The short answer to this question is no. It’s likely your heat pump’s not broken at all but simply defrosting and performing less efficiently due to cold weather. While very cold weather is often associated with many “No Heat” HVAC service calls caused by genuine heating equipment failure, complaints about heat pumps blowing cold air is very common. In extremely cold weather, even a properly functioning heat pump may seem to have trouble maintaining the usual set temperature. It’s working harder and somewhat less efficiently to keep you comfortable.
Even though your heat pump is actually working harder to keep up with your home’s heat loss to the surrounding cold environment, you are actually feeling the relative loss of heating efficiency.
It Helps to Know How Heat Pumps Work
Heat pumps are engineered to remove heat from the air and exhaust it either inside or outside depending on whether it’s in heating or cooling mode. By simply reversing the process it uses to keep you cool in the summer a heat pump warms your home in winter. Almost magically, it can always pull heat from the cold air outside and push it indoors!
Compared to conventional forced-air gas or electric furnaces which forcefully blow hot air, from 130 to 140 degrees for short periods of time, a heat pump usually gently blows warm air, from 110 to 115 degrees and circulates it longer.
When outdoor temperatures drop below freezing, ice can form on the coils outside. In the dry desert, this should only happen when outdoor temperatures are at their coldest – 0 to 30 degrees. If it’s raining or snowing ice will form more readily. When ice forms your heat pump will automatically reverse its operation to defrost those parts causing it to blow colder air inside which is then warmed by the backup heater for a short time. This is completely normal and it will cycle back to normal heat pump operation after the defrost interval.
If the Air that’s Blowing is “Warm” … Why do I Feel Cold?
When it’s below freezing (32-degrees) outdoors, heat pump output drops to 85-95 degrees. Because the air temperature is lower than your body temperature, and less than the 110 to 115 degrees of warmth you usually feel blowing, it seems like your unit is blowing “cold” air even though it is actually warmer than your indoor house temperature and warmer than where you might set the thermostat. Also, your heat pump fan stays on longer to circulate the warm air when outdoor temperatures are above freezing.
When the temperature in the house drops about 2 degrees below the set thermostat temperature, supplemental heat comes from less efficient backup electric heaters to assist the heat pump. When the room temperature gets to within one and a half degrees of the set thermostat temperature, the back-up heat cycles off and the heat pump continues gently heating unassisted. Because of the extreme exterior cold, the heat pump will keep working to come to within about one to one and a half degrees of the set thermostat temperature, but since the building is losing heat as fast as it is producing heat you may not reach the set temperature.
What Can You Do to Feel More Comfortable?
To feel more comfortable during these very cold conditions, Oasis recommends you can try temporarily setting your thermostat two-degrees warmer to compensate for the loss of efficiency and to maintain a comfortable temperature. For example, if you normally set your thermostat at 70-degrees in the winter and your house only ever seems to get up to 68, move your thermostat to 72. This will push your ambient temperature up to 70 and you will feel comfortable! Understand that while this choice will require more energy consumption and may show up on your power bill you are still employing one of the most efficient methods of home heating.
Whatever type of heating and cooling equipment you have, it is very important to be sure you have energy-efficient insulation, windows, window coverings and weather stripping to minimize heat gain and losses during extreme weather.
Uncomfortable? We Service All Brands- Call Oasis Air Conditioning & Heating, Inc. (520) 648-1755 We’re Not Comfortable Unless You’re Comfortable!
Please keep in mind this information is intended as a courtesy to our customers. It is not inclusive of all possible situations and Oasis does not assume any liability resulting from the informational guidelines we present here. Your HVAC system should be regularly inspected and serviced by a trained technician.
Trane. (2015). Heat Pump Troubleshooting Guide. https://www.trane.com/residential/en/for-owners/troubleshooting/heat-pumps.html
Published on LinkedIn 3/6/19