Waeco compressor fridges

[Stuwsmith]

I have a Waeco MDC50 compressor fridge fitted in my 'van. I am quite happy with it and, for me and my 'van think it is a good accessory. However, I was surprised at how often it switches on and off.  I use the fridge on its minimum setting as I find that on this setting this is sufficent and will freeze chicken breasts put in its small freezer compartment. I, perhaps naively, thought that once the fridge got down to temperature and providing its insulation was good, its on cycle would be significantly less than its off cycle. Is this regular on/off cycle even in cool weather normal?   

[Mel B]

Just a word of caution, unless the fridge specifically says you can freeze fresh food in the freezer compartment (3* or more I think), don't do it. It might not freeze it correctly/safely - can't thing of the exact reasons why you shouldn't do it but I just know you shouldn't. Don't want any jippy tummies!!! *-)

[Stuwsmith]

Thanks for the warning Mel. I hasten to add that I don't intentionally freeze meat in the fridge, it just happens even on the minimum setting and as it is only a small fridge I have to use all available space including the small "freezer". I use any frozen items quite quickly and always make sure they are well defrosted. I think the danger occurs when you keep frozen meat for a long time at a less than ideal temperature then eat it.

[Mel E]

We too have a Waeco fridge. It also switches on and off relatively frequently, but spends much less time 'on' since I made sure the ventilation was clear (it was partially blocked at the back). The fridge must have a clear air flow from underneath the front, up the back and then out through the grill at the top. I also added a small computer fan ducted externally that is connected to the fridge and switches on whenever the fridge does, tho' it's got its own switch so we can leave it off at night. Your model is rated by Waeco as requiring 0.8 amps at 25C and 1.0amps at 32C ambient temp, both to maintain 5C in the fridge. If, however, you turn it fully up, it is likely to be on much more as you're effectively telling it to maintain an even lower temp inside. The compressor unit used by Waeco is a Danfoss BD35 unit, the same as that used in home fridges, and widely used in the industry, so it should perform very similarly. Just like any other fridge, it will perform best when it is not packed chock full, of course. Hope that helps. As far as I am aware, all the Waeco fridges are rated so that you may freeze in their freezer compartments. But you must not try to freeze too much at once, or you will slow down the process allowing bacteria to breed before the freezing is complete.

[Stuwsmith]

Mel,Like the bit about the fan, presumably it uses less battery power than is saved by the fridges "on" cycle being shortened. I do have the correct ventilation although having a dark coloured panel van conversion, things get quite hot between the fridge and van side when the sun is on it.  What really puzzles me is that the fridge still cycles on and off fairly regularly even at night in winter. I don't have heat on in the van and on occasion wake up with ice on the inside of the windows and a temp of around 40F registering on the thermometer yet the fridge still goes on and off although the off period does increase under these conditions. I would have thought that in theory, with the fridge set to maintain 5C and given that the temp inside the van was 5C the fridge shouldn't switch on at all but perhaps I am missing something

[Mel E]

The computer fan uses less than 0.1 amps, and I mounted it on soft rubber pads to keep its noise to a minimum. Surely if you have the dial turned right up, you are asking for a lot less than 5C. The answer is to get a fridge themometer (Boots, or similar), put the fridge to various settings and see what you get. Remember that all a fridge is is an insulated box, some tube that runs from the inside to the outside of the box and a compressor. As the liquid in the tube is compressed it gives up heat (outside), cooling and absorbing heat as it does so inside the fridge as the liquid is allowed to expand again. Once the liquid gets back outside the fridge, compression causes the heat to be given up. If this heat is noit being got rid of, then the fridge effeciency will be severely compromised. All Waeco fridges of the MDC range have a wiring point on the back to wire in a fan. But do put an accessible switch in this fan circuit as, however carefully you mount the fan, it will create some noise as it shifts the air. I got our fan from Maplins and the brown flexible ducting from out local caravan dealer.

[olley]

hi Mele you description of the workings of a compressor fridge is not quite correct. The cooling cycle is from liquid to gas, under pressure from the compressor the gas is turned into a liquid and in doing so gives up heat, it then enters the fridge where it is allowed to turn back into a gas, to do this it needs heat, which it takes from the interior of the fridge, it then passes out to the compressor where it is liquified and then the cycle starts again. Olley

[Brian Kirby]

[QUOTE]olley - 2006-11-08 7:15 PM hi Mele you description of the workings of a compressor fridge is not quite correct. The cooling cycle is from liquid to gas, under pressure from the compressor the gas is turned into a liquid and in doing so gives up heat, it then enters the fridge where it is allowed to turn back into a gas, to do this it needs heat, which it takes from the interior of the fridge, it then passes out to the compressor where it is liquified and then the cycle starts again. Olley[/QUOTE]

Just like us then, really!

[twooks]

We have a Waeco compressor and have been very impressed with its efficiency, it does freeze anything left in the little compartment very quickly and so is presumably ok? Like Stu it was not intentional and now I'm very careful about what I use that area for. B-)