im going to enclose the rear exhaust section of the unit and send it outside through a pair of large vents. Is there any reason I need to vent outside air into the condenser intake? Or can I let it just intake air from inside the trailer?
seems to me it may be even more efficient to let it intake cooler inside air instead of warm outside air? I'm not an expert. :)
In reply to Lof8 - Andy :
Can't do! Air conditioners create condensation and if you don't want a whole bunch of water running down the walls you'll hang it outside like they are designed to be used.
In reply to frenchyd :
I plan to collect the condensation and drain it outside. People have done this successfully on the camper forums. But on the build I'm looking at, the guy is piping in outside air for the condenser intake. I'm not sure that's necessary.
Using conditioned air can make the condenser side more efficient, but the air pulled through the condenser has to be replaced. It is replaced by unconditioned air pulled in through gaps around the doors/seals in the walls. Yes using colder air helps the condenser, but the unconditioned air that replaces it hurts the indoor temperature causing the unit to work harder to compensate resulting in more energy use than if you use outside air through the condenser.
In reply to tomtomgt356 (FS) :
Thank you for the explanation. Makes perfect sense.
I'll start by saying that 10k btu would not cool my 20' enclosed trailer if the sun was out or the temps were above 85 degrees. The pictured unit is likely too small to do much good unless you add lots of insulation. A 15k BTU roof unit would work much better.
SanFord has 17k BTUs. It still gets warm on a sunny hot day. The Blunder Bus has 26k BTUs and barely keeps up on the worst days.
Next, any air sucked out of the trailer has to be replaced by air sucked in. If you are pulling 90 degree air in to replace what is used across the condensor coil, you have lost any gain you might have gotten by using cooler air to start with. The unit is designed to use warm air so I would plumb it accordingly.
I only intend to use the a/c at night, when the sun is down, and going to sleep.
In reply to Lof8 - Andy :
Then it sould work perfectly for that. Reducing the humidity does wonders for sleeping even if the temps are higher than preferred.
They need to pitch slightly out to help drain condensate and the condenser section needs to be outside. Cut the hole or you’ll end up disappointed. That little prop fan on the condenser side isn’t going to be able to deal with vents.
What's the motivation? Is it just a unit you already have? Seems like an awful lot of work to end up with something that doesn't work as well as an AC designed for trailer use -- either a roof unit or a mini-split.
My Jayco has a home A/C for an A/C unit, right from the factory.
They mounted it in a cupboard and it extends through a hole in the wall, drains to outside.
Works fine for us.
codrus (Forum Supporter) said:What's the motivation? Is it just a unit you already have? Seems like an awful lot of work to end up with something that doesn't work as well as an AC designed for trailer use -- either a roof unit or a mini-split.
I'd say the main motivation is cost. This unit cost $130. Those rooftop units are significantly more expensive (about $500 at a minimum is what I'm seeing) and they require cutting a big hole in the roof of the trailer. Its really not a lot of work to build a shelf, cut a few vent holes and get the thing mounted. I just want the interior comfortable to sleep in at night, I don't need the interior frosty on a hot summer day. And if the unit ever goes bad, grab a new one at walmart. No $500 replacements and no leaky roof.
If I were doing this with this AC, I would completely separate the AC at the "window line" - that part with the L bracket, and where you slide in the accordion sliders in. Put that entire back section in its own space, have it be as air tight as you possibly can (even though the AC itself is likely not air tight), use some pink foam board. Put in an exhaust fan from that space to the outdoors - that part may be overkill.
The AC is not pulling in air from the outside. It pulls air in from the front, cools it, and pushes the cool air back out the front. It is also not creating cold - it is really a zero sum game, with an equal and opposite reaction creating hotter air. So keep the back, where it is creating that hot air, vented and completely separate from the front of the machine and the air that you're trying to keep cool.
I did the window A/C unit on my black 6x12 enclosed and when I bumped up to the 8k BTU model, it kept the trailer a nice 70 degrees even when it was 100+ and humid outside. I ended up cutting a hole in the front of the trailer and used the cutout to make a door that I would clamp in place while traveling and would remove and put the A/C unit when parked.
I chose the window unit because it was much cheaper than the roof mounts (I saw $1000+) and they always seemed to be riddled with problems. At the track, everyone I knew with a roof unit would end up dropping $500 or more on it every year to get it fixed. One guy had a 6x12 like I did with a 10K unit on his and it couldn't keep it nearly as cool as my little window unit did. He replaced it twice in three years. I kinda figured if mine crapped out, it was less than $200 at any big box store to replace, but it never did in 5+ years of use. Still works as I have in the bedroom of my house today since my central A/C went out last night.
FWIW, I bought some roof reflective paint from Home Depot and coated the roof and put foam core insulation between the inside and outside walls of the trailer. The roof paint seemed to make the biggest difference.
-Rob
I went with a stand up unit for the van. Just vent and drain out the floor, keeps it down right frosty at the track and no holes in your trailer wall. You could hang a tarp curtain to keep the sleeping area separate from the whole trailer.
tooms351 said:I went with a stand up unit for the van. Just vent and drain out the floor, keeps it down right frosty at the track and no holes in your trailer wall. You could hang a tarp curtain to keep the sleeping area separate from the whole trailer.
While I'm generally not a huge fan of the portable AC units, which is what I think you're referring to, if the space is available it is probably a good solution here. (I have experience with 3 of those portables, still use one at my parents vacation house)
Yes a portable unit, I think it would work out good for the OP. The window unit works great but the look, hole in the wall and resale value leave something to think about. You can pull that unit up close, but bring a blanket lol.
Works great! I'm actually pretty excited to sleep in it. It'll get some cosmetic treatment down the road but very functional for now. Under $200 and no holes in the roof.
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