Rigid HVAC Micro DC AirCon

[CoyoteThistle]

For those of us with real small campers, 1500BTU sounds about right. There are lots of BTU vs. room size calculators out there (and I'm no expert!) but in playing around, it seems likely you could get at least a 20 degree F temp drop from this unit in a small area, especially if it's nighttime (i.e., sun not beating down on the camper).

Also, the problem with the bigger 5000BTU units in small campers is that they cycle on and off a lot and don't run long enough to dehumidify the air - you wind up with cool and clammy instead of the true a/c experience. So, could this unit be the difference between a 90F/95% humidity night and a 70F/50% humidity night in a bed-sized space? Seems plausible to me.

 

[luthj]

Most home type heat/cooling calculators will provide much lower numbers than reality for a camper. Thermal bridging, air infiltration, solar gain, etc. These all combine to make the needs much higher typically. A 30ft class B/C in the sun can need well over 15k btu to stay under 80F. To be fair most are barely insulated, but that is still only 200 square feet!

 

[turbothrush]

A person can check the heat transfer of their small camper or maybe check the cutained off cabover section with a kilo-a-watt meter and small 110 volt electric heater that has a thermostat. You could raise the interior temperature of the camper to say 20 F degrees above ambient . Heater needs to cycle on and off for a few hours then calculate the watts used per hour from the meter. Convert the watts/hr used to Btu/hr

Hardside foam insulated campers with essentially no thermal frame bridging and insulated glass really excell at this heat transfer and therefor Btu's required.

Thanks to the OP for posting as I did not know this 12 volt A/C existed.

 

[john61ct]

Yes at a give temperature delta

a given BTU unit could keep X cu ft comfortable in a normal barely sealed not well insulated unit

but ten times that space / volume if well sealed and insulated.

So if you can, getting the space well sealed and insulated should be a high priority.

Money invested in energy conservation has a very quick ROI.

A hundred times the payback when off-grid energy is used, compared to having shore power available.

 

[turbothrush]

A person can check the heat transfer of their small camper or maybe cutained off cabover section with a kilo-a-watt meter and small 110 volt electric heater that has a thermostat. You could raise the interior temperature of the camper to say 20 F degrees above ambient . Heater needs to cycle on and off for a few hours then calculate the watts used per hour from the meter. Convert the watts/hr used to Btu/hr

Thinking that someone maybe was considering making a kind of a cabover insulation retrofit with xps foam board or someone building DIY from scratch and wondering if micro DC a/c would be enough I thought I would post this.. I am not trying to be an expert.

Not really sure how a pop-up would compare but I did test my own camper. I tested 2 different ways for 10 hours each test. First tested the complete camper (20 degree F difference outside vs inside temp ) and also tested just the cabover section with the opening just curtained off ...not sealed off at all. Second test probably only one relevant to pepole here.

The cabover only result was 220 watts/hr = 750 btu's . I should add that my cabover has 2" xps foam floor and ceiling and 1" foam walls with insulated windows. The partitions separating the cabover from the main camper are also 1" foam . The curtain was like R=0 and not sealed..... i know tooo much info but hey its free

and to John61's point above I was surprised how warm the rest of the camper was... as in warm air moving around /thru curtain

 

[DzlToy]

If you know the R-value of your camper walls and windows, it isn't that difficult to calculate heat lost through a wall or roof section. Do this for each panel, i.e. wall, floor, roof, etc. and you have the amount of heat lost or gained in an hour.

It isn't much of a leap from there to calculate how much cold or hot air is required to maintain the desired temperature inside, in nearly any condition.

As electronics are cheap as chips and most people stay in a campground or RV park, the prevailing mentality is to put a 15,000 BTU HVAC unit on a teardrop and call it good. No one seems to be interested in energy efficiency, great insulation or high quality windows, doors and hatches that don't leak like a sieve.

 

[john61ct]

Yes as soon as shore power comes into the picture - or running a genset, or while driving, there really is no practical issue anymore.

The complications of maximising energy efficiency is completely driven by fantasies of inexpensive off-grid living with aircon fed by solar-only, or from battery stored energy.

 

[Jaredsalinsky]

Hello
so whatever happened to the thread? Did anyone ever get that HVAC unit? I myself am looking at it. I only have about 100 ft.² so I think this would work perfect. Any opinions?
thanks
jay

 

[Chuck1]

This tech area is mostly vaporware, or they want $5000 and the tests shown are dubious and or shows the tech knowledge (company) isn't what it should be for a $5000 unit, which makes me believe its just rebranded china stuff.

The only real "buy" it choice is a name brand small heat pump.

or

Build it yourself using well known and tested Danfos/secop compressor

 

[kerry]

Not a chance a unit like that will cool down a pop top camper in Nebraska in the summer. We have a small window unit bought at HD at end of season sale for $75 and installed in the front pass through window of our Northstar TS 1000. It will run off a Honda 2000. It is acceptable on a hot summer day in CO but it’s at the margin. Spend your money on a generator and a window unit. We camped at Glendo Reservoir last summer at around 105 degrees and 60 mph winds. That’s as close to hell as I want to get. We found shade trees until the sun set.

 

[john61ct]

There are 48Vdc powered aircon units, super efficient and very effective, designed for marine use.

Cost the earth though

 

[VDBAZFJ]

Well, I’m your huckleberry! I ordered the Rigid MicroDC to install on my teardrop. The area in my trailer is under 2 cubic meters so I am hoping it will work. At least to some extent. Most of my use will be at night so it won’t be fighting the sun.
Im installing a Propex heater at the same time.
time will tell if I wasted several hundred dollars.

 

[FlipperFla]

I was suspicious when I didn’t see a spec for BTUs. Watts? 1W=3.41BTU/h so at 450 watts that comes out to 1535BTU. Which isn’t Jack. My first AC/ van build I used a 4000btu which didnt cut it. The van was brown, as soon as the morning sun hit it. Game over.Plus opening and closing the doors the cold air would just dump out. Our present van, was definitely going to be white. The new unit is 5500BTUs which does very well. Sometimes borderline on extremely hot days, over 100, which is very common with Florida Summers.
IMO from experience anything under 5k is going to be a waste of money. Our 2K Yamaha gen/inverter powers it with no problem. I removed the left rear window and made a fiberglass blank. I dissassembeled the new unit and replaced all the screws with stainless and thru-bolted whenever possible instead of just sheet metal screws before installing the unit. Custom cover made at local canvas shop. Been working great for over 10 years. Another point being that small it’s going to struggle and run constantly and not cycle

 

[DzlToy]

I am not so sure you will even get the 1500 BTU calculated above, as one video from the manufacturer shows a 3 amp draw with the unit running. Some quick math reveals the unit produces 131 BTU at 100% efficiency, in this mode. Even if this is the lowest setting, you have to be realistic about what you are doing here. Everyone loves the idea of low voltage/amperage HVAC, but if it were that easy to make a 12V unit and cool your van or tiny house, the industry would have done it long ago, saving billions of dollars in the process. The math simply does not work.

In another video, a gentleman attempts to put one of these 12V units into an older car that does not have AC. Little does he realise that vehicle AC units are often equivalent to TONS of AC in a house. The amount of energy needed to cool a poorly insulated car with lots of glass, in anything resembling warm weather, is staggering. Large vehicles have rear AC for a reason. Crane cabs and large, off-highway machinery with lots of metal and glass use large roof-mounted AC units for a reason. Sorry, there is no free lunch here.

Spend your time, effort, energy, money and other resources making your van, tiny house, boat or whatever you have as well insulated and air tight as you possibly can. Reflectix is not insulation. A half-inch foam board from Lowe's is not (good) insulation (R-2.5). This does virtually nothing to keep your van cool. Most houses have R-19 walls, R-30 in the ceiling or attic and R-50 or more in cold climates such as northern Canada, Alaska and Scandinavia. A R-3 or R-5 wall leaks heat like a sieve and will never be cooled by a few hundred dollar, low voltage AC unit, made in China. Save your money and some shipping and do it right, once.

 

[john61ct]

^^ yes yes wisdom here ^^

to add, we are **mobile** for a reason

whenever possible relocate, follow the 60's

many parts of the country, just driving up into altitude gets you a much cooler climate

when it's cold, head back down to the flat