Gas Central Heating - NZ gas supplies

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Wazza69

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#238122 4-Jul-2018 03:27

Hi,

We have a 5 bed 273sq/m house which currently only had a fire to heat (don’t ask!) and are looking to invest in a central heating system. We looked at a ducted heatpump system but was told our house was too big. We are looking at gas central heating which is quoted at $20k so a big investment.

I am concerned at the lack of gas supply in NZ over the next 10-15? years. Are other people worried about this? I don’t want to spend that amount, then get bigger and bigger gas bills and then not be able to sell the house as no one wants a house with gas.

Is anyone else currently looking at gas central heating? Any installers have any thoughts?

Thanks

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#2048689 4-Jul-2018 07:16

I've been looking into it for heating our place (110m2), I've not had an actual quote but was told to expect $7-8k.

Thing I'm also wanting is cooling for the summer, the person we spoke to at a recent Wellington Homeshow said that could be added on but would be looking at $15k.

So at the moment I'm leaning towards putting heat pumps in, part of the reason for this is I'm considering Solar + Battery at some point also which would help make it cheaper to run.

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1eStar

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#2048754 4-Jul-2018 09:17

Look elsewhere for your advice. I have friends with a large house with central ducted heat pump. They have two commercial units in the ceiling.

dt

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#2048767 4-Jul-2018 09:48

Wazza69: Hi,

We have a 5 bed 273sq/m house which currently only had a fire to heat (don’t ask!) and are looking to invest in a central heating system. We looked at a ducted heatpump system but was told our house was too big.

my house is a 4 bed @ 333sq/m and last summer we had a ducted heatpump system installed.. it cooled the house great and now its winter its doing its job by keeping the family nice and warm too.

It was never once mentioned that our house would be to big to heat / cool.. I would suggest you get a second opinion from another company

I also have a rental property in Queenstown with a gas heating system in it and the tenants would always complained that it created to much condensation so I had to end up putting in a heatpump anyways.

old3eyes

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#2048790 4-Jul-2018 10:28

Several people I know here in Morrinsville have pulled out their gas connection for central heating due to paying $46 / month line charge for using nothing over the summer. They installed aircon units.

Regards,

Old3eyes

Wazza69

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#2048795 4-Jul-2018 10:43

dt:

Wazza69: Hi,

We have a 5 bed 273sq/m house which currently only had a fire to heat (don’t ask!) and are looking to invest in a central heating system. We looked at a ducted heatpump system but was told our house was too big.

my house is a 4 bed @ 333sq/m and last summer we had a ducted heatpump system installed.. it cooled the house great and now its winter its doing its job by keeping the family nice and warm too.

It was never once mentioned that our house would be to big to heat / cool.. I would suggest you get a second opinion from another company

I also have a rental property in Queenstown with a gas heating system in it and the tenants would always complained that it created to much condensation so I had to end up putting in a heatpump anyways.

Hi DT,

Could you please let me know what system you went with (inc model if possible)

Thanks

Wazza69

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#2048799 4-Jul-2018 10:44

Thanks for all there input everyone. I'll try some more installers, struggling a bit as even the ones I have been recommended by friends are non responsive. Assume because of demand.

Scott3

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#2048821 4-Jul-2018 10:54

Residential style ducted heat pumps are available up to 20kW, and there is nothing stopping you having multiple of them.

Only thing to check is that you have enough electrical capacity to your house. A 20kW ducted heatpump will need 26A of capacity, a lot to allocate if you have a single phase 63A conection, especially if cooking is also electric.

Regarding gas, I assume you are talking natural gas from the street, not big LPG bottles. (avoid LPG for this application, as running costs will be way higher). Are you already connected to gas?

That said, natural gas is not a bad option. Capital cost will be lower than heat pumps, running costs in good condition will be a little more, but in adverse (frost) conditions, I would expect a natural gas system to cost less to run than a heat pump (generally heat pumps are capacity is rated when outside is +10 degrees, and drops somewhat at lower conditions, especially if it has issues with iceing (never noticed any iceing conditions in Auckland). Also Gas heaters, heat a much smaller volume of air much hotter than a heatpump. Heatpumps rely on a small temperature increase to a lot of air. The latter can be associated with creating drafts.

Are you set on a ducted system? The other thing with gas is because of the higher grade heat, you have the option of going for a european style water based system, with radiators in each room. the gas boiler can also handle your hot water needs.

Regarding gas supply, residential gas only makes up 3.3% of our use, and the gas industry thinks that the more price sensitive commercial / industrial consumers will start reducing their use far before there is a meaningful impact on residential users.

If you want lower cost, there are allways a few used gas central heating units on trademe for very cheap. That said, if you are going to pay for a professional install, it may be worth getting new gear, so it lasts many years.

dt:

I also have a rental property in Queenstown with a gas heating system in it and the tenants would always complained that it created to much condensation so I had to end up putting in a heatpump anyways.

The type of gas central heating OP is looking at will almost certainly have an exhaust flue, so will not add any moisture to the house.

That said, good can on changing to a heat pump in Queenstown. Power is relatively cheaper their than in the north island, and gas is much more expensive as there is no piped natural gas in the south island, therefor you are stuck with using relatively more expensive LPG.

antoniosk

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#2048828 4-Jul-2018 11:14

Wazza69: Hi,

We have a 5 bed 273sq/m house which currently only had a fire to heat (don’t ask!) and are looking to invest in a central heating system. We looked at a ducted heatpump system but was told our house was too big. We are looking at gas central heating which is quoted at $20k so a big investment.

I am concerned at the lack of gas supply in NZ over the next 10-15? years. Are other people worried about this? I don’t want to spend that amount, then get bigger and bigger gas bills and then not be able to sell the house as no one wants a house with gas.

Is anyone else currently looking at gas central heating? Any installers have any thoughts?

Thanks

You don't mention what part of the country you're in, but I'm guessing piped gas is an option which is always good. We installed a BRIVIS system 9 years ago and it's still running well, have had it serviced once because the fan became crusted up (think moisture+dust = concrete), which cost $220. Not bad in my view. I do wish BRIVIS had better controllers for Home Automation, but that's a separate question.

I wouldn't try anything else, as gas warmth is beautiful and room filling.

So a few questions:

1. Is your house split over 2 levels? (I'm guessing it is given the size). It's worthwhile thinking about how the downstairs air pipe will go upstairs and be nicely finished off... the ugliest outcome is to go up the outside of the house inside an ugly wooden box. The ducting for BRIVIS is an internal pipe of about 25cm diameter inside a larger duct pipe that acts as a barrier and insulation. The underneath of our house looks like a spacestation!

2. Thermostat location for heat control. REALLY consider how to control heating in each of the zones and price it in, otherwise you will end up with inconsistent warmth which is tiresome.

3. Flooring. Think about where the vents will up... it's hot air, and hot air sucks moisture out of the room and timber. Some timber won't like it.... 100yr old matai flooring is pretty good, but 10yr old pine flooring will expand and contract

4. State of insulation in your house - walls, windows and roof space/underfloor. Goes without saying, but heat goes out the gaps like you wouldn't believe until you see it happening.

5. The future of gas... yeah, a good question as nobody really knows. That the planet is running out of carbon fuels is not in question, but as to how much we have in NZ to keep going is just unknown and trying to future proof this is like exchange-rate investing.

________

Antoniosk

1eStar

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#2048856 4-Jul-2018 11:25

If your only worry is gas supply in the future... bear in mind there is a new gas powered electricity generation plant to be built on the outskirts of New Plymouth shortly...

TLD

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#2048897 4-Jul-2018 12:20

Not really to do with full central heating, but we have a fluted gas fire in our big lounge, that is incredibly efficient. It is comparable to a wood burner, but whereas I am told that a wood burner might use three chords a year at $250 a load, we only use four five small gas bottles at $40 each.

An expat buddy from the UK had full UK style central heating with radiators and an oil fired boiler (which apparently uses diesel). He said that cost a fortune to run, but I never got any meaningful figures from him.

We are in the middle of a big refurbishment at the moment, and have replaced the two heat pumps we had with a 13.5KW ducted system which covers two thirds of the house, and a 5.5KW wall mounted system for the main bedroom. The ducted system heats up the rooms from 12° to 18° in about ten to fifteen minutes, but we have not been using it long enough to see what it is costing to run. The experts told us to get a system that could easily cope with the area, so that it could tick over, rather than slog its guts out, to keep the house warm. I keep thinking about the huge cable the electrician put in to supply the big heat pump, and envisioning the electric meter spinning off its bearings with the speed it must be racking up units, so we are reluctant to 'over use' it.

Out of interest, any thoughts on turning on the pump for a while in the morning, and again in the evening, or keeping it ticking over all day?

Trevor Dennis
Rapaura (near Blenheim)

dt

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#2048903 4-Jul-2018 12:30

Wazza69:

Hi DT,

Could you please let me know what system you went with (inc model if possible)

Thanks

It's a Mitsubishi, I'll check the model this evening and come back to you :)

Scott3:

The type of gas central heating OP is looking at will almost certainly have an exhaust flue, so will not add any moisture to the house.

That said, good can on changing to a heat pump in Queenstown. Power is relatively cheaper their than in the north island, and gas is much more expensive as there is no piped natural gas in the south island, therefor you are stuck with using relatively more expensive LPG.

Ahhh ok, It was already in the house when we bought it I wasn't to sure on the setup and being up in Auckland was all a bit hard to sort out.

Same tenant 4 years later so glad I switch it over for them :)

Wazza69

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#2049033 4-Jul-2018 14:20

Great discussion here. To update from my first post on our situation. Our house is in Kapiti, outside of Wellington. We have mains gas outside our house. Our house is single story and really long. For some reason the previous owner installed a log burner down one end and no heating at the other (where the bedrooms are). It has gas bottles and a external boiler for the water and a separate bbq style bottle for the cooker. All very weird. Our preference is for gas radiators and convert the cooker and water to mains gas. Especially as my wife is English and is used to radiators. My main concern is the gas supply.

I dug into the issue with the heat pump capacity as i wasn’t at home when it was quoted. Apparently the issue is the electricity connection is too small for the large single unit that would be required. A bit strange since our house is only 6 years old.

Thanks

da5id

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#2049045 4-Jul-2018 14:41

Isn't NZ supposed to run out of gas in about 7 years, thanks to this govt's completely idiotic move to ban gas and oil exploration?

mattwnz

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#2049074 4-Jul-2018 15:30

The problem with heating, is it is almost impossible to get independent advice about the different systems, and which works out as the best value. My big issue with ducted systems is that being in a roof space above the insulation layer, they require a decent amount of roof space, and the ducting needs good insulation. You potentially also lose heat the further away the outlet is from the main unit. I would have a look at heatpump multiunits, as you can get enough of them to heat a large house, even if you have multiple outdoor units.

I understand gas is one of the cheaper ways to heat a house, but it doesn't cool. Not sure about availability long term, but they have talked about it running out for decades. But I guess if we do run low, it will be imported. But whether it will rise in price significantly. Depends on how long you expect the system to last for, and whetehr you have priced in a 10 year life on it, or longer.

Scott3

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#2049114 4-Jul-2018 16:29

da5id:

Isn't NZ supposed to run out of gas in about 7 years, thanks to this govt's completely idiotic move to ban gas and oil exploration?

Existing exploration permits are still valid.

New Zealand households which rely on natural gas won't have to switch to another energy source despite the latest advice showing there may be as little as seven years' reserves left, the Government says.

...

Advice to the minister from oil and gas companies Shell and OMV said New Zealand's existing gas reserves would last for between seven and 11 years

...

"Seven to 11 is often the figure that's put out there," she said. "I think that's probably a pessimistic figure."

...

Woods said that based on industry estimates, there was significant potential for new finds from existing gas exploration permits.

https://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=12037465

As I mentioned above, residential users only use 3.3% of NZ's natural gas. Compare to say exporter Methanex that uses 46%... any "running out" will likely be accompanies by price rises for commercial users (which pay far less for gas than residential customer's), which will force companies like Methanex out of business, freeing up heaps of gas.

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