Renovating newly purchased home to be warm

Forums › Home Workshop DIY › Renovating newly purchased home to be warm

1 | 2

rjdvsk

12 posts

Geek
Inactive user

#2265081 26-Jun-2019 14:53

I've attached photos of the underfloor gas heater system. Again it's not something I've seen before. I've since learnt it expels any vapor through a pipe on the roof.

Thanks for the tips on insulation, I'll be needing those over the coming days. There is a sub-floor cavity so I'll be looking at getting a vapour barrier on the ground, along with the insulation under the floor and in the ceiling. The house is carpeted through out and it seems to be in reasonable condition, not wool though.

As to if this is a "forever" house or not, it's a slightly tricky question to answer... it depends if my wife gets made permanent at Waikato Uni or not :) So we're here for the next 3 years (due to funding) for certain. We would like to stay much longer, as we've been moving around the past 15 year and are bloody tired of it.

Taking the above into account, it might make sense for the interim to look at some sort of window film with regards to double glazing. If we end up here longer later down the road, then go for the double glazing option.

It's starting to sound like

Standard roof option
Insulation
Fix up air gaps in windows and doors
Window film for glazing
Air / Heat ventilation (maybe?)

Thanks again all, invaluable information for such a greenhorn NZ homeowner like myself.

Aredwood

3885 posts

Uber Geek

#2265272 26-Jun-2019 20:48

That heater is definitely flued to outside. So no moisture added to indoors when you use it. Energy efficiency would be around 70% approx. If the inner most barrel rusts out, then that would write it off. New gas control valves etc can still be bought brand new for them. Although might be uneconomic to repair if you have a complete valve failure. Most common failure would be thermocouple & pilot burner. Both cause the pilot light to go out and be unable to be relit. But are an easy fix for any proper gasfitter.

rjdvsk

12 posts

Geek
Inactive user

#2265385 26-Jun-2019 21:43

Aredwood:

That heater is definitely flued to outside. So no moisture added to indoors when you use it. Energy efficiency would be around 70% approx. If the inner most barrel rusts out, then that would write it off. New gas control valves etc can still be bought brand new for them. Although might be uneconomic to repair if you have a complete valve failure. Most common failure would be thermocouple & pilot burner. Both cause the pilot light to go out and be unable to be relit. But are an easy fix for any proper gasfitter.

Brilliant, thanks mate! That's definitely good information to know. How much more (or less) cost efficient is it running one of these to warm the house vs a couple of heat pumps?

Handle9

11386 posts

Uber Geek

Trusted

Lifetime subscriber

#2265390 26-Jun-2019 21:56

rjdvsk:

Aredwood:

That heater is definitely flued to outside. So no moisture added to indoors when you use it. Energy efficiency would be around 70% approx. If the inner most barrel rusts out, then that would write it off. New gas control valves etc can still be bought brand new for them. Although might be uneconomic to repair if you have a complete valve failure. Most common failure would be thermocouple & pilot burner. Both cause the pilot light to go out and be unable to be relit. But are an easy fix for any proper gasfitter.

Brilliant, thanks mate! That's definitely good information to know. How much more (or less) cost efficient is it running one of these to warm the house vs a couple of heat pumps?

Costwise they are generally pretty similar if you are on reticulated gas. If you are on bottles - $$$$

Natural gas is much cheaper per kwh than electricity but you do have the cost of the connection. If you are using it for hot water and cooking ti makes sense.

Heatpumps may be a bit cheaper overall but usually central heating will produce more heat. Personally I like central heating more than heat pumps, especially if you have floor grills through the whole house. YMMV obviously.

rphenix

985 posts

Ultimate Geek

Lifetime subscriber

#2265403 26-Jun-2019 22:30

SATTV:

We live in high wind zone and had no floor insulation, we put in expol, that made zero difference warm wise, but did stop dust coming out of the cracks when there was a gust of wind.

Insulation alone is no good, you need good heating, I find heatpumps useless, a good gas heater is great, make sure it is vented outside otherwise you will have condensation galore.

We insulated everything except the lounge walls as we progressed with renovation the house got warmer but not as much as I had hoped. Still on a windy night in Auckland it would be cold without the fireplace. Then we had dual glazed uPVC windows installed in all the bedrooms, bathroom everything except lounge and kitchen (plan to do this separately as finances allow) made a huge difference including in the lounge since there is less heat loss in the rest of the house.

We've gone from using a fire always on a winter night particularly if it was windy to being completely satisfied with the heat pump we are probably going to remove the fireplace over the coming summer as its an eyesore didn't need it last winter.

bfginger

1268 posts

Uber Geek

#2265415 26-Jun-2019 22:54

rp1790:
Instead of double glazing I'd recommend having a good look at a quality thermal film for your windows. I installed it in my lounge, dining area and kitchen (open plan) and it made a noticeable difference at a small fraction of the cost of the cheapest double glazing..

I used these guys https://www.glasshield.co.nz/

That reminds me, with traditional wooden windows you can use float-over plastic DIY window insulators. That's the most cost effective thing and can be used in addition to an on-glass thermal film.

https://www.energywise.govt.nz/at-home/windows/diy-window-insulation-kits/

https://www.mitre10.co.nz/shop/3m-indoor-window-insulator-kit-5-windows/p/173006

https://sustaintrust.org.nz/products/space-window-insulation-film-20m2

Good thermal curtains are an asset.

Aredwood

3885 posts

Uber Geek

#2265424 27-Jun-2019 00:31

rjdvsk:
Aredwood:

That heater is definitely flued to outside. So no moisture added to indoors when you use it. Energy efficiency would be around 70% approx. If the inner most barrel rusts out, then that would write it off. New gas control valves etc can still be bought brand new for them. Although might be uneconomic to repair if you have a complete valve failure. Most common failure would be thermocouple & pilot burner. Both cause the pilot light to go out and be unable to be relit. But are an easy fix for any proper gasfitter.

Brilliant, thanks mate! That's definitely good information to know. How much more (or less) cost efficient is it running one of these to warm the house vs a couple of heat pumps?

Heatpump efficiency varies with outside temperature. Worst temp is between 2degrees and -2degrees. As this causes the outdoor unit to ice up and require defrosting.

Also consider your power pricing plan. If low user, then it would be quite close for running costs. And some houses on the WEL power network are on time of use pricing. So maybe use the gas heater during peak hours and when outdoor temps are close to 0 degrees. And the heatpumps at other times.

That gas heater would also be really easy to control via a home automation system. As those control valves are normally the Robertshaw Millivolt type. The pilot light is used to generate a small amount of electricity, which in turn is used to control the gas valve to the main burner via the thermostat. This system has 0 interconnections with your mains wiring and will work even during a power cut.

Just get a HA controller that has dry contact terminals that go to a mechanical relay. And just wire it in series with the thermostat. Also add a bypass switch in parallel with the HA controller. So you can still use the heater during a power cut. AFAIK the Sonoff controllers have the right kind of relay.

Just double check that it is the millivolt system. With the thermostat off, should be 3V or so going to the thermostat. Otherwise it might be mains power or 24VAC from a small step down transformer.

Equinox IT

Cloud spending continues to surge globally, but most organisations haven’t made the changes necessary to maximise the value and cost-efficiency benefits of their cloud investments. Download the whitepaper From Overspend to Advantage now.

JayADee

2148 posts

Uber Geek

#2265500 27-Jun-2019 08:52

Thermal, floor length curtains and extraction-to-outdoors bathroom and stovetop ventilation. I put our bathroom vent right over the shower.

My husband cooks a lot and if the window isn’t open then the vent has to be on low otherwise all those soups etc. puts a lot of moisture in the air!

Also I did find underfloor insulation (polyester batts) and plastic on the ground made a big difference to how warm the floors feel on the bare wood. I have indoor/outdoor dogs (now dog) so rugs aren’t practical otherwise I'd have at least throw rugs on the floor.

Also I've been around a few times with rolls of that sticky sided gap filler foam for around doors and windows. Our 1950 house has plenty of 'natural ventilation'. I also put a plastic strip inside at the bottom of each inward opening front door to get rid of the gap between the door sill and the door. On the outward opening French doors I added a strip of wood between each set of doors, also to allay the gap there.

I just bought some new lounge curtains so the old ones are being repurposed to go over a couple of the French doors which currently have none. The curtains make a big difference winter and summer. Even the wooden horizontal blinds we have in some windows help a bit with cold.

Nudibranch

86 posts

Master Geek

ID Verified

#2265550 27-Jun-2019 09:13

I'd do the cheaper roof option then go hard on the highest R rated in roof insulation you can afford.

Then see how it goes. Maybe consider window treatments, thermal curtains and pelmets.

Sounds like you've got yourselves a nice little handful of projects ahead of you.

rjdvsk

12 posts

Geek
Inactive user

#2265658 27-Jun-2019 10:32

Nudibranch:

I'd do the cheaper roof option then go hard on the highest R rated in roof insulation you can afford.

Then see how it goes. Maybe consider window treatments, thermal curtains and pelmets.

Sounds like you've got yourselves a nice little handful of projects ahead of you.

Yup no kidding! Seems like the wise option though, start with roof and insulation, then work from there. Bit by bit :)

Thank you all for the great insights and solutions, a huge help!

1 | 2