I have an Carrier air heat pump at the back of my house (installed 1 year ago). It is generally fine and stays defrosted with the smaller amounts of ice/snow. With a larger amount of snow, should I consider building a temporary lean-to above it to keep snow away from the unit? If so, how high above the unit should it be to not impede air flow?

  • The cross sectional area of the side openings should be at least as large as the area of the fan exhaust.
    – Dan D.
    Feb 12, 2014 at 19:18
  • Top blower? How much "larger" snow can you reasonably expect? Three inches? Fourteen feet? Would you consider building a permanent decorative/protective gazebo around the unit? Aug 19, 2014 at 2:23
  • I too have a Carrier, and my problem is with ice build-up. I live in South Carolina and we're more likely to get ice storms than a snow storm. The ice accumulation, and large icicles present problems hanging down and eventually coming in contact with the fan, as well as accumulation of ice on the surface and dripping down into the unit building up from the side eventually dragging and banging into the fan.
    – Cyberchipz
    Aug 31, 2016 at 7:47

2 Answers 2


There are several advantages to having a permanent roof over an outdoor heat pump:

  • keeps direct sunlight off during cooling season
  • keeps rain, leaves, twigs, and branches further away and keeps the unit cleaner
  • no freezing rain can put the blower out of balance with lopsided icing
  • keeps snow away from the top and sides where it would impede airflow
  • possibly provide some noise reduction

The first installation manual I could find says (page 7) there should be a 48 inch (120 cm) minimum space above the unit.

Depending on the typical maximum snow accumulation, I would extend the roof out at least three feet from the edges of the unit. This also avoids the problem of the roof supports from blocking service access (some units have hinged panel doors).


I out up an inexpensive metal awning over my propane grill, so we could use it all winter. It is tilted enough that snow does not built up on it significantly. I think I got the awning from Home Depot.

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