It’s getting cold out and now is the time to understand a few ins and outs of your heat pump! Juneau homes are rapidly embracing the beauty of ‘heating locally’ thanks to the inexpensive, efficient, and climate-friendly reality of air source heat pumps. Hundreds of these rock star heating systems are being installed around Juneau each year and for most of us, they represent a fairly new technology, at least as far as home heating is concerned. While your old, dirty diesel stove could push out some pretty hot air in pretty short order, your shiny new heat pump operates a bit differently.

A heat pump moves heat. It does not create heat, implying that how you heat your home needs to be rethought a bit. The heated air from your heat pump will never reach the temps from an oil stove, but the pump is completely capable of heating a lot of space. Renewable Juneau always has an ear (or two) on the heat pump buzz and we’ve gleaned a few tips for getting the most from your heat pump in cold weather. This following list of tips is a work in progress and we continue to refine our methods and search for tweaks that will pull more heat and save more money from this exciting space-heating technology.

Boost air circulation.

• Your heat pump is designed to move a large quantity of warm air often. When temps drop outside, the indoor air handler can blow night and day. It’s a good thing that these devices cost so little to operate, meaning that there is little need to worry about massive electric bills from 24/7 operation.
• Set the fan speed higher. 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. Often, an increase in fan speed can make your home feel warmer than if you turned up the temperature a couple of degrees.
• Do not run your unit on “auto” heating 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. Set the unit on heat mode and only adjust your fan speed and temperature.
• Adjust 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.
• Clean the air filter often and make this a habit. You’ll be warmer and you’ll save money.
• When below 20, you can 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 feedback suggests that this can add a few extra degrees of warmth 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. If you just don’t like this idea, try just lowering the temp at night by two degrees and then bumping it back up in the morning.

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. Ideally, your outdoor compressor has lots of room, is protected from snowfall, and has a small roof a few feet above it to keep it out of the bulk of our wet weather.

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 over. 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!