It's not unusual to see a light coating of frost on your heat pump during the winter. However, it's the last thing you should see during the summer. If you see ice anywhere on your heat pump as it operates under summertime conditions, then chances are your system is in need of some serious attention.
The following talks about the potential causes of ice formation, as well as the things you can do to fix it and hopefully prevent it in the future. There are also solutions that only your HVAC technician from a site like http://www.perryheatingandcooling.com can adequately perform.
How Ice Buildup Affects Your Heat Pump
A heat pump uses its refrigerant to transfer heat to and from your indoor spaces, depending on the type of demand. During the summer, the heat pump removes the latent heat found inside of your home and expels it outdoors. At the same time, it also condenses the moisture found in the indoor air from a vapor to liquid state.
It's possible for the evaporator and/or condenser coil's temperature to drop below freezing, causing the surrounding moisture to freeze and form sheets of ice over the coils. The longer the unit runs, the more ice accumulates until it becomes impossible for the heat pump to function properly. There are several reasons why this happens:
Low refrigerant levels – When your heat pump runs low on refrigerant, it creates a drop in overall pressure that results in colder temperatures. The effect is akin to a can of compressed air that's being emptied out – the lower pressure allows the gases within to expand, causing surface temperatures to drop as well.
Restricted airflow – When there's not enough air flowing over and through the coils, it allows the moisture on the coil to freeze over. A blower malfunction, clogged air filter or blocked return air vents could cause freeze-ups.
Dirty coils – Dirt makes an excellent insulator, especially the dirt and grime that's accumulated on the indoor coil for quite some time. Layers of dirt and grime directly on the coil prevent the refrigerant from transferring heat energy from the surrounding air, creating pressure imbalances and other issues that result in a freeze-up.
Mechanical issues – These typically range from faulty thermostats and expansion valves to damaged coils and broken fan relays.
Things You Can Do
In the event of a freeze-up, the first thing on the agenda is quickly and safely defrosting the heat pump. This means either leaving the heat pump off for a few hours or using the pump's own defrost cycle to melt away the ice. Afterwards, you can do the following to curtail future freeze-ups:
- Make sure the return air vents are open free of any obstructions.
- Change the heat pump's air filter to avoid clogs and blockages caused by dust and dirt accumulation. Most experts recommend that it be changed on a monthly basis.
- Make sure the thermostat isn't set low enough to trigger freezing. Setting your thermostat at or below 70 degrees Fahrenheit not only makes freezing more likely, but it also doubles your energy bills.
- Clear all debris and vegetation from around the base of the outdoor cabinet. This ensures the outdoor cabinet receives the ventilation it needs for frost-free function.
What Should Be Left to the Pros?
No matter how extraordinarily handy you are around the house, there are just some things that are best left to professionals. That includes checking and replenishing refrigerant levels. Working with potentially hazardous high-pressure gases requires specialized equipment and expertise that's outside the scope of the average do-it-yourselfer.
Other tasks, such as replacing the expansion valve or compressor, also require a high degree of expertise for a satisfactory job. If you need to replace a major component just to unfreeze your heat pump, it's usually better to have a certified technician do the work on your behalf.Share