Nice workshop!

Glad that you're listening to the buildingscience people.

Spray foam might be an option in lieu of removing mechanicals from walls, DIY 2-part foam kits are available. Extending receptacles outward would work, obviously some things won't be amenable to being sprayed over. In either case, rigid or spray foam, a fire-rated surface needs to cover the insulation in living/work areas. That means something like drywall with some sort of support framing.

Looks like the windows could stand upgrading at the same time.

Good luck.

Any reason you don't just insulate the ceiling if the issue is the first floor?
There's no magic solution for the wall insulation. Move what you need to move, insulate and put it back.
Second the window upgrade.
Ron

Formula1 & Ron,

Thanks for the responses.

Windows down there are history. If I end up insulating walls, will definitely follow code on fire resistant covering. Have heard that someone makes a fire rated facing for rigid foam, but have yet to find who makes it.

I have seen the Tigerfoam DIY spray foam. Might be worth a look. It looked expensive but need to do the math versus (rigid 1" over same area + time investment of moving everything).

I have considered doing an unvented basement, sealing all penetrations and using fiberglass batts in the basement / crawl ceiling without insulating basement walls. But, am concerned with controlling humidity and mold in basement / crawl. Anyone with thoughts on that? My guess is that I'd end up needing to then get a dehumidifier in the basement....or would it be possible do ventilation from the first floor with a return and supply duct in the basement to keep humidity in check. Lastly, if I went the batt in ceiling route, would I want a vapor barrier / retarder?

Lots of moving pieces here. Thoughts?

Thanks,
Scott

If you're wanting to hold down costs, I would think laying a vapor barrier, adding vents in the non-vented area, insulating the ceiling and the crawlspace would help prevent the humidity problem. Adding heat ducting and a return in addition to the other would definitely be an advantage.

We had to deal with moisture problems in a commercial bldg (early 1900's) in Miss. and solved it by improving drainage, adding vents and laying a vapor barrier.

Thanks annz, good info.

Due to the fact that my workshop is in the basement, I definitely want to go unvented in the basement / crawl IOT prevent the high local humidity from turning my equipment to rust. Without insulation in the ceiling now, humidity levels down there are reasonably controlled by the air movement between the basement and the conditioned first floor. Should I decide to insulate the basement / crawl ceiling however, the issue then becomes how do I control the humidity level down there in an unvented application without having to go through the pain of insulating the basement walls that are covered in mechanicals. Also, in the summer, how do I prevent condensation between the warm air in the basement and the cool floor above it? Finally, there is the issue of comfort while working in the basement which is third in my prioritization of issues because the weather here is just not that extreme.

The house will be cooled in the summer by central AC with the air handler in the basement. The house will be heated in the winter by a hydronic system (boiler in the basement with emitter combination of radiant floor and cast iron.)

Is there an HVAC strategy that would allow me to do an unvented basement / crawl with rigid foam insulation on as much of the exterior walls as I can reasonably get to. Plus, insulation in the basement / crawl ceiling (plus sealing all penetrations) to keep the first floor warm? The idea would be that in the summer with the AC running, put a return and supply duct down there large enough to remove moist air as well as reduce the temperature differential enough to prevent condensation between the basement and first floor. In the winter, I'd have a cast iron radiator down there to provide some level of comfort on the coldest days, but really don't forsee high humidity levels in Winter.

Anyone with thoughts? What am I missing?

Best regards,
Scott

If I read your post correctly, you said all the crawlspaces are connected to the basement without barrier walls.

I had a partial crawlspace connected to the basement of the house we purchased 4 years ago. First thing I did was build a barrier wall with a door. studded it out with 2 by 4s and covered it with plywood I used during the move, put 2 barrel bolts in too hold the door in place and put 2 handles on it. then sealed it off with caulk. building barriers will keep the rest of the basement warmer. Then use a dehumidifier to control the moisture to keep your tools from rusting.