Thread: Gas or Electricity heating

Jim - how old is the house and what insulation does it have?

It MAY be cheaper to install a heat pump and boost the insulation than to replace a heater.

We use a wood stove and a central gas unit (gas is cheaper). I tend to use the wood stove for occasional final finishing of some projects and offcuts, that keeps running costs down marginally

Electric reverse cycle requires good insulation and the house to be buttoned up, plus it is expensive (ish) to run.

gas for sure .....and I fitted external blinds and internal timber venitians ..with pelmet boxes on all windows , made a big difference .......

If you can tell me what rate you pay for electricity (it should be on the bill somewhere as a rate in cents per kWh) and also for gas (cents per MJ) then I can give you a fairly accurate answer.

In general though, natural gas (not LPG) and reverse cycle air-conditioning are similar in cost to run.

Worth noting that air-conditioning has become very popular in recent years in Tasmania. Most use it solely for heating and rarely if ever use it for cooling. That's to the point where locals and even the electricity authority call them "heat pumps" and not "air-conditioners".

Generally speaking:

Cheapest - air-condtioners, natural gas, wood combustion heater in areas with cheap wood. Off-peak electricity is also cheap in some areas.

Avoid - Oil, kerosene, LPG, open fires and other non-airtight wood heaters.

OK under some circumstances - wood pellets, ordinary electric heaters. Check local costs for these though as in some cases they'll cost an outright fortune to run.

If you need a lot of heat and want to heat the whole house then air-conditioning, gas, off-peak or wood are the sensible options. Heating the whole house 24/7 by ANY means will be expensive though.

If you don't need much heat then cost isn't so much of an issue. Generally stick with whatever you have now until it breaks. Then go for air-conditioning reverse cycle assuming you'll also need it for cooling in a place that doesn't need much heat. Failing that get a cheap electric heater.

Jim,

Don't confuse efficiency with cost. If you read the ads for reverse-cycle air conditioners and heat pumps they will claim high efficiency - which is true as you get more heat out of them than they use. BUT they use electricity and it costs about $0.135 per kWh or 3.75 cents per MJ. Gas costs less than 1 cent per MJ. (Melbourne prices quoted.)

It is worthwhile checking the claimed efficiency and fuel costs for each system yourself.

Greg the house is a weatherboard home 18 squares about 40 years old.
No insulation in the walls and the batts in the ceiling would be just as old so probably the original 1.5R or smaller.

The blond loves the wood fire as she can sit in front of it and toast herself. Other heaters have outlets that dont give the same effect.

What sort of heat pump do you use.

We have only just had the gas connected to the house as we are going to instal gas appliences in the kitchen, getting rid of the old electric ones so do not have any costings of gas.

We get charged $0.1752 for the first 985kw then $0.1778 for the next 1315kw of electricity

Originally Posted by Jim Carroll

Greg the house is a weatherboard home 18 squares about 40 years old.
No insulation in the walls and the batts in the ceiling would be just as old so probably the original 1.5R or smaller.

Ok, you may want to investigate reducing the hot/cold air you lose, versus introducing more heating/cooling.

Originally Posted by Jim Carroll

The blond loves the wood fire as she can sit in front of it and toast herself. Other heaters have outlets that don't give the same effect.

Think I married her sister . Trouble with wood fires is their heat is localised and they also cause a 'draw' of air from the rest of the house, cooling it down. (Mythbusters tried this and proved it). Not a lot mind you, but a few degrees.

Originally Posted by Jim Carroll

What sort of heat pump do you use.

There are transfer duct pumps available which are essentially a tube like dust collector hose with a fan in the middle. They are designed to suck hot air from one room and move it to another. They are handy for moving air from a log fire room to the other end of the house. Their efficiency drops marginally over distance but they are reportedly quite good over about 10m.

Originally Posted by Jim Carroll

We have only just had the gas connected to the house as we are going to instal gas appliences in the kitchen, getting rid of the old electric ones so do not have any costings of gas.

We get charged $0.1752 for the first 985kw then $0.1778 for the next 1315kw of electricity

Gas heating is effective and cheap, if you have a gasfitter on site, the ready $$$ and a cold house it may well be the better option.

Originally Posted by Groggy

... Trouble with wood fires is their heat is localised and they also cause a 'draw' of air from the rest of the house, cooling it down. (Mythbusters tried this and proved it). Not a lot mind you, but a few degrees....

The main trouble with wood fires is that a great deal of the heat goes up the flue or chimney so they are quite innefficient. They look cheerful though. We put in an eco fire for cheer and to take the chill off and have gas central heating and good insulation (including waffle blinds, pelmets and heavy curtains) to cope with Canberra winters. Works well.

Originally Posted by Pusser

The main trouble with wood fires is that a great deal of the heat goes up the flue or chimney so they are quite innefficient. They look cheerful though. We put in an eco fire for cheer and to take the chill off and have gas central heating and good insulation (including waffle blinds, pelmets and heavy curtains) to cope with Canberra winters. Works well.

Not necessarily true with every woodheater, a lot of woodheaters manufactured these days are very efficient nowadays. My place is about 16sq weatherboard and is fully insulated in the walls and roof. Quite often I can get too warm in the middle of winter that I need to put shorts on or let the fire burn down till it's almost out.

For those in the country like I am, the cost of putting in a gas heater can be very high due to having to used bottled gas. So we have to look to either wood or electric and for me wood is cheaper as I have access to an almost unlimited supply of redgum from my Uncle's farm.

Sorry for the hijack Jim but felt I needed to point out that woodheaters are not always inefficient.

Originally Posted by Jim Carroll

We get charged $0.1752 for the first 985kw then $0.1778 for the next 1315kw of electricity

A reverse cycle air-conditioner of decent quality ought to deliver heat at about 5.9 cents per kWh using electricity at that rate. That's based on an assumed 300% efficiency which is typical for a QUALITY system.

Assuming typical 80% efficiency, gas would work out the same cost as electric if it cost 1.3 cents per MJ. Check with the gas supplier what rate you would pay.

Personally, I'd go with the air-conditioner unless gas was a lot cheaper or I specifically didn't want cooling in Summer. That said, no way would I even consider any of the cheap and nasty air-conditioners as they won't deliver when it comes to efficiency and especially heating performance in cold weather.

Originally Posted by DJ's Timber

Not necessarily true with every woodheater, a lot of woodheaters manufactured these days are very efficient nowadays. My place is about 16sq weatherboard and is fully insulated in the walls and roof. Quite often I can get too warm in the middle of winter that I need to put shorts on or let the fire burn down till it's almost out...
Sorry for the hijack Jim but felt I needed to point out that woodheaters are not always inefficient.

I think that is effectiveness. You still pass lots of hot air out of the flue or chimney rather than into the house. Granted slow combustion units are very effective and are cheap to run if you have a cheap fuel source.

In Scandinavia they use internal metal flues to use some of this escaping heat as the flue pipe heats up and acts as a secondary radiator. But much hot air just leaves the building.

An eco fire produces no carbon monoxide and has no flue or chimney so the heat is contained in the room. It just means you get more effective heat energy for a given calorific value of fuel.

Why not keep the woodheater and fit another heater for the farend of the house.
Then you're not lost if the elec/gas supply gets interuppted as you can still heat with wood.

Originally Posted by echnidna

Why not keep the woodheater and fit another heater for the farend of the house.
Then you're not lost if the elec/gas supply gets interuppted as you can still heat with wood.

Bob, we have both, in practice this is what happens (at our place anyway). The boss lights the log fire and I freeze in the study, so I start the gas unit which happens to have the thermostat near the lounge, so it thinks everything is ok and shuts off.

The boss goes to bed suffering heat exhaustion and I go in there too cold to stop shivering.

The lesson is in where you locate the thermostat - make sure it is well away from the wood fire. The gas unit works well by itself . An afterthought I have is that it may be a good move to put the return in the same room as the wood fire .

Everybody forgets a 3 phase machines are far more efficient and quieter than a single phase ones.
Get a 3 phase air con and never look back!
Its initial cost will be more but once set up it will be the cheapest of the lot
year after year.
Get a 2 rate meter as well to take advantage of the off peak low price power!
If three phase is available pay for it once and you have it forever.
Plus the added bonus!
You are then free to buy any power tool you like for your shed too!
cheers Rileyp

Riley we do have 3 phase connected so will add that to our options.