Experimenting with portable AC unit

Van Living Forum

Help Support Van Living Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

gkb2016

Well-known member
Joined
May 8, 2016
Messages
65
Reaction score
17
I bought a Hisense 5000 BTU portable air conditioner at Lowes.

My current setup isn’t optimal, but I have some hope this could work somewhat well. At least well enough to have a few cool hours every other afternoon or maybe every afternoon if I don’t feel like being around people. Mornings I usually spend at places like Panera, Starbucks etc. My Maxx Air fan is good enough at night.

300w of solar and 400ah of batteries.

Right now I don’t have window shades except a windshield shade, so sun is definitely heating the vehicle pretty fast once the compressor turns off. I have ordered some of these to see for all my windows to see how they much they mitigate the heat. Except the very back windows, because I couldn’t find any covers that fit the 2016 Transit Connect Titanium XLT. Found windshield, front side, and sliding door side covers but nothing for the very rear. Planning on cutting the cheaply windshield cover I got from Walmart for the backs or maybe Reflectix.

My AC exhaust is also going out the window, and hot air is able to get in because there isn’t a proper seal, there are some gaps.

Wondering if there is something I can buy, like a gasket or something, that would accommodate the exhaust pipe / adjustable window adapter to create a stronger seal.

If this works well enough, may cut a hole in the roof for exhaust if I can think of a way to keep the rain out, probably some sort of sliding cover from the outside.

Bolded to highlight the main point of my post lol.

Other ideas of course are insulating the exhaust pipe, insulating the van (really don’t wanna do this one because I’m already living in it), and separating the cab. Kinda hard with my setup but have been trying to think of ways this could be done.
 

Attachments

  • 94EFC8C1-46A8-4BFE-840F-980EB325B1F1.jpeg
    94EFC8C1-46A8-4BFE-840F-980EB325B1F1.jpeg
    156.6 KB · Views: 22
Last edited:
Oh yeah, haven’t used the Killowat on it yet but input wattage is stated as 750w.

Hoping to figure out a setup to keep the compressor on for 30 mins every hour at most in full sun or 15 min in cloudy conditions, which should mean only a slight net draw on the battery (that would be made up in the mornings when I’m inside anyways).
 
Use 1” thick foam insulation and duct tape the exhaust to a hole in the insulation. Roughly cut the insulation to fit where the glass is open and roll the window up till it seals. Also you can use a heavy plastic garbage bag and tape it around the opening and fill it with spray insulation foam, allowing it to expand slightly through the window opening. Let it set a couple days to harden or allow some air to get inside the bag or try a pillow case possibly which could get messy. Clean up with spray Brake Cleaner. After it has hardened cut the hole and seal with duct tape. You can combine the two by roughly cutting the foam then covering all mating surfaces with plastic and spray Window and Door foam insulation around the board and let it set up. I will not be held responsible for any mess you make as it can be a messy process till you get the hang of it.
 
Thanks for the idea above.

I guess I should have put the disclaimer, since this is a temporary setup it needs to be able to be taken down and put back up easily.

If the electricity usage is reasonable enough with a temporary setup, might cut another hole in the roof for the exhaust … til then not wanting to make any permanent or semipermanent mods.

The part about using a foam insert sounds like it might work though, if I can cut some foam to line up with the window.
 
Foam is super easy to cut, bread knife, soldering gun with blade tip, Harbor Freight hot knife set on low (they burn up on high as cutting foam doesn’t dissipate enough of the heat) or simple home made hot wire cutter as seen on YouTube.
 
Noticing the inside roof on your picture is bare metal. All the heat is getting in where there is bare metal. On my astrovan I have 3 inches of rtech foam insulation on my roof. Also the sides of my van has another 1 inch of foam. I also noticed your 12 volt fridge, if the fridge exhaust isn't vented outside thats more heat going in your van. I measure the air coming out of the fridge at over 115 degrees, when its hot the compressor runs more time.
No need to make a hole on the roof to vent the AC or fridge, you can use side vents, you would have to cut a hole on the side of your van, that will help in keeping the rain out.
The AC itself will also heat up your van, the 700 watts has to go somewhere, some is vented outside, but the AC unit itself will heat up also. On very hot days, I wouldnt use my 70 watt laptop because the small amount of heat coming out of it would heat up my van.
Without insulation, the AC will have to work extra hard to keep you cool. Its all about the insulation, right now on my heavily insulated astrovan, I have my 12 volt fridge exhaust vented outside, all I been using is a small 12 volt swampcooler (about 2 amps) to keep my van cool. I can park in the sun and stay all day inside with all the windows/doors closed and be nice and cool.
For window shades, use rtech foam (4x8 foot sheet cost about 10 dollars at home depot) and cut it to size with a box cutter. All my van rear windows are heavily insulated. But it won't help much if the windows are insulated but you still have bare metal walls. The rtech foam can also be cut to make a gasket for your AC exhaust hose, just use duct tape on it to build whatever you need. Anything you do to remove/keep out hot air from inside your van will help. Definitely vent your fridge compressor exhaust, it helped me in keeping the van cool.

picture of my side vents
side vents.jpg

This is a picture of the thermometer of the back insulated section(94f) of the van and the front bare metal/window section(148f) of the van on a very hot day. A swamp cooler or AC can keep you cool when its 94 degrees, but even an AC will struggle to work with 148 degrees.

high humid.jpg
 
I used a similar unit (9000 BTU) in a small apartment a few years ago; my observations:
- I lost about 40% cooling capacity because the unit dumps a lot of waste heat back into the living area.
- I got about half of that back by insulating the exhaust tube (I used an old down comforter). The rest is from the unit itself that gets warm (no easy solution to that).
- Its big advantage was reducing humidity; I was removing about 5-10 gallons of water from my space per day in a humid Minnesota summer.
- eliminating a small amount of leakage around the exit won't improve things enough to worry about (unless you can feel a hot breeze coming back into the living space).
 
I decided to scrap the idea for now. It just draws too much power and takes up too much space in my van. Maybe once I make some more space in the van (or get a bigger van) but also think I'll need to set up a way to control the tilt of my panels. I saw this sweet setup on YouTube (), think I need something like this to make it work right.
 
I bought a Hisense 5000 BTU portable air conditioner at Lowes.

My current setup isn’t optimal, but I have some hope this could work somewhat well. At least well enough to have a few cool hours every other afternoon or maybe every afternoon if I don’t feel like being around people. Mornings I usually spend at places like Panera, Starbucks etc. My Maxx Air fan is good enough at night.

300w of solar and 400ah of batteries.

Right now I don’t have window shades except a windshield shade, so sun is definitely heating the vehicle pretty fast once the compressor turns off. I have ordered some of these to see for all my windows to see how they much they mitigate the heat. Except the very back windows, because I couldn’t find any covers that fit the 2016 Transit Connect Titanium XLT. Found windshield, front side, and sliding door side covers but nothing for the very rear. Planning on cutting the cheaply windshield cover I got from Walmart for the backs or maybe Reflectix.

My AC exhaust is also going out the window, and hot air is able to get in because there isn’t a proper seal, there are some gaps.

Wondering if there is something I can buy, like a gasket or something, that would accommodate the exhaust pipe / adjustable window adapter to create a stronger seal.

If this works well enough, may cut a hole in the roof for exhaust if I can think of a way to keep the rain out, probably some sort of sliding cover from the outside.

Bolded to highlight the main point of my post lol.

Other ideas of course are insulating the exhaust pipe, insulating the van (really don’t wanna do this one because I’m already living in it), and separating the cab. Kinda hard with my setup but have been trying to think of ways this could be done.
Wow. So much fuss.... i went to Home Depot, bought a 5000 btu floor ( apartment room air conditioner... placed it on the front passenger seat ...cut a piece of ply foam to fit the top of the van window, cut a hole to fit the hose .. rolled up the window to the foam board...cut to fit....pushed the ON Button...voila !
 
Where did the condensation go? If you are in a dry climate you may get away with it but I was draining 5-10 gallons a day.
 
You mentioned temporary, but also mentioned cutting a hole in the roof to vent it, which sounds more permanent.

I looked into how to keep my vehicle cool with my dog and ended up with a small window AC in the right rear side window and small Honda Gen in a rear cargo box. Ive been using it for about 4 summers and am very satisfied with its performance. No permanent changes to the vehicle, but its secure and takes up effectively zero room inside. I set it at 61 or 62 degrees, whatever its lowest setting is and the dog stays quite happy, everything in the vehicle feels cold when I get back in.

I painted the outside part of the AC to match the vehicle color, I get a little less pointing and picture taking, but I really dont care much, as it works rather well and I can take my dog shopping or whatever around town and on the road I dont have to worry to go in and eat, use the facilities, shop, whatever. On Eco mode the gen uses about a gallon of fuel in 6 hrs to run the gen. Its also pretty handy to have power if I want to use power tools for projects. This is one of the best modifications to my vehicle Ive ever made.

0729181711.jpg

0729181711a.jpg
 
With what you are trying to do insulation will help tremendously. In a Transit Connect with decent insulation you SHOULD be able to control the temperature with a very minimal capacity air conditioner since it's a very small space. If you don't insulate, well, steel has a moderately good thermal conductivity and has the capability to carry quite a load of heat, so you will be absorbing heat from outside pretty quickly (which your cooling system will have to compensate for constantly). Some of the window air conditioners supposedly run on about 500w (this is at 110v AC, so if using an inverter more likely between 550-600w). Seems like this would be a much better solution given your power system. The 750w from your portable unit is going to more likely be between 825-900w once you take the inverter loss into consideration.
 
I also hang a 5000 BTU window a/c out the passenger window when needed. Obviously, this is only when we're parked where shore power is available. (A generator like Malamute uses would work too.) It actually doesn't look bad, and is quieter than most RV roof a/c's. The downside is hefting 30 pounds to window height, which I can't do by myself, so we tend to stay put when it's in use.
 
At some point I'll circle back around to the idea. With the limited amount of space in the Transit Connect and the fact I built it on next to no budget (other than the electrical system / fan) - it'll just end up being a hack job without doing it right by insulating the van as a lot of you have suggested. I like to keep stuff neat and out of the way, that way I can sleep / lounge in my bed comfortably. Had a Thetford toilet but ended up ditching it just because it makes the space more comfortable to be in, and I prefer city camping anyways.

Plus, if I reorganize the setup I could definitely make enough space for the unit without getting in the way (or maybe a swamp cooler, I have been looking at one of the Hessaire units which seem legit, and based on the temp/humidity chart they advertise, should provide enough cooling on hot days, even with the humidity levels in Michigan. I don't have anywhere to work on my van at the moment, so for now just going to stick with the Maxxfan til next year probably.

There is one people are saying is pulling under 100w to cool their RV.
 
Where did the condensation go? If you are in a dry climate you may get away with it but I was draining 5-10 gallons a day.
Modern window units have slipper ring on the condenser fan that picks up the water, slings it on the hot condenser fins and cools them by evaporation lowering your amperage draw.
 
Where did the condensation go? If you are in a dry climate you may get away with it but I was draining 5-10 gallons a day.
Oh. I forgot to mention i put a large turkey roasting pan under t to catch the condemnation and dumped it ever morning.....
 
I broke down and bought the Hessair MC18M. Ambient temp outside is 87. Temp in van 77 and feels pretty comfy compared to not having it, even though the humidity is high. This is with front windows open a few inches each and Maxxfan running on 4 (highest speed) and a separate fan pointed at the back of the cooler. Cooler running on low (which allegedly uses 54 watts according to an Amazon review or question, I forget which). From what I can tell so far seems to work a little better with the Maxxfan going, not sure how much the second fan is helping.

It’s also 34% humidity outside. Will see how well it works in the middle of the day when sun is beating down and report back.

Also running on high (100w supposedly) and temp dropped to 75, but doesn’t seem worth it given another 2% humidity and nearly double the power usage.

It’s not as comfortable in here compared to the portable unit with hose, but seems to be using a LOT less power, which is really the main concern.

There are 2 problems.

The humidity which I don’t really think is that much of an issue since I’ll only be using it for a few hours in the day time (and at night will just use the maxxfan). Things should dry out once I turn it off. Maybe not though since night is more humid.

Other problem is that it uses water and where I’m at, I can’t find any cheap places to refill water so I have to buy 1 gallon jugs for $1 each. Walmart here doesn’t have a water machine. Due to gas prices and that I don’t have room for a big water storage tank at the moment, it’s not really any cheaper to go fill up at a campsite or something like that.
 

Attachments

  • DC252E19-FAEC-453A-9E0B-712B1E949711.jpeg
    DC252E19-FAEC-453A-9E0B-712B1E949711.jpeg
    100 KB · Views: 9
Last edited:
It seems to retain some cooling capabilities in fan only mode too (if you were running it with the water pump going before). The manual says to run fan for 30 min before storing, so I assume this effect will last for a little while at least. Only makes since since the media is still wet.
 
Top