If you are not connecting gas you don't need venting to the outside just make sure that the fridge isn't too boxed in and can get rid of its heat.

If that is the plan why not go further and install a 12V compressor fridge

 

Compression type fridges can manage without vents.
Absorption type fridges need a good flow of cool air across their condenser, so they will need upper and lower vents. Don't confuse this with the small gas flu vent.
I think that a larger compressor unit would require more power than your batteries could manage. I guess that this is why larger motorhomes are fitted with evap units. And vents of course.

 

Hi Russell a Frank says no vents needed-- but if going that route just go for a normal house fridge possibly using via inverter as you can charge the battery's while running.I do not think 12V compressor fridge are made that big
terry

 

The vents to the outside serve a double purpose.

1. To vent combustion fumes when on gas so not applicable to your application.

2. To allow rejected heat from the cooling process to escape. If you enclose the heat exchanger its efficiency will be reduced, possibly to the point that it no longer works as a fridge.

3. I happen to have a built in fridge & it's an interesting question. The rejected heat is carried away into the void at the rear of the fridge. In my case this void is'nt completely sealed & the warm air can simply escape & is replaced by cooler air entering around the kick boards at the base of the kitchen units. Probably not the best idea for efficiency & I suspect will make the compressor work harder in an effort to keep things cool.

Lastly. The 3 way dometic on my van relies on convection to carry away the rejected heat. I guess these vents could be made a lot smaller if you had something like a computer fan to drive the air across the coil.

D.

 

I would second the 12V compressor fridge suggestion - far more efficient than a three-way fridge.

3-way absorption fridges are even less efficient on 12V/240V than they are when running on gas. They produce enormous amounts of heat compared with a compressor fridge.

Why?

Because an absorption fridge relies on heating the refrigerant gas/liquid (ammonia). So, you have all that heat plus the heat that is removed from the stuff inside the fridge.

A compressor fridge takes the refrigerant gas and mechanically compresses it back into a liquid. Far less heat is produced.

You can test that for yourself (CAREFULLY!) by simply touching the compressor at the back of your home fridge while it is actually humming.
It will be warm to the touch.

There is sufficient natural ventilation around your home fridge. If it is built-in there will be some ventilation slots anyway..

Do not even think of putting you hand anywhere near the back of a 3-way fridge flue. You WILL burn yourself.

 

Compressor fridge

Hi

Just so I am clear, does a compressor fridge work solely on 12v? In fact that could be a problem as I think coach electrics are 24v. Certainly the in dash radio/CD player is 24v. What difference does that make?

Only 22 other problems to go. Two more tomorrow!

Russell

 

IF the electric's are 24v then a 'step-down' transformer to 12v should do the trick

 

Compressor fridges for mobile use generally have a 12V/24V compressor.

They can easily be run from a simple mains convertor when on hookup or simply run it from your 12V/24V which is being charged up on hook-up anyway.

Look at the WAECO range, there is a lot of info and I think you can get quite large ones.

If not, go for two so that you can run them at different temperatures or even as freezers.

An absorption fridge takes a constant 10A or so on 12V.

A compressor fridge takes much much less and cycles on-off (depending on temperature differential) just like your home fridge so the draw is not constant.

 

I have often wondered about compressor noise. Those that have them say it isn't a problem, but the thought of sleeping in my kitchen at home does my head in. It is "quiet", but I still notice it start and stop when I'm having breakfast , say.

Dave

 

The WAECO site is partly down but I found this:

http://www.waeco.co.uk/page.aspx?page=powercon&s=4

http://www.waeco.co.uk/docs/Ins_cabinet fridges manual .pdf

http://www.waeco.co.uk/docs/Ins_cb36,40 & rhd-50 manual.pdf

We used the CB30 top-loader in our pop-top camper van.

The leisure battery would run it for about five days!

It was quite quiet and we soon got used to it even though our pillows were next to it.

The other really handy thing about these WAECO compressor fridges is that the compressor is connected by an umbilical and can be sited remotely up to 18" away from the fridge.
Fixed outside in a locker on sound absorbent mountings it would be largely inaudible.

I wish we had one in our Hymer!

 

Fridges

Oh Gee! I am confused.com already.

Questions then....

What type of fridge freezer would a Hotpoint built in appliance be as found in houses etc?

And the Dometic one in my 'van?

Russell

 

Virtually all domestic fridges are compressor run.

Your Dometic is almost certainly 3-way absorption.

 

Hi Russell, any ventilation a domestic fridge needs would be from around the top bottom and sides. The 3 way type would have to be sealed from the inside of the van, hence the need for vents on gas.BIG difference in price size for size. HOPE that clears things a bit :lol:
terry

 

Some more WAECO links:

http://www.waeco.co.uk/docs/050-055_Top Loading_Drawer_OTM-07.pdf

This is the one that you will find the most interesting.

http://www.waeco.co.uk/docs/056-063_Cabinets_CR_OTM-07.pdf

They all work off 12V or 24V.