Yes, so much so that you might as well not fill them. Use continuous, external rigid foam.
Posted: 01:20 pm on November 12th 2018
Note that Chiltrix offers a backup heat option: http://www.chiltrix.com/hydronic-backup-heater/
Posted: 08:37 pm on November 12th 2018
Lstiburek: "No interior attic assembly side vapor control is required or recommended in climate zones other than Climate Zones 6 or higher..."
Posted: 09:11 am on November 13th 2018
> outside with a portable rec saw-zaw Which also cuts plywood and OSB quite well. And windows are very easy to break. I wouldn't put much weight on this issue. Taped foam is a good air barrier - so don't expect much difference with Zip here either.
Posted: 02:55 pm on November 13th 2018
If $2K is the accurate difference, then it might be worth it on indoor and/or outdoor aesthetics alone. I'd expect geo to be slightly more efficient, but the real answer is "it depends".
Posted: 06:05 pm on November 13th 2018
No sheathing to rot significantly decreases moisture risk. As does R10 external foam (depending on R ratio and temperature). Even .55 perms of outward drying helps. So I expect you have an excellent wall. But imagine some no-interior-side-air-barrier scenario where lots of moist air flows from the interior, to cold sheathing/foam where it condenses (depending on R ratio and temperature) and then returns to the interior (convection will cause this loop). You could get enough water accumulation to cause problems. Be careful with external only air barriers.
Posted: 03:13 pm on November 13th 2018
Note that as explained in BSI-092, a reason that external R5 foam and interior side poly works is that the interior air sealing is better than the exterior air sealing. Tape the R5 foam (or sheathing) and this is no longer true. Not all partitions are safe with external air barriers!
Posted: 02:30 pm on November 13th 2018
At least consider a wood boiler with water storage. Clean, fast burn and excellent control of interior temperature. About 1/2 the space for the same thermal storage.
Posted: 01:07 pm on November 12th 2018
> Oversized AC units will do a crummy job of dehumidifying See below, figure 5-45, showing that the effect is quite small, even when capacity is 10x the current load. And at 72F outside, any AC will do a crummy job. Because it won't run - you need a dehumidifier. http://www.fsec.ucf.edu/en/publications/pdf/FSEC-CR-1537-05.pdf
Posted: 12:50 pm on November 12th 2018
Agreed - pick one or the other. Friends in Panama that sometimes keep things open (allowing mold to get established) and then sometimes close up and run AC (limited ventilation) have reported getting sick from mold.
Posted: 11:55 am on November 12th 2018