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I also bought an old house and going for 12 cm of Expanded Polystyrene (EPS) insulation for outer walls in southern Germany. Plus simple combined heat pump for
by lnsru 4y ago
I also bought an old house and going for 12 cm of Expanded Polystyrene (EPS) insulation for outer walls in southern Germany. Plus simple combined heat pump for mild weather in living rooms and gas heating for real winter for whole house. With all this setup I am going to install central ventilation system for living rooms. It’s really really nice to have fresh air during the night. The morning in previous rental apartment was always ugly with condensed moisture on all the windows.
- stuaxo 4y agoI've been looking at spray cork. You can have it applied indoors and skimmed at only about a cm total or outdoors.
- ericd 4y agoSpray… cork? Is that just glue+cork bits? Does it end up airtight? I’ve been pretty excited about steam expanded cork boards, they apparently make for excellent (albeit expensive) exterior cladding. Ditto granules for replacing attic fiberglass, though the additional weight of a thick layer seems like it might be a problem for ceiling drywall.
- mikeyouse 4y agoNo matter the substrate, there is almost no insulation benefit to 1cm of material. It looks like cork has an R value of ~4.0/inch so 1cm is roughly R-1.5? That’s about equivalent or a single pane of glass.
- drjasonharrison 4y agoSometimes you can only economically and aesthetically add a bit until you get to the "tear it down and rebuild".
- stinos 4y agoWhy do you choose a hybrid system and not just a heatpump? I have the impression that unless your energy demand is still fairly high or the heatpump rating is too low, houses are doing fine with a heatpump and the high COP in mild weather balances the lower COP in cold winters such that overall it's still worth it.
- pitaj 4y agoMoreover, why gas instead of electric backup?
- djbusby 4y agoMaybe, like me, they've got existing gas heaters/boilers installed. When you get a heat-pump you need the backup for really cold (-20c). So you just leave the existing one in for that case.
- deleted 4y ago[deleted]
- letitbeirie 4y agoDepending on where the furnace is located, it can be cheaper and have a lower carbon footprint. In my area of the US for example, gas costs 32￠/therm, which equates to 1.1￠/kWh. Electricity on the other hand costs 6.4￠-10.9￠/kWh (depending on time of day), and while a third of it comes from renewables, another third of it comes from coal, so it ends up being net worse for the environment than just burning the gas.
- Freak_NL 4y agoWhy EPS and not PIR?
- lnsru 4y agoEPS is like one third of PIR in €.
- Freak_NL 4y agoBut those costs are marginal in the bigger picture. With only 12cm not going for PIR while you have the chance seems just a waste of effort. It's not bad, but you're really limiting the options you have for heating.
- lnsru 4y agoThanks, I will redo my calculations. PIR 0,026 W/mK. EPS 0,035 W/mK. There is a nice difference.
- brnt 4y agoWhat costs money is mounting it onto your house. It's a really bad idea in terms of fire safety, EPS.
- tinco 4y agoEPS is a filler material for concrete structures and floating installations that easily catch fire and has mediocre thermal properties. Is it even allowed to use EPS on your walls? PIR is the typical economical material used for that kind of application. And 12cm is about the minimal thickness you'd want for decent insulation.
- lnsru 4y agoEPS will be plastered afterwards. I don’t see any problem having it between brick wall and plastered layer. 12 cm is ok for an old house. More is not economically viable.
- tinco 4y agoI got used PIR panels for cheap for my renovation. There's companies who operate large barns filled with that stuff selling it online.
- brnt 4y agoEPS is not allowed for new builds here in NL, it doesnt meet fire safety codes. To me, that means Im not using it for renovation either. PIR can be had for good prices and is superior in every metric.