Shop AC

[Drahthaar117]

What system would be better to AC shop 40x60 14 foot eaves mini splits or conventional package unit.

 

[fat rat]

Conventional is what I used 5 ton for 2000 square foot with 18’ foot ceiling, thats a lot of volume for a mini split.

 

[Boat 405]

Two 2.5 ton mini splits.

 

[dezertrider]

Instead of guessing why not do a heat load calculation? WHat R value is the insulation and what temperature do you want on the hottest day

 

[Racey]

What system would be better to AC shop 40x60 14 foot eaves mini splits or conventional package unit.

Package units used to be nice and cost effective, i just priced 6 tons for my shop (3 phase) Rooftop package, They have literally more than doubled in price since covid. It's actually cheaper for me to put 3 individual 2 ton minis, and i get a 12 year warranty on the minis, Package unit is 1 year. Not to mention redundancy and no ducting.

The only downside to the mini is the filters in a shop environment, you will have to do some more periodic coil cleaning depending on what type of work you do in the shop.

Each circumstance is different. I went with the minis.

Single phase package units might be cheaper than 3 phase.

 

[Drahthaar117]

I was asking because I didn’t know if a mini split would move enough air volume compared to a package unit.

 

[dezertrider]

I was asking because I didn’t know if a mini split would move enough air volume compared to a package unit.

They won’t for that size shop and Racey has a point. The filtration on them sucks and they are prone to issues with dirty environments.

 

[RiverDave]

I am far from an ac expert and I hope one chimes in..

Something I have noticed is when Carey installed my mini splits he put them halfway up the wall. My garage is not insulated and even though my units are old as dirt and tired they still keep it as cold or colder than my house without any issues.

I goto new home Construction on the regular and they mount them up way high in the rv garages and it doesn’t seem to matter what they set them too or how long you leave them on it never gets “cold” just varying degrees of warm.

I have climbed a ladder in my garage before and noticed a radical temperature change when you get up near the ceiling.

Have 2 theories on this.

1. The mini splits when mounted high are sucking hot ass air and then with the vector on temp change they are putting out not as cool of air.

2. They just don’t have the horsepower to move the air from the ceiling down to where the people are located..

Either way interested in hearing others opinions.. but if I went mini splits I’d mount them halfway up, not all the way up.

RD

 

[azsunfun]

Package units used to be nice and cost effective, i just priced 6 tons for my shop (3 phase) Rooftop package, They have literally more than doubled in price since covid. It's actually cheaper for me to put 3 individual 2 ton minis, and i get a 12 year warranty on the minis, Package unit is 1 year. Not to mention redundancy and no ducting.

The only downside to the mini is the filters in a shop environment, you will have to do some more periodic coil cleaning depending on what type of work you do in the shop.

Each circumstance is different. I went with the minis.

Single phase package units might be cheaper than 3 phase.

Why not balance the load to two single phase? Understand the 3 phase but you would get warranty instead of commercial unit warranty. And not everyone lucky enough to have 3 phase. There is one neighborhood in east/ central tucson has residential 3 phase.

 

[dezertrider]

I am far from an ac expert and I hope one chimes in..

Something I have noticed is when Carey installed my mini splits he put them halfway up the wall. My garage is not insulated and even though my units are old as dirt and tired they still keep it as cold or colder than my house without any issues.

I goto new home Construction on the regular and they mount them up way high in the rv garages and it doesn’t seem to matter what they set them too or how long you leave them on it never gets “cold” just varying degrees of warm.

I have climbed a ladder in my garage before and noticed a radical temperature change when you get up near the ceiling.

Have 2 theories on this.

1. The mini splits when mounted high are sucking hot ass air and then with the vector on temp change they are putting out not as cool of air.

2. They just don’t have the horsepower to move the air from the ceiling down to where the people are located..

Either way interested in hearing others opinions.. but if I went mini splits I’d mount them halfway up, not all the way up.

RD

They should not be mounted as high as they do. First off cleaning the air filter requires a tall ass ladder, and they need regular cleaning. Who wants to store a 12-14 foot A-frame ladder just for cleaning them? Second reason is if you mount them on the top and you have a 24’ wide, 16’ tall, 80’ long RV garage you need to cool 30,720 square feet of space. If you mount them at 8 feet you only need to cool 15,360 square feet. That’s ½ as much. The hot air will always rise above the cooling due to thermal stratification. Leave the hot ass air in the ceiling and only cool the space the people are in



I think they are mounting them up so high that a large RV wont block the throw of air to the other side on the garage. I think a ducted split system would work better. It will give you better circulation if you have the supply duct at one end and the return at another. It doesn’t look as clean as a mini split but would work better and last 15 years instead of 5.

 

[Riverbound]

doesn’t look like the structure will support a pack unit on roof.

i’ve done some similar projects and suspended split systems with ducting.

i would stay away from mini splits for sure. traditional will work better.

 

[shan]

I am far from an ac expert and I hope one chimes in..

Something I have noticed is when Carey installed my mini splits he put them halfway up the wall. My garage is not insulated and even though my units are old as dirt and tired they still keep it as cold or colder than my house without any issues.

I goto new home Construction on the regular and they mount them up way high in the rv garages and it doesn’t seem to matter what they set them too or how long you leave them on it never gets “cold” just varying degrees of warm.

I have climbed a ladder in my garage before and noticed a radical temperature change when you get up near the ceiling.

Have 2 theories on this.

1. The mini splits when mounted high are sucking hot ass air and then with the vector on temp change they are putting out not as cool of air.

2. They just don’t have the horsepower to move the air from the ceiling down to where the people are located..

Either way interested in hearing others opinions.. but if I went mini splits I’d mount them halfway up, not all the way up.

RD

I mounted mine according to the instructions, IIRC ~3-4" from the ceiling and they are fine. My shop is insulated and I had load calcs done for the space to properly size them. My $.02.

 

[Riverbound]

I am far from an ac expert and I hope one chimes in..

Something I have noticed is when Carey installed my mini splits he put them halfway up the wall. My garage is not insulated and even though my units are old as dirt and tired they still keep it as cold or colder than my house without any issues.

I goto new home Construction on the regular and they mount them up way high in the rv garages and it doesn’t seem to matter what they set them too or how long you leave them on it never gets “cold” just varying degrees of warm.

I have climbed a ladder in my garage before and noticed a radical temperature change when you get up near the ceiling.

Have 2 theories on this.

1. The mini splits when mounted high are sucking hot ass air and then with the vector on temp change they are putting out not as cool of air.

2. They just don’t have the horsepower to move the air from the ceiling down to where the people are located..

Either way interested in hearing others opinions.. but if I went mini splits I’d mount them halfway up, not all the way up.

RD

you’re a basically correct on 1 and 2. there are some high ceiling air handlers that will work better. but the way your garage is set up is how i would do mine.

 

[TBulger]

Don’t forget heat rises, so cold air comes down and hot air goes up.

 

[EPL]

Mini splits work great !

 

[Racey]

Why not balance the load to two single phase? Understand the 3 phase but you would get warranty instead of commercial unit warranty. And not everyone lucky enough to have 3 phase. There is one neighborhood in east/ central tucson has residential 3 phase.

Because I don't want to cut another set of holes in the roof, navigate around the fire sprinklers, and breach the drop ceiling in another spot. Another roof curb and more issues with dealing with water. The minis i can hang on the parapit wall of the adjoining building (common wall, they are about 8' higher)in the shade, not mount on the roof.

Not to mention dealing with a crane etc. Believe me i weighed all the options including 3 single phase packages before deciding.

Im sandwiched between two building so my R value is pretty good

 

[rrrr]

I've been planning the installation of a standard split system in my shop. It's similar to the OP's building. The building has good insulation, and it'll require a four ton unit to maintain a 76° temperature in the work area on a 100° day.

I will size the ductwork and have someone fabricate it, and do all of the required labor with the help of a couple of friends. I'll probably hang the duct 11' from the floor.

 

[D19]

We have 50' x 50', 12' ceilings. 5 ton. Stays 72 all summer long at the river with ease. Takes about 25-30 minutes to cool back down after opening the door to back boat in/out.

 

[petie6464]

Whatever Havasu builders do you can guarantee its the cheapest and quite possibly completely incorrect.

A/C with the discharge air up high in a garage/shop... Can anyone really be that ignorant? Yes.