The construction methods (laws) used in those northern countries make a
house just about airtight. The environmental air system exchanges heated
fresh outdoor air (in cold weather) to maintain oxygen levels for the
inhabitants.

Their construction methods aren't new.. I saw a program over 30 years ago
where the airtight methods were the only way new homes could be constructed,
as a matter of government regulations/laws.

Air leakage and infiltration are a major sources of heat loss. Caulking is
the most cost effective heat-saving product you can buy. Sealing air leaks
isn't particularly hard work, but commonly ignored.
When a hundred feet of cracks are added up, it can represent a fairly large
hole to the outdoors. Many homes probably have many hundreds or thousands of
feet of leaks.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Existential Angst" wrote in message
...
Awl --

PBS's World Focus had a little ditty on Denmark energy efficiency -- $15
per YEAR heating bills! Holy ****....

ROI on these systems seems to be about 10 years, whose initial cost is
about 10% of the house value -- which was either $60,000 or 10% of
60,000 -- heh, just a zero....

But inyway, one method was a heat pump/AC that uses buried coils (3 feet
underground) as the heat exchanger. I don't know if it's a formal heat
pump as in a minisplit ($15 wouldn't go very far, even with inverter
technology), or if the underground is just a passive equalizing heat
resevoir, with water as the transfer medium.

One home-moaner smartly distinguished "solar heating" from "solar cells",
and uses the solar heating for direct heat transfer for hot water, and
solar cells/panels (photovoltaics) for electricity -- a separation that
allows much bigger bang fer yer photonic buck.

The diff between Denmark and the US in all this is that there seems to be
much more government interest, ergo more apparent development and
progress -- depending on the PR spin. It's not clear whether this stuff
is in the "every man's" home, or still for experimenting arkytecs.

Rainwater is collected in underground tanks, as well, for less critical
water usage.

You might be able to catch archives on pbs.org.
--
EA, and PV'd with $15 per DAY utility bills.....