038. District heating instead of a heat pump

Back in March (link to the post here), I had written that we would be using a heat pump made by a company called Heliotherm to heat the house and warm water. That model had been suggested to WA by the company that did the first round of energy calculations for us. Since then, there have been some significant changes in the construction elements, and a new energy calculation is being done by a different firm. Also, a new opportunity became available in May, that of district heat[1]. Earlier in the year REFUNA, the company that runs this network, was in the process of adding capacity and they couldn't promise that they could serve us. By May they were able to give us a positive answer.

The advantages of this type of heating system is that they're generally more energy efficient and cleaner than local systems and boilers. They take up less room for installation and are very low maintenance. Wikipedia had a good write up on it, see the link in the footnotes below. In our case, the costs associated with the installation and hook-up should be below that of what it would be for the heat pump system because a lot of the necessary earth removal work will have to be done for the other connections anyway.

I'm actually very pleased about this development as I was not so happy about the air-source heat pump. At very low ambient temperatures, they basically become electric heaters.

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[1] District heat is also known as waste heat, or utility-supplied heat. The term in German is Fernwärme, literally "distance" heat or warmth. REFUNA gets its heat from the waste heat of the nuclear reactor in Beznau near where we'll be. The Wikipedia article mentions this → District heating

037. Design consideration: wall finish

This is a case where we've had a really big change in our opinion, catalyzed by the suggestions of WA. Our original thought was plaster walls painted white (or in shades somewhere between white and grey in some rooms) with a dark industrial-type floor (more about the floor in another post).

WA suggested that this combination is a dime a dozen and that a much better choice for our house would be to leave the wood of the construction elements visible. Our first reaction to this was quite negative as the examples we had seen so far were too rustic and we didn't really like them except maybe in small chalets surrounded by fields of snow and pine trees. This discussion kept coming up and we kept shaking our heads and finally we went to see a house with an application similar to ours. Actually, if I understand it correctly, ours will be one grade higher than what we saw. The manufacturer, Pius Schuler[1], has recently started producing panels with knot-free, A-grade wood on the visible side which is quite smooth and we were pleasantly surprised and agreed that it does look very nice and airy. The company also has a planning service and they're (re)designing the walls for our house right now. I'll put up detailed drawings once the design is decided. Quite possibly the energy performance will be much better than that of the version I had written about before. More on that topic later.

Figure 28. A close up of a AB-grade Pius Schuler panel in spruce and fir. One half of the panel has been treated with a UV protectant to prevent darkening. Figure 29. Interior of a house built using Pius Schuler panels in larch. Our version in spruce or fir should be lighter, and have less variation in the strips. More images can be found at the Schuler website.

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[1] Pius Schuler is well-known in the Swiss low-consumption wood construction circles → Examples of houses built using Pius Schuler wall elements