Shop insulation and HVAC

[CamB25]

My new house in Wilmington, North Carolina includes a 24x36 detached shop. I can't wait to get this finished! Older picture:

https://www.amazon.com/photos/shared/D8 ... ELNeUxPczU

Stick built. 11 foot ceiling in the shop and A1 attic trusses upstairs. I plan to turn the attic (16 x 36) into a guest room/apartment with a small bath.

Both areas, shop and attic, will need insulation and HVAC. Does anyone have experience designing an insulation/HVAC plan for this type of structure? I'm thinking the shop and attic should be on separate systems, maybe 2 mini-splits? Should I insulate the floor/ceiling between the shop and attic or just the walls and attic ceiling? The roof has a ridge vent.

I'm doing all the work myself and currently running electric.

thanks!
Cam

[ktm_2000]

Cam,

I have no experience doing hvac so I'm of no help for you there, I'm pure out jealous of your new shop. I would love to have a place to work indoors.


The big question is, since you are almost done with the B25, what is going in that nice new shop?

[Seapalm]

Spray foam insulation and mini splits!
You can buy DOW foam insulation kits. The mini splits come charged, so if short copper runs install won’t require an HVAC guy and vacuum pump.
Enjoy!

[CamB25]

My B25 is almost done?? Could have fooled me! I seem to find more and more that needs doing every time work on it. I'm in a dash to get it floating.

Spray foam is an option...not sure it's the best option for the shop. Mini splits are definitely on the option list. I have an HVAC engineer stopping by the next time I'm down there to give me his opinion.

The shop will be used for all my projects to finish the new house next door!
thanks
Cam

[Kevin]

Cam,
I installed mini splits at my last house. My AC guy did the final vacuum prior to releasing the gas into the lines. His words were at least 45 minutes to an hour on the pump. He has seen them fail without doing so. Just passing along what I have experienced.

[CamB25]

Agreed. You have to get the moisture out.

[ktm_2000]

I have a small vacation house near the beach which I have been using a 10,000 BTU window A/C to cool in the summer, the unit works fine to cool the house but is way too loud. I've considered a mini-split but when I got a quotes it was stupid $$$, essentially 2x the cost of the unit itself for installation.

The install I need is straight forward, I have an 220v in-wall electric heater that could be removed from the bathroom which is right inside the house where I'd want the compressor to go and should be able to get a pre-made line with the correct hose flares and install all the components myself, how does one find a person just to do the final vacuum and charge the system at a reasonable cost?

[Rawleigh]

KTM: The units are precharged. You just need to get a vacuum pump (Harbor Freight) to evacuate the lines after you connect them. Once the vacuum is drawn you turn the valve to release the refrigerant that is captive in the compressor.

https://www.ebay.com/itm/12-000-BTU-Duc ... 2403585634

https://www.ebay.com/itm/12000-BTU-19-S ... 0005.m1851

Quad zone

https://www.ebay.com/itm/48-000-BTU-Qua ... 3494401285

[ktm_2000]

wow - I didn't dig into it too much, the quotes I was getting were $3500-4000 for a mitusbishi installed.

at those prices I might attempt it myself as I've had a desire to try vacuum bagging a fiberglass part and could use the vacuum pump more than once.

[Rawleigh]

Harbor Freight has one for $129 right now.

[Tony Meola]

Kam

A builder friend of mine swears by foam. He claims it blows fiberglass away, but not cheap. You can also use the foam insulation boards that Home Depot and lowes sell. Works really well. Also a little better at killing outside noise, not that it matters in a shop, but also will cut down on the noise leaving the shop.

[ianupton]

Cam -

Just seeing this old post.

How did your shop progress end up? I would be interested in hearing what you did.

I finished a loft space above a barn I had a few houses ago. Was a great space. Warmest (least drafty) space we had. The rest was an 1820's farmhouse.

Ian.