Reverse Cycle Air Conditoner vs Gas Log Heater?


I am looking at buying a gas log heater for warming the house in winter.

Currently we have a fujitsu ‘inverter’ reverse cycle air conditioner, which is the primary heating source for the house.

I have read that reverse cycle air conditioners are very efficient for heating the house, as they draw atmospheric heat from outside the house. However, we live in a cold part of Victoria, Australia, and the average temperature outside is about 8 degrees celsius in the evenings, during winter.

I am skeptical about the efficiency of a reverse cycle air conditioner, and I was wondering how viable a gas log heater might be for warming the house.

The gas log heater would be running off natural gas, and at the current prices, looks like it costs about 40c to run per hour. I have tried to do a comparison with the reverse cycle air conditioner, but I can’t come to a reasonable estimate of cost per hour, as I really don’t know how much energy it is consuming.

Also, the house is shaped so that the living area is down one end of the house, and the bedrooms are up the other. We are looking at installing a heat transfer pipe from the living area to the rest of the house, to compliment the gas log heater.

Any suggestions/advice are most welcome. Also, if possible I would like to know how to work out the energy required to run the reverse cycle air conditioner in these conditions.

Should I get a gas log heater?

3 Responses to “Reverse Cycle Air Conditoner vs Gas Log Heater?”

  1. oil field trash Says:

    The problem with a gas log is venting of the products of combustion and combustion air. Unless it is done properly you may actually lose ground.

    All of the air you use for a gas log has to come from outside one way or the other. If you have a direct duct that brings combustion air to the gas log that is better than just taking air from the room. The other problem is all of the products of combustion must go up a chimney of some sort and when that happens they also take a good deal of the heated room air with them.

    This means to get any real benefit from a gas log as a heater, it must be enclosed so the combustion air and products of combustion are sealed from the room. To do this you need a heat exchanger built into the system to get significant heat from the gas log to the room.

    All reverse cycle units have to have an independent heating source to provide heat when the unit is in the defrost mode. These are usually called the auxiliary or emergency heat source. The most common source is a electric heating coil built into the air handler. This heat source will also come on when the outside temperature is too low for the unit to provide normal heating. The thermostat should have an indicator light that tells you when the auxiliary heat is in service.

    We have a reverse cycle unit that heats our house and it does very well down to below zero degrees Celsius. I don’t think your unit will have a problem heating the house if it is properly sized and maintained.

  2. hww22 Says:

    Heat pumps work great in cold areas with auxiliary heat built into them. So a separate gas log should work. Heat pumps lose efficiency the colder it gets.

  3. Marko Says:

    I’d agree with the other answer above.
    I would want a gas backup that uses a pilot generator which doesn’t require an electric starter, in case the power goes out.