I am looking to build a 30'x50' shop with 14' walls in North DFW. It'll be insulated with 2" closed cell on roof with 3" batt on walls.

There will be a bathroom/mud room (8'x10') and an office (10'x10') that will need to be conditioned as well.

One 12'x12' roll up door and one 8'x8'.

I would like to heat and cool the space.

I currently have a much smaller shop with similar insulation and an 18,000 btu mini split does a great job. I am wondering if a multizone mini split would be better or if a central heat and air unit would better serve the larger shop.

I would be concerned a mini split isn't going to push the volume of air you'd need to condition that large a space.

My experience: Mini Splits are great after the fact or for one room. Cheap one's are disposable, 2-5 years. By cheap, I mean a facebook marketplace importer crossed the border with a trailer full of units. These are fantastic because the power hookup is outside. I don't believe that's kosher on units sold in the US.

If you have the ability to have a real system, whether it be a traditional split like your house or a package units. These are much longer lasting, have much better filtration, and do much better for a multi room environment.

If you have a true multi-zone mini split (3 zones with one condenser), that might work. Assuming the overall duty is like 3-4 tons.

I have seen some that offer like a 2-1-1 split (24k, 12k, 12k) duty, so you could have 3 evaps inside and one (1) condenser outside. That might run cheaper ($3k-$4k, last I looked pre-tariff) than a whole system, but would have to honestly compare apples-to-apples.

The advantage of a mini split is they are typically much higher in SEER and/or efficiency vs. central air system. A 'cheap' central unit may only be 13 (or 15, I thought the minimum was raised recently), so not exactly on similar footing.

But I could see installation being a little easier with a mini-split if the rooms are all together in one spot vs. spread out.

~egon

I did a project that was 40x40 with 14 ft ceilings. Spray foamed the walls and ceiling.
Had one separate utility room/bath and rest open space. The air handler/ return air sits on top of the utility room and feeds that one room with a small duct and then the rest is exposed metal duct for the large open area.

JP nailed it

If you have rooms of at least 150-250 square feet, then mini-split would be a stronger contender here

Mini split the office/living/bath, window unit the shop

JP76 said:

---

I did a project that was 40x40 with 14 ft ceilings. Spray foamed the walls and ceiling.
Had one separate utility room/bath and rest open space. The air handler/ return air sits on top of the utility room and feeds that one room with a small duct and then the rest is exposed metal duct for the large open area.

---

This has been my plan. But I Saw some people on a group I follow recommend going mini split, got me thinking.

The simplicity of the duct runs with this set up makes this option seem the best route though.

Depends on the mino-split.

We just put a 2.5ton unit in my wife's bakery and good Lord, that thing is tremendous!

The problem with a mini split is once you start going multiple zones, the cost escalates to what a standard hvac system would cost and sometimes even higher if you are using a name brand . I like mini splits for efficiency but they work best usually for single rooms or smaller areas. Are you doing insulated garage doors on the shop ? If not keep in mind you may need more cooling if they face west from thermal transfer.

Is it a single zone or multi ?

JP76 said:

---

Is it a single zone or multi ?

---

Single zone for us.