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Guide to proper installation of insulation on refrigerant piping: why is refrigerant piping insulation needed, what problems occur if the insulation is incomplete, missing, crimped, or otherwise improperly installed, and how do we fix these problems.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
Proper Method for Installing Insulation on Air Conditioning & Heat Pump Refrigeration Lines & Condensate Drains
Do Not Compress Insulation on A/C or Heat Pump Refrigeration Lines
The same split system air conditioner installer we described above at A/C Condensate Disposal for Split System Air Conditioners violated the manufacturer's recommendations against compressing the insulation on the refrigerant lines - one more picky issue that we decided to let go since the wall was to be insulated with blown-in foam.
But he made the same mistake on the insulation on the refrigeration lines and condensate drain where they extend outdoors between the building wall and the compressor/condenser unit.
Our photographs illustrate that the importance of not compressing refrigeration line insulation is no joke. In our photo at below left, notice those drip stains below the condensate lines at each location where the insulation was compressed by a too-tight plastic tie?
And in the two photos at below right, notice the incomplete insulation on the refrigeration line? It leaves me worried about condensation and water accumulation inside the wall cavity as well. Since I know this installer is not stupid we're left thinking he has a bit of contempt for his customers, or a limited concept of workmanship.
Imagine that same dripping and accumulation of water where the installer made the same mistake in a fiberglass-batt insulated wall or a wall or ceiling inside which the dew point may be reached on the refrigeration lines? The accumulation of water in a building cavity is asking for a costly mold, insect, or rot damage problem later on.
Missing insulation on the refrigeration lines outdoors is not a catastrophe - at least for a short un such as at this split system compressor/condenser unit. Perhaps a little loss in efficiency of the system operation in some weather conditions. On a long refrigeration line run, say between an attic air handler and a ground level compressor/condenser, the effects may be more significant.
Interior Leaks On & In Wall Below a Split System Air Conditioner Wall-Mounted Unit Traced to Missing Insulation
Watch out: The split system air conditioner installer we described at A/C Condensate Disposal for Split System Air Conditioners violated the manufacturer's recommendations against compressing the insulation on the refrigerant lines not just outside or in the walls, but also inside the wall-mounted unit itself. During the first season of use of the newly-installed Sanyo split system air conditioner the building occupants noticed water stains and rippled wall paint extending down the wall below the indoor air handler cooling unit.
Our photo (left) shows where the refrigerant lines rise in the wall to enter the wall-mounted half of the split system air conditioner (that larger white area below the left end of the unit) and the blue tape marks where we first saw condensate water dripping from the unit.
On inspection we ran the air conditioner for an hour or so on a hot humid day, then inspected the wall surface for moisture. Simply touching or pressing on the plastic bottom of the wall-mounted cooling unit sent a cascade of water droplets down the building wall interior surface.
We gave our A/C installer a call and asked for help. To his credit, the tech came immediately to the job site. Disassembling and inspecting the indoor cooling unit by removing its plastic cover and then lifting it carefully away from the wall mounting bracket (watch out to avoid bending refrigerant lines and causing a refrigerant leak), he found that there was no insulation whatsoever on the refrigeration lines that ran horizontally along the rear bottom of the unit. The result was condensation on the refrigeration lines that did not drip into the unit's condensate tray but rather fell into the plastic bottom where water leaked out onto and into the building wall.
The condensate tray in a wall-mounted split system air conditioner or heat pump unit is designed to catch water condensing on the cooling coils, directing it to a drip pan and then to the condensate drain line. But depending on routing of the refrigerant lines, these may provide another source of condensation that does not fall into the tray.
The "fix" for this condensate leak was the installation of foam insulation along the refrigerant lines inside the unit, from their point of exit from the building interior wall surface to their point of connection to the cooling coil. The leak was stopped.
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