Convert an AC air conditioner to a 12v dc?
- Thread starter DanielVictor
- Start date
30 Sqft, x 12 watts is 360watts draw. Figure 8 hours a day overall, you have 2880Wh just for the floor heat...
Water heat will be in the 1-2000 watt range, a small tank can heat in an hour, then be used for a quick shower, so add in another 1000Wh...
So, 4000Wh daily demand in winter, just for heating and water. /4 less solar in winter... you will need minimum 1000 watts solar input per day... it’s often cloudy in winter, so I would recommend 4 times this much solar...
Just to heat 30sqft in winter with electric radiant...
it can be done, but that is a HUGE awning setup when parked... no way to fit this even on an RV roof...
Water heat will be in the 1-2000 watt range, a small tank can heat in an hour, then be used for a quick shower, so add in another 1000Wh...
So, 4000Wh daily demand in winter, just for heating and water. /4 less solar in winter... you will need minimum 1000 watts solar input per day... it’s often cloudy in winter, so I would recommend 4 times this much solar...
Just to heat 30sqft in winter with electric radiant...
it can be done, but that is a HUGE awning setup when parked... no way to fit this even on an RV roof...
DanielVictor
New Member
- Joined
- Feb 22, 2020
- Messages
- 12
I don’t live in a cold climate. It’s more of a luxury that will prob be ran 3 hours a day once in a while max. I have a recirculating water system. Same 2 gallons of water being filtered through a 4 step filtration system which includes a
UV light.
Replace the compressor with a DC one from Danfoss
Replace the whole system with a 12V DC mini split.
sharkaire.com
Either option will need deep pockets.
Replace the whole system with a 12V DC mini split.
12 Volt DC 6000 BTU Ductless Mini Split
6000 BTU, 12 VDC Mini Split Ductless, Solar Ready Heat PumpAir Conditioner.
John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
The Danfoss is rated for the applicationsReplace the compressor with a DC one from Danfoss
Replace the whole system with a 12V DC mini split.
Either option will need deep pockets.12 Volt DC 6000 BTU Ductless Mini Split
6000 BTU, 12 VDC Mini Split Ductless, Solar Ready Heat PumpAir Conditioner.
HBP
LBP
MBP
Air conditioning compressors are designated
AC
LBP, MBP and HBP - Meaning and Application Overview - kaeltepartner.fr
Info about the different application areas of compressors.
kaeltepartner.fr
Full disclosure: I don't know what I'm talking about.
In my field compressors are rated low, medium and high temp... a high temp would be heat pumps and ac, medium would be coolers/refrigerators, and low would be freezers...The Danfoss is rated for the applications
HBP
LBP
MBP
Air conditioning compressors are designated
AC
LBP, MBP and HBP - Meaning and Application Overview - kaeltepartner.fr
Info about the different application areas of compressors.
Full disclosure: I don't know what I'm talking about.
richard cabesa
New Member
- Joined
- Mar 16, 2021
- Messages
- 176
The other thing to remember about floor heat is that it doesn't work like any other kind of air heater/furnace.
When you first turn it on, it takes awhile for it to heat the thermal mass of the floor and then radiate that heat to the air around you. I think it would be the absolute poorest way to heat a mobile living space.
When you first turn it on, it takes awhile for it to heat the thermal mass of the floor and then radiate that heat to the air around you. I think it would be the absolute poorest way to heat a mobile living space.
Idk, floor heat has advantages too... firstly, it doesn’t NEED to heat the air. It sends radiant heat to the body... the room and air can be 45F, and the body can be very comfortable with radiant heat keeping the feet warm, and skin heated from the radiant.
now, I’ve never used it in an rv... but I bet there is a way to achieve comfort with it...
Zwy
Emperor Of Solar
First, you must not understand how radiant heat works. I have it in my shop, the concrete mass is heated which then radiates the energy. The "mass" takes time to heat up, you don't turn the system on and think you will have instant heat. The "mass" must be heated at all times.
You would do much better using a heat pump (mini split) than electric radiant heat. Electric heat is about 90% efficient btu emitted, a heat pump is close to 5 times that. The reason is the heat pump is extracting the btu's from the medium (air in this case but water based are better).
Now if you were to use radiant heat from your engine cooling system (such as a sidearm heating a tank of water or glycol mix - preferred) and circulating that under the floor, then you might get by for a few hours, however you increase the weight of your vehicle. Second, is using propane to heat glycol mix or water which circulates in a closed loop under the floor (like my shop). This has weight also, the liquid circulating and the boiler plus a pump.
Really, the best heating system would be using something like the Espar heater, either as forced air or radiant. These sip fuel (gasoline or diesel) and are very efficient. https://thewanderful.co/blog/why-the-espar-d2-is-a-great-heat-source-for-your-van
Shop heat radiant is good, but it is not the only way radiant heating works.
Aluminum reflectors mounted below a subfloor, or flooring surface could heat a surface quickly.
sure, heating a concrete mass and having it radiate works great and is slow because speed isn’t the way it is designed, but that isn’t the only way to utilize radiant heat.
Aluminum reflectors mounted below a subfloor, or flooring surface could heat a surface quickly.
sure, heating a concrete mass and having it radiate works great and is slow because speed isn’t the way it is designed, but that isn’t the only way to utilize radiant heat.
EricHudson
New Member
- Joined
- Dec 11, 2020
- Messages
- 2
Huh, nice story. I guess your brother learned his lesson for the rest of his life. Electrician is not an easy job.
Everyone wants cheaper taxes, but there's nothing we can do and just pay the real tax prices.
Last edited:
0truck0
New Member
I think part of the answer is to swap out the alternating current compressor for a DC compressor so you can run the compressor straight off the battery. This have to be 12v compressor. Then you have a fan that is still alt current, so you still would need , though be it a smaller inverter, or to swap out the alt current fan for a DC fan. The air cond electronics are all DC too, but not necessarily 12v DC, so you need to step up the DC voltage, and skip the Alt current converter (which makes DC for the circuit board to use).
You can use whatever size compressor is right for your intentions, so can size a bit smaller compressor if your current compressor is over-kill.
All this assumes price is no issue.
I would build from scratch if I had more time and money and knowledge....
Use a car air cond parts but a DC compressor. DC comp are available for cars, but you could use any DC air cod compressor.
Place the evaporator in the cabin, runs auto a/c hoses to outside where the condenser is and use fans on both.
You can use whatever size compressor is right for your intentions, so can size a bit smaller compressor if your current compressor is over-kill.
All this assumes price is no issue.
I would build from scratch if I had more time and money and knowledge....
Use a car air cond parts but a DC compressor. DC comp are available for cars, but you could use any DC air cod compressor.
Place the evaporator in the cabin, runs auto a/c hoses to outside where the condenser is and use fans on both.
