3 mini splits vs central ducted in large shop

[thymer]

You are running under 500sf per ton -- I would hope it would work.

The Op is trying to do more sf with 3 ton in what looks to be a colder climate.

I went a little large for the cooling aspect. Hot and Humid down here in the Summer, nice chilly and dry 70 in the shop in August.

 

[James-W]

Personally, I would go with the central ducted since it will see a limited amount of use. It will no doubt work quicker to get you to the temperature you want. It may cost a wee bit more to use, but I think in the long run you will be a lot happier with it.

 

[finn]

I have a Mitsubishi in my house, primarily for the a/c, but also to back up the propane boiler.

I would be reluctant to recommend the mini for a working shop because of the limited filtration.

I'd go with a household type forced air furnace for a shop, and a conventional ducted air conditioning system. The hanging heaters common for shops blow dust everywhere, and I don't see a tiny mini split filter handling that well.

 

[justinjoyal]

I went a little large for the cooling aspect. Hot and Humid down here in the Summer, nice chilly and dry 70 in the shop in August.

If you want comfort and relatively dry air you dont want to oversize.

 

[thymer]

If you want comfort and relatively dry air you dont want to oversize.

As hot as it gets and with the high ceiling it doesn't short cycle at all. Any smaller and it wouldn't keep up

 

[nsula_country]

If the AC will not be set at a constant temp (think continuously during the cooling season) dehumidification will not occur. System must operate 24r/day to achieve this.

Oversizing for quick cool down in a shop environment may not be a bad idea.

For our shop... 40x60x17, 3/12 pitch, all steel, R3 radiant insulation... I'm going to start with a 5ton ducted HP. It will work it's *** off to cool that to 80 in the South. Heat will probably be OK. May need another 3-5 tons to properly cool and dehumidify. 18x24 climate controlled room will get a mini split.

CT

 

[dshop]

Raleigh, NC I have a 60x40 conditioned with a 3.5T heat pump.
Heat is not a problem, so I had the installer disable the heat strips.
We seldom get into the 30's, so heat is not really an issue.
the shop is totally spray foamed, floor to ceiling to floor, no gaps.

 

[Ohmthis]

For what you are telling us that you want, a conventional split is what I recommend. It will be able to raise the temp quicker from your "base" temp, it will have superior filtration to the minisplit, you can a more even distribution of air with out fans (but with high ceilings, fan may be recommended), you may (depending on area) have better access to techs that are familiar with your equipment, equipment costs for replacement/repair are lower, and it can be programmed to not run the backup in certain situations to save some $$$. I would shop around though as I believe you can get a better price on a conventional split. I also would entertain branches off of the trunk in your layout to better distribute the air. It can be hugged to the ceiling or roof line.

 

[dshop]

I have a 3.5 T heat pump for my 40x60 shop, open cell foam top to bottom.
On the install I had the tech disconnect the heat strips.
In my area of Raleigh, NC seldom see 20's 30's in the winter.
With the foam insulation I haven't seen 50* inside in 10 years now, no heat strips needed.