Desert Aire SelectAire Plus SP Series, Installation And Operation Manual, Page: 93 / 110

93
Recovery of Systems with a Refrigeration System Leak
As much refrigerant as possible must be recovered into separate refrigerant cylinders appropriate for
the refrigerant being serviced. System pressure near the leak site should be monitored closely to
ensure this area is not pulled to a vacuum. Isolated sections of the system as required and recover
independently to avoid refrigerant contamination. Uncontaminated refrigerant can be reused in the
refrigeration system it was recovered from.
Recovery of Systems without a Leak
Systems that do not have leaks, but still require refrigeration system service, may have charge
isolated in condensers if these particular components do not require direct service.
Desert Aire dehumidifiers have different receiver sizes depending on the model and size.
Condenser sizes and configurations may also vary. In general, larger receivers will come equipped
with isolation valves that will allow for a portion of the charge to be contained in the receiver during
servicing. Unit equipped with the remote condensers will have isolation valves located inside the unit
cabinet near the area where the connections are made.
The compressor can be used to move refrigerant to the system components that will be used to
temporarily hold the charge. Note that cooling a condenser by running as many fans as possible
and/or cooling the coil surface with a stream of water can assist in storing charge.
The low side pressure should be monitored closely while using this procedure to store charge. Under
no circumstances should a compressor be allowed to run in a vacuum. When most of the refrigerant
is isolated in the condensers, recover remaining charge into separate refrigerant cylinders
appropriate for the refrigerant being serviced. Carefully track the amount of refrigerant charge
removed as this exact amount should be placed into the units when recharging.
Repair / Component Replacement
• If any portion of the system was at a vacuum, place dry nitrogen in the system until
atmospheric pressure is reached.
• It is preferred that components are removed by heating the braze alloy to the re-melt
temperature and mechanically moving the component. When this is not possible due to
proximity of cabinet structure or other components, a tubing cutter can be used to remove
sections of piping. Where new tube is required for replacement, use dehydrated tube
where possible. Use the same type of fittings as original. Route the pipe in the exact
manner as originally routed.
• Use Type K per ASTM B 88 or ASTM B 819 or Type ACR per ASTM B 280 copper tubing
or for all tubes 1-1/8” and smaller.
• Tubes 1-3/8” and larger shall use Type K per ASTM B 88 or ASTM B 819.
• Cap sections of tube and components that are not actively being installed to prevent
infiltration of moisture and contaminants.
• Use only braze alloy to join tube
- The selection of filler metals is highly dependent on the tube fit, clearance, and
operator preference for flow. When flux is to be used, care should be taken to
Desert Aire - SP Manual