sizing question

[edl]

We have enclosed a portion of our warehouse into 2 roughly 40x40 sections - 3 of the walls are outer walls (block...no insulation) so 2 40' sections and an 80' section and the wall we built to close it off is 2x6 batt insulated that is 80'- ceiling height is 14' - ceiling is metal and is spray foam insulated...maybe an inch or 2 in thickness

we built another stick frame wall as the divider, with an 8'x7' roll up door separating the 2 spaces

I am trying to get a sense for what size a/c i will need and whether a minisplit diy can work in this set up?

the thought is one unit that can do both sections at once and have each be a separate zone? - or would it be more economical to run each as its own zone with own closed loop system?

(i realize many will want to say insulate the block and insulate the ceiling more...feel free...but i know)

thanks!

 

[dcg9381]

"What size" is a HVAC load calculation question - there are tools to answer that.
You're also listing geography as "SE" - so needs may vary by state a bit..

Arm chair advice:
For me, running 2 x 2 ton systems was less expensive than trying to do a larger multi-head system. Also easier to install and gives me the ability to run a single unit if I want. The multi-head units (as I understand it) are less efficient.

It sounds like walls are bat, inside of concrete block and 2" foam up top - that should be enough, depending on HVAC size and geography. Also note, where you spend money is depending on how you use the shop and how often you use it. IE - I wouldn't spend $10k to get R24 on a shop that I just use weekends, I'd probably just increase the HVAC size a bit.

 

[edl]

Thanks dcg9381 - more specifically, NE FL near the GA border

looking at an hvac calculator it looks like 4 to 5 tons

on your 2 x 2 ton...you talk about multiple "heads" so yours was a mini-split system? - if so, understood

if you were to do traditional a/c, would you still opt for 2 x 2 ton - or in the world of traditional a/c are you better off with one 5 ton unit v 2 x 2.5 ton units?

 

[edl]

the shop is not a production shop - so used 30% of the time...definitely think I would err on a bit more a/c than starting to spend the money to buy foam board to glue to all the block walls...so great point there!

 

[dcg9381]

on your 2 x 2 ton...you talk about multiple "heads" so yours was a mini-split system? - if so, understood

Yes, mini-split. Sorry, didn't understand you were considering conventional or zoning...I can't speak to that other than to say that you need to be more careful with sizing than you are with a mini-split - I'll let an HVAC guy answer.

I have two mini-splits (side by side) each unit is 2 tons each. I'm in Texas, 2400 sqft, 16 foot eves, 3.5" foam insulation, but I've got 3 big doors.. I was comfortable installing mini-splits myself.

 

[edl]

Thanks DCG9381

No worries - I am considering a mini split and a conventional

I am trying to figure out if one exceeds over another in this application - if each were a standalone zone, 1600 sft - 3200 total

this is all interior...so the stick wall we built as the fourth wall for each section has a people door and garage door, but it opens on to warehouse and not outdoors...having said that, the entire warehouse is not climate controlled and is pretty much like the outdoors.......

 

[edl]

any other thoughts?

 

[dcg9381]

I am trying to figure out if one exceeds over another in this application

Price point? Mini-splits are a bit more flexible for over cooling. Might allow to only selectively cool what you need when.

The big advantage I see of traditional ducted AC is that the units have better parts replacement and IMHO, are built to last longer... Perhaps better filtration options too.