COLD Weather Heat Pump TIPS

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IT’S COLD OUT! Juneau is feeling some of the coldest days in over half a decade and with so many heat pumps buzzing away out there, we have been curious how they have been performing.

The crew at Alaska HeatSmart conducted a recent survey recently and below we share some quick results and a smattering of tips that can help you to enjoy the more heat from your heat pump!

We would love your survey input if you haven’t offered it yet! Please take a few minutes and answer some quick winter heat pump questions HERE!

About half of the survey respondents have not needed supplementary heat during this cold snap, while roughly half have needed some additional heat as temperatures dropped below about 15 degrees. These differences probably have to do with the air tightness and insulation levels in the home, how open the home’s floor plan is for good air circulation, as well as heat pump sizing.

Below are some useful tips we received for getting the most from your heat pump in cold weather:

Boost air circulation.

  • Set the fan speed to high. It is important to move the heat away from the air handler. This not only pushes heat further into your home but helps to draw cooler air across the air handler, increasing its efficiency and allowing the air to draw off more heat. 
  • Do not run your unit on “auto” mode. If you have different temperatures set for day and night, auto mode could cause your heat pump to switch to AC mode to bring the house down to the night time setting.
  • Turn the vanes on the air handler so that air blows horizontally out into the room, rather than down. This action will increase the speed of the air movement and allow for greater heat circulation.
  • Make sure your air filter is clean.
  • Use an auxiliary fan to help move cool air toward the air handler. This can be particularly useful if you have a cathedral ceiling. Some survey feedback suggests that this can add a few degrees to your living spaces.

Adjust the thermostat until you’re comfortable and leave it there.

  • Don’t worry about the temperature reading of your air handler. Your heat pump measures the temperature at the air handler and since warm air rises, the temperature can be higher up by the air handler.
  • Don’t set your heat pump thermostat back at night during cold spells. The house will stay warmer and not take so long to get comfortable in the morning. If you have some hourly programming set, turn it off and just leave the unit set at the same temperature both day and night. Once our outdoor temps warm a bit, turn the programming back on.

Do not allow snow and clutter to pile up around your compressor!

See the image associated with this post of the compressor half under snow. While it seems that these units can deal with moisture just fine, they need good air flow. Any obstructions will force them to work both harder and more inefficiently.

Relax…your compressor is just defrosting.

You’ve probably noticed that your heat pump seems to randomly turn off when the outdoor temps are down. This is normal and involves the defrost cycle of the heat pump. Condensation water builds up on the outside coils of a heat pump and when the temperature is below freezing, the coils will ice up. To prevent the heat pump from failing, it will periodically reverse itself, going from heating to cooling. A cooling cycle involves taking warm air from inside the home and ejecting it outside. This warm air will defrost the outside unit’s coils and you may even see steam coming from the outdoor unit. When defrosting is finished, the air handler will turn back on. Odd noises are common with the defrost cycle, such as sloshing and gurgling.


For more background see this great article by Efficiency Vermont,  “Who knew? 8 ways NOT to use a heat pump”.

And, for a Juneau heat pump geek’s detailed ‘at-home’ analysis of heat pump fine tuning, read Shawn Eisele’s great entry, “My Heat Pump Isn’t Keeping Up – But It Probably Can”

For loads of great heat pump info and links to heat pump resources, visit the heat pump section of Renewable Juneau’s website!