The average heating system operates by creating heat directly, generally employing components that heat up when an electrical current passes through them. These systems are referred to as direct element heaters and include systems such as portable heaters, panel convectors, and off-peak storage heaters. At their best, these systems can only achieve 100 percent energy efficiency, meaning that all of the electricity used is placed into the room as heat.
Reverse Cycle Air Conditioning operates a little differently. Instead of using electricity to create heat, a refrigerant is used to absorb heat from outside the home. The refrigerant is then pumped through a fan coil known as a condenser, releasing the heat it gathered into the home. It may seem counter-intuitive to use outside air to heat a home, but heat is available outdoors even on the coldest winter nights.
Reverse Cycle Air Conditioning offers a number of advantages over direct element systems. Each unit of electricity used can produce up to three units of heat, giving it a 300 percent energy efficiency rating that other systems cannot even approach. Better yet, the process is reversible, meaning that the refrigerant can absorb indoor heat and transfer it outside during the summer months. Reverse Cycle Air Conditioning units also remain cool to the touch, last up to 20 years before requiring replacement, and filter indoor air so it does not become stale.
The Types of Reverse Cycle Air Conditioning Units
Split Air Conditioning System
There are an array of Reverse Cycle Air Conditioning models to choose from. The first is a Split-System, a permanently mounted system utilizing an external compressor unit and interior condenser unit. Banishing the compressor outside allows the system to run more quietly than systems located entirely in the dwelling, though noisier systems may annoy your neighbors. These two units are attached via piping, which the refrigerant flows through to provide heating and cooling. As a rule, Split-Systems are more expensive than traditional wall units and are suitable for rooms with an area of 100 square meters.
The interior portion of a Split-System Reverse Cycle Air Conditioning unit is most commonly installed on a wall, but it is also possible to install it near the floor, on the ceiling, or in the ceiling as a cassette. Each option includes its own advantages and disadvantages. Wall-mounted units must be placed in an exterior wall in order to allow adequate condensate draining. Floor-mounted models are better at heating the home, but suffer in performance when cooling it. If you use heat more often than air conditioning, it may be the perfect option for you. You can get the best of both worlds if you purchase a wall unit with adjustable louvres that can be directed downward for optimal heating and upward for optimal cooling.
Multi-Split Reverse Cycle Air Conditioning
The above location recommendations are also applicable to Multi-Split Reverse Cycle Air Conditioning units. Multi-Split systems also involve an external compressor, but it is connected to multiple interior units instead of just one. This allows each room to be heated or cooled independently from the others while maintaining most of the advantages of a Split-System model. They are suitable for spaces measuring up to 200 square meters.
The downside of a Multi-Split system is its total output, which does not change no matter how many rooms you are trying to heat or cool at once. These systems can have separate settings for up to seven rooms, but using them all at once will prevent any of them from getting warm. If you anticipate this issue, you can double check a system’s specs before you buy it to ensure that it can handle however many rooms you need climate control for simultaneously.
Ducted Reverse Cycle Air Conditioning units are fundamentally different from the systems described above, as they are intended to heat and cool an entire dwelling at once rather than a few rooms at a time. They consist of a heat pump located outside or in the roof space, ducting above the ceiling that distributes climate-controlled air throughout the dwelling, and vents that control where in the house that air goes. Additional vents called grilles recirculate air to keep the cycle going. It is recommended that filters be attached to grilles to limit dust circulation through the home.
You should look into zoning on any ducted system. Zoning splits the system into two or more separate entities that may be operated independently, reducing the higher costs associated with ducted units. This allows you to heat living areas during the day and bedrooms at night instead of everything all the time, for example. You can also purchase a smaller system if it will not be responsible for the climate of the entire building, saving money on installation as well.
A ducted Reverse Cycle Air Conditioning unit can effectively control the climate in 200 square meter spaces. Alternatively, a duct can be installed in a Split-System model to heat and/or cool an 80 square meter space. This option can be a good compromise between the cost and performance of ducted models.
Inverter technology is a new feature available on some Reverse Cycle Air Conditioning Units that allows you to control the output of the compressor. This allows you to turn the machine down without turning it off, allowing you to save money on your power bill. This is especially true during periods of heavy usage. Inverter air conditioners also tend to work faster and keep indoor temperatures more consistent, making it an excellent option wherever it is available.
Reverse Cycle Air Conditioners may not work in temperatures lower than five degrees Celsius, though many newer models have auxiliary heaters or de-icing capabilities to better handle the chill. These options frequently run on peak rate electricity, making extended use very expensive. You should double check the effective temperature threshold of any system before buying it as a result.
What Else To Look For
There are a number of other factors that should inform your purchasing decision, including energy rating labels, programmable thermostats, insulated ducting, and required maintenance. New reverse cycle air conditioners in the window/wall and Split-System categories are required by law to display an Energy Rating between one and six stars, with more stars equating to superior energy efficiency. More efficient models are labeled as such because they produce more heat per unit of electricity used, leading to energy savings of up to $220 per year. In general, systems rated three stars or better are efficient enough for everyday use.
Ducted systems tend to be larger and more powerful, making it unfair to compare them to their smaller cousins. These models have their energy efficiency rated by Coefficient Of Performance, or COP, which is a direct measurement of how many units of heat are produced per unit of electricity used. A COP difference of 0.5 equates to about $220 of annual energy savings, and the minimum rating you should look for is 2.5.
Programmable thermostats help you save money by granting greater control over what your unit does when. In general, living areas should be kept between 18 and 20 degrees Celsius while bedrooms should be between 16 and 18 degrees. Any external thermostat should be placed in a draught-free area of your primary living quarters to ensure that it picks up the temperature you are feeling most often. Do not expose it to direct sunlight or a return air grille, as these can throw off its readings.
Economy cycles can also help save energy. They gradually decrease the output temperature produced by the unit over a period of a few hours, lowering your energy costs in the process.
Even the best air conditioners lose efficiency if their ducting is poorly insulated. Duct efficiency is measured by R values and range from R1.0 to R4.0, with higher values meaning increasing resistance to heat loss. You need a minimum of R1.5, which any reputable supplier will have available. All joints must also be well-sealed, as otherwise the quality of the ducting is irrelevant.
Notes On Ducted Systems
Ceiling diffusers should be placed in a central location away from internal walls, which can obstruct air circulation. Four directional ceiling vents or those with adjustable louvres provide the most efficient heating. Return air grilles should also be centrally located. Zoned systems require special placement that your supplier will be able to tell you about.
Reverse Cycle Air Conditioning units are more efficient means for cooling and heating your home or office.