THE BASIC HVAC-r CYCLE

Factors Affecting Reverse Cycle Heating in Winter

 

Outdoor Temperature:

 

Reverse cycle systems work by transferring heat from the outdoor air. As the outdoor temperature drops, the amount of heat available for extraction diminishes, making the system less efficient.(Note:  This figure is below 15 degrees C.  It currently is lower)

 

Frost and Ice Buildup:

 

When the outdoor unit tries to extract heat from very cold air, the refrigerant coil can freeze, causing frost and ice buildup. This can lead to defrost cycles, which temporarily stop heating to melt the ice, potentially reducing overall efficiency.

 

Defrost Cycles:

 

Defrost cycles can be triggered to prevent ice buildup on the outdoor unit, but they disrupt the heating process and can result in a temporary drop in temperature.

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Limited Heating Capacity:

 

Reverse cycle systems may not have the same high heating output as traditional heating methods like gas or electric heaters, especially in extreme cold conditions.  

 

Consider a backup heater:

 

In very cold climates, a backup heater may be needed to supplement the reverse cycle system.  (Electric Element / Cafe / Bar Heaters)

 

Use your ceiling fan:

 

Running a ceiling fan on low in the "winter" mode can help distribute warm air more evenly, improving comfort

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In summary:

 

While reverse cycle air conditioning can be a viable heating option in mild winters, it may struggle in colder climates due to the outdoor unit's ability to extract heat from very cold air and the potential for defrost cycles to reduce efficiency