Many of them are user-installable, if you are handy.
Look for one that is “pre-charged.”
Those two windows are quite large. Do they get direct sun? If so, try an experiment where you tape aluminum foil over them. That will reflect almost all the light energy back outside rather than warming up your room. If the outside walls get direct sunlight, you could also look into ways of shading those walls. If the walls stay cooler, less heat will get into your office. You could do an experiment where you put up some tarps or something outside to keep the walls shaded. With tricks like these, you may be able to keep enough heat out of the office that a fan alone is comfortable enough.
It’s modest (typically 50-60% in Portland). But a swamp cooler isn’t a great option. There’s just the one door so air flow is a challenge. And end-of-day cooling doesn’t help, since I’ve left the office long before sunset.
Thanks, I’ll check into them. $700 is more than I was looking to spend, and the heater is pretty cheap for this size space despite its relative inefficiency. I’m also guessing the $700 models aren’t the most efficient, so I probably lose some of the potential gain over resistance heating. But it’s definitely worth checking out.
If you do go with a portable unit, get the one with both an exterior intake and exhaust.
Many just have the exhaust to the outside, and draw air in from the room.
This means that you are sucking air from outside into your room, which can drastically lower the cooling efficiency.
The windows are both north-facing (along with the door), so no direct sunlight. Unfortunately, my office is in the back corner of my yard, so I’m limited in what I can do to shade the sun-facing walls.
I would agree that a minisplit is probably the best option for a situation like this, but they are expensive and while some can be self-intalled, if you’re not fairly handy it can be a bit of a challenge, professional installation will add to the cost.
I think window units are a non-starter, you don’t really want to mess with altering those large windows as that’s going to add a lot of expense either way you do it. You could cut and frame a smart-sized hole in the wall and vent a portable AC hose out that as probably the best option below $500–but good portables are going to run $300-400 these days. By good I mean you need to find a dual hose model, which have become rarer, I generally am not a fan of the single hose models and think they have a number of problems.
Cutting out and installing an insulated wall sleeve and mounting a through-wall AC would probably cost more than the portable AC option through wall ACs tend to be built for more of a higher market than window ACs, which are often intended to be used for a few months out of the year, a lot of through wall units are designed for apartment type construction, so most of the time you’re looking at $400+ for a through wall unit, and cutting and framing a hole for a sleeve is going to be a bigger job than the relatively small hole you could cut for a portable AC vent hose to attach.
You know, for what it is, and how often you need to use it, I would be tempted to go the lazy route.
Get an icemaker, and then put some fans on a cooler.
Fill the cooler with ice on the hot days, bring it into your office, and turn on the fans.
You can get an ice maker that will make enough ice to fill a cooler in a day for under $200, and you can cheap out on the cooler as much as you want, get a styrofoam cooler for $30 or so.
If you need to cool your office a lot, then maybe a more permanent solution is preferred, but if it’s really just a couple dozen days, this would be a cheap solution that doesn’t require any cutting holes in walls.
I skimmed through these posts, didn’t read them all word-for-word, but I was struck by one thing: they largely seemed to be opinion, posters spitballing possibilities.
I moved into a Baltimore rowhouse in the 90’s, long and narrow, with no way to easily move conditioned air around. Began by cutting through brick walls, front and back, and installing cheapo window units, all I could afford, downstairs. I did not install the ACs flush with the inside wall, but set them back, in an insulated plywood panel, so the side vents were clear of the outside wall. Later, when I had rehabbed the top floor, I did the same with the bedrooms, Four inexpensive window units, all doing a good job for me.
Some years later, I bought an adjoining lot and doubled the size of my house, and framed in two openings, one up and one down, for two more window units.
These solutions were effective and CHEAP! The key was an AC installation that put the unit toward the exterior face of the wall.
But…I will give you that this was a noisy solution. Wndowshakers are inherently noisy.
In the years following, I had experience with two portable units, and I found one to be bearable, and one to be horrible. If you elect to try a portable, try to test it for noise first. The big home improvement stores may take a noisy unit back.
If noise is not a huge prob, try a small window thru-the-wall, tons cheaper than a portable. When a hot day is coming up, let it run all night, and shut it down when you’re in the space.
Cost no object? Do they make a really tiny split system? Do you like to nap in your home office? I wish I could have afforded these things.
Don’t fear a TTW installation of a window unit.
Dan
I’m also in Portland and have gone around and around the last few years with A/C solutions for my tiny house. I’m seriously considering having a TTW unit framed in because my shed house has 11 ft ceilings in the middle and I sleep in a loft and when we do get a heatwave it’s murderous because we’re wimpy little cloud dwellers who can’t handle the heat lol. I do have a shed that needs to be at a more or less constant temperature and I use a portable unit out there–it’s a 14x9 space with no windows and the portable does both heating and cooling, does a great job. In my house, though, not so much. A mini split would be great but it’s a bit more money than I want to spend at the moment. Think I need to do a bit of research!
What kind of wall construction do you have there? Is it just siding nailed to studs?
Something that is worth noting is in TTW units it’s not uncommon to have combination heat / cool in the same unit, so TTW units are going to be around $450 minimum (I did some research in the last few hours), and you likely will need to buy an insulated sleeve to fit it right in the hole you make, which those seem to add at least $50 to it. On the flipside they are pretty darn powerful so you’ll have really nice climate control.
While you can get a wall unit for as little as $180, and set it up in a ghetto / jerry-rigged way to work in a wall void, as a landlord I have a natural aversion to jerry-rigging on this kind of thing. I’ve just seen too many things go too wrong to be comfortable with it. Putting an AC through a wall is a “solved” problem, with TTW units, I’d be loathe to try to best what the people making ACs have come up with a home hack.
One thibg to consider is unit longitivity and resale. I feel like if you are considering selling in the next 5-10 years, a separate structure with a mini-split seems much more like “more house” than a shed with a window unit. But i come from the South where climate control is taken very seriously.
I also live in the PNW and was going to suggest the quick, cheap route which is filling a five-gallon bucket with ice and setting a box fan on it.
At one point in my career, I worked in a very old brick military building that was not equipped with air-conditioning. We would fill buckets with ice, stick box fans on top of the buckets, and let 'em rip. It worked very well. Since your space is small, I think one bucket would do the trick, really.
I think this is a good addition to the thread.
Tagging along on that idea … if a properly sized mini-split:
- Could cool the office space properly (meaning: it would not be oversized, causing it to ‘short cycle’ and to fail to dehumidify effectively), and
- Could heat and cool the entire garage if a potential buyer wanted to knock down any partition wall and have a single, larger, open garage space
Then that might be a longer-term consideration with its own ROI.
Also, if a more conditioned (if not fully conditioned) garage space means anything to you, the larger BTU mini-split that I’m talking about here might do a good job with the minimal installation of:
Good luck with whatever you choose.
Mini-splits must be the most expensive way to do it. There are ACs similar to mini-split systems designed to hang on a window opening, or any wall opening really. I forget what these are called, but they are like a window AC except the inside and outside portions hang below the window with just the piping passing through the window opening. These can be used as through the wall ACs also.
Here’s a one I found by on Amazon by searching on U-shaped window AC. In the details it says it can be mounted in walls for 4.5" to 13.75" thick. I don’t know how small they make them though, you are cooling a tiny space.
A mini-split is definitely the most expensive (and complex to install) option of the “viable” ones. But he also is facing a bit of an annoying situation, I’ve made use of all of the AC systems discussed in this thread at one time or another in various properties / weird situations I’ve had. If this office had a window that could open, a cheapo window AC would be the clear best answer. But instead, it has fairly large windows not made to be open, so modifying or replacing those is going to be fairly expensive, and if you don’t know what you’re doing, you have to call in a window guy to do it, which is going to be probably more expensive than even a minisplit because full window reconfiguration/replacements aren’t super cheap.
A portable AC unit while it doesn’t need a full window, still needs a way to vent outside, they are also the “least performant” of the AC options, they are also usually the loudest because the entire mechanism of the unit sits in the room with you, and it also takes up the most interior floor space.
A through the wall unit is a better option than a portable in most respects, other than it’s going to cost probably $150-200 more, and will require cutting out and framing a larger hole in the wall than will the portable unit’s vent.
I’ve actually used the “cooler of ice and a box fan” solution mentioned as well–it does absolutely work.
They actually make coolers specifically designed for cooling with ice, like this:
And there are many DIY versions of similar things.
One problem with home use would be where to get the ice. I would guess that regularly freezing enough water to get you through the summer would put a lot of extra stress on your home freezer. Perhaps one option would be to get a dedicated freezer for the garage and put a bunch of 1-gallon jugs of water in it. You could also use the freezer for extra food storage, so that would be a year-round benefit.
Follow-up thought:
Code in your area may not permit openings between a garage and a living or office space (fumes or fire from automobiles).
So … be circumspect if this route is of interest to you. Check codes (presuming your arrangement meets them today 
)
Yeah, and for a whole lot cheaper.
The most basic is just a styrofoam cooler, with a couple holes cut out to put in a computer fan or two to blow in, and a hole to put a PVC pipe so you can can direct the outflow in the direction you want.
They make icemakers that would do a good job for it, but not many cheap ones that have enough capacity to just run and scoop all the ice you need at once, they would need to be run and transferred fairly regularly.
I did see a youtube DIY where he got a deep freezer and installed a couple of icemakers into that. It was actually a pretty simple process. If I still went camping as much as I used to, it’s something I would strongly consider just for that.
Or you can once again stick with the theme of doing the lazy method*, and just put a bunch of jugs or bottles of water in it, and transfer those. If the OP already has a deep freezer, that would make this whole process pretty easy.
The full kit out will not be saving a whole lot of money over an AC unit, but on the other hand, you get a deep freezer for all you deep freezer needs, and all the ice you need for parties and outings, rather than just an AC unit that is used a couple weeks a year.
*I don’t disparage lazy methods. To paraphrase Heinlen, almost all human progress was accomplished by lazy people trying to find an easier way to do something.
Energy wise I think the use of ice is also less efficient. In a meta sense using a freezer to freeze water into ice and then using an electric fan to make the ice melt faster (and thus cool the room more quickly per unit of time) is kind of the same thing as running an AC, but with a decent bit more inefficiency. Where it’s a good solution is situations where you aren’t needing it very often or for very long. If it’s running for say, 3 months a year the ice solution is fairly undesirable. If it’s really like 10-12 days a year, for 8 hours a day…probably worth considering.