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How to build homes with virtually no heating (2020)

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Re: How to build homes with virtually no heating (2020)

#311

Post by goldcd »

lostlogin wrote: post #99
goldcd wrote: post #79

Earlier quoted context omitted.

Have you looked at modified woods like Accoya? (50 year guarantee above ground, 25 in water)

Thanks - I hadn’t. I haven’t had any degrade to the stage where it needs replacement, I just have to keep maintaining. I’ll look into it further, the product looks impressive.

It's good stuff - but not cheap.

For decking where you're going to have to clean it yearly anyway, I wouldn't bother (no real effort to just add on some maintenance) - and probably works out cheaper even with a few replacements over decades.

Where it shines is where it's a pain to replace and a nice bit of weathering is what you're after (say the eaves on a roof) - not too expensive to run a plank around the perimeter and no ladders/scaffolding/treatment required for the rest of your life.

Re: How to build homes with virtually no heating (2020)

#312

Post by voisin »

jmrm wrote: post #171
poseva wrote: post #43

I've also built a simple and small (99sqm) PassivHaus in Romania, 5 years ago. Everybody, and I mean everybody from family to friends called me nuts, but I've got my payback this winter when the energy prices went trough the roof and I'm just slightly affected. The house is elevated from the ground on 12 concrete columns so that I can insulate under the foundation beams using glass foam, insulation on walls is 30 cm…

People doesn't give the massive importance the isolation has. Some years ago we remodelled our home and added XPS (Extruded Polystyrene) to insulate the roof of the house. After that we use the AC only three or four days in the year, and before that we had to use it at least a complete summer month. That house is in the south-interior of Spain, so heat is no joke here. If somebody are constructing or remodelling any…

What about windows? I find buildings with few or small windows to be unmanageably dreary, but the math works out that no matter how insulated you make the walls if you have a good amount of glazing on the walls the effective R value drops quite low.

Re: How to build homes with virtually no heating (2020)

#313

Post by voisin »

kitd wrote: post #64
poseva wrote: post #43

I've also built a simple and small (99sqm) PassivHaus in Romania, 5 years ago. Everybody, and I mean everybody from family to friends called me nuts, but I've got my payback this winter when the energy prices went trough the roof and I'm just slightly affected. The house is elevated from the ground on 12 concrete columns so that I can insulate under the foundation beams using glass foam, insulation on walls is 30 cm…

It is interesting that you insulate under the house. One of the more intriguing passive house designs I saw was one where the insulation went down 2-3m into the ground all around the house footprint. This trapped the natural ground heat within that area and fed it upwards into the house. It took about 18 months for the ground to warm up, but once it was there, the ground/house warmed itself with virtually no input. T…

Do you have a link on this? I’d love to read more about this.

Re: How to build homes with virtually no heating (2020)

#314

Post by hazza_n_dazza »

franciscop wrote: post #310
jmrm wrote: post #171

Earlier quoted context omitted.

People doesn't give the massive importance the isolation has. Some years ago we remodelled our home and added XPS (Extruded Polystyrene) to insulate the roof of the house. After that we use the AC only three or four days in the year, and before that we had to use it at least a complete summer month. That house is in the south-interior of Spain, so heat is no joke here. If somebody are constructing or remodelling any…

What people definitely don't give enough importance is CO2 buildup as well. The more isolated a place is, and smaller, the more environment friendly it is BUT the more likely it is to build up CO2, which leads to headaches. I installed a CO2 meter both at my current home, and at my parent's home for when I go back for Christmas. In my home, it's a fairly big open place so it takes ~2 days of closed windows (0-3C outs…

that is why you need a Heat Exchanger

Re: How to build homes with virtually no heating (2020)

#315

Post by Mandatum »

lostlogin wrote: post #99
goldcd wrote: post #79

Earlier quoted context omitted.

Have you looked at modified woods like Accoya? (50 year guarantee above ground, 25 in water)

Thanks - I hadn’t. I haven’t had any degrade to the stage where it needs replacement, I just have to keep maintaining. I’ll look into it further, the product looks impressive.

The reason the stuff lasts so long is it's chemically gone from cellulose/wood fiber to acetate.

There's a lot of issues with using it aside from expense; anything touching it will be impacted by the acidity of the wood, so you'll want to use things like stainless steel.

It's a great wood, but it's not all roses. The other thing to keep in mind, the process behind it doesn't HAVE to be applied to New Zealand or Chilean radiata pine, they only use that wood as it's more marketable and people are more likely to stomach the costs.

Something to also keep in mind the wood is only treated on the outside. If you cut into it, for example the endgrain on every plank you buy - it'll need to be sealed just as regular radiata pina. When "perennial wood" was originally sold decades ago, people installed it expecting zero maintenance and then found their decking started to rot less than a decade later. Keeping that in mind, similar issues can arise if you sand the wood.

Re: How to build homes with virtually no heating (2020)

#316

Post by voisin »

CrazyStat wrote: post #255
changoplatanero wrote: post #252

Earlier quoted context omitted.

how do you ventilate without losing all the heat?

Heat recovery ventilation [1] can bring in fresh air and output old air while recovering the vast majority of the heat. [1] https://en.wikipedia.org/wiki/Heat_recovery_ventilation

These are only compatible with forced air systems, correct? I.e. using in-floor radiant heat would require an entirely separate ventilation system with heat recovery?

Re: How to build homes with virtually no heating (2020)

#317

Post by voisin »

madaxe_again wrote: post #87
poseva wrote: post #43

I've also built a simple and small (99sqm) PassivHaus in Romania, 5 years ago. Everybody, and I mean everybody from family to friends called me nuts, but I've got my payback this winter when the energy prices went trough the roof and I'm just slightly affected. The house is elevated from the ground on 12 concrete columns so that I can insulate under the foundation beams using glass foam, insulation on walls is 30 cm…

We’ve just built a 45m2 log cabin to passive standards here in Portugal - heavily insulated in walls, floor, roof, lifted off the ground on concrete columns, double glazed, only heat source is a 2.5kw log stove. Everyone here (who all live in uninsulated concrete houses heated by open fireplaces) said we will freeze in the winter, roast in the summer. We situated the house on a north facing slope, to minimise sun exp…

What do you do for fresh air? We have a very well insulated cabin heated by fire, but find the CO2 builds up, particularly overnight with no doors opening, and if we aren’t very quick to close the fire once it gets going, PM2.5 can jump quickly.

Re: How to build homes with virtually no heating (2020)

#318

Post by shostack »

franciscop wrote: post #310
jmrm wrote: post #171

Earlier quoted context omitted.

People doesn't give the massive importance the isolation has. Some years ago we remodelled our home and added XPS (Extruded Polystyrene) to insulate the roof of the house. After that we use the AC only three or four days in the year, and before that we had to use it at least a complete summer month. That house is in the south-interior of Spain, so heat is no joke here. If somebody are constructing or remodelling any…

What people definitely don't give enough importance is CO2 buildup as well. The more isolated a place is, and smaller, the more environment friendly it is BUT the more likely it is to build up CO2, which leads to headaches. I installed a CO2 meter both at my current home, and at my parent's home for when I go back for Christmas. In my home, it's a fairly big open place so it takes ~2 days of closed windows (0-3C outs…

I suspect I'm experiencing some of this in a small home with poor circulation. Any suggestions for inexpensive room monitoring sensors?

Re: How to build homes with virtually no heating (2020)

#319

Post by Arbalest »

franciscop wrote: post #310
jmrm wrote: post #171

Earlier quoted context omitted.

People doesn't give the massive importance the isolation has. Some years ago we remodelled our home and added XPS (Extruded Polystyrene) to insulate the roof of the house. After that we use the AC only three or four days in the year, and before that we had to use it at least a complete summer month. That house is in the south-interior of Spain, so heat is no joke here. If somebody are constructing or remodelling any…

What people definitely don't give enough importance is CO2 buildup as well. The more isolated a place is, and smaller, the more environment friendly it is BUT the more likely it is to build up CO2, which leads to headaches. I installed a CO2 meter both at my current home, and at my parent's home for when I go back for Christmas. In my home, it's a fairly big open place so it takes ~2 days of closed windows (0-3C outs…

These are starting to catch on, as someone else said Heat Exchanger, but that's a more general concept and this is the thing you'd actually want https://en.wikipedia.org/wiki/Energy_recovery_ventilation

Re: How to build homes with virtually no heating (2020)

#320

Post by fouc »

jmrm wrote: post #171
poseva wrote: post #43

I've also built a simple and small (99sqm) PassivHaus in Romania, 5 years ago. Everybody, and I mean everybody from family to friends called me nuts, but I've got my payback this winter when the energy prices went trough the roof and I'm just slightly affected. The house is elevated from the ground on 12 concrete columns so that I can insulate under the foundation beams using glass foam, insulation on walls is 30 cm…

People doesn't give the massive importance the isolation has. Some years ago we remodelled our home and added XPS (Extruded Polystyrene) to insulate the roof of the house. After that we use the AC only three or four days in the year, and before that we had to use it at least a complete summer month. That house is in the south-interior of Spain, so heat is no joke here. If somebody are constructing or remodelling any…

It seems like historically people underestimated the insulation value of polyurethane because apparently it doesn't necessarily do well on the conventional R-value score.

Apparently a solid inch of sprayed polyurethane can provide 90% insulation, and 2 inches gets you to 99% insulation.

https://www.monolithic.org/blogs/presidents-sphere/r-value-f...

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