Homeowners accustomed to gas or oil furnaces, which generate their own heat though combustion, may find confusing the idea of a heating system that needs to be defrosted while it heats the home. But the heat pump defrost cycle is actually closely related to a heat pump’s operation, and is the same mechanism that gives a heat pump its exceptional efficiency.
In essence, a heat pump works like this: using the heat exchange properties of refrigerant, it takes heat from one part of the environment and puts it in another. In the winter, that means taking heat from the outside air – even when that air feels cold to us – and transferring that heat into your home. It does the opposite in the summer to provide efficient cooling.
As heat energy is removed from an area, temperature in that area drops. If the air near a heat pump’s outdoor coil has a certain amount of moisture and is near freezing, removing that extra bit of heat energy can trigger a freeze, and frost will form on the coil. That frost will make it more difficult to extract heat from the air, so it needs to be melted off in order for the heat pump to return to its full operating efficiency.
To do this, the heat pump defrost cycle temporarily puts the heat pump in reverse, pulling heat from the indoor air and using it to warm the frost off the coil. This should only occur for a few seconds to a couple minutes in each defrost cycle – usually not long enough to significantly affect the indoor temperature. After the frost is gone and the air around the outdoor coil is warm enough to defer the risk of another frost, the heat pump switches back into normal operation and continues extracting heat to warm your home.
To learn more about heat pump operation and how to best heat your Dayton area home through the winter months, please contact us today at Ace Hardware Home Services, Inc.
Our goal is to help educate our customers in Dayton, Ohio about energy and home comfort issues (specific to HVAC systems).
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