High Efficiency Air Conditioning Units for non-generator powered campers

[Tronix]

I am joining this thread late and have not had the time to read each post, but from my few pages of reading thought you might be interested in my findings. Solar AC is something I kinda of stumbled apon. I never set out to do this, but have found my setup works fairly well. I cannot run mine all night but can get a couple hours of AC during the night to cool the truck down for sleeping purposes.

I have a 24v Masscombi@230v with* about 400ah of battery(Trojan lead-acid). Solar is 4 panels controlled by a Victron Bluesolar MPPT. I have the Dometic HB2500 that feeds primarily to the 'bedrooms' the secondary to living area.

During the day with full sun my panels can just keep up with demand from the AC unit. The batteries will take up the slack if there is a passing cloud or if the sun is at a low angle. There is never enough to run the AC and charge the batteries. I find that I am always chipping away at my batteries when doing this, the solar just slows down the process alot.

What I found works (for me anyway) is the HB2500 can give us a break from the heat during the day totally off solar for a few hours and this usually coincides with my 1.5yr old sons nap, which happens to be around mid day. The HB2500 will cool the bed areas but the living area will always be a few degrees warmer. Most likely due to my ducting placement, but I prioritised the sleeping area first.

At night I find a fully charged battery will essily give me a few hours of cooling. Which I spread throughout the night. Mostly due to me (or wife!) waking up hot and putting the timer on for an hour! I could in theory go longer but try to keep the battery discharge to a minimum. I feel a 30A draw for a hour is hard enough on (lead acid)batteries. Most nights we have tried AC off grid + battery, its only on at the beginning of the evening b/c generally where we have been using it , the evenings are cooler. If we need it more through the night, I break down and run the generator.

 

[S2DM]

I am joining this thread late and have not had the time to read each post, but from my few pages of reading thought you might be interested in my findings. Solar AC is something I kinda of stumbled apon. I never set out to do this, but have found my setup works fairly well. I cannot run mine all night but can get a couple hours of AC during the night to cool the truck down for sleeping purposes.

I have a 24v Masscombi@230v with* about 400ah of battery(Trojan lead-acid). Solar is 4 panels controlled by a Victron Bluesolar MPPT. I have the Dometic HB2500 that feeds primarily to the 'bedrooms' the secondary to living area.

During the day with full sun my panels can just keep up with demand from the AC unit. The batteries will take up the slack if there is a passing cloud or if the sun is at a low angle. There is never enough to run the AC and charge the batteries. I find that I am always chipping away at my batteries when doing this, the solar just slows down the process alot.

What I found works (for me anyway) is the HB2500 can give us a break from the heat during the day totally off solar for a few hours and this usually coincides with my 1.5yr old sons nap, which happens to be around mid day. The HB2500 will cool the bed areas but the living area will always be a few degrees warmer. Most likely due to my ducting placement, but I prioritised the sleeping area first.

At night I find a fully charged battery will essily give me a few hours of cooling. Which I spread throughout the night. Mostly due to me (or wife!) waking up hot and putting the timer on for an hour! I could in theory go longer but try to keep the battery discharge to a minimum. I feel a 30A draw for a hour is hard enough on (lead acid)batteries. Most nights we have tried AC off grid + battery, its only on at the beginning of the evening b/c generally where we have been using it , the evenings are cooler. If we need it more through the night, I break down and run the generator.

How many total watts on the panels?



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[jonyjoe101]

I have to agree that insulation is the only way to make AC work in a camper environment. Its just too much sun hitting the metal/windows of the camper to be overcome by a small AC no matter how powerful.

Myself I rely on swamp coolers to keep cool and they are a magnitude less powerful then the smallest AC. When I first started using the swamp coolers unless I was standing a foot away from it, I was sweating even on relatively cool days. I almost gave up on the swamp coolers and go the AC route, but I have a small astrovan and very little room for any type of AC. I started putting shades on the windows than little by little started adding foam insulation to the interior of my van. The more insulation I added the cooler I got. Before long the entire rear of my van is insulated with up to an inch of foam on the roof, all the rear windows have foam on them. I even build a sliding insulated door separating the rear of the van from the front of the van. Its not perfectly insulated but it made a major difference. Now my small swamp cooler will keep the rear of the van cool as long as I leave it running all day.

The more insulation you use the less energy you need to use, you can run your AC on low and extend the run time on your batteries. As an example I built giant swamp coolers that ran on power hungry car radiator electric fans (6 amps) to keep cool, but I added so much foam to my van that now I just use a smaller 2 amp swamp cooler and rarely run it at full power.

Foam is cheap, you can buy a 4 foot by 8 foot sheet of rtech foam insulation at home depot for less then 10 dollars. And you can install it quickly with a hot glue gun, which drys quickly and sticks very well to most surfaces. The foam insulation on my roof has never fallen off after 3 years that they been up there with just hot glue holding it.

The only disadvantage is your camper will be dark, if I see light entering the van I put foam over it, light = heat. Many people might want to have windows to look out of and not want to cover them up with foam, you can always make a removable foam window insert. The only rule of thumb for foam insulation is get an infrared thermometer and point at different areas in your camper, where you see heat, put some foam there. If you have a layer of foam and you still have heat, stick another layer of foam over it. You can double and triple the foam in hot areas. Put enough foam and the heat goes away. It works extremely well. I always park in the hot sun, no matter what the outside temperature and have all my windows and doors close shut. Just the foam and a small swamp cooler to keep cool.

 

[Tronix]

How many total watts on the panels?



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4x250w - I dont have room for anymore!

 

[Tronix]

I have to agree that insulation is the only way to make AC work in a camper environment. Its just too much sun hitting the metal/windows of the camper to be overcome by a small AC no matter how powerful.

Myself I rely on swamp coolers to keep cool and they are a magnitude less powerful then the smallest AC. When I first started using the swamp coolers unless I was standing a foot away from it, I was sweating even on relatively cool days. I almost gave up on the swamp coolers and go the AC route, but I have a small astrovan and very little room for any type of AC. I started putting shades on the windows than little by little started adding foam insulation to the interior of my van. The more insulation I added the cooler I got. Before long the entire rear of my van is insulated with up to an inch of foam on the roof, all the rear windows have foam on them. I even build a sliding insulated door separating the rear of the van from the front of the van. Its not perfectly insulated but it made a major difference. Now my small swamp cooler will keep the rear of the van cool as long as I leave it running all day.

The more insulation you use the less energy you need to use, you can run your AC on low and extend the run time on your batteries. As an example I built giant swamp coolers that ran on power hungry car radiator electric fans (6 amps) to keep cool, but I added so much foam to my van that now I just use a smaller 2 amp swamp cooler and rarely run it at full power.

Foam is cheap, you can buy a 4 foot by 8 foot sheet of rtech foam insulation at home depot for less then 10 dollars. And you can install it quickly with a hot glue gun, which drys quickly and sticks very well to most surfaces. The foam insulation on my roof has never fallen off after 3 years that they been up there with just hot glue holding it.

The only disadvantage is your camper will be dark, if I see light entering the van I put foam over it, light = heat. Many people might want to have windows to look out of and not want to cover them up with foam, you can always make a removable foam window insert. The only rule of thumb for foam insulation is get an infrared thermometer and point at different areas in your camper, where you see heat, put some foam there. If you have a layer of foam and you still have heat, stick another layer of foam over it. You can double and triple the foam in hot areas. Put enough foam and the heat goes away. It works extremely well. I always park in the hot sun, no matter what the outside temperature and have all my windows and doors close shut. Just the foam and a small swamp cooler to keep cool.

I agree on the insulation. I have 50mm insulation in my walls and 80mm on the roof. Windows are doible glazed with inert gas in between the panes with blackout blinds. My door is not so thick and when the sun is on it, you can feel the radiant heat coming off of it compared to my walls/windows.

Swamp coolers are a good alternative if your travelling in dry climates. Not so effective when the RH is pushing 90%+

 

[1aquaholic]

I agree on the insulation. I have 50mm insulation in my walls and 80mm on the roof. Windows are doible glazed with inert gas in between the panes with blackout blinds. My door is not so thick and when the sun is on it, you can feel the radiant heat coming off of it compared to my walls/windows.

Swamp coolers are a good alternative if your travelling in dry climates. Not so effective when the RH is pushing 90%+

Tronix what kind of windows are those? Non metal frame? Do they open up? Thanks

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[Tronix]

Tronix what kind of windows are those? Non metal frame? Do they open up? Thanks

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Hi yes they open but they are aluminium frame with thermal breaks. They are just home windows, but I specified the glass to be laminated and toughened, which i found out later to also increase the pane thickness.

As you can imagine the trade off to such a window is the weight. The Alu is not all that heavy but glass is. On one of the last forums I used to participate, it was a concern home windows would not hold up to the rigors of the road. Well happy to report that two continents and about 10k miles, they are doing just fine. Truck will spend its first hard winter in Canada this year so interested to see how that goes... perhaps I need to start another thread as winter is obviously not an AC related topic.

I am not sure how to post photos but if you PM me I can send more details. Been a lurker for a while but very new to posting on this forum.

 

[Ramdough]

I finally made it through this thread.

Is am also looking for an air conditioning solution without needing a roof top unit.

I am curious if the residential units are still surviving and how rough off-road they are seeing.

 

[TooMuchHair]

I finally made it through this thread.

Is am also looking for an air conditioning solution without needing a roof top unit.

I am curious if the residential units are still surviving and how rough off-road they are seeing.

That's my question also. How about it
LeishaShannon
Is your Mitsubishi still kicking it? Thanks

 

[patoz]

I would be interested in some updates also, especially concerning the mini-split units!

 

[LeishaShannon]

Ours is still kicking along after just over 2 years of full time travel. If something was to go wrong there are household AC repair guys in almost any town who could work on it.. unlike the low volume 12v units where parts may be difficult to come by. Total replacement cost is only $500USD or so too! (that said both the inside and outside unit are available for purchase separately, so it'd be around half that depending on what went wrong)

Couldn't be happier with our AC , its done plenty of work @ >40c and a little at <0c , all while sipping on relatively little battery juice.

 

[TooMuchHair]

Thanks!

 

[patoz]

Yes, thank you!

 

[adam88]

Ours is still kicking along after just over 2 years of full time travel. If something was to go wrong there are household AC repair guys in almost any town who could work on it.. unlike the low volume 12v units where parts may be difficult to come by. Total replacement cost is only $500USD or so too! (that said both the inside and outside unit are available for purchase separately, so it'd be around half that depending on what went wrong)

Couldn't be happier with our AC , its done plenty of work @ >40c and a little at <0c , all while sipping on relatively little battery juice.

Definitely a big reason for having a residential unit is that it could be easily fixed. The 48v DC unit looks really impressive, but parts for it basically would be very hard to come by. Also finding someone to fix it would be difficult. The 240v mini splits are so common they are easily fixable.
.
How did you hook it up again? Did you use flexible lines or copper?
.
What do you think of this product LeishaShannon: http://www.rectorseal.com/rectorsea...mini-split-air-conditioner-installation-time/

 

[Grenadiers]

What does the collective think of this idea. A Tripp-Lite 230v or 110v portable server rack cooler? Runs 7-10amps on the 230v version. I was thinking of the 230v version, since I already have that in my vehicle. I was also thinking of cutting a port in the cabin to run an insulated hose to the cab of the truck. So, bottom line, for me, use existing electrical system, cool the cab and the cabin, but not at the same time. Have 420ah in the batteries to possibly use this on 'low' setting while driving, and a generator to power it when camping/hot weather.


https://www.tripplite.com/smartrack...mall-server-rooms-network-closets~SRXCOOL12K/
https://www.amazon.com/Tripp-Lite-P...1514133&sr=8-4&keywords=tripp+lite+SRXCOOL12K