I read through a bunch of threads completely. I am in the process of planning a 40x80x16 or 40x100x16 shop. The shop will have a mezzanine but the rest will be open air. I plan on doing some pretty aggressive passive solar heating via windows and overhangs on the south facing side. I live in upstate NY where modulating temps is tough. It commonly reaches single digits in the winter, is humid and is in the high 90s much of the summer. I only want to the shop to maintain around 40 degrees in the winter maybe 45. In the summer 75 would be ideal. I would love to do mini splits. I am trying to figure out the best way to insulate. Also if well insulated could I heat and cool this shop with mini splits? With a massive thermal surface of all that concrete I am hoping I can pull this off. Thanks!
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Help with shop new guy here.
- Thread starter tjbailey
- Start date
ericm
Well-known member
There is a Manual J calculator at http://loadcalc.net/ that you can use to find out how many BTUs you'll need to heat and cool it to your target temps.
Pick the window placement and eves correctly for your passive solar.
I don't know of any mini splits whose thermostat can be set for heat as low as 45. Some like Mr Cool have "freeze protection" which is 42 but may have other features. The lowest normal heating temp setting on those is 62.
Your climate is cold enough that in-floor radiant heating would make sense if you have gas available to heat it. There are also air to water heat pumps for radiant heat but they are pretty new in the US so it may be hard to find an installer. The tubing requirments may be different since the temp is lower than the usual gas fired heater.
Pick the window placement and eves correctly for your passive solar.
I don't know of any mini splits whose thermostat can be set for heat as low as 45. Some like Mr Cool have "freeze protection" which is 42 but may have other features. The lowest normal heating temp setting on those is 62.
Your climate is cold enough that in-floor radiant heating would make sense if you have gas available to heat it. There are also air to water heat pumps for radiant heat but they are pretty new in the US so it may be hard to find an installer. The tubing requirments may be different since the temp is lower than the usual gas fired heater.
Welcome! Couple Questions:
Stick framed or metal?
What type of insulation are you thinking in the walls and ceiling...batt, blown in or spray? What/if any under slab insulation? Any consideration on in slab radiant heat?
How many and how big of doors?
Do you have any options for Natural Gas?
Any plans on ceiling fans or other means to keep air moving in that large of a space to minimize cold or hot spots?
Bottom line...that's a lot of volume which is awesome when you have lots of stuff but from a HVAC side in upstate NY that seems like a hefty bill on several large mini-splits but it's going to be highly influenced on other items as well.
Stick framed or metal?
What type of insulation are you thinking in the walls and ceiling...batt, blown in or spray? What/if any under slab insulation? Any consideration on in slab radiant heat?
How many and how big of doors?
Do you have any options for Natural Gas?
Any plans on ceiling fans or other means to keep air moving in that large of a space to minimize cold or hot spots?
Bottom line...that's a lot of volume which is awesome when you have lots of stuff but from a HVAC side in upstate NY that seems like a hefty bill on several large mini-splits but it's going to be highly influenced on other items as well.
Metal building, I am still trying to figure out the best way to insulate but I plan on certainly insulating the slab. I do not have access to natural gas. I plan on using ceiling fans to circulate in the winter. I will have 4 doors as large as 10x13 or 14.
WisJim
Well-known member
PVs are cheap enough, especially if you install them yourself, that they can offset a lot of the heating expense. It depends a LOT on your local utility and how they credit you for your energy production. Where I am my excess production is accumulated as energy credit from January 1st to December 31st, so I use my heat pumps a lot until December 31st, and they cut me a check for the remaining energy I have accumulated, paying me a small fraction of what I pay for electricity. Then by March I am again producing surplus due to longer and sunnier days.
PVs are cheap enough, especially if you install them yourself, that they can offset a lot of the heating expense. It depends a LOT on your local utility and how they credit you for your energy production. Where I am my excess production is accumulated as energy credit from January 1st to December 31st, so I use my heat pumps a lot until December 31st, and they cut me a check for the remaining energy I have accumulated, paying me a small fraction of what I pay for electricity. Then by March I am again producing surplus due to longer and sunnier days.
Did you buy and install your own PV? Thats what I was planning on. If so where did you get everthing?
WisJim
Well-known member
I've been doing PVs since 1982 and got stuff from many sources. Today I would check with RENVU, they have good prices and a very helpful website and estimator on line. I've had more than half dozen friends do their own systems using RENVU as supplier and design help.
I've been doing PVs since 1982 and got stuff from many sources. Today I would check with RENVU, they have good prices and a very helpful website and estimator on line. I've had more than half dozen friends do their own systems using RENVU as supplier and design help.
Thank you!
Firebrick43
Well-known member
Windows for solar heating are usually a zero sum gain. They add heat in the day but are so have so much loss in the night(even good triple pane windows) you did not gain anything
A solar wall is a much better method as you get good gain, cheaper than equal square footage of good triple pane windows, and low loss at night.
https://www.builditsolar.com/Projects/SpaceHeating/ShopThermosyphon/ShopThermosyphon.htm
Using PV for heat, is an energy loss sum. The only way PV make financial sense is if you live to far away from the grid. The energy/cost of manufacture will never be made up by the power they produce. The environmental impact of mining the materials is terrible for a "green" product. The only way its been made to work financially is through forcing utility companies to purchase the energy at 3-4 times the cost of other methods, therefore forcing their customers to bore the cost, and tax rebates making other tax payers to bear the cost.
A solar wall is a much better method as you get good gain, cheaper than equal square footage of good triple pane windows, and low loss at night.
https://www.builditsolar.com/Projects/SpaceHeating/ShopThermosyphon/ShopThermosyphon.htm
Using PV for heat, is an energy loss sum. The only way PV make financial sense is if you live to far away from the grid. The energy/cost of manufacture will never be made up by the power they produce. The environmental impact of mining the materials is terrible for a "green" product. The only way its been made to work financially is through forcing utility companies to purchase the energy at 3-4 times the cost of other methods, therefore forcing their customers to bore the cost, and tax rebates making other tax payers to bear the cost.
1953mercury
Well-known member
Three words, insulate, insulate, insulate. I have 2100sf on the main floor, 15' ceilings+700sf of loft area. R-19 walls, R-57 ceilings, all fiberglass batts, heat with a 120k btu, 96% efficient propane furnace. Looks like this winter I will use around 400gal of propane for heat. I keep the shop at 50, and move it up to 62 when in the shop, which this year is pretty much 8hrs a day six days a week. In the summer I try to keep the doors closed, and the temp never gets above 70, even through we get 90deg summer temps. Mike
Last edited:
b-boy
Well-known member
I'm in WNY, and I second the insulation route. I think that's the biggest factor in keeping the building warm/cool at the right time of the year.
I have a pole barn, and I used a mix of 2" foam, spray foam, and batts to insulate the walls. For the ceiling I used high R-value faced insulation above a corrugated metal ceiling. The building is pretty air tight. Most of the loss is through the garage doors, but it's not too bad.
The biggest shock was during the Summer. Before the insulation, I could barely stand to be in the building in July/August. The insulation made it very comfortable. I added a few ceiling fans, and I've decided I don't really need A/C.
I have a pole barn, and I used a mix of 2" foam, spray foam, and batts to insulate the walls. For the ceiling I used high R-value faced insulation above a corrugated metal ceiling. The building is pretty air tight. Most of the loss is through the garage doors, but it's not too bad.
The biggest shock was during the Summer. Before the insulation, I could barely stand to be in the building in July/August. The insulation made it very comfortable. I added a few ceiling fans, and I've decided I don't really need A/C.
Im looking at doing one of the passive solar walls on the south side since I have so much surface area to use. Sounds like large Thermosyphon Solar Collectors when done right provide a significant amount of BTU's for heat. I think my heating load will be well above my cooling load. I cant believe how much it is going to cost to insulate this place well. Looks like I will be going with a 40x80!