How To Stop Heat Pump From Freezing Up?

Heat pump is a vital item for keeping the home warm during the frigid, cold, and freezing months during the winter seasons. Heat pumps are devices transferring heat energy from an energy source to a thermal reservoir. A thermal reservoir is thermodynamic structure with a heat capacity. Thermodynamic structures are matter or radiation restricted in space by walls. This is away from its surroundings. It can be surrounded by thermodynamic systems and non thermodynamic systems. Thermodynamic systems can be isolated, closed, or open. The isolated ones have non-conductive walls of heat. They are immovable and are impermeable to all matters. This also includes forces too. Closed thermodynamic systems are confided by walls that are impermeable to matter, but can be permeable to heat. In closed thermodynamic systems, there is volume change and agitation with internal friction. An open thermodynamic system has a wall that is separated from another thermodynamic system. It is part of the environment of the open system. In an open system, the wall that is permeable to a chemical, radiation, or wall does not sustain temperature differences. This post will be about how to stop heat pump from freezing up. You can also go to this article: Antifreezing Measures for Air Source Heat Pumps in Winter. 

Reasons Why A Heat Pump Freezes Up

One reason why a heat pump can freeze up is due to its airflow. Heat pump goes to heat mode by reversing the refrigeration cycle. The cycle is an important part of the heat pump. The state of the refrigerant from a liquid to a vapor/gas is known as evaporation. On the opposite side, the change of gases to liquid is condensation. A heat pump requires enough energy to change from evaporation or condensation. If a heat pump has higher pressures, this can affect the heat pump's airflow. This is due to the fact that it can cause the temperature to fall below freezing. With less heat being pumped through a heat pump, the area where the air refrigerator is located means a colder area.

A refrigerant works by getting airflow is through a closed system of refrigeration lines between the outdoor and indoor unit. As the heat energy is absorbed from the air outside by the condenser, the air is released inside by the evaporator coil. But when there is not enough energy, this can cause the heat pump to freeze up. When the air from the heat pump is not being pulled into ductwork by a motorized fan, it can cause issues with the heat pump. It freezes it. The refrigerant is used for pumping from the interior coil to the exterior coil. This is where it absorbs heat from the air. The air is then pushed through the connecting ducts to air vents in the home. This affects the interior of home's temperature.

Another reason for a heat pump freezing up is due to cold water. During winter weather, the heat pump can produce chilled water down to temperature of 5˚ C. The water is passed through the cooling coils. It can enter into one or more air handlers. This is where it goes to cool. It also dehumidifies the home's space. When there is freezing water on the heat pump during winter months, the water that is on top of the heat pump freezes.

Lastly, a reason why a heat pump may freeze up is due to the way that it is settled into the ground. When the ground above a heat pump is parched, it shifts and cracks. Over time as the ground settles, it becomes uneven. Heat pumps should be on the level ground to function. The reason why that heat pump may not be on level ground is due to tilting. When the pump is off balanced, the oil and refrigerant is caught in the tubing. This keeps the pump from being lubricated. If the system is tilted sufficiently, slugs of liquid can be released into the compressor in heat pump.

How To Prevent A Heat Pump From Icing Up

One way to prevent an air source heat pump from icing up is to keep the area around and from it clear. Throughout the year, you should perform maintenance routines. As you know, dust and dirt can build up on the filters. When dust and dirt is built up on the filters, the performance of the heat pump becomes affected. You should vacuum the dust and dirt off. You should also check the filters. If they are dirty, rinse them off and wipe the top of the unit with a dry or damp cloth. You should clean the filters every two to three months. Changing the air filter helps the air that flowing through the heat pump from being restricted.

During the winter, spring, and fall seasons, you need to check on the unit. By doing this, you are checking for debris, trash, tall grass, leaves, and other things. These things can get caught up in the heat pump fans. This can affect the overall performance of heat pumps. Weeding and mowing the area ensures that the heat pump can operate normally helps a lot. During the winter season, you should check the heat pump to make sure that there is no snow accumulation. You can do this before each snowfall in your neighborhood. This can be done by clearing the snow that is built up around the pump each time that you're shoveling your driveway of snow. The snow and the cold moisture in the air can freeze the evaporator and condenser coil. By doing these things during the winter, spring, and fall seasons, you can stay on top of any issue that your heat pump may encounter.

Another way to prevent an air to water heat pump from freezing up is ensuring that your unit on the ground is level. If the unit is not level during the winter seasons, ice can block the drainage path. This can affect the unit's airflow. You want to make sure that ice is not blocking the drainage path. Vibration can also cause a heat pump to freeze up. If the unit is rest on a frozen, icy, and uneven surface, it is not supported properly. As a result of this, the unit can vibrate when it is turned on. Constant vibration can cause the tubing to become loose. If the unit is on a frozen, icy, and uneven surface, you need to contact a professional heating and cooling expert to level the unit. You can leg the unit yourself if it has legs. You check it in this way to make sure that the unit itself is not rusted or wobbly.

If you try to level a heat pump unit that is on a frozen, icy, and uneven surface, you risk bending the refrigerants lines. When the refrigerant lines are bended, a leak can form. Lastly, you can have a technician check on the defrosting component of the heat pump. Temperatures fall to mid 20 to 30 F during the winter months. As a result, the air's moisture freezes on the heat exchanger. When this occurs, the defrost cycle on the heat pump starts to run to eliminate the ice.

When the defrosting cycle that eliminates ice begins, the indoor fan stops. The unit stops heating. The outdoor fan also stops. However, the compressor will continue to operate. A timer on the unit controls how often it goes into a defrost cycle to eliminate ice. As temperatures outside are in the mid to low 30's the defrosting cycles begins in 30, 60, and 90 minutes cycles. 

DC inverter heat pumps normally have better and smarter defrosting since they adopt the intelligent defrosting technology to make optimal decisions on whether it is time to defrost or not.  

Tips For Dealing With Frozen Heat Pump

If the heat pump is covered in frost and ice, you need to shut the unit off. After you shut off the unit, you need to contact your cooling and heating professional. Before you contact your cooling and heating professional, you need to check the unit’s air filter. You should be cleaning and replacing the filter regularly in case it is damaged or clogged. If the filter is broken, replace it. Another tip for dealing with frozen heat pump is to make sure that the indoor air vents are not blocked by anything. If there are items blocking the vents, the unit will not get enough ventilation to function properly. After you check the air filter to ensure that it is in good working order and making sure that the vents are not blocked by debris, you can turn on the fan manually. When you turn on the fan manually, air should be coming out from the vents. If there is no air coming out from the vents, you may have an issue with the motor inside the heat pump itself. Lastly, you can remove the ice that has built up on the heat pump. You remove the ice from the heat pump by turning off the circuit breaker on the heat pump. Afterward, you spray the pump with water until the ice melts. If pump is warm, run it on fan mode.