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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)

#171

Post by jmrm »

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 house I recommend it to add any insulation they can in any shape, in less than five years you'll recover what you spend, and if you add PV panels for electricity or a thermosiphonic system to heat water, you'll recover the investment in about 10 years, with a healthy amount of available health in the devices to continue saving money with a proper maintenance.

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

#172

Post by jmrm »

mrweasel wrote: post #81
kitd wrote: post #64

Earlier quoted context omitted.

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…

> It is interesting that you insulate under the house. Isn't that pretty normal, I mean maybe not three meters down, but modern foundations are required to be isolated in many places. The legal requirement in Denmark is at least 300mm of isolation under the house.

That depends of the the place where you live. In middle to the south of Spain, the floor of houses are normally made of marble (or other ceramic material) slabs on top of a little layer of some glue cement, on top of the armoured concrete slab foundation, but on the north is a lot common to have wooden floors with air chamber of a similar size.

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

#173

Post by bogle »

jwr wrote: post #109

While this is at the extreme end of the spectrum, there is a much easier way to save lots of energy: just build modern well-insulated homes. I lived in California and I was appalled at the monstrous energy waste: houses are generally made pretty much from cardboard. You need to cool them in summertime and heat them in wintertime, and the energy expenditure is enormous. I now live in Poland and have recently built sma…

"About the only part of a Californian house you can't put your foot through is the front door." 'The Big Sleep', Raymond Chandler (1939).

Good to see nothing's changed!

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

#175

Post by netjiro »

KaiserPro wrote: post #114
poseva wrote: post #47

Earlier quoted context omitted.

Instead of a heat recovery ventilation you can use energy recovery ventilation which gets back some of the humidity, otherwise just buy a cheap electric boiling humidifier and it you get the job done. What is important that in the coldest part of the winter you can turn down the ventilation to a minimal, something like 0.3 hourly exchanges per hour.

> winter you can turn down the ventilation to a minimal The problem is that the Heat exchanger actively draws moisture out, as it has a huge cold surface area that forces water out of the air. If you don't change the air it feels stuffy.

You can buy heat exchangers with very high efficiency and good moisture reclamation or suppression for a slightly higher cost. The problem is usually that the customer does not look into the details and the construction company can increase profits by buying cheaper versions.

A good modern ventilation energy exchange unit for a 300m2 house can be 90% efficiency, and return a lot of humidity.

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

#176

Post by naikrovek »

In 1989 my grandparents built a home with 12" thick walls (6" was normal at the time, in the area) and carefully vapor-sealed the entire house, taking extra special care to avoid holes which would let air move through the house in an unplanned way.

They paid extra (a lot extra) for the highest insulation value available for the fiberglass rolls they installed in the outside walls. They double-stacked the insulation, as well, which is why they built the walls so thick.

They poured the basement foundation on top of layers of foam insulation, and used piers (I don't know what they're called) down to the bedrock for structural integrity; the majority of the outside of basement floor was in contact only with insulation. Only 16-20 8" columns went through the insulation down to bedrock and could be good conduits for heat to the earth. All of the walls in the basement were double insulated from the earth they held back.

That house was heated entirely by the heat that the water heater released through its insulation. Once or twice a year they would light a candle on the dining room table, to bring the heat back up if it ever got below what they felt was comfortable. Most days they had windows cracked open on opposite sides of the house in the middle of winter because it got too hot even with the furnace turned off entirely. It was never less than 75F in that house, even when it was -15F outside. I spent months on end in that house, just wondering when the furnace would come on. It never did. Not once while they lived there was the furnace ever needed. They lived in Missouri, US.

Years later my grandfather realized that he had left the petcock which allowed hot water to circulate to the radiator over which air was blown and heated to circulate heat throughout the house closed for over a decade -- since the house was built. "I knew I wouldn't need this damn furnace. Building code requires it, and I fought that but lost."

If you're careful, thoughtful, and determined, you can make a little bit of heat go a very long way. They were tired of paying heating bills. They paid to get rid of them, but they were rid of them.

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

#177

Post by inglor_cz »

jakub_g wrote: post #161
ricardobayes wrote: post #142

Earlier quoted context omitted.

Mainland Spain falls into the single digits at night at winter so definitely would need insulation, because there is also no central heating. People resort to heating with their aircons and portable heaters. I'm sad because I expected better infrastructure from 45% income tax at the highest bracket.

I come from Poland (sub-zero in winter; can be anywhere from -20C to +10C but typically 0-5C), but the winter I lived on the Spanish eastern coast was the coldest in my life: thin walls and windows, stone floor, no heating apart from little portable heaters, 5 degrees and rain outside. Now I live in French southern coast, the buildings are slightly better but still poor. In my place even with all heaters I have on ma…

I have an acquaintance in Madrid. Visiting her, I never know what to prepare for.

An Easter visit was miserable, because the condo building did not even have central heating. With night temperatures around 5 degree Celsius, I could barely sleep.

Then comes the summer and 40+ Celsius is at least as unbearable...

Spanish construction standards are pretty ascetic.

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

#178

Post by signaturefish »

sambeau wrote: post #130
SenHeng wrote: post #6

I'm in the middle of building a PassivHaus. The building itself is mostly done and we're working on the interior. There are still a few gaps that haven't been plugged and the heat exchangers have not yet been installed. I'm above 800m elevation, snowstorms every weekend. It's cold here. My house also actually faces West instead of South, so I'm not getting much heat from the sun. This was a surprise to use because th…

Is a stove like that not really dangerous in an air-tight house? Where do the fumes go?

Most air-tight houses have an integrated MVHR (mechanical ventilation with heat recovery) system, which is kind of the inverse of an HVAC setup. There's a constant small air current being moved through the house, and when it exhausts to the outside world a heat-exchanger captures as much heat as possible from the exiting air and uses it to heat the entering air. Airtightness means you can control where the air enters and exits, which means this trick is possible.

All that being said, I'd expect a permanently-installed stove to have a flue (which results in the stove technically being a leak, but that's solvable). I assume the kerosene stove mentioned above is in use while the house is incomplete, so not yet airtight.

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

#179

Post by lelanthran »

markvdb wrote: post #146
kitd wrote: post #64

Earlier quoted context omitted.

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…

> It is interesting that you insulate under the house. Near our place in the countryside, required foundation depth is 1.4m to protect from frost heave. Use an insulated slab and that requirement goes away. The insulation keeps the heat in the ground. It protects the ground under the house from freezing. Nobody cares about regulations here, but they do about getting proper foundations...

> The insulation keeps the heat in the ground. It protects the ground under the house from freezing.

If it is preventing the ground under the house from freezing, then it is supplying heat to that ground. That's a energy-negative process - some of the heat you generate is used to maintain the warmth of the ground.

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

#180

Post by maxerickson »

jaclaz wrote: post #141
Sankozi wrote: post #113

Earlier quoted context omitted.

5% return per year (or more in case of price changes or regulations forcing you to change heating source) does not seem that "philosophical".

I don't understand fully your way of reasoning. A normal house costs - say - 200,000 "units" (dollars, euro, whatever). Making it "energy saving" costs an additional 60,000 units. In 20 years time you will be spending 60,000 units (3,000 per year) less for energy costs (and here we are assuming that ventilation and heating/cooling machines in the "better" house have the same maintenance costs than the ones in "normal…

If you step back a bit, it makes sense for society to push for the construction techniques that minimize the lifetime cost of the building. Here, buildings typically last for much longer than 20 years.

And then there's the whole thing where energy costs may not be fully priced into the use.

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