Solar Shed: Part 8: Installing the HVAC

This is the eighth post about my solar shed, and I can say that the shed has been working very nicely for me!

This is a companion discussion topic for the original entry at

(Comments from Blogger)

2016-07-03 by Ned Funnell

How will you get a data connection to your office? LTE? Microwave network to the house? Directional wifi antennae?

2016-07-04 by Russell Graves

I’ve got a few Mikrotik Lite2 (2.4ghz wifi) units doing the link between the house and office, though I may replace them with a 5ghz link at some point (when I actually get around to mounting the office unit outside instead of laying it on a shelf).

They’re not perfect right now (latency is a bit more erratic than I’d prefer), but they’re good enough for now. The link is “hundreds of feet,” and those radios are good for a lot further. It’s not like I set the office out on a desolate mountain top (though that would be quite tempting).

At some point, I’m going to be adding another internet connection to the property for redundancy, and that may run straight to the office (rural wifi on licensed bands).

Basically, my noise floor on 2.4 and 5.8 is “nearly zero” (-107 on 2.4, -109 on 5.8, measured from the shed AP), so I can get away with a lot. I plan on doing a property area network at some point with good signal strength everywhere so I can toss wireless soil moisture monitors and the like in my gardens and lawn.

2016-07-16 by Unknown

Query: Why did you do this step now? Wouldn’t it have made more sense to do it before all the insulation and wall building steps? Tighter seals and all that?

2016-07-17 by Russell Graves

Because I didn’t think it would be as difficult as it was.

I’ve never installed a through wall unit before.

2016-07-18 by Unknown

Keep it Up Russell, well done that Man.

Hindsight is an amazing phenomenon, I have yet to master…


2016-07-18 by Unknown

Thanks for answering>

2016-08-01 by Dave

Did the HVAC unit instructions specify angling it down for condensate drainage? You would think they would make the unit drain properly when installed level.

2016-08-01 by Russell Graves

Yes, they specified angling it down half a bubble or so.

2016-08-24 by ef

As it happens, I’m having this exact same unit delivered to my garage tomorrow. Unlike you, however, I’m not even sure I can build the square box, much less do the rest of the stuff. But is that going to stop me from trying? Nooooo. A few questions, if I might.
My walls are 7.5" thick, so my plan is to build the box out of 2"x8"s. That sound about right to you?
(I’m going to be expanding a smaller pre-existing opening that was used for a propane-stove vent.)
What tools, besides the drill, did you use to cut your opening? On hand, I’ve got a circular saw, a recip saw and a jig saw …
How did you build in the angle?
What kind/brand of foam did you use and do you just squirt it in once everything is in place?
Got any other hints and/or tips you can offer (besides get a pro to do it, ha ha)?
Thanks a bunch!
Oh – did you use a support brace outside in back?

2016-08-24 by Russell Graves

The 2x8s sound right. Be aware that the measurements in the manual do not include the tab width, so you’ll need to adjust for that.

I cut the opening with a reciprocating saw and the hole drill - that was it. Cut it small and enlarge it as you fit the square in it.

As far as the down bubble angle? Just play with it - it’s not built in. The cabinet fits slightly loose in the enclosure, so I had room to move it around a bit.

Foam? Great Stuff from my local hardware store. And, yeah, squirt it in, let it set up, trim it.

No support brace in the back.

Otherwise, any tips and suggestions I might have are in the post!

2016-08-24 by ef

Thanks. I’m as nervous and twitchy about doing this as a cat on a hot tin roof but I’m gonna give it a go. i mean what’s the worst that could happen :-)?

2016-08-25 by ef

Well, my a/c arrived … but with some pretty smushed fins on the rear of the unit. Here’s a pic: . I’m loath to send the thing back to Amazon, just because it’s so damned hot out and I need a/c. Do you have a sense of how critical those fins are and how crippled my machine might be? i googled and found you can straighten em out with either a fin comb or a butter knife, etc., but most of my bent ones are almost fused to their neighbors – ie, they’re bent beyond redemption. Sigh. what do you think?

2016-08-25 by ef

here’s another pic. . man, am i upset or what? i’m sure if i want to keep the thing, i can get amazon to refund me some dollars but i’ll do that only if’n the thing isn’t ruined.

2016-08-25 by Russell Graves

Wow, that’s pretty beat up. I’d return it and ask for a replacement.

2016-08-26 by ef

I spoke to Frigidaire and was told that if 20% to 25% of the fins were damaged beyond repair, the unit would still run fine. I bought the thing from amazon warehouse for 290. it was supposed to be in ‘very good’ condition. I wrote amazon about its actual condition and amazon said that if i wanted to keep it, they’d refund me 35% of the purchase price (or $100). My plan today is to hook it up and see how it blows. If it still seems to work well, I guess i’d keep me, for a new price of 190, though that could just make me pound wise and penny foolish in the longer run. Arggg!

2016-08-26 by Russell Graves

For $190, I’d take my risks with it if they say that it’s OK with damaged fins. All they affect is the heat rejection side of it, but if it’s designed to work with a bunch beat up, then it should be fine. As long as it’s blowing cold and hot (in cooling or heating mode), it’s fine.

Be aware that it will need to run for a few minutes before it turns the compressor on initially. Let it run for 10 minutes or so before you get concerned about a lack of compressor.

2016-08-29 by ef

Got it done two days ago and it works great, no problems at all. the only thing about the a/c i don’t like is that every time you turn it on, it starts up in econ mode. does yours do the same thing? would love it to start in cool / auto. btw / thanks for your help and encouragement and for all the pix showing me what to do. knowing i had to add 1/4" to the width measurement saved me hours of sweating and cussing, i am sure. bueno!

2016-08-29 by Russell Graves

Yes, mine starts in econ mode. I don’t mind, though you should run it for at least a few hours in “cool” every now and then to keep enough airflow that it doesn’t get funky.

2016-08-29 by ef

thanks. and thanks again.

2017-05-31 by Toby

Just wanted to say thanks for this series. I’m purchasing a very similar studio from Tuff Shed and will be following this tutorial pretty much exactly. I’m in Portland Oregon and will be on-grid so I’m considering just using 1" styrofoam, but I haven’t settled on that one yet. The exacting pointers here were great, and it’s so cool to see where you had to step back a bit as things didn’t go to plan.

Side note I liked your super-short explanation of why heat-pumps are more efficient than simple electrical resistance generators.

2017-05-31 by Russell Graves

Awesome! I’d love to see pictures of the process, and would be happy to share them if you have no objections - my contact form is over in the right column.

If you’re grid tied, it gets so much easier. You might consider getting a mini-split unit installed as well - they’re a large heat pump with an outdoor unit and small indoor wall unit, but my unit works just fine, and in the winter it would be fine except for the grey days. I have a post coming up this weekend about winter heating, but it won’t be particularly relevant to you, since it doesn’t get nearly as cold in Portland, and you’ll have grid power to brute force through.

Going with the foam insulation and sealing up the enclosure would be a good idea - my foam shell is as much a wind block as anything else, but there’s definitely no need for 2" foam if you’re not going for maximum insulation.

I definitely enjoy my plywood interior - being able to mount things anywhere is awesome.