It may seem strange that a heat pump could blow cold air during the winter. There are many possible causes of this. Most are quite normal and no cause for alarm, while others may indicate the heating system needs servicing.
Understanding the Defrost Cycle
The defrost cycle helps protect the heat pump from damage by removing frost and any ice that may form. This typically happens when the outside temperature drops below 42 degrees. As the cycle progresses, it will blow a little bit of cold air through the vents.
The defrost cycle can continue every 30-90 minutes depending on how cold it is outside and whether the system senses frost/ice formation. Each cycle typically lasts for around 20 minutes.
As the cycle goes through its paces, keep an ear out for odd noises and sounds. If these are accompanied by frost and ice accumulation that doesn’t melt away, you will want to contact an HVAC technician to come and take a look.
How Defrosting Works
The outdoor coil serves as an evaporator. When the weather drops, the moisture that condenses on the unit can freeze. During the defrost cycle, the unit shifts refrigerant flow to help remove this.
The outdoor fan will cycle off, which allows the unit to heat up, thus melting the ice. However, as it does this, it means the indoor coil gets cold. This causes cold air to blow through the vents.
Problems to Note
If the unit is going through overly frequent defrost cycles and the temperature inside your home does not match the settings you have put into the thermostat, it may be a sign that the heat pump needs servicing.
Your heat pump may be undersized for your home, or there could be a maintenance fault that needs to be taken care of. Sometimes it signifies that the filters are clogged, while other times it could be because electrical components have shaken loose and need to be reconnected.
Day & Night Air can help you take care of your heat pump this winter. We invite you to contact us at 602-497-4662 to learn more about our HVAC services and the ways we can help keep you warm and comfortable throughout the Arizona winter.