Winters Magic and Keeping warm- Heat Pumps

Leavenworth and Cle Elum Home Inspection Services

Well winter finally has settle into the Wenatchee Valley. One thing that as home inspectors inspecting components that will be in snow country we should be looking for is how the heat pump is set up.

As the temperatures drop heat pumps will start to frost up as part of normal operation. The heat pump will then go through their defrosting mode to rid the unit of this frost. This will create water that needs to be able to drain away from the unit, if this is not properly accounted for will create an issue for the heat pump.

Heat pumps need to be elevated off the ground to allow the water during the defrost cycle to flow away from the unit. Snow build up even at the bottom few inches of the unit can prevent the unit from completing the defrost cycle properly. If the snow is not cleared the unit more than likely will not function as it should and if operated under those conditions for any length it could even lead to damage to the unit.

The IRC (International Residential Codes) states-

M1403.2 Foundations and supports.
Supports and foundations for the outdoor unit of a heat pump shall be raised at least 3 inches (76 mm) above the ground to permit free drainage of defrost water, and shall conform to the manufacturer's installation instructions.

Ah, manufacturers specs…  Here is what Trane suggests

1. Units should be elevated three (3) to twelve (12) inches above the pad or rooftop, depending on local weather. This additional height will allow better drainage of snow and ice (melted during defrost cycle) prior to its refreezing. This should prevent a build-up of ice around the unit which occurs when unit is not elevated. Insure that drain holes in unit base pan are not obstructed preventing draining of defrost water.

2. If possible, avoid locations that are likely to accumulate snow drifts. If not possible, a snow drift barrier should be installed around the unit to prevent a build-up of snow on the sides of the unit and should be of sufficient distance from the unit to prevent restriction of airflow to and from the unit. Also allow for proper maintenance space. The barrier should be constructed of materials which will blend in with the building design.

3. Avoid locating the unit where condensation and freezing of defrost vapor may annoy the customer. For instance, installing the unit under a bedroom, kitchen, or picture window may be annoying to the customer since condensate and fog will occur during the defrost cycle.

4. Avoid locating the unit under the eaves or other overhead structures as sizeable icicles may form and the unit may be damaged by these falling icicles.

These are expensive components and proper care, maintenance and set up will help with the longevity of these units.

Ancora Imparo

NCW Home Inspections, LLC  is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…  

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www.ncwhomeinspections.com                                                 509-670-9572