HVAC Advise For New Shop

[1jeepfan]

My new shop is nearly finished. I need to make a decision on the HVAC. The shop is red iron, 40x60 with 14’ side walls. It’s spray foamed and has 2 insulated sectional doors. There is no interior ceiling, it’s all open to the roof. The DIY mini-split sounds good, but I had a mini-split in my last shop and thought it didn’t push much air. I‘m not sure which way to go.

 

[Notgrownup]

I am no HVAC expert but I truly believe if you have any kind of HVAC in that big open space you need adequate air movement to make it reach the bottom of the building where we need it. Mini splits are nice and probably with 2 units and 6 to 10 nice 60” high mount fans running at high speed would benefit you in heat or A/C

 

[slimcake]

Mini splits don't like dirt. Not sure what you plan to do in the shop but keep that in mind if welding or dusty jobs ect. I love my mini split in my 1650 sq ft garage and it has no trouble moving air. Some fans would def help. Add a tube heater down the middle if you need more heat.

 

[dcg9381]

I have 2 x 24K BTU mini-splits in my 40x60. They are somewhat directional. They will cool the shop down, but honestly, another unit wouldn't be a bad idea. These buildings are pretty big, a fan to move the cool air is helpful.

 

[1jeepfan]

Mini splits don't like dirt. Not sure what you plan to do in the shop but keep that in mind if welding or dusty jobs ect. I love my mini split in my 1650 sq ft garage and it has no trouble moving air. Some fans would def help. Add a tube heater down the middle if you need more heat.

I do a lot of woodworking in the shop. I cleaned the filters in the old shop mini split quite often. It’s pretty easy, but they do get dirty fast. Tube heater is a good idea. Seems like the mini split did a better job of cooling than heating.

 

[Jackfre]

What kind of dust collection are you running? In a 14’ place you are likely stacking the heat while enjoying the cooling as thee cool air is more dense and settles to the floor. The heat stays up top. You could go conventional with a spiral duct down the center or sides, either hp or gas fired. A unit that I had good luck in commercial applications was a 3 ton Fujitsu ceiling suspended. A couple of those and you are done.

 

[pcmeiners]

"high mount fans running at high speed would benefit you in heat or A/C"

High mounted fans do not benefit in the cooling arena, cold air sinks, having a ceiling fan mix it with warm air above just costs money. Texas rarely needs appreciable heat, though a ceiling fan does help for heat distribution.

Agree with other, for a mini to work in a large area you need more than one unit, preferably single zone individual split systems, far more efficient and provides redundancy.

 

[niget2002]

I have a 28'x50' shop. I have a single residential AC unit in the corner of my shop with a large vent at the top that blows across the top of the shop. It works well to cool the shop. A ceiling fan or two helps to circulate the air around to help reduce hot spots.

The same AC unit has a heat pump for heat during the winter.

The AC unit on the shop is the same as the House. It gives me the bonus that if the house AC dies, I can scavenge parts from the shop AC to get the house back up and running until a replacement part comes in. I've had to do this once or twice.

 

[4x4Pete]

I have a 28'x50' shop. I have a single residential AC unit in the corner of my shop with a large vent at the top that blows across the top of the shop. It works well to cool the shop. A ceiling fan or two helps to circulate the air around to help reduce hot spots.

The same AC unit has a heat pump for heat during the winter.

The AC unit on the shop is the same as the House. It gives me the bonus that if the house AC dies, I can scavenge parts from the shop AC to get the house back up and running until a replacement part comes in. I've had to do this once or twice.

But have you scavenged parts from the house AC to get the shop up and running??
That would be the GJ thing to do.

 

[niget2002]

But have you scavenged parts from the house AC to get the shop up and running??
That would be the GJ thing to do.

well.... maybe.

 

[My Old Tools]

I'm near Tyler. My shop is 30x40x12 with a 6/12 roof, 22 feet tall. 7 large windows, man door, 12x12 insulated door. My insulation is standard roll 4" with plastic backing. I added an extra 8 inches to the roof. I put in a 36k MrCool. It does a great job in my shop. single head mounted dead center of the 40 foot side at 9 feet up. With your spray foam, it would maybe be adequate. Two 24k units might be better. I have a wood shop and metal working. After 5 years it hasn't complained about dust yet. I have a common box fan in the attic pointed down and I run it in the winter to bring the heat down. Turbo mode moves plenty of air for cooling. The AC ***** a ton of moisture out.

 

[1jeepfan]

What kind of dust collection are you running? In a 14’ place you are likely stacking the heat while enjoying the cooling as thee cool air is more dense and settles to the floor. The heat stays up top. You could go conventional with a spiral duct down the center or sides, either hp or gas fired. A unit that I had good luck in commercial applications was a 3 ton Fujitsu ceiling suspended. A couple of those and you are done.

Thanks for the info. I use a 3hp dust collector attached to most of the machines. I also have two ‘air scrubbers’ hanging from the ceiling.

 

[1jeepfan]

I have a 28'x50' shop. I have a single residential AC unit in the corner of my shop with a large vent at the top that blows across the top of the shop. It works well to cool the shop. A ceiling fan or two helps to circulate the air around to help reduce hot spots.

The same AC unit has a heat pump for heat during the winter.

The AC unit on the shop is the same as the House. It gives me the bonus that if the house AC dies, I can scavenge parts from the shop AC to get the house back up and running until a replacement part comes in. I've had to do this once or twice.

What size unit are you using?

 

[1jeepfan]

I'm near Tyler. My shop is 30x40x12 with a 6/12 roof, 22 feet tall. 7 large windows, man door, 12x12 insulated door. My insulation is standard roll 4" with plastic backing. I added an extra 8 inches to the roof. I put in a 36k MrCool. It does a great job in my shop. single head mounted dead center of the 40 foot side at 9 feet up. With your spray foam, it would maybe be adequate. Two 24k units might be better. I have a wood shop and metal working. After 5 years it hasn't complained about dust yet. I have a common box fan in the attic pointed down and I run it in the winter to bring the heat down. Turbo mode moves plenty of air for cooling. The AC ***** a ton of moisture out.

I’ve been thinking about 2 mini splits. Just wasn’t sure what size. I’ll need to come up with a fan solution.

 

[1jeepfan]

I have a 28'x50' shop. I have a single residential AC unit in the corner of my shop with a large vent at the top that blows across the top of the shop. It works well to cool the shop. A ceiling fan or two helps to circulate the air around to help reduce hot spots.

The same AC unit has a heat pump for heat during the winter.

The AC unit on the shop is the same as the House. It gives me the bonus that if the house AC dies, I can scavenge parts from the shop AC to get the house back up and running until a replacement part comes in. I've had to do this once or twice.

Did you install this yourself?

 

[niget2002]

Did you install this yourself?

We bought the house used. Came with the shop already in place. Previous owner made good decisions on the build.