We spent a month in Sweden this summer.
According to a builder I met there, 20 years ago, about 80% of the
country heated with oil. Today it is down to 15%. Oil is very
expensive. In fact, gasoline hit $.00 per gallon while we were
visiting. The government is giving a subsidy to remove old oil tanks
What many Swedes are switching to is BHE or Bore Hole Exchange. BHE is
their version of ground-coupled geothermal heating. Since most oil
systems were hydronic radiator-type systems, it is difficult to adapt
them to also use the geothermal for air conditioning. Their summers
are getting warmer and some type of AC would be desirable.
Ground temperature is in the upper 40's once you are down 10 feet, so
engineered closed-loops make perfect sense. The homes are extremely
insulated with exterior (sometimes foam) walls a foot thick in many
The Swedes are also delivering co-generated hot water in many cities.
The hot water or, in some cases, steam, is generated by a local
factory of trash to energy plant and the excess is exported to local
homes. Homeowners are metered for the BTUs the receive.
Interesting but "a foot thick"?
Let's see. 4 inch brick, 1 inch air gap, 2 inches of foam, 2x6 studs,
1/2 inch drywall = 13 inches. Would adding another layer of 2x4 @ R12
be too much then? Was the foot only the insulation layer?