Converting ducted gas to electricity in Canberra

JC said :

Who told you that? If let’s say you have gas heating and evap cooling the opposite to what you have said is true.

It was true in the past but no longer.

But here are number of reasons.

1. Ducted reverse cycle is now very efficient surpassing gas for efficiency.
2. You can control the price of electricity through solar, you can’t control the price of gas.
3. Gas prices are expected to rise dramatically over the next few years with the Australian gas market being floated and thus held to international prices.

References:

http://www.smh.com.au/business/mining-and-resources/reserve-our-gas-campaign-launched-to-fight-for-lower-gas-prices-20140929-10ned9.html

http://theconversation.com/dont-get-burnt-by-gas-price-rises-tips-for-homes-and-industry-28198

http://www.abc.net.au/news/2014-11-29/concerns-lng-exports-could-see-spike-in-domestic-gas-prices/5927400

http://aglblog.com.au/2015/04/aemo-forecasts-show-impact-of-rising-gas-prices-on-manufacturing-sector/

Quotable quotes:

“At the same time because prices are so much higher overseas, gas prices will approximately triple within Australia. They’ve already gone up quite a bit from about $3 per kilojoule to an expected level of $9 per kilojoule in the future, so about three times.”

“Gas prices are on the rise, starting tomorrow with a 17.8% increase this year in New South Wales, with other parts of eastern Australia expected to follow in coming years.”

“A BIS Shrapnel report found a rise could see one in five manufacturers shut down over the next half-decade. It also showed households gas bills could rise by 26 per cent over three years from 2015.”

“Australia’s eastern gas markets are currently undergoing unprecedented change, with the development of Liquefied Natural Gas (LNG) export projects in Queensland causing a tripling of demand for natural gas between 2013 and 2016, leading to an incredibly tight supply/demand market dynamic and resulting in price increases. Unfortunately, AEMO is forecasting that higher prices will lead to a substantial decline in gas-intensive manufacturing;”

I can run my heating and cooling during the day for free via solar, once the house is at temp and the sun goes down i’ll be able to turn it off or have it running minimally.

You do the sums.

justsomeaussie said :

Largely the thinking with ducted a/c is that you have two ducts in the ceiling. The heating duct you have near the entrance to the room because you want the warm air to create a barrier for colder ear. The cold duct you want on the opposite side of the entry as to push the hot air out the entry.

Since yours are in the floor not much you can do.

On another note, I’m building a house at the end of the year and am not even having gas fitted to the block because of the same conclusions as you. An all electric house + solar is definitely the way to go.

Congratulations going solar. I have a solar house and don’t need either gas or electric heating, and so have none installed. That would have been a wasted, unnecessary expense. I have a wood fired heated for the very rare nights I want extra heat. If you don’t want this, an instant electric heater is all that is needed for those colder occasions. With good insulation, etc a small heater can heat a large space. I have never needed to heat during the day, and it’s only the occasional winter evening I light the fire. I usually use it to cook on as well those rare evenings I light it, to save turning on the electric stove. I do however need to boost the solar hot water one month a year. If I were to add extra tubes I would probably reduce this need. I don’t have gas connected, as it’s not worth paying an extra basic fee (whether I use any gas or not), just for cooking and the one month a year I boost the hot water system.

Oh, and it re-used everything except you get another controller/thermostat

I did it a couple of years ago and it cost a tad under $6k IIRC. Climate Master, I think. Totally happy with it although I might consider reverse cycle if I had it done again.

You cannot run both gas and electricity at the same time but it would be good to be able to choose which heating fuel you use depending on the cost.

justsomeaussie said :

Largely the thinking with ducted a/c is that you have two ducts in the ceiling. The heating duct you have near the entrance to the room because you want the warm air to create a barrier for colder ear. The cold duct you want on the opposite side of the entry as to push the hot air out the entry.

Since yours are in the floor not much you can do.

On another note, I’m building a house at the end of the year and am not even having gas fitted to the block because of the same conclusions as you. An all electric house + solar is definitely the way to go.

Who told you that? If let’s say you have gas heating and evap cooling the opposite to what you have said is true.

The heating goes to the outside of the room and cooling inside. The theory is the heating gets draw in towards the return air and the evap cooling you want the flow out the window. So heating is outside normally near the window.

With ducted reverse cycle it is the same as gas heating as you want your air drawing through the room towards the air return.

Largely the thinking with ducted a/c is that you have two ducts in the ceiling. The heating duct you have near the entrance to the room because you want the warm air to create a barrier for colder ear. The cold duct you want on the opposite side of the entry as to push the hot air out the entry.

Since yours are in the floor not much you can do.

On another note, I’m building a house at the end of the year and am not even having gas fitted to the block because of the same conclusions as you. An all electric house + solar is definitely the way to go.

Thanks for all the comments. The people at the suggested link are coming out to do a quote, but as some others have said, they think the old ducts will not be suitable to reuse.

My main worry with the reuse wasn’t so much the waste of the materials or the cost of installing the ducts, but the fact that I have insulated under the floorboards by myself, and it took me many weekends over a couple of years to get it done. Thinking about ripping that out and starting again is exhausting me!

FHW, we went from ducted evap/wall mounted heaters to ducted reverse cycle. The existing outlets were too big, in the wrong locations and ducting wasn’t able to be reused either. I imagine it would be the same for gas. I love the ducted reverse cycle and wish I’d done it sooner.

I haven’t done a conversion but I did have a ducted gas heating system replaced with a ducted reverse cycle system which of course runs on electricity. Now I have heat and cooling in summer which is nice. I did it at the same time I put in solar panels so the all up running cost is much lower. I think it cost about $5k to make the change. And I got a $1,200 BBQ free from Fujitsu as part of the deal. I’ve never even unpacked the BBQ if anyone is interested in a deal. I’d sell it for half price.

pajs said :

vintage123 said :

I think the ACT government will introduce a subsidy for gas if the supply price of gas increases too much.

These guys may be able to help with a solution if you are fixed on swapping.

http://www.mrairconditioningcanberra.com.au/index.php/products/ducted-gas-heating

Why on earth would the ACT Government subsidise the price of gas?

It would be yet another cost for an already way over-stretched ACT budget. The only argument I could think of might be for people who were pushed in the direction of gas water heating (and for whom solar was not practicable). As the proportion of public renewable in the overall electricity supply increases, the case for zealotry against electric water heaters should be reduced (assuming, of course, that a degree of common sense was to apply).

JC said :

arescarti42 said :

Whether or not you can do this will probably depend on site factors, i.e. are the ducts located in the ceiling or floor, where is the ducted heating unit located, is there adequate access to power in the vicinity, etc.

Theoretically I can’t see any reason why you couldn’t do this. What you essentially want is a ducted reverse cycle air conditioning system. Even if you can use the existing ducts, this won’t be a cheap system however.

A simple electric ducted system if they make them would probably be cheaper to buy than reverse cycle airconditioning, but would use maybe 3-4x more electricity.

Modern split inverter systems use no where near that much power and for the most part are now cheaper than gas. This is the reason why in new build homes these have now become the norm vs ducted gas and seperate Evap cooling for example.

To the op there may be issues with duct size and placement. Also with a ducted electric of the type I am talking about the indoor unit generally contains the return air and gets mounted in the ceiling somewhere central which may be different from where the old gas furnace was. So again effects ducts.

Bottom line the cost of duct and outlets is minor in the cost of a new system so wouldn’t be too worried about trying to reuse them.

Ps retail cost of a ducted inverter system is about the same as a ducted gas and Evap system combined. So around $76-10k depending upon system size. Plus fitting and sundries.

“Modern split inverter systems use no where near that much power and for the most part are now cheaper than gas. This is the reason why in new build homes these have now become the norm vs ducted gas and seperate Evap cooling for example.”

What a shame new homes are not built properly, so that they need neither.

Hi,

vintage123 said :

”
I think the ACT government will introduce a subsidy for gas if the supply price of gas increases too much.”

But even if the government subsidised gas, it would still be a fossil fuel and would still be backed by Coal Seam Gas (unless I can find out from Energy Australia that they don’t supply fracked gas – but they are hard to get info from). The cost is one factor, but not the only one.

My ducts are underfloor and the heater is outside (so accessible) and near to power, so I suspect they would not pose a problem. I am more concerned that they may want different sizes or types of ducts or outlets – or maybe the placement is so different for electrical heating that they would have to be completely replaced or something.

I have sent off an enquiry to the link suggested and will keep you posted. I was hoping someone would have personal experience with this.

arescarti42 said :

Whether or not you can do this will probably depend on site factors, i.e. are the ducts located in the ceiling or floor, where is the ducted heating unit located, is there adequate access to power in the vicinity, etc.

Theoretically I can’t see any reason why you couldn’t do this. What you essentially want is a ducted reverse cycle air conditioning system. Even if you can use the existing ducts, this won’t be a cheap system however.

A simple electric ducted system if they make them would probably be cheaper to buy than reverse cycle airconditioning, but would use maybe 3-4x more electricity.

Modern split inverter systems use no where near that much power and for the most part are now cheaper than gas. This is the reason why in new build homes these have now become the norm vs ducted gas and seperate Evap cooling for example.

To the op there may be issues with duct size and placement. Also with a ducted electric of the type I am talking about the indoor unit generally contains the return air and gets mounted in the ceiling somewhere central which may be different from where the old gas furnace was. So again effects ducts.

Bottom line the cost of duct and outlets is minor in the cost of a new system so wouldn’t be too worried about trying to reuse them.

Ps retail cost of a ducted inverter system is about the same as a ducted gas and Evap system combined. So around $76-10k depending upon system size. Plus fitting and sundries.

Whether or not you can do this will probably depend on site factors, i.e. are the ducts located in the ceiling or floor, where is the ducted heating unit located, is there adequate access to power in the vicinity, etc.

Theoretically I can’t see any reason why you couldn’t do this. What you essentially want is a ducted reverse cycle air conditioning system. Even if you can use the existing ducts, this won’t be a cheap system however.

A simple electric ducted system if they make them would probably be cheaper to buy than reverse cycle airconditioning, but would use maybe 3-4x more electricity.

pajs said :

vintage123 said :

I think the ACT government will introduce a subsidy for gas if the supply price of gas increases too much.

These guys may be able to help with a solution if you are fixed on swapping.

http://www.mrairconditioningcanberra.com.au/index.php/products/ducted-gas-heating

Why on earth would the ACT Government subsidise the price of gas?

Just my gut feeling after reading through the energy white paper released on the 8th of April 2015
http://ewp.industry.gov.au

vintage123 said :

I think the ACT government will introduce a subsidy for gas if the supply price of gas increases too much.

These guys may be able to help with a solution if you are fixed on swapping.

http://www.mrairconditioningcanberra.com.au/index.php/products/ducted-gas-heating

Why on earth would the ACT Government subsidise the price of gas?

I think the ACT government will introduce a subsidy for gas if the supply price of gas increases too much.

These guys may be able to help with a solution if you are fixed on swapping.

http://www.mrairconditioningcanberra.com.au/index.php/products/ducted-gas-heating