5 ms·
Air sealing is also critical. The insulation can be defeated if unconditioned air can leak into the house and conditioned air can leak out. It's a difficult thi
by leguminous 8y ago
Air sealing is also critical. The insulation can be defeated if unconditioned air can leak into the house and conditioned air can leak out. It's a difficult thing to get right because it requires attention to detail and if done poorly it can result in moisture problems.
- fastbeef 8y agoIt is indeed critical and all new houses in Sweden are tested for leaks under pressure. Those that leak sufficiently little get to call themselves Passivhus and you have some taxation benefits.
- daveFNbuck 8y agoHow do they test that?
- leguminous 8y agoAt least in the US, blower door testing: https://en.m.wikipedia.org/wiki/Blower_door https://en.m.wikipedia.org/wiki/Blower_door
- thomk 8y agoI've had this done before, very, very informative. Those machines are like $3K to buy, you can hire someone to come out and do it, but this seems like a perfect DIY project.
- masklinn 8y agoAn other very informative thing to get done is thermal imaging of the walls (from inside and outside both). Very good at uncovering damp spots and water infiltration too.
- leguminous 8y agoA handful of US states have also made blower door testing mandatory in new homes, but we still have a long way to go. A few states don't even have state-wide building codes, much less efficiency requirements.
- js2 8y agoAre there no health issues associated with a house being that well sealed, or do you have some sort of air exchanger that is temperature efficient? Edit: e.g. googling brought up this article - https://www.architectsjournal.co.uk/buildings/airtightness-blamed-for-health-risks-in-homes/10014252.article https://www.architectsjournal.co.uk/buildings/airtightness-b...
- PopeDotNinja 8y agoI wonder what carbon dioxide levels get up to in a well-sealed house.
- praseodym 8y agoYou’ll want mechanical ventilation (with heat recovery) to prevent that: https://en.wikipedia.org/wiki/Heat_recovery_ventilation https://en.wikipedia.org/wiki/Heat_recovery_ventilation
- dzhiurgis 8y agoHeat recovery + well sealed house with some humans inside can potentially mean no heating at all!
- dTal 8y agoSome good comments on that in this HN thread from a few weeks back. In short, not good. https://news.ycombinator.com/item?id=18959796 https://news.ycombinator.com/item?id=18959796
- PopeDotNinja 8y agoThanks for the link.
- Abekkus 8y agoshouldn't houseplants be sufficient?
- 8y ago
- pfranz 8y agoI wonder how feasible maintaining that is? I feel like it's very common to find people who work on your house will mess this up (cable or satellite dish installers, for example). That seems to happen for everything, but it depends on the resiliency. I bought a house where satellite dish installers drilled right through the shingles, likely compromising the water permeability of the roof. Ironically, I had heat pumps installed last year. Soon after I had rodents. I feel like they did a good job of weatherproofing exterior holes they made, but after patching up the crawlspaces the rodents disappeared. People are grossed out by rodents and a leaky roof has to be addressed, but if their heating/cooling cost goes up slightly because a cable installer messed up are they going to hire someone to hook up a blower door, patch things up, and charge this back to the cable company?
- DoofusOfDeath 8y agoI just had a minisplit head installed at my house, and when they used a hole-saw on my external wall, it basically trashed the fiberglass insulation in that stud cavity. Fortunately this was part of a project to finish my home office, so I still had access to the space between the internal and external walls. Not only could I see the insulation damage, I could also repair it without too much effort. But in general, I agree there's a responsibility gap when it comes to these installers. I think the best practical solution for now is to factor into such projects the cost of restoring a building's thermal envelope. EDIT: I should mention that a blower-door test might not have detected this damage. The cavity whose insulation was damaged has pretty good draft-blockage from the rest of the house, due to fire-code requirements.
- buttcoinslol 8y ago> But in general, I agree there's a responsibility gap when it comes to these installers. I think the best practical solution for now is to factor into such projects the cost of restoring a building's thermal envelope. What, $5 for a tube of exterior grade caulk? Vapor barrier seal tape is 10 cents a foot. Add in $10 in labor per penetration and you're done. You could leave it out of your estimate entirely and not even notice if your guys did the work. edit: I'm a commericial construction estimator
- l4yao 8y agoFor anyone interested, Building Sciences Corp is a great resource on different methods to build functional, airtight, well insulated walls. Here's a starting point: https://www.buildingscience.com/documents/insights/bsi-001-the-perfect-wall https://www.buildingscience.com/documents/insights/bsi-001-t...
- dashundchen 8y agoI'll add https://greenbuildingadvisor.com https://greenbuildingadvisor.com for a site that has a lot of quality discussion and analysis on energy efficiency for buildings. The forum and comments can teach you a lot.