Detached Garage - Ductless MiniSplit

[kenmbz]

I put an 18K head on a 24K usable mini-split for the garage.
I have a smaller head for supplemental, for in the house.

Mine is a 22 seer, trying to keep running costs down, more money up front though.

I still need to seal the garage doors better (2 standard wxh) but the 18K keeps the 900 sq ft <8foot high - cool/warm. Has some difficulty with heat when less than 10F, but we don't get a lot of that here.
There are units with better low outside temp heat capability, but more $. If temp stays below 15 for long periods, will be worth the extra.

 

[Sigarms]

You really need to do the load calculations.

Stand next to the wall of the structure, extend your arms out to the wall with your thumbs touching each other (making like a field goal post).

Walk backwards from the structure keeping your arms fully extended with thumbs touching.

Count the steps it takes to fit the structure "between" your hands with arms still extended.
#1 - Steps X 3

#2 - multiply interior ceiling height and multiply step #1

#3 - Take total length of building and multiply step #2

#4 Take total from step #3 and multiply by 400 (cfm per ton).

#5 Take the total of #4 and divide by 12,000 (btu/h per ton).

Give or take, you should be in the ballpark tonnage wise (this is for a block load only mind you).

That or spend the money on Wrightsoft, but more importantly, learn how to use it correctly. Garbage in, Garbage out. Other option would pay someone to run one (although good HVAC contractors should do a load on every job, very seldom do they).

 

[Pettrix]

The mini was installed but the rubber bushings it sits on pits a slight tilt to the unit. I measured and it's about a 1/8 - 1/4 inch tilt. The AC guy said it's fine but just wondering if having a slight tilt will cause any issues?

 

[bdhsfz6]

I'm not an expert but I would level it. The crew that installed mine took great care make sure it was level. They used washers for shims under the rubber feet to get it level.

Here's some info:

The Importance of Keeping Your HVAC System Level

If you want to ensure your air conditioning unit provides many long years of comfort, make sure it’s kept level. Here’s why it's a good idea.

www.pioneerminisplit.com

 

[2manyrocks]

^ Mini split refrigerant lines rely on flare connections. All this is just my personal opinion, but I made sure my mini splits were installed to reduce the chance of vibrations loosing the flare connections so the refrigerant doesn't leak out. With your compressor visibly tilted like that, you'd want to be careful about not loosening, kinking or damaging the lines while trying to level the compressor. You may want to check whether the linesets are maybe a little too long causing the unit to be tilted and/or try to determine why else it is tilted (something related to the mounting brackets?) and how to correct this without causing a leak.

 

[Pettrix]

^ Mini split refrigerant lines rely on flare connections. All this is just my personal opinion, but I made sure my mini splits were installed to reduce the chance of vibrations loosing the flare connections so the refrigerant doesn't leak out. With your compressor visibly tilted like that, you'd want to be careful about not loosening, kinking or damaging the lines while trying to level the compressor. You may want to check whether the linesets are maybe a little too long causing the unit to be tilted and/or try to determine why else it is tilted (something related to the mounting brackets?) and how to correct this without causing a leak.

I double checked. The bracket is level and the lineset is not in the way. It's the rubber bushings and attachments points on the condenser that make it tilt.

I'll see if I can shim it level

 

[ponytug]

It is ok if the concrete pad slopes, but not the actual unit itself. I think that you really, really want it level for the best compressor lifetimes.

I would shim the unit with something that won't move or compress, or buy different vibration isolators.

All the best,

Peter

 

[Pettrix]

I got some metal U-shape shims at HF and got the compressor level. It's now less than 1/8th of an inch slope which is fine. Being it has rubber mounts, it changes by 1/8th of an inch with temperature, movement, etc.

 

[CH4Ohio]

Span is 48 feet.

Beam is 21" tall x 6.50" wide with a thickness of 0.45 at the top and bottom plates and a web thickness of 0.35. Yield strength of 36,000 psi. The beams weighed 2,110 pounds per beam. Price was about the same at $2,200 per beam.

Steel plates were embedded into the wet concrete during the wall pour. The beams rest on these steel plates and were welded down to the steel plates.
View attachment 873926View attachment 873928

Why did you use these long beams instead of relatively short trusses running front-to-back? You'd still have the same clear span / open floorspace. Just trying to understand the construction philosophy. Thanks.