Frequently Asked Questions - and their Answers

Ducted Gas Heating | Refrigerated Air Conditioning | Evaporative Air Conditioning

Ducted Gas & Evaporative Cooling System in Sydney | FAQs

How does ducted gas heating work?

Ducted Gas Frequently Asked Questions

Ducted gas heating is one of the cleanest, effective and most energy-efficient forms of home heating available. It operates by drawing air from inside the home and passing it through a specially-designed gas heating unit. The air is rapidly warmed and gently distributed throughout the home from outlets in the floor or ceiling.

What is the Gas Energy Rating of ducted gas heating units?
The latest and most efficient range of ducted gas home heating units supplied by Combined Heating and Cooling have an energy star rating of 5.6.  Every gas heating appliance sold in Australia must be tested and certified for use by a NATA accredited laboratory. These results are used by the Australian Gas Association (AGA) to measure performance levels. The more stars, the better the efficiency rating.  This means less gas to heat your home, and annual savings that are significant. Use of the zone controller can lower running costs even further, giving you the flexibility to turn off heating in different parts of the home, or reduce the temperature in rooms that require less heat.

How does gas ducted heating compare to other central heating systems?

Gas ducted heating is more effective and cheaper to run than any other form of central heating, including reverse cycle air conditioning.  Reverse cycle systems lose heating efficiency once the outside temperature drops below 10°C – the very time when you need the heat most.

Can I operate my ducted heater and cooler with the same controller?

Yes. The multi-zone controller can control both your gas heating unit and your evaporative or refrigerated air conditioning unit. You simply switch between the heating and cooling mode and program your ideal temperature settings. These operate on a 24 hours a day weekly time clock, so you can set the various on off times and temperature ranges to suit your away or at home modes, and night or day modes.

Where is the gas heater installed?

The ducted gas heating unit can be installed inside the roof space, on an external wall or, in some cases, under the house. The heating outlets can be positioned in the floor or ceiling, depending on your preference and the type of house.  Most modern homes are built on concrete slabs so ceiling ducts are the only option.

Will a ducted gas heater have enough capacity to heat my home?
Combined Heating and Cooling offers a complete range of ducted gas heaters to suit every application. All CHC professionals are expertly trained to ensure correct heater selection and installation.

Is ducted gas heating suitable for people with allergies?

Ducted Gas Heating is ideally suited for people with allergies. Natural gas is a clean burning fuel, and all flue emissions from the heater are safely expelled to the exterior of the home. Unlike some other forms of heating, gas systems do not significantly dry out the air, which can cause irritation to the skin, eyes and throat. 

What form of heating is the most environmentally friendly?

Combined Heating and Cooling has chosen Australia’s most efficient range of ducted gas systems. Research commissioned by the Australian Gas Association in 2000* found that in the residential sector gas is a clear winner in limiting greenhouse emissions. As well as saving on running costs you’ll be contributing towards a healthier planet.  *Source: Assessment of Greenhouse Gas Emissions from Natural Gas, Australian Gas Association, 2000

Is ducted gas heating safe for children?

There are no exposed hot surfaces or naked flames inside the house for little fingers to touch and no fume emissions inside the home.

Refrigerated Cooling System Frequently Asked Questions

How does a refrigerated air conditioner work?

Air conditioners work the same way as refrigerators, but instead of cooling just the small, insulated space inside a refrigerator, an air conditioner cools a whole house. It does not add cool air, but instead removes heat from existing air, leaving the temperature cooler.

Air conditioners use a refrigerant chemical that easily convert from a gas to a liquid and back again. This chemical is used to transfer heat from the air inside the home to the outside.  The system has three main parts – a compressor, a condenser and an evaporation coil. The compressor and condenser are located outside, while the evaporation coil is located inside the house, in a roof space or under the floor. The refrigerant arrives at the compressor as a cool, low-pressure gas. The compressor squeezes the fluid, packing the molecules tightly together. The closer the molecules are compressed, the higher their energy and temperature.  The refrigerant leaves the compressor as a hot, high-pressure gas and flows into the condenser, which acts like a radiator in a car that allows heat to escape.

When the refrigerant leaves the condenser, its temperature is much cooler and it has changed from a gas to a liquid under high pressure. The liquid goes into the evaporation coil where it changes back from fluid to gas. As the liquid changes to gas it extracts heat from the air around it.  Connected to the evaporation coil is a fan that circulates this cooled air inside the house, lowering the home temperature.

What size air conditioning cooling system do I require?

The efficiency of a refrigerated air conditioning system is measured by its coefficient of performance (COP). This is a measure of two factors: an air conditioner's output capacity (the amount of heat that will be removed by cooling) and its energy consumption (the energy the air conditioner uses per hour at rated capacity). The size and capacity of the unit you will need depends on the size of the home you want to cool and its heat load, which is determined by environmental factors such as the number of windows, amount of sunlight entering the room, outside weather conditions and what type of insulation you have. Generally, the bigger the area you have to cool, the larger unit you will need to service it. Your Combined Heating and Cooling professional will take all these factors into consideration when assessing your needs and recommending a unit appropriate for your home.

What is a split system?

A split system has an indoor and outdoor part that is connected together. They provide quieter and more efficient air conditioning than a single package unit. They work by placing the cooling parts of the air conditioner in the outside unit and then having one or two inside components that contain the fans.

Can I leave doors and windows open while operating the air conditioning?

It is not recommended to leave doors and windows open if you're trying to cool your home. On hot days it is also advisable to close curtains and blinds to minimize heat entering through glass areas during the hottest part of the day. This will keep your house cooler and prevent your air conditioner from having to work harder than necessary. If you prefer to leave windows and doors open in summer, then consider an evaporative system, rather than a refrigerated system.

Are there filters that need to be cleaned in air conditioners?

Yes. You should inspect the air filters in your air conditioner twice a month to see if cleaning is necessary. Trapped particles in the filter can build up and block the airflow. This reduces the air conditioner's cooling ability. Most residential systems have easily accessible filters on the air return grille that can be removed and cleaned according to the manufacturer's instructions.

How does the temperature control panel work?

Your system will come with a control panel that has both ‘auto’ and ‘manual’ settings on the thermostat. You can program the temperature you require for both ‘away’ and ‘at home’ mode and night/day settings for an entire week. The unit will run only when the temperature requires it, maintaining a steady temperature and reducing energy use by only working when needed.

Can I reduce energy usage while running the unit?

You can gain maximum economy if you close windows, doors, curtains and blinds, which can help your air conditioner, cool a room more quickly. When a hot day is expected, turn on the air conditioner early rather than wait till the building becomes hot (it operates more efficiently when the outside air temperature is cooler).

Evaporative Cooling System Frequently Asked Questions

How does an evaporative cooling system work?

A pump draws water from a reservoir onto a cooling pad, which remains saturated during operation. A fan draws air from outside the unit through the moistened pad, cooling the air by evaporation. The unit's fan and motor size are selected and matched to the size of your home, to deliver the appropriate airflow. The evaporative cooling system is sited on the roof and the fan and motor are quiet in operation, ensuring a constant, even flow of fresh air to the home. The whole unit uses only a small amount of energy to produce a constant, refreshing breeze. 

Does an evaporative cooling system use much water?

All evaporative air conditioners use water to provide the cooling effect.  The amount varies with the size of the unit, the amount of cooling selected, and the ambient outside temperature and humidity. Evaporative cooling systems have a computerised setting which regularly flushes the reservoir, replacing it with fresh water to ensure a clean operation.

How much electricity do evaporative cooling systems use?

Running costs are estimated to be 15% of an equivalent sized refrigerated air conditioning system so they are very cost effective to operate. The savings in energy costs compared to refrigerated systems can be hundreds of dollars a year.

Will an evaporative cooling system keep my home cool during the long hot Australian summer?

Yes, definitely.  When temperatures rise the evaporative air conditioner works at its best.  Unlike refrigerated air conditioners, which are relatively noisy both day and night, evaporative cooling systems work with hardly any sound!

Can we control the amount of cooling in various areas of the home?

Yes, you can regulate the air from the outlets by opening or closing windows in various parts of the house so the cool air can exhaust through to another area where an external opening has been provided. The air from the outlets must be exhausted to the outside of the building in order for the unit to work effectively. It will always take the path of least resistance, allowing you to control airflow to each area by the opening or closing of doors and windows. Cool air can even be directed through the house and out the back door onto a verandah, to provide a cooling breeze while you are sitting outside.

How do I control the outside air so my evaporative cooling system gives the best results?

To provide effective cooling, evaporative air conditioners need to be able to create airflow through the home, exhausting hot air outside. To assist the cool fresh airflow through the home, open windows and outside doors that are furthest from the outlet vents.  In the rooms that have vents you should provide an opening to outside that is approximately twice the opening area of the vent. In areas where you experience hot winds you may need to reduce the openings on the windward side of the house and increase the openings on the other side to compensate.  Experiment with this and you will quickly learn how to create the best situation for you and your lifestyle.  Evaporative air conditioners are great for families as you don’t need to worry about the kids opening and closing doors and leaving them open, as this helps with the cooling process.

Contact Us For Ducted Gas and Evaporative Cooling Systems For Your Sydney Home

If you are looking for the most effective way of heating your home, you needn’t look past our range of ducted gas heaters and ducted gas heating solutions. Combined Heating and Cooling have specialised in bringing the unique benefits of ducted gas heating and electric cooling to Sydney homes since 1975, and no one knows how to heat and cool your home better. We offer our ducted gas heaters and electric cooling solutions to homeowners throughout Sydney and the surrounding areas. For a free quote on your new ducted gas heating and electric cooling solution, contact us today. We invite you to make an appointment now for an obligation-free quote here.