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I have a small 5000 BTU window unit that I believe will run off my Yamaha 2000W inverter generator or shore power when available.... I just measured it at 16" in width. My original plan for quick-relief of a hot summer night was to make a plywood insert for driver or passenger front window and plop this baby in --- however, now that my ProMaster finally arrived from the dealership -- I measured the window opening and it's just over 15".

I did some quick internet shopping and haven't located a window unit that is under 16" width and am wondering if any of you folks have any leads for me.

Thank you.
 

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Have you considered a portable A/C instead so you only need to install a hose/duct through window? Smallest I've seen is around 8,000 BTU/hr though.
 

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Agree with RD. My experiment with single hose was a disaster. Portable units take up a lot of floor space. The hoses are big & have to be stored then attached to external vents so set up time is significant. The exhaust hose gets HOT and radiates all that heat inside.
 

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I've seen videos of guys installing a window unit through a van's front window or other door window and it wasn't particularly fast or easy either. They have to rig all kinds of supports and seals to make it work. I'm not saying a hose or two are easy, but how can they be harder than a 40~50 pound A/C? I'd also be concerned about accidentally dropping it and/or scratching the interior or paint. Personally, I wouldn't want either.

Just glad my window unit is mounted permanently. :)
 

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I have a small 5000 BTU window unit that I believe will run off my Yamaha 2000W inverter generator or shore power when available.... I just measured it at 16" in width. My original plan for quick-relief of a hot summer night was to make a plywood insert for driver or passenger front window and plop this baby in --- however, now that my ProMaster finally arrived from the dealership -- I measured the window opening and it's just over 15".

I did some quick internet shopping and haven't located a window unit that is under 16" width and am wondering if any of you folks have any leads for me.

Thank you.
I installed a 5kbtu window air below one of the rear twin beds. 4" plumbing elbows provide the intake and exhaust air and the intake has a 150 cfm computer box fan to boost airflow. Seems to work quite well but that would depend on number of windows and insulation level. It is a Frigidaire FFRA0522R1 with remote. Open box at Best Buy was about $120.
 

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I installed a 5kbtu window air below one of the rear twin beds. 4" plumbing elbows provide the intake and exhaust air and the intake has a 150 cfm computer box fan to boost airflow. Seems to work quite well but that would depend on number of windows and insulation level. It is a Frigidaire FFRA0522R1 with remote. Open box at Best Buy was about $120.
That's similar to my installation which has worked without a single issue for over 10 years now. Even if I had to replace it now it would cost very little.

Anyway, just noticed specs on your A/C show it only pulls 450 watts, and Frigidaire also lists an energy star unit that pulls 410 watts (presumably at rated conditions). At night I'd expect even lower power consumption.

With a small energy-efficient A/C like these I'm confident I could cool overnight from batteries -- would need only 4 kWh at most for 8 hours assuming 80% inverter and wiring efficiency. I figure 4 large or 8 medium batteries should about do it. Granted that's a lot of lead weight.
 

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Looks great Wbullivant!!

Can I ask a few questions...

What is the small closed compartment in the box, to the left of the A/C used for ?

Do the plumbing elbows just exit through the floor?

And finally... did you have install a drain for the A/C for the condensation?

Thanks,
Tom
 

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I would love to do this. Can you post more diagrams and photos so we all can get a better idea of what is going with the intake and exhaust including vehicle exits, etc.

Any draw backs to installing a setup like yours up near the ceiling vs floor?
 

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I would love to do this. Can you post more diagrams and photos so we all can get a better idea of what is going with the intake and exhaust including vehicle exits, etc.

Any draw backs to installing a setup like yours up near the ceiling vs floor?
There shouldn't be as long as you meet the A/C's primary need that you get enough cool air flow over the condenser. My A/C has been on floor also but on new van I would install it higher for better placement.

It's hard to tell dimensions from pictures but I would allow more room around A/C for better cooling, particularly off the back. I did a lot of testing with different arrangements in garage prior to finalizing design, and ended up with 2 ports 4" in diameter and short as possible venting through floor.

And the most important thing of all is that you don't let warm exhaust off the back circulate back to the condenser's intake side. That will lead to overheating, poor performance, and failure.
 

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wbullivant, This is an interesting and important alternative to roof air. Posting the pics on this site could insure they are always available. I can see how this could be modified for a side wall also. Do you have any performance experience to share? My intuition wonders if the single 4" in/out vents are adequate. Looks like doubling that to both sides would only add a few extra inches. Thanks for sharing.
 

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wbullivant, This is an interesting and important alternative to roof air. Posting the pics on this site could insure they are always available. I can see how this could be modified for a side wall also. Do you have any performance experience to share? My intuition wonders if the single 4" in/out vents are adequate. Looks like doubling that to both sides would only add a few extra inches. Thanks for sharing.
Roblee
Subjectively I would say that the unit cools effectively but I'll get come temperature drop data (delta air return to output) when I have the opportunity to operate it for a longer period of time. It was somewhat challenging to find appropriate locations for having the 4" elbows go through the floor in the rear location I used. A side installation would give greater freedom but I ruled it out from an aesthetics standpoint. I think the most important issue is adequate airflow through the condenser and my Sythe DFS123812H-3000 case fan booster is quite effective yet uses about 8 watts. Even more powerful 120mm fans are available but noise db increase rapidly. The fan is barely audible in my installation.

With my 654 watt PV panels the 450 watt AC will run on a sunny day without taking energy from the battery pack (four 230 amp GCB's). At night I calculate about four hours of AC without going below 50% of pack capacity and allowing for my compressor frig and other minor draws. My guess is that a 5kbtu unit is not going to be adequate for most Promaster conversions. I have only rear windows and 3" of Polyiso foam in the walls, 1" in the floor, and 1.5" in the ceiling. Solar panels shade much of my roof. It may be feasible to build in a compact 8kbtu unit in a similar fashion.

So far we are quite happy with the performance of the AC installation. In our two previous RV's the roof AC was so loud we often used ear plugs. This installation is a significant improvement.
 

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wbullivant, This is an interesting and important alternative to roof air. Posting the pics on this site could insure they are always available. I can see how this could be modified for a side wall also. Do you have any performance experience to share? My intuition wonders if the single 4" in/out vents are adequate. Looks like doubling that to both sides would only add a few extra inches. Thanks for sharing.
Two 4" ports work better than one 4" port. I have two on discharge side which can be easily closed off, so I tested with one versus two and it does affect air flow some. It also affects current draw a little because head pressure goes up, making A/C work harder. In cooler weather it's not as important but in very warm weather it can be more critical if A/C shuts off due to high pressure.

I do not use screens in large part because it limits air flow. Since my A/C compartment is not open to rest of van or storage compartments, I did not see the need in that it's no different than installing same A/C in your window at home. I do close the vent ports when in transit, or van is not in camping use or A/C is not needed. In over 10 years I have not had any pests or animals get into system that I'm aware of. When I occassionally pull A/C out for inspections, area has always been clean.


These kinds of window units are being used on many trailers and even motorhomes, but with the difference that condenser discharge (back of unit) is free to flow into open space. If you read most manufacturers' installation instructions, they state not to place objects within a few feet from back of A/C. We have to break that rule, but should keep back side as open as possible in my opinion.

I would highly recommend not placing the back wall of compartment so close to A/C discharge as shown on his pictures. I know storage is important, but I'd personally sacrifice a little space and move it back at least to other side of 4" port (or ports if you use 2 ports). You want as direct a path as possible.

Lastly, I designed mine to add a fan if needed to supplement air flow, but it turned out it wasn't needed. I prefer to keep it simple because if not sized large enough it can actually restrict air flow. On my A/C the condenser fan is fairly large (in range of 9" in diameter, more or less) so it moves a lot of air. Picture of my two discharge ports below.

Your results may differ since details can make a big difference.


P.S. -- For what it's worth, I did see a Ford van with an 8,000 BTU/hr window unit installed inside which worked OK from 8 batteries and an inverter, but A/C venting was a absolute mess; which was one reason I passed on buying that particular van. That an cost was too high.
 

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wbullivant,
If you hadn’t said it works I would never ever believed it would. This opens a huge opportunity for a really cheap AC under the bed. I have to get over the idea of drilling the holes but since I have several huge ones now for the windows and vent- why not? Thanks!
zwarte
I am sorry to hear this as I have been thinking of getting a small one to put in the van for camping in the hot of the south or summer.
 

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I opted for a 2 hose portable A/C. I only use it a few times a year. I made the adapter for the CRL window and it works great.
Nice job making those fit tightly. Will you share more info? Like size of your van, number of windows, type of insulation, A/C capacity, where you store it while traveling, how it's powered (generator or campground?), etc. Mostly I'd love to hear how well it cools during the day if parked in sun.
 

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Hi,
Don't mean to get off topic, but just wondering if this solution would work for some? Or, if anyone has tried it?

http://www.turbokool.com/

Its an evaporative cooler, so dry climates only -- not likely to work in Florida. But, in dry climates it provides a lot of cooling for very little power. It runs on 5 amps and 12 volts, so it would work fine with solar and batteries -- no shore power or generators needed.

RD posted a really "cool" DIY version of an evaporative cooler a little while back.

Gary
 

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.....cut.... Or, if anyone has tried it? ....cut....
Not a small RV unit, but I installed a large evaporative cooling project in California at a manufacturing plant, and it definitely has its limits (which we knew going in). Normal air conditioning would have been way too expensive because of all the heat being generated in building so we compromised.

Like you say, it would work in dry desert-like conditions very well. In Florida, or along Gulf Coast, or even East Coast, I would personally not try it. The wet bulb temperature in these areas is often too high, and I'd also be concerned that the swamp cooler would make humidity too high in van to the point of supporting mold, mildew, etc.

My daughter lived in a small town near Death Valley and I recall seeing swamp coolers sold at hardware store. In that environment they would have been great -- in large part because they help humidify the air which was way too dry for me.
 
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