Cooling and Heating my foamed shop

[NakeDiesel]

My shop: Smart *** Garage is a 40x80x14 pole barn with 4 to 5 inches of open cell spray foam on walls and roof. I've closed off the ceiling with steel in the shop. I have a room inside the shop 24' x 11' with walls and ceiling insulated between it and the shop with storage over that room and the compressor room attached on the end of it. Compressor room is 6' x 11'. Small bathroom is 5'8" x 5'5" opening to the shop next to the big room. All walls in the shop are covered in steel on the inside. Shop has 3 insulated 12'x12' doors on the south side and an insulated man door on the south side. I also have an insulated man door and 2 windows in the room on the north side. Shop has 2 more windows on the north side and 2 on the south side down at the storage ends. It's located in NE Oklahoma

Built the shop almost 8 years ago and in the winter I've run a couple of those oil filled electrical radiators down at the end with the bathroom and where my work benches are, other end is long term storage for projects and the like with pallet racking. Keeps it above freezing and in the 50's to 60's most of the winter except when it dips down really cold for long periods. If it's really cold out and I'm working in there I'll run a propane bullet heater to add heat to the shop while I'm in there working. I don't open the big door very often, but it's variable depending on if I'm doing maintenance on a vehicle then it will open and close twice. But most of the time I'm working on long term project like my current rebuild of my John Deere 4010.

Summer time I don't have anything but 3 ceiling fans and a big pedestal fan to circulate air. I put a temp/humidity gauge in there this summer and temps stayed in the 80's even with 100+ outside but humidity was 80%. I've gotten where if I'm using it in the summer time I open the big doors and windows to get a breeze through there to help with the fans going.

The small room my son lived in through the winter and summer last year before he finally got an apartment and we heated it with a 110 little window AC unit using a heat strip and an electric rotating heater with a fan. AC unit cooled it in the heat. Room was very comfortable that way. I have a storm door on that north man door as well.

We are on propane out here in the sticks for our house heat, but looking for an all electric setup for the shop. I don't plan on heating it up to high temps in the winter mainly keeping it in the 60's unless I need to paint something and then I can still use my propane heater to bump it up if needed. Biggest is removing humidity and cooling it to 70's in the summer.

Looking for either a packaged unit setup and will make my own ducting to spread the air in the main shop building or a multi head mini split system, but I worry about the dust from my projects with them.

What size package unit or mini split should I be looking for. Had one AC guy tell me I needed a 10 ton unit for the shop, but he didn't have any experience with spray foam insulation and that just seems what too freaking big.

Ignore the room on the top right of the floor plan pic. I've chosen a different route for a paint bay in the future and never built it.

 

[PoorUB]

In my head I come up with a little over 5 tons for cooling, probably 6 ton. 5 ton would probably do it on most days but probably not those 100 degree, 100% humidity days. Those days the temp might creep up, but it would be much more comfortable than no AC at all. It might be fine. No way you need 10 ton!

Around 75,000 BTU should heat it in the winter.

 

[jacks2000]

I'm almost identical. I'm in Kansas so our temps would be about the same.
My shop is 50 x 64 x 14, so same cu ft. Spray insulation with metal interior walls and ceiling. I have 16" of cellulose in the attic. I have a 5 ton AC. It never goes over 82 or so in the summer and it cools down to 74 in about 15 min. Also two 72" ceiling fans. I have in floor heat which is fantastic.

 

[NakeDiesel]

I wanted radiant heat, just couldn't fit it in the budget when I built the shop. I stretched for size and insulation, the rest of it came as I have had funds to do stuff in it like interior steel, electrical, plumbing, commercial kitchen, bathroom, compressor room and lights. All done in stages over the years. I just finished off the interior of the commercial kitchen a little over a year ago and started my bees. Planning to eventually be producing a large volume of honey as I figure out the whole bee keeping thing and will need a clean place to process it.

Has anyone dealt with mini splits in a shop environment where sanding, grinding, painting, etc.. is going on? When painting they would be shut off, and eventually when I get my front lean too added on, I'll build a real paint bay on one end of it. With the prices of steel, that's a year or two at least down the road.

 

[Hobby_Man22]

I'm almost identical. I'm in Kansas so our temps would be about the same.
My shop is 50 x 64 x 14, so same cu ft. Spray insulation with metal interior walls and ceiling. I have 16" of cellulose in the attic. I have a 5 ton AC. It never goes over 82 or so in the summer and it cools down to 74 in about 15 min. Also two 72" ceiling fans. I have in floor heat which is fantastic.

I call bs. How does it drop from 82 to 74 in 15 minutes?

 

[yeldogt]

My new project that will be my house is spray foamed --- over 4k sf w/ 36k BTU VS carrier unit.

You are only looking for about 10 degree delta .. how much heat will the bee work add?

 

[NakeDiesel]

bees won't add any heat or negligible at unnoticeable levels since just running a motor to spin frames in a centrifuge to get the honey after decapping them. That room is insulated between the shop and the room and the ceiling is insulated to the storage area above. Did it partly to allow greater cooling or heating in that room vs shop as well as to reduce noise infiltration.

I add more heat in the main shop from my compressor or welding or grinding or etc... I'm working on an air circulation vent system in my compressor room to cycle air in there to cool it so I can keep the door closed all the time. Will be using a 4" powered vent fan to push air out and a 4" vent down low to get air in. Will also draw fresh air in from outside for the compressor as well. Just finished gathering all the parts for that, it's my next project in the shop: see Smart *** Garage build thread it's a long thread of building the shop and projects done in it and around the house/farm.

 

[Yankeefarmer]

…

Has anyone dealt with mini splits in a shop environment where sanding, grinding, painting, etc.. is going on? When painting they would be shut off, and eventually when I get my front lean too added on, I'll build a real paint bay on one end of it. With the prices of steel, that's a year or two at least down the road.

My best friend from childhood owns a large HVAC company in another state. He advised against using mini splits in a shop environment because of the dust concerns. Although mini splits have easy to clean filters, over time smaller particles do penetrate the filters and can require deep cleaning of fans and heat exchangers. Although we have a very clean house, the mini splits there can collect lots of dust on their filters in a short period of time.

My shop (26x48x15) has a conventional split heat pump system. I chose it in part because I can use regular furnace filters and discard as needed, but also because if the heat exchanger should need a wash down it would be easy to do. Earlier this year I replaced the bed supports on my pickup, which entailed a bit of grinding to remove the old welded on supports and prep the old steel to weld in the new ones. The A/C only ran for about half the total project time, but the filters were badly blinded by the dust. I am very happy with my choice.

 

[Yankeefarmer]

I call bs. How does it drop from 82 to 74 in 15 minutes?

I can understand how you would feel this way, based on the challenges you have faced with your building. You seem to be dealing with a building that has a high heat gain, and, IIRC, it wasn’t until you ran your system continuously that you were able to achieve acceptable inside conditions. We don’t all have the same conditions or situations. My shop was happy to stay below 75 deg F throughout all of our above 90 degree heat waves without A/C if I didn’t open the large overhead doors. It only took 10 or 15 minutes with an overhead door open for the the temperature to rise to the mid 80s. After closing the doors, the temperature would only very slowly decay back to the 70s. When I say, “slowly decay” I mean many hours. A shop that had been tolerable to work in had quickly become uncomfortable. The important thing, though, is that the slab and contents weren’t heat soaked. The A/C would drop the temperature to comfortable levels within 15 minutes. I have a temperature recorder in my shop that verifies this.

So, I believe @jacks2000 is conveying accurate, truthful information about his situation, which is different than your situation.

 

[NakeDiesel]

That's what I was afraid of with the mini split, my shop get's very dusty at times when I'm doing body work on something or building things with the welder. Guess I'll start looking around for a 5 ton packaged unit to put in when I get the funds available.

 

[Hobby_Man22]

I can understand how you would feel this way, based on the challenges you have faced with your building. You seem to be dealing with a building that has a high heat gain, and, IIRC, it wasn’t until you ran your system continuously that you were able to achieve acceptable inside conditions. We don’t all have the same conditions or situations. My shop was happy to stay below 75 deg F throughout all of our above 90 degree heat waves without A/C if I didn’t open the large overhead doors. It only took 10 or 15 minutes with an overhead door open for the the temperature to rise to the mid 80s. After closing the doors, the temperature would only very slowly decay back to the 70s. When I say, “slowly decay” I mean many hours. A shop that had been tolerable to work in had quickly become uncomfortable. The important thing, though, is that the slab and contents weren’t heat soaked. The A/C would drop the temperature to comfortable levels within 15 minutes. I have a temperature recorder in my shop that verifies this.

So, I believe @jacks2000 is conveying accurate, truthful information about his situation, which is different than your situation.

Then again up north 95 degrees still feels like 80 degrees for some reason. No humidity I guess.

 

[Yankeefarmer]

Then again up north 95 degrees still feels like 80 degrees for some reason. No humidity I guess.

Actually, we can get a lot of humidity here. This summer was the worst I remember, with dew points in the low 70s, and sustained periods with dew points above 60. I was running my A/C in the shop set to between 68 and 72 just to get the humidity down. It helped a lot, despite not running much. I’d typically see about a 5 minute run time, then 20 to 30 minutes before it came back on for another 5.

 

[Yankeefarmer]

That's what I was afraid of with the mini split, my shop get's very dusty at times when I'm doing body work on something or building things with the welder. Guess I'll start looking around for a 5 ton packaged unit to put in when I get the funds available.

I considered a package unit, but wasn’t comfortable with the duct penetrations I’d need to keep sealed. I used a Mr Cool Universal, where the warranty is valid with a self install if you use their no-vac/ precharged line set. Very happy with it so far, as we head into what will be it’s first full New England heating season.

 

[PoorUB]

Then again up north 95 degrees still feels like 80 degrees for some reason. No humidity I guess.

I live in North Dakota and get comments about cooling being easier up here. I don't know, but I am pretty sure that 100F and 100% humidity is the same here as in any part of the country! We deal with similar summer time temps that most of the country deals with, now granted seeing over 100F is very rare where the SW sees 110 pretty often. But we deal with -40F to 100F and high humidity.

 

[NakeDiesel]

I've travelled all over the US and many other countries, high temps **** everywhere... I don't care how much humidity is in the air. We hit 109 on the bike this summer in sw co/se ut and it was hot as could be and like riding through a blast furnace.

Funny side story, went to south africa around joburg back in the 90's for 2 weeks for a job I did there, left in Oklahoma 100+ temp and it was in the 70's there (their winter), they were in coats and stocking caps. I was in heaven with the 70 degree weather

 

[NakeDiesel]

After searching and looking around the interweb, I've decided on a goodman split heat pump. https://www.nationalairwarehouse.co...riable-speed-heat-pump-split-system-1241.html

I'm leaning toward not adding electric heating elements. I've kept my shop 50+ degrees for 7 years with 2 of those cheap oil filled radiators from walmart running 24/7 all winter long and the occasional heat provided by a propane turbo heater when out working and it was cold or I needed it 70 to paint.

Any thoughts? We rarely get sub zero temps for a long period of time here.

 

[Hobby_Man22]

After searching and looking around the interweb, I've decided on a goodman split heat pump. https://www.nationalairwarehouse.co...riable-speed-heat-pump-split-system-1241.html

I'm leaning toward not adding electric heating elements. I've kept my shop 50+ degrees for 7 years with 2 of those cheap oil filled radiators from walmart running 24/7 all winter long and the occasional heat provided by a propane turbo heater when out working and it was cold or I needed it 70 to paint.

Any thoughts? We rarely get sub zero temps for a long period of time here.

It doesn't hurt anything to have them.

 

[Hobby_Man22]

I have a 15kw on my goodman. Wish they would have went with 20. It only puts out 70 degree air by itself on emergency heat mode.

 

[Yankeefarmer]

NakeDiesel, that looks like a nice unit. I think you’ll be happy with it. I chose a Mr Cool Universal for mine, so I’ll list a few comparison points:

Goodman has a longer track record than Mr Cool, and I’d bet most any good HVAC tech has experience with Goodman. The industry might still be a bit reluctant to work on a Mr Cool.

Will you be doing a self install? How will that affect warranty? Mr Cool is warranted even with self install.

The Goodman system is more “elegant,“ in that it uses a variable speed indoor blower to ramp airflow based on whether the outdoor unit is on high or low stage. The Mr Cool is on/off, meaning it has only one indoor fan speed (full, depending on whether the DIP switch is set to 4 ton or 5 ton capacity.) Conversely, the Mr Cool is designed to provide more heat at lower outside temperatures, claiming it will provide full output down to 14 deg F outside. The specs for the 60,000 BTU/hr Goodman you listed show only 33,000 BTU/hr heat output at 15 deg outside temp. Nevertheless, based on what you’ve done with your cheap Walmart heaters, I can’t imagine you’d need heating strips.

Hobbyman mentioned that it doesn’t hurt to have heating strips. True, it doesn’t hurt anything to have the sitting there unused. But, you’ll need to provide larger electrical service to feed them, and, if they come on, they’ll start spinning your electrical meter a lot faster. I have not installed heating strips in mine. On the coldest mornings we’ve experienced so far, at about 25 deg outside temps, my shop heats from about 48 deg F to the 61 deg F I use when working out there in a little under an hour. I intend to post a separate “my experience” thread with data once I get some data at colder temperatures. I’m real interested in seeing how it performs in single digits.

 

[Yankeefarmer]

I got to thinking about what I wrote in my last post and remembered that I had doubts about Mr Cool's claims of full heat output down to -5F in 4 ton mode and 14F in 5 ton. So I searched for their more detailed performance specs and plotted them against the Goodman specs. I've posted the comparison below. It looks to me like Goodman prioritizes efficient operation (at the expense of output) while Mr Cool prioritizes capacity. Now I'll need to graph claimed efficiency for both to see if I'm right.

 

[NakeDiesel]

I ordered the Goodman this morning. I ordered a 10k heating element for it. I looked at both the Goodman and Mr. cool when I was looking, I picked the Goodman because I can get parts locally for it and wasn't sure on the Mr. cool.

I'll be having a high school buddy that is a plumber/hvac/electrician install the system for me, I'll run the wiring and conduit to the locations for the inside and outside units. He does good work and has always done me right on projects I couldn't get done out here and needed someone to do them.

With the way things are with my dad right now, might be months before I have enough time to dedicate to it to complete the install and I'm still gimped up strength wise from my shoulder replacement at the end of Sept.

 

[Yankeefarmer]

Yeah, there is an uncertainty about the Mr Cool support going forward. Sounds like you’re on the track to success with your plans. My best wishes for your shoulder, health, and dad!

 

[NakeDiesel]

lol, just got a call on the hvac system, the air handler is 4 to 6 weeks out it looks like. Maybe they can get it out sooner. I've come to expect it on about everything anymore. Ordered a blasting cabinet from Cyclone and it was 4 to 5 weeks out, got it shipped and went to pick it up and fedex freight has smashed the top in, so another 5 weeks later a replacement one shipped out today. Hopefully this one isn't smashed.

 

[PoorUB]

Many of the Mr Cool units are built by Gree. If you look up both it is pretty obvious. The electric air handler/HP from Gree is their Flexx line.

Gree Flexx