Gas for a new build

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Hammerer

2476 posts

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#1340075 9-Jul-2015 15:57

andrew027:
mdf: If you have most of your heating and hotwater on energy efficient options (i.e. heat pumps), and only want a gas hob, you don't actually need the big (45kg?) cylinders. You can get hobs that run off a BBQ cylinder (9kg?). Keep it in the kitchen cupboard with a spare and you're sorted

I know people used to do this, but I'm about 99% sure it's not legal to have the cylinder in your kitchen any more - it has to be outside. Maybe someone else can confirm?

9kg cylinders are OK indoors but there is a limit. It's something like two 9kg cylinders for a single residence or one 9kg cylinder for flats/apartments. The EPA (Environmental Protection Authority) document LPG in the home spells this out in more detail.

mattwnz

20164 posts

Uber Geek

#1340137 9-Jul-2015 18:12

Hammerer:
andrew027:
mdf: If you have most of your heating and hotwater on energy efficient options (i.e. heat pumps), and only want a gas hob, you don't actually need the big (45kg?) cylinders. You can get hobs that run off a BBQ cylinder (9kg?). Keep it in the kitchen cupboard with a spare and you're sorted

I know people used to do this, but I'm about 99% sure it's not legal to have the cylinder in your kitchen any more - it has to be outside. Maybe someone else can confirm?

9kg cylinders are OK indoors but there is a limit. It's something like two 9kg cylinders for a single residence or one 9kg cylinder for flats/apartments. The EPA (Environmental Protection Authority) document LPG in the home spells this out in more detail.

Depends on the council, as I know one council who didn't give a code of compliance on a property, until the gas cylinder was moved outside. Also you have to be just slightly mad to have one inside anyway.

floydie

474 posts

Ultimate Geek

#1340198 9-Jul-2015 20:17

Whoops double post

Bobdn

222 posts

Master Geek

#1340254 9-Jul-2015 21:14

Got rid of the hot water cylinder and electric stove and went for infinity system and gas hob. I've saved between $50 to $70 per month since the installation.

bfginger

1269 posts

Uber Geek

#1341122 11-Jul-2015 14:05

Gas hot water cylinders aren't as slow to reheat as electrics so they're like having a bigger cylinder. Quality is important as they can't have insulation wraps added because of fire risk.

Many areas aren't cold enough for more than a slight amount of condensation to appear on a window frame unless indoor humidity is too high. The real reason to avoid thermally unbroken aluminium window frames is their transportation of heat out of the building in winter. Low end uPVC won't be thermally better than thermally broken aluminium.

surfisup1000: I'm on gas -- house built 7 years ago.

I don't think it's worth it. The daily fixed charge pretty much kills the economics.

My latest bill is $750 (400 gas plus 350 electricity). The gas is usually around $50 in summer, winter is higher due to underfloor heating which costs around 350 a month to run in winter.

Underfloor heating is rubbish too - they sold us on how efficient it would be, unfortunately the sales people are long gone and we are left to pay the bills.

$350 is a huge amount of gas heating. That's around 7kW of heat into the house every hour of the day for the whole month. That's like three full sized electric heaters running non stop.

I don't think the concepts of gas and underfloor heating are likely to be why it's using so much energy. Unless the house is shadowed, enormous or the set up of the central heating system was faulty the problem is more likely to be with how the house was built.

The building code doesn't require houses to be built to a high standard. If it wasn't an exceptional build for 2008 it probably has lots of heat escaping from the edge of the concrete floor and windows.

In countries where central heating is normal they have better building codes to reduce energy consumption. If a house is correctly designed it will need little heating in winter if it is in the upper North Island and isn't shadowed.

Hammerer: +1 As a user of solar water heating (with evacuated tubes) I would prefer to have solar PV now that the prices are more economic. The benefits of flexibility outweigh the lower efficiency. In summer we have to run off 80C water on many summer days. With solar PV we would have more options to use that excess energy.

Having one doesn't exclude having the other. Solar thermal hardware is much cheaper than a PV setup but hefty overcharging, rusty plates from Australia and incompetent installations have given solar thermal a bad name in New Zealand.

See what angle your solar tubes were installed at. Normally they install them at the same angle as the latitude so if you're in the upper North Island they'd be at around 35 degrees. As your system is overheating in summer it may solve the problem to move the tubes to a higher angle like 45 degrees so they're less optimised for the summer sun and more for the winter.

darylblake

1162 posts

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#1341151 11-Jul-2015 15:28

Yeh so I think it comes back to the reasons for wanting gas in the first place as to how I am going to decide to set it up. I wanted it initially for cooking. But since its a new build I might not bother buying a HWC and get an infinity instead.

Now I am thinking well > 2400kw/h per year is the spot between going on natural gas and going with LPG bottles. If I plan to use more gas then I start thinking with natural gas I can buy cheap energy at about 7 cents per kw/h which is about 90 percent efficent. So why not get heating kit as well which is gas flued.

I cant really see solar being worth it until the price of the solar kit halfs again. Its about 7 years to pay itself off. And I dont really know how long it will last... But if you are a greeny then I guess its not a bad option.

If you just want gas for cooking then I rekon using a 9KG bottle. No point renting 45kg bottles.

Cooking + Hot water would depend on your usage. Less than 2400kwh per year (4 whole cylinders) its cheaper to be on bottles. More than that (5+) cylinder changes its more expensive. (I used on-gas and genesis energy pricing to work it out and asumed you would get about 620kw/h out of a bottle.

So now I need to pick all the kit.

Bobdn

222 posts

Master Geek

#1341369 11-Jul-2015 21:52

surfisup1000: I'm on gas -- house built 7 years ago.

I don't think it's worth it. The daily fixed charge pretty much kills the economics.

My latest bill is $750 (400 gas plus 350 electricity). The gas is usually around $50 in summer, winter is higher due to underfloor heating which costs around 350 a month to run in winter.

Underfloor heating is rubbish too - they sold us on how efficient it would be, unfortunately the sales people are long gone and we are left to pay the bills.

I see (from adverts on GZ) that Genesis has all you can eat gas plans for $129 per month for 12 months.

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lchiu7

6476 posts

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#1341544 12-Jul-2015 12:44

surfisup1000: I'm on gas -- house built 7 years ago.

I don't think it's worth it. The daily fixed charge pretty much kills the economics.

My latest bill is $750 (400 gas plus 350 electricity). The gas is usually around $50 in summer, winter is higher due to underfloor heating which costs around 350 a month to run in winter.

Underfloor heating is rubbish too - they sold us on how efficient it would be, unfortunately the sales people are long gone and we are left to pay the bills.

I used to get bills like that. I then moved to Flick for electricity and Energy Direct for gas (from Genesis). I saved a bit on gas and lots on electricity (changed electricity usage a bit like dishwashers and laundry at night).

I signed up for the Genesis all you can eat gas plan for $129. It's not exactly all you can eat but "capped" at 31KWh per year after which they will charge. Since I used 21KWh the previous year with gas cooking, hot water and heating (fires and large wall furnace) with prudent use of heating, I feel I won't get to the limit if I don't go crazy. I asked how people can use 31KWh and was told it was usually usage like heated pools.

I use electricity only for light/appliances and with Flick it's about $150/month and doesn't really change. With the flat rate gas plan of $129 I know I will only be spending about $270/month for both which is fine for me.

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bfginger

1269 posts

Uber Geek

#1393999 24-Sep-2015 23:24

surfisup1000:Underfloor heating is rubbish too - they sold us on how efficient it would be, unfortunately the sales people are long gone and we are left to pay the bills.

You can have concrete slab edge insulation retrofitted to an existing building. That should make your underfloor more affordable

http://magroc.co.nz/product/insulfound/

gchiu

1211 posts

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Trusted

#1400086 5-Oct-2015 10:53

@lchiu7

When summer comes, you'll still be paying $129/month for gas, but only using it for cooking.
Can you drop to a lower fixed price plan for summer, or change back to pay for use?

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