Air Coditioners and Refrigerators

[Karebru]

The first thing I need to do before I start cutting holes in the sided of my trailer is pick out an air conditioner and a refrigerator.
I've settled on using a window unit on heavy duty drawer slides that deploys out a hatch when operating. And like others are doing, I want to mount it on top of a (110v) refrigerator enclosure.
We've looked at a few compact fridges and she likes the ones with a separate freezer on top. I'd rather use a home unit instead of a fancy RV one with outside venting. Being enclosed, it will need to be a front vent.
Here's my worry...
A front vent would be the simplest, but will it put out so much heat that it conflicts with the air conditioning?
Thanks!

[NO David!]

This is what I use: (although I recall 5,000 BTU model, but it's been awhile). Quiet, effective, the remote control is used way more than I ever thought it would be.
https://www.lowes.com/pd/Frigidaire-250-sq-ft-Window-Air-Conditioner-115-Volt-6000-BTU/999990672

[McDave]

Refrigerators basically just pump the heat around in circles. The heat removed from the interior eventually finds its way back in and the cycle starts over. The only way to remove it without venting it to the outside is with a AC. Of coarse the lower the ambient temp the less heat going into the fridge, the less it will need to cycle. The only extra work for the AC is the heat produced by the fridge compressor. If possible, keep the cabin cooled when using the fridge. in general it is easier to keep a set temp than to try to remove massive amounts of heat all at once. 10-15 degrees is not much for 100sft. and the reefer wont need to fight the heat as well. Take advantage of the shade, coat the roof with reflective paint, insulate walls and ceiling, use vents and windows, awnings keep one side shaded till PM. If you have A/C power just set the Air Cond. for the temp you like and keep the doors shut as much as possible. Once the mass is cooled it doesn't take too much to keep it there, but removing a days worth of heat from everything inside can take a while.

McDave

[working on it]

This is what I use: (although I recall 5,000 BTU model, but it's been awhile). Quiet, effective, the remote control is used way more than I ever thought it would be.
https://www.lowes.com/pd/Frigidaire-250-sq-ft-Window-Air-Conditioner-115-Volt-6000-BTU/999990672

• If you want a 6k btu air conditioner, and want a remote control for i, then why not get this other version of the suggested Frigidaire unit: https://www.amazon.com/Frigidaire-FFRE0633S1-Window-Mounted-Mini-Compact-Full-Function/dp/B01B4XUPYC I've used three 10k btu versions of it, and two 15.1k btu units, all with the remote temperature sensing remote, and loved the way it/they worked. By placing the remote controller in a "hot spot" will serve to make sure that the entire room/cargo conversion reaches your desired temperature; without remote sensing, the A/C will read the temperature of the return air, being drawn into the filter area, which will be cooler since it is closest to the unit's output. In my old house, I could really feel the difference when using the remote sensor.

• 

  FFRE0633S1 controller.JPG (190.11 KiB) Viewed 5065 times

• Be aware that all Frigidaire A/C window units produce a lot of water condensation (at least my 5 units did), that constantly drips from the backside. Make sure that you allow for this in your placement of the unit, especially when you slide it into storage position. On the other hand, I've used both a 5k btu LG in my trailer, and an 8k btu LG unit to cool my wife's office (in the now-demolished old house), and neither unit dripped water at all, but used it all up cooling their internal parts. Both units cooled very well, though neither had a remote temperature sensing controller (the 8k model did have a regular remote; the 5k model is manual controls only).
• About using a regular home-style refrigerator-freezer in your trailer, the heat output should be minimal, and easily overcome by the A/C unit's output (especially if the suggested "remote sensing controller is placed in that "hot spot" near the fridge). I just now measured the temperature variance between our kitchen floor 2 inches from the heat vents? of our std. size Whirlpool fridge/freezer, and our small 7.1 cubic foot Igloo chest freezer, and the temperature of the floor 12 inches away from each. The Whirlpool heated up the floor only 3 degrees, and the Igloo only 5 degrees. The whirlpool has 4" of clearance all around, so it can ventilate as the manual suggested, but the Igloo is crammed into a space with 3 inches max, possibly contributing the the elevated temperature reading. No heat is felt rising from them while standing near either unit.

[flboy]

Insulate well in the walls, double in ceiling and insulate under floor also. If you spend the time and $ doing that correctly up front, you will have no problem keeping it cool with a lower BTU air conditioner and warm in the winter with minimal power.

I just recently insulated my floors and that made a noticeable difference in the cycling off time.


Btw.. would not worry about dorm fridge heat created. It is almost a zero sum game inside the camper with heat generated(transfered) to cool contents which then slowly absorbs heat or looses cool air when door is opened . I think most only use 60W of power when the compressor is on and that is only 25% of the time or less in most cases. There is some ineffciency in the process that creates heat, but your laptop or TV probably creates more heat than that.

Sent from my SM-G935P using Tapatalk

[hankaye]

Karebru, Howdy;

The first thing I need to do before I start cutting holes in the sided of my trailer is pick out an air conditioner and a refrigerator.
I've settled on using a window unit on heavy duty drawer slides that deploys out a hatch when operating. And like others are doing, I want to mount it on top of a (110v) refrigerator enclosure.
We've looked at a few compact fridges and she likes the ones with a separate freezer on top. I'd rather use a home unit instead of a fancy RV one with outside venting. Being enclosed, it will need to be a front vent.
Here's my worry...
A front vent would be the simplest, but will it put out so much heat that it conflicts with the air conditioning?
Thanks!

The second line of your initial post (I underlined it), let's me think that you might build a cabinet like the one flboy (Don),
did for his a/c only place your 'fridge below the a/c instead of the electronics package that Don did. It would be very
similar to the manner that my rv 'fridge is installed using either 2 side 'fridge vents or one side and one top vent and
insulating the sides would keep it very quiet plus any heat from the 'fridge would be eliminated from the main cabin area
and eliminate the need for the rollers. It would just be there.
Just an idea while working on my morning coffee.

hank

[Karebru]

Insulate well in the walls, double in ceiling and insulate under floor also. If you spend the time and $ doing that correctly up front, you will have no problem keeping it cool with a lower BTU air conditioner and warm in the winter with minimal power.

I just recently insulated my floors and that made a noticeable difference in the cycling off time.


Btw.. would not worry about dorm fridge heat created. It is almost a zero sum game inside the camper with heat generated(transfered) to cool contents which then slowly absorbs heat or looses cool air when door is opened . I think most only use 60W of power when the compressor is on and that is only 25% of the time or less in most cases. There is some ineffciency in the process that creates heat, but your laptop or TV probably creates more heat than that.

We live in the same climate, Don. Do you think R-5 in the walls and R-10 in the roof is reasonable if it's all taped up and I use spray foam where needed?
I'm sure the floor insulation helps too, but that will probably be a project for next spring, or once I get her on the road. I assume you did it from underneath?

The second line of your initial post (I underlined it), let's me think that you might build a cabinet like the one flboy (Don),
did for his a/c only place your 'fridge below the a/c instead of the electronics package that Don did. It would be very
similar to the manner that my rv 'fridge is installed using either 2 side 'fridge vents or one side and one top vent and
insulating the sides would keep it very quiet plus any heat from the 'fridge would be eliminated from the main cabin area
and eliminate the need for the rollers. It would just be there.
Just an idea while working on my morning coffee.

hank

Something like this? (Not sure I have the air flow right.) It would keep me from having to go through the roof.

[flboy]

We live in the same climate, Don. Do you think R-5 in the walls and R-10 in the roof is reasonable if it's all taped up and I use spray foam where needed?
I'm sure the floor insulation helps too, but that will probably be a project for next spring, or once I get her on the road. I assume you did it from underneath?

I did R5 in wall and 2 layers (R10) in ceiling and ramp door. I added 2" foam panels underneath the trailer just recently. I did not do the floor right away either as I figured that was more for cold weather, but I can tell the difference for sure. Must transfer a lot through the floor.

I edited your pic. I think what you have will work fine, except you should isolate the input from the output with foam board and duct tape.





Here is what my setup looked like as I was building it.



Just cut and tape the blue foam board as needed. Very easy to work with. Yours should be similar except your intake will come in from the side instead of the ceiling which is how I did mine.



I hope this gives you an idea of what to do with yours.



The Outside View of the side and roof vents. I used the LP Gas RV Refrigerator Vents which are readily available. Intake is on the roof and exhausts through the side.




This is how the appliance stack looks today after finishing interior. The AC works great. This is not the original AC. I swapped it out for a GE unit that worked well on startup from ECO mode on my generator. It is a 8,000 BTU. I now use the 6,000 BTU as a hurricane backup for the bedroom window. It worked fine, except for some reason it had a huge current inrush and it would trip on the Honda 2000 ECO mode. It is funny, because the larger GE unit does not trip in ECO mode. I think it has a soft start circuit built in that the other unit did not have. The 8,000 BTU makes light work of cooling the 7*18 with 2ft V down on hot summer days. The 6,000 did it, but it was working longer.

[Karebru]

Don't want the heated air mixing with the cooling air...Makes sense.
Sounds like I'm on the right track, though. Thanks, Don.
Between the narrow windows I'm ordering, and a compact, 5,000 BTU AC mounted that way, I should be able to get away without cutting any 16" o.c. framing members.
That would be a beautiful thing.

[flboy]

Don't want the heated air mixing with the cooling air...Makes sense.
Sounds like I'm on the right track, though. Thanks, Don.
Between the narrow windows I'm ordering, and a compact, 5,000 BTU AC mounted that way, I should be able to get away without cutting any 16" o.c. framing members.
That would be a beautiful thing.

You can probably get away with that for sure. I was in the cutting mode at the time I did mine. I probably could have got a smaller vent and not had to cut, but I wanted this specific type of vent so I didn't have any water ingress issues going down the highway in the rain and I like the look of it. It is really no big deal to cut the studs as long as you frame it out to brace and transfer the load around. I used 1" aluminum stock and screwed them into the vertical studs which were the "P hat" type and had a great area to screw into. I did not have to weld or etc. It is strong enough and once the plywood ties it all together, it is even more robust.

This is what my hole looked like. :-)

[Karebru]

I probably could have got a smaller vent and not had to cut, but I wanted this specific type of vent so I didn't have any water ingress issues going down the highway in the rain...

That's one concern that I immediately go to... because it does rain here.
What type of vents are those and where did you them?

[flboy]

That's one concern that I immediately go to... because it does rain here.
What type of vents are those and where did you them?

I got it on Amazon. It is made by Dometic (link below). They sell various sizes, but I could not get anything that would have fit between studs. 20" wide was as narrow as I could find.

If you look at how these vent.... the water will not get in driving down the highway or etc. The other types don't look like they would keep water out in a wind driven rain. I have opened mine up at a rest stop after a downpour on the highway and it was dry in there. Alternatively, you could build yours so it does not matter if water gets in. Just build a pan that catches everything and drains down through the floor. If you look real close, I did make mine water resistant in that area just in case. Any water that should get in will be on rubber mat and drain toward the side and back out.


https://www.amazon.com/Dometic-3109350- ... rator+vent

[McDave]

Just a word of caution before you go shopping for fridges and AC's. Many of the smaller "compact" fridges do not have a external mounted condenser coil or a condenser fan. The condenser is the radiator type coil you would usually see in the back or underneath with a fan that draws cool air across it to remove the heat. Instead these units actually use the cabinet to radiate the heat away. The condenser tubes are welded to the inside of the cabinet before the foam insulation is injected between the metal outer and plastic inner liner. These are "economy" fridges and will give you about what you paid for. They should not be built in or under cabinets and need about 5" on all sides to operate correctly. Also, they can't really tolerate high ambient temps or low temps, or frequent door openings or inverter supplied A/C power. And the list goes on and on. Also, the "freezer" is really just a chiller. It may make ice cubes, but it won't freeze raw hamburger or fish fast enough to prevent spoilage. It will keep previously frozen food frozen, but ice cream may get too soft.
The reason I mention this is I have over 40 years of tech experience in appliance repair, refrigeration, HVAC, Auto Mechanics, as well as being a DOD Test Tech Pilot. Now I like a bargain as much if not more than the next guy, but things have changed over the last 20 yrs. There are only 2 kinds of products it seems. Top of the line ultra expensive but high quality stuff, and crap. If you wanted crap you could have just bought a pre manufactured camper off the lot. So choose wisely and be informed as to how things work. You can get the higher quality stuff at reasonable prices if you are willing to do the homework, ebay craigslist, etc. Not everything you see that looks good is good. Just because someone else did it that way does not make it good. However, if you can accept the disposable quality items, there is plenty of it out there.
I just picked at random a compact Magic Chef fridge and downloaded the Owners manual. Take a look and see if this is what you want. I would not. Pay attention to the installation instructions.
https://www.teledynamics.com/tdresource ... 48044b.pdf

McDave

[flboy]

The first thing I need to do before I start cutting holes in the sided of my trailer is pick out an air conditioner and a refrigerator.
I've settled on using a window unit on heavy duty drawer slides that deploys out a hatch when operating. And like others are doing, I want to mount it on top of a (110v) refrigerator enclosure.
We've looked at a few compact fridges and she likes the ones with a separate freezer on top. I'd rather use a home unit instead of a fancy RV one with outside venting. Being enclosed, it will need to be a front vent.
Here's my worry...
A front vent would be the simplest, but will it put out so much heat that it conflicts with the air conditioning?
Thanks!

Karebru, if you go with a 110VAC dorm fridge, unless you are just going to run off shore power, I'd recommend a pure sinewave inverter and not the modified sinewave. The pure sinewave inverters run cleaner than shore power and you will have no troubles. Same for the generator. An inverter generator is the way to go also. Most appliances are damaged when the older non-inverter type hiccup or run out of gas... worst surging brown out event ever for your appliances. Use clean power and they will last a very long time just as they do in your house. Inverter generators will just cleanly disconnect if the gas engine starts to do funny stuff.

12VDC appliances specially made for RV's applications of course work great too, albeit at a premium because of the supply/demand aspect.. I think in general there are less issues with them because 12VDC is very clean power by definition and they will just shut off when it gets too low. Some of the 12VDC/110VAC RV items just have a sine-wave inverter built in and really just run off 110VAC inverted from the 12VDC, some do just have DC motors also and use a power supply when running off 110VAC.. all similar circuitry and components. All, very good stuff. At the end of the day, people kill their stuff with bad power and really do not understand why and blame the appliance maker. It is especially bad with TV's and sensitive electronics. Clean power is key.

The modified sine waves, which are less expensive and okay for some applications, are hard on the compressor motors due to the waveform and will reduce the lifespan.

Lastly, the venting of the typical 3 way RV Fridges is primarily because they burn propane and it will kill you otherwise. Secondary, and just as important, is they are boiling the refrigerant (use to be ammonia, but not sure these days) to create the expansion and subsequent evaporation, and if that ever leaked inside, it could harm/kill you also. They have to vent outside for safety... not efficiency.

In any case, just make sure there is good airflow/convection around the fridge as they do shed heat through the "skin" and have a good clean power source and it will work fine and last a long time.

Can't wait to see your pics when done.

[Karebru]

Thanks, Don. That all works things out well enough to get this thing started. I did an Amazon order in the wee hours, so now I'm committed.
AC, fridge, and windows.
Yeah, a generator can tear up the modern computer controlled stuff. There were a lot of burned up window ACs and fridges after Irma... Even garage door openers and well pumps. We ran ours for 12 days after the storm. I'd rather camp with candle light and ice than with a stinkin' generator. I'll stick with shore power for now, if I can get it.

And thank you, McDave. I already had to explain to my wife why the $120 units she saw in Lowe's wouldn't work. I'm not what you'd call appliance savvy, but being a cabinetmaker, I do have to deal with their installation requirements. I've got a GE zero-clearance, under-counter on the way.
Reasonably priced... There's no limit to the amount of money someone who thinks that, "I must have the very best" can spend on home appliances!