for a pressure drop. During that time also check for leaks with a soapy solution.
(Caution: Make sure your gauges are rated for the test pressure you want to test at.)
Vacuum down the line set to a minimum of 350 microns preferably 200 microns.
Once 350-200 microns has been reached, isolate the vacuum pump. Vacuum will be complete if the Micron Gauge does not rise above 500 microns within 15-30 minutes.
Release pre-charged refrigerant.
If needed, add new refrigerant to manufacturer specs based off the length of the line set.
This would be a good time to make sure the entire suction line is insulated.
Ensure proper breaker/fuse size and a weather tight conduit is used for the whip.
Connect high voltage and low voltage wiring as described in the manufacturer instructions.
Complete the A/C start-up form for new A/C systems found on the Utah WAP resources page (https://jobs.utah.gov/housing/scso/wap/iwtc/resource.html)
Ensure the Sub-cooling & Superheat are within the manufacturer specs and pressures are within range of the chart posted inside the panel.
Conduct a Worst Case draft test to verify Category I, II and III are venting safely before leaving home for the day.
Testing shall be recorded using the Utah WAP Worst Case Draft Test form.
All equipment must be installed according to manufacturer specifications.
Work must be performed by a certified technician holding a EPA-608 Universal or Type II