Wall Unit AC Install in former Console TV cabinet?

[V'sGlassSleeper]

I replaced the loud, heavy and dying original rooftop AC on my Bigfoot B19 with a lovely MaxxFan, which should suit my needs 80% of the time. However, I really want to add a wall unit AC because they are more efficient, lighter weight, quieter, use less power (can even run on a generator if needed) and are much less expensive and easier to replace.

I really like the unit my housemate has in her T@b (the one she is selling that I listed for her previously) - it's very quiet and cools her little camper down in the blink of an eye. Since my Bigfoot is 19', from my research, it seems that an 8,000 BTU wall AC unit would be perfect. Is there a way I can reinforce the back wall (if needed) and cut out enough to install the necessary vents to put a wall unit where the old console TV storage is? I have a 15A power outlet right there, and could easily install a drip pan, run a small plastic tube for any potential overflow to drain right down through the closet and out through the bottom of the trailer, and could enclose the unit as needed. I have enough room that I could also run insulated exhaust and intake tubes down and through the floor if that would also be feasible (but my assumption from the videos I have watched so far on YouTube is that exhaust tubes may not move enough air in each direction to adequately exhaust the hot air from and feed cooler air into the unit, but if that is not accurate, I kind of like that method even better).

See photos for details on what I am proposing. First 3 photos are of where I would like to put the AC unit in my Bigfoot B19. The next 2 photos are of my housemate's AC unit in her T@b - the unit install inside and the exterior vent. She has never had any issues with water leaking in from the exterior vent, but I could cover the outside of the vent when not in use just to be extra-careful. Ideas, suggestions, helpful input? Thank you!��

[BarbinBC]

Val, I'll be following this to see what you come up with. I've been doing some research along these lines as well but I'm none the wiser. It will be interesting to see how you problem solve the hoses, etc.

Looking towards a hot summer in Winnipeg at the Boler 50th Anniversary event in August!

[patrick crawford]

you might want to look at a casita 13' or 16' trailer. both have residential type air conditioners mounted in the front down low. casita doesn't use vent "tubes" but instead builds divider walls (for lack of a better term) for the intake and exhaust. there are corresponding vent panels on the exterior walls. there's an additional louvered vent panel under the ac unit for condensation drip. perhaps this approach could be adapted?

p@

[Tom 72]

Not an expert. But to run well and efficiently, a room air conditioner needs plenty of air flow around the back, and sides in some units. That part hangs outside by design. Any restriction or reduction in the airflow around the back may well reduce performance. The hole required to vent could create a major challenge in heating season. Measure twice, cut once. Good luck.

Any experts?

[V'sGlassSleeper]

Thanks Patrick, The photos of the T@b AC unit that I posted above are even closer to the type of install that I would be doing in that it is an enclosed wall unit housed entirely inside the camper and installed on a wall rather than on a floor.

I will check out the Casita installs to see if there is a way to adapt the drainage and exhaust set-up, thank you for the suggestion! You are correct, it is very important to isolate the exhaust from the intake - there are some great videos on YouTube about this by people who have installed wall units in their "skoolies" or schoolbus campers. Haven't found any good videos for fiberglass unit installs.

I was really hoping to hear from anyone who may have stripped the inside of their Bigfoot 19 or similar unit on whether or not that back wall could be modified for an exhaust vent. I guess I will have to do some exploration by carefully removing the interior panel to see what I can see. It isn't the only spot for a potential AC install, just the preferred one. There's plenty of room above the gaucho as well or in the side closet as well. I don't want to install it under the bed area because that would be way too noisy for me at night. For this project, I will likely enlist the help of an engineering-minded craftsperson. As with anything I do on my Bigfoot, I want it done right.

Would love to hear from any of the craftsman-engineering type Bigfoot owners out there - any ideas?

[Timber Wolf]

I installed a 6K unit in the side of my old Scamp in place of the non-operating 5K that came in it. No drip pan required as the AC unit's bottom was sealed with a bayonet fitting overflow. I connected a flexible hose that dumps under the trailer. I never see any condensate dripping, I think it all blows out with the exhaust.

I did install a small automotive radiator fan behind the unit to help get the hot air out of the small space it is installed in. The outfit works, but am sure could be better. I think I will install a fan (maybe a round bilge fan) in the bottom of the trailer to pressurize the AC compartment. That should help a lot.

[k0wtz]

tim I put one of those in a room that doesn't cool well its been in there a long time I never see any water run out of it.

something to do with the efficiency of it I think!


bob

[stevebaz]

Its not as easy as popping it in a box and cutting out the back.

There are 3 main sections to the window mount air conditioner. The front where room air goes in and cool air comes out. The middle section where the outside air goes in and absorbs the heat and the back where hot air blows out.

The middle section where outside air goes in is the problematic section. you don't want room air going in there and you don't want to be sucking in the hot air from the back. In a normal window installation the back and middle section sits outside of the window opening and properly do its thing. If you mount the unit inside you have to seal both ends of the middle section and feed fresh air into the section. this means you need to put in ducting and possibly a fan to bring in this air.

another issue is water being removed from the air conditioner most new ones force the moisture in the warm air exhaust and are not a problem unless there is extremely high humidity then water may collect and cause a drainage problem. old units just used a dedicated drip pan and it just drained out in a known location. Obviously you need to deal with a drainage over flow if the unit is mounted in the trailer. There are quite a few installations of wall mounted air conditioners on this site and before jumping in head first you should read as many as you can.

One thing to watch for in your installation is short cycling your cooled air from the unit.

In a small trailer you can get very little of air mixing in the space before it gets sucked back into the unit to be cooled again. In a roof top unit it is blowing cool air down to the floor and out to the sides of the trailer and as warm air rises it gets sucked into the air conditioner to be cooled again.

In a window unit mounted low you start to suck in the cooler air from lower in the trailer and you don't get much circulation with the warmer air in the top of the trailer. You may want to think about redirecting the cool air going out and air being sucked in to the air conditioner and think about where the cool air is bouncing off of in the interior.

[V'sGlassSleeper]

I'm not sure why I haven't been getting notifications of replies to my original post, but thank you all who have taken the time to respond. TimberWolf, your response is very helpful, thank you! If you have any photos and tips from your install experience, they would be much appreciated.

Steve, I never just jump into any project. I am very methodical. And I do not want another roof unit, for all the reasons I previously mentioned. My preferred install location would not sit low, but rather is up high. I have already seen some great videos where people have managed to put the entire unit inside and have put insulated walls between the hot exhaust going out and the cool/outdoor air intake and the air conditioned air going into the unit and it's worked quite well, plus, as I already noted, my housemate's T@b trailer comes with one factory installed and it works like a charm, so clearly it can be done right. I will definitely scour the forums more - the Search function was not bringing up AC installs for me, but I will have to try some different keywords to see what I can pull up. Obviously, the most important aspect is designing everything to allow the unit to function as intended.

[Tom 72]

Steve, Excellent explanation of the complex issues. It may explain why some people have mounted "mini-split" AC/heat pump units which require a much smaller hole in your trailer. I think some mount the outside condenser on their trailer hitch. There are numerous threads here about them.

PS, when people reply to your posts you only receive notice of the first one, to get others, you need to click the link and view each one.

[k corbin]

There are already some threads on this forum showing people's step by step photo installations of the window AC units into their trailers. Just do a search for the links.

[V'sGlassSleeper]

Thanks for tip, Tom, I could swear that once I subscribed to a thread in the past, I got emails everytime someone posted a response, but maybe the settings have changed since? I'll just make a point of checking back more often!

Thanks, K, I will definitely be looking through every part of the forums before taking any steps. I am curious why some people have chosen to install window units inside a travel trailer as opposed to through the wall units, because from the research so far, it seems as though the through the wall models would only need insulation between the front (which is used both for air intake and for releasing cool air back into the camper) and the back of the unit, an exhaust vent out the back and, just for added protection (since the newer units apparently are not likely to "drip" condensation unless I am in a very, very humid environment) a drip pan with a drainage tube. By comparison, a window unit also has to have a separate, insulated vent to the outside to draw in outside air which it cools and releases out the front. Seems like considerably less work to install a through the wall unit and according to a number of home improvement store employees, the efficiency and noise are no different between through the wall and window units. I will continue my research and will post my findings and of course, my progress once I start. Living in the Southwest, having some AC is just a good idea. If there is some major barrier to installing a wall / window unit, then I will be looking at a portable dual-hose unit instead.

[k0wtz]

I have a minisplit in my house heavy!

bob

[David B.]

Val, our Lil Snoozy comes with an 8,000 BTU “window” AC unit mounted out through the back wall, with a fiberglass cover over it to glamp it up. Here in the Phoenix Arizona area, this unit was marginal, so I took off the Lil Snoozy factory cover to see if the unit needed cleaning. It was clean, but the AC unit really improved it’s cooling without the cover on it, as it restricted the vents some. I cut the openings over the vents to match the size on the AC, applied screening, and re-installed the cover. My point being that air flow is so easily restricted, and the cooling ability will suffer, so you may need several trial and error attempts before perfection is achieved...... sort of like WD40...the 40th attempt was the charm.
Dave & Paula

[k0wtz]

david I once had a small bush in front of my mini split compressor it was not much at all but I had to cut it down as it also restricted my air flow. doesn't take much!

bob

[V'sGlassSleeper]

Bigfoot is the best company and I love Canadians! I just called them to see if the current company owner, Gary (who is an electrician and started with the company way, way back when), could tell me if I would be compromising the structural integrity of the back wall of my B19 if I were to put in an AC and he was just great - said that it should be no problem, as long as I reinforce the opening. I have been busy with other things and the heat has been oppressive, so had not started on that yet, but will post updates as I make progress.

[V'sGlassSleeper]

Hi Dave,

Thanks for your input about the Lil' Snoozy AC. Sounds like you really figured out how to maximize the airflow, so I will keep that in mind during this install. There is thankfully plenty of room if I need to expand or create more room around the unit for additional airflow.