Please explain converting a window unit AC to ducted.

dbhost · 04-09-2018, 04:00 PM

I've seen it mentioned a couple of times here. But folks are converting window units to ducted units somehow. What is the process, and concepts behind this? I know Window units are inexpensive comparatively, and I am just trying to figure out how to use them in a skoolie without hanging a big box out of the back window...

jjhwick119 · 04-09-2018, 04:09 PM

this should help you
https://www.quora.com/Can-I-modify-a...ir-conditioner

( there are two examples they used on that page. the youtube example happens to be a pot grower, but the video is all about his ac unit)

dbhost · 04-10-2018, 09:03 AM

Okay I get the duct over the part inside, heck the inside part can be exposed to the interior 100%. Perhaps I wasn't clear on what I was thinking...

A window unit, mounted in a bus, say enclosed in a vented box. Does the intake and exhaust air have to be vented / exhausted so that they don't mix? How would you go about doing that?

What else are folks doing for AC in their busses that doesn't involve RV rooftop air conditioners? Not trying to avoid them, just not sure they are the right solution.... Especially since you can separate out a room at a time with window units and say just cool the bedroom with a 5K window unit, and use WAY less energy than a 15K rooftop unit would use....

cadillackid · 04-10-2018, 09:20 AM

there was someone here who basement mounted a couple wimdow AC;s and ducted them.. I dont remember seeing the results.. Mini Splits are fast becoming the popular option esp if you asre planning to go solar or run off of an inverter as there is no surgew current.. plus since they are variable speed, they reduce their energy usage by slowing down (they arent on / off like window units.. and are Much more efficienct)..
-Christopher

oredigger · 04-10-2018, 12:20 PM

I don't remember which build threads these were from, but here are some picts I've saved during my research.

dbhost · 04-10-2018, 12:34 PM

Quote:

Originally Posted by oredigger

I don't remember which build threads these were from, but here are some picts I've saved during my research.

The thought process is sort of, how to make the first pair of pics, and the second pair of pics match... I am guessing it will involve a good amount of metal or fiberglass work to get it to work well... But yeah, have the face of the unit face into the bus so controls / airflow is unimpeded, and then have the back of the unit so that it is flush with, or recessed into the body work of the bus, but maintaining proper air circulation to have the unit work well...

I hadn't thought of mini splits, but cost wise, and installation wise, they seem to be a bit easier to deal with than a couple of window units. Yeah initial cost of a window unit is lower, but expensive to install if done right I assume...

oredigger · 04-10-2018, 12:41 PM

Quote:

Originally Posted by dbhost

I hadn't thought of mini splits, but cost wise, and installation wise, they seem to be a bit easier to deal with than a couple of window units. Yeah initial cost of a window unit is lower, but expensive to install if done right I assume...

yeah, I have 3 window units sitting around that I'd like to be able to use. Probably just put one in the bedroom. I just haven't seen an easy way to mount it.

Toyman01 · 04-10-2018, 01:38 PM

I basement mounted one a/c in SanFord. The other was a cabinet install. I'll try to remember to share how I did it when I get to a computer.

dbhost · 04-10-2018, 02:25 PM

Quote:

Originally Posted by Toyman01

I basement mounted one a/c in SanFord. The other was a cabinet install. I'll try to remember to share how I did it when I get to a computer.

SanFord is the one that got me thinking... Look what you started here!

dbhost · 04-10-2018, 04:01 PM

Okay correct me if I am wrong here... The vents on the side are the cool air intake, and the vent / coils on the back would be the hot air exhaust correct?

Toyman01 · 04-10-2018, 04:02 PM

So you have a general idea. The 12K btu mounted through the side is what they call a through wall unit rather than a window unit.

A lot of wall units draw condenser air through the back and discharge it through the back as well. That way you can be flush to the exterior without worrying about ducting condenser air to the side of the unit. That unit is unmodified other than some sheet metal to keep the cool air separate from the hot air. It works very well.

The 12K BTU was about $250 from Amazon.

The 5K BTU unit was about $100 on clearance...

Well, I wrote a nice step by step post showing how I converted it, but due to the forums policy regarding Photobucket, none of the pictures will post.

Lets try a link to the page. Nope those won't work either.

I'll try to get those pictures duplicated to Smugmug in the near future.

1olfart · 04-11-2018, 10:25 PM

Sojournes was the install I remember. It was on pg. 41 of his build.

Good luck, and let us know what you decide, and how it works for you.

dbhost · 04-12-2018, 10:22 AM

Quote:

Originally Posted by 1olfart

Sojournes was the install I remember. It was on pg. 41 of his build.

Good luck, and let us know what you decide, and how it works for you.

Will look into his build.

I already have 2 units which is why I am asking about window units. I have a 12K and an 8K BTU Goldstar unit. I've been using them for tent camping (don't judge me until you try sleeping on a summer fishing trip in Texas in a tent!)

I've seen one that used the front overhead light space, modded some clear lenses and ducted the AC to use the lens openings to breathe from. I love that idea! SanFord the Great has a basement mounted unit that if I remember right has the face of the AC in the stair well. Not sure how well that would work. Hot air rises, cold sinks and the unit is already below floor level...

I'd like the 8K unit in the bedroom (back of the bus) and the 12K unit at the front of the bus / living room area...

I am narrowing down bus options, and I think I might have a line up on a 7 window conventional Thomas. 6' 6" interior height (important for me as I am 6' and don't have the best back. That should put the entire bus around 30', with 20' behind the drivers seat...

Toyman01 · 05-17-2018, 07:09 PM

I finally duplicated some of the pictures to Smugmug.

Unit stripped.

This piece of ducting will run through the floor to a standard residential register.

Since all of this will be hanging below the bus, I insulated the ducting and reinstalled the case.

The unit hangs under the bus just behind the step well. The ducting is run through the floor, the return air is in the step well.

As installed.

The unit does a pretty good job of keeping the front of the bus cool until the temps get above 85. At that point it starts loosing ground to the heat coming off the roof.

Add in the 12K btu back unit and they will keep things cool on the worst day.

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