New building: have builder put in mini splits or wait?

[Tanis]

Just joined after reading for a bit. I'm having a 2,500 sq ft pole shed with 16 ft ceilings built for a workshop so about 40k cubic feet of air to deal with. It will be used for cars, RV, as well as some hobby woodworking but nothing commercial. The building is in rural Wisconsin. R50 with vapor barrier up top and R19 in the walls as well as the entire concrete floor insulated.

The builder might think I am fussy but I asked for no LP, only electric for heat (cooling is only a secondary concern). The initial proposal was for overhead heaters (four large Marley Muh-Pro series) running 36 amps each (it will have a 200 amp panel).

I asked for quotes on mini-splits and the his regular subs came back with quotes from 15k to 35k. The option from the builder I might go with will result in four 18k BTU indoor high-wall units and three 36k BTU outdoor units for about 20k (from Byrant). The size of the system seems overkill to me since it isn't a building I'll be living in and I will probably avoid it in temperature extremes anyway.

Cost is not my main concern. My question here is:

am I better off just putting in some minimal system to maintain temp during winter (i.e., the Marley units) and get quotes from contractors once the building is done?​

I like the builder and I like the idea of having subs he trusts do the work. I am sure I want splits I just don't know if I should go with the builder's proposal or wait and see how I use the building and find someone later to install. I imagine install is easier before everything is finished.

So any thoughts on my question? Am I over-thinking this? Under-thinking?

Let me add that I am in a rural area and some of the companies that advertise splits systems told me their don't service my area.

 

[pcmeiners]

Did a search on minisplit for you, take a couple hours to read the results. Many purchase minisplits with low prices, with little reseach and pay for it in the decade or more to come.

I would say do it during the build before it is insulated and sheet-rocked), 220v, #10 (minimum) lines would need to be run to the outside, along with a 4 wire control cable run to the outside.
I have (2) 12k Fujitsu (33 Seer, 12.8 HSPF, low temp units in my 1180 Squft garage, R15 walls R19 ceiling, 2 large roll down doors, 2 windows, 10 ft ceiling.
I only use (1) of the 12k units, other is for redundancy, I have never used the second unit. The 12k could easily heat my garage if it was twice the size, it has been down to 7 degrees and the unit cycles on/off, not strained at all. The units I have are more expensive and more efficient than the average minisplit. Due to your garage size, (2) 15 to 18k units should do, PA. temperatures are close to your home state ( bet (2) 12k would do it) . My 12k unit raises my electric bill about $10-15/month at $.11/kw

"four large Marley Muh-Pro series) running 36 amps each" hope these units would be delivered with their own nuclear generating plant and control rods.

Minisplits are between 2 and 4 times more efficent ( on average) than electric resistance heaters. The low temp Fujitsu units linked below are 3.5-4 times as efficent.

Each minisplit take a day to install, if the outside unit slab and electric is in place (for a garage) and contractors will not install a high efficency unit unless you demand it, as it takes away their very high profit margin . I have installed (5) low temp minispilts between my garage and home, totaling about $13500+ tax, plus about $2000 for every tool I could every use in installs/repairs as a home owner.

Search results.....

Search results for query: minisplit

www.garagejournal.com

Fujitsu units...

https://www.goodlifehvac.ca/images/Fujitsu_LZ_Series.pdf

 

[Tanis]

Thanks for the detailed reply @pcmeiners. I know long-term I want the splits I was mainly concerned it would be better to wait and see the usage for the building before committing to a particularly sized system. Lots to think about I know.

 

[Toomanytools?]

You could pre-wire for future install, 4/18K units sounds like 1 too many but I'm comparing that to my shop. The problem with doing minimal to heat a space is the unit(s) is always trying to get there ( heat the place) but just can't. You end up not having a very efficient system. The other thought is waiting a year or so the price is sure to go up.

 

[pcmeiners]

With your insulation values your building will not use a great deal of energy.

"I might go with will result in four 18k BTU indoor high-wall units and three 36k BTU outdoor units for about 20k (from Byrant)."

Unless you plan on leaving your garage doors open while you are in it, the above is over board. Make sure you get efficient units. Also Wisconson can get pretty cold at times, you would benefit from low temp minisplits.

 

[Montauket]

I would do the mini splits now if you can swing it .