Why are Absorbtion type Refrigerators used in RVs?

[Derrek]

Sent: 9/22/2002 8:44 AM

Can anyone in the group tell me why absorption units are used for motorhome refridgerators/freezers and not for a/c units? I have tried to do research on the net but have had no luck. I know that these units are used in large office buildings and on college campuses for air conditioning with steam as the heat source. So why not motorhomes with propane as the heat source? My only guess is that small absorption units are not as efficient as large ones. Is this true? Has any motorhome manufacturer ever offered an absorption style a/c unit?

[denisondc]

Sent: 9/22/2002 5:28 PM

I would presume an absorption type unit would be too large and heavy if it were sized to move as many btu/hour as a roof a/c unit does. I don't know its btu rating, but the current draw of my Winny fridge is less than 2 amps, and the running current of my (small) roof unit is 11 amps. That much energy would be a large propane flame. The nice thing about absorption units is that they will work from any heat source, 110V, propane, 12V, but they sure take their time making ice cubes. Whereas 2 minutes after I turn on the roof a/c I want cool air blowing in my face! Denison

[chip]

Sent: 9/22/2002 7:46 PM

pound for pound, ammonia is eight times more efficient than freon but refrigeration by absorption is a relatively slow process like the previous post said.

[Derrek]

Sent: 9/23/2002 8:38 PM

Thanks for your responses guys! Again as with each time I come to this site, I picked up some more interesting info. Your responses got me thinking so I went back to the search engines and began searching for more info. In the end what I gathered was this. Large office buildings, college campuses ect use absorption units because they are cheaper than electric compressor units. Sound funny? Here is the catch. The heat source for there units is steam or actually waste steam. Steam that has already been used for hot water heaters, some production process ect. and would simply end up being wasted, but instead is used for the chillers. So in these situations the absorption process is the cheaper way to go. In an RV setting it would be just the way you both pointed out. Need a large cooling unit. Need a large heat source. And in the end would cost more to run than a compressor unit.Thanks for the help guys!