What maintenance is required on my air conditioning system?
Air conditioners do require regular maintenance. They have air filters that need cleaning and/or replacement.
The filters protect the indoor fan and coil from being blocked up with dust and dirt. The filter media in a ducted system should be replaced three (3) years. The outdoor coil does not have filters therefore the coil needs to be cleaned as well. This coil is much more accessible for cleaning and can be done with a hose.
The filter in a split system should be cleaned every 3 – 6 months. You can clean the filter with a vacuum or with a mild detergent and rinse filter clean with water.
The coil of the outdoor unit should be kept clear of any rubbish or debris, as this will reduce air flow and therefore reduce the unit’s capacity.
Do I need a Services Technician to carry out the maintenance required?
You will only need to have a Services Technician carry out the maintenance if you are unable to do this yourself.
Upon installing a unit we go through and explain the required maintenance and give our customers a maintenance sheet. We don’t pressure to sell our customers servicing contracts however are more than willing to provide servicing to your air conditioning system.
How long does it take to install an air conditioning system?
It is usually best to allow at least half a day for a split system and two days for a ducted system, depending on the size of the unit and house.
What maintenance is required on my air conditioning system?
It really depends on the air conditioner – some require a high level of maintenance and some don’t. Domestic air conditioners are manufactured so that they require less maintenance with maintenance free sealed bearings on the fans, direct drive fan motors and hermetically sealed compressors.
What is cheaper – Gas heating or reverse cycle?
A reverse cycle high wall split is around half the running cost of natural gas heating and about a quarter of the cost of resistive electrical heating. This difference in cost can change from state to state therefore we would recommend using our calculator to work out your cost using your providers of energy, gas and electric.
Should I have my unit installed on a wall bracket or a concrete slab?
We recommend installing the outdoor unit on a wall bracket, as it keeps the unit off the ground and reduces slugs, bugs, cockroaches and geckos from making their home under the unit. This is the perfect place for these creatures to live and we have seen many air conditioners fail due to them shorting out electrical components in the outdoor unit.
Where is the best location for the return air – the wall or the ceiling?
For air conditioning we recommend installing the return air grill in the ceiling. The air flow from an air conditioner is higher than ducted gas heating and velocity out of the outlet forces the warm air down to the floor. You tend to not have the same problem with stratification as you would with ducted gas. Having the grill mounted in the ceiling also reduces noise, as the grill can be larger in size and reduce air noise. It also saves you losing precious cupboard space.
Terminology to help you communicate what you want. Knowing some of the common terms used with air conditioning systems.
Heat pump + reverse cycle = these terms mean the same thing. The unit is capable of heating as well as cooling.
Reversing valve = this is the part in the system that changes the gas flow, sending hot gas inside and the cold gas outside for heating and reverses that for cooling.
Split system = meaning the system is split in two. You can have a ducted split system, wall mounted split system, cassette split system.
Condenser = the part of the system that rejects heat from the gas. In refrigeration this is the outdoor coil. On a reverse cycle system, it’s the coil that is rejecting heat, so in cooling mode it’s the outdoor unit coil and in heating mode it’s the indoor coil.
Evaporator = is where the liquid refrigerant evaporates (boils) absorbs heat, and changes from a liquid to a vapour. This is where the energy is absorbed or the cold part of an air conditioning system. With air conditioning, the outdoor unit is referred to the condenser unit.
Coil = is a radiator-like heat exchanger, where it transfers heat energy from the air passing over. This heat energy is either absorbed or rejected into the refrigerant gas.
Refrigerant = is the working fluid used within a refrigeration cycle. It undergoes a repeated phase transition from a liquid to a vapour, absorbing and rejecting heat throughout the process. It doesn’t wear or run out, however it can leak out if there is a leak on the system.
Defrost = defrost is the process that a reverse cycle system will go through during cold outside weather conditions. In heating mode, the cold gas is sent to the outdoor unit where it boils off absorbing heat from the air outside. This absorbed heat, is the same heat the indoor unit is rejecting or the heat that’s heating your home.
How can the gas be boiling when it’s -5 degrees outside? The refrigerant gas’s evaporating temperature will usually be around 8-15 degrees below the outside temperature, so the gas is boiling off at -15 to -20 degrees Celsius, when the outside air temperature is -5 Celsius. When the gas in the outdoor unit’s coil is this cold, moisture in the air will freeze to the coil. When the coil becomes saturated with frost, it reduces the air flow and thus in turn reduces capacity. When moisture is forming, it is still absorbing heat, because it takes energy to change moisture to a liquid and then liquid to a solid (latent heat change of state without a change in temperature). Most systems have a trigger to set a defrost, usually time and temperature based, for example, operation of the compressor for 40 minutes with a coil temperature below -7 degrees. During defrost, the indoor fan turns off, the outdoor fans turn off, the compressor reduces in speed, the reversing valve is deenergised sending the hot gas to the outdoor unit and cool gas to the indoor unit. The compressor increases in speed and the ice starts to melt. Termination of defrost occurs in several ways however usually the outdoor coil temperature is above 8 degrees Celsius, as there should be no ice on the coil by that time. The compressor slows down the reversing valve, changing the gas flow and the outdoor fans start back up (sometimes you can get a big puff of fog from the outdoor unit, as the warm, moist air hits the cold outside, instantly turning into small water droplets fog). The indoor fan won’t start back up until the coil temperature is above 35 degrees Celsius. A simple icon will be displayed on the wall controller indicating defrost or pre heat of the coil and this is also displayed upon start up, so cool air is not blown out of the vents.
Return air = This is where the air returns to the indoor unit to be heated or cooled. With a ducted system it’s usually located in the ceiling. This is also where the return air filter is located. On a high wall split system, it’s the top/front section of the indoor unit and again this is where the filters are located.
Sensible heat = is a change in temperature of a substance, (added or removed heat) without a change in state. For example, if you put a pot of water on the stove and add heat, it increases the temperature of the water from 25 degrees to 100 degrees therefore sensible heat has been added (assuming we are at sea level).
Latent heat = is a change in the state of a substance, (added or removed heat) without a change in temperature. For example, if you keep heating the pot of water that’s 100 degrees, the pot of water does not increase in temperature however the water starts to boil and change state from a liquid into a gas and latent heat has been added.
