Fridge not cooling - R-pod Owners Forum

That is most impressive marwayne, like everything else you do on your R-Pod! My temp has not changed inside the fridge although outside it is up to 94. I have the fridge side facing north so the sun only hits it until 10:30 so now it will reside in shade the rest of the day.

God's pod
'11 model 177
'17 Ford F-150 4WD 3.5 Ecoboost
Jim and Diane by beautiful Torch Lake
"...and you will know the Truth and the Truth will set you free."

Haven't seen such a chart either, probably because an RV absorption fridge is a a pretty complex device thermodynamically. Check out this slide presentation:

https://www.slideshare.net/IanLouiseCelestino/simple-vapor-absorption-refrigeration-system

If you go to around slides 17-20 you can see that the COP of an absorption fridge is related to three temps (To-condenser/absorber), Te -evaporator, and Tg -generator). I didn't run the numbers, but since To (essentially the ambient temp) is showing up twice, in the denominator in one case and subtracted in the numerator in another) COP is going to fall off quickly with higher ambient temps. And if COP drops cooling capacity drops along with it. To run the numbers you would need Tg, essentially the hot air from the propane flame or electric element. I found one reference for that which is around 350F. Note that you would need to do this calc in degrees above absolute zero (Rankine or Kelvin degrees), not in F or C.

The reference with the Tg of 350 was this, which is an interesting discussion of what causes damage to RV fridges and how to prevent it.

https://myamericancoach.com/wp-content/uploads/2018/02/ARPRV-Absorption-Fridges.pdf

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

Marwayne, that sounds like our weather here in NV last week. 23℃ in the afternoon and down to near 0℃ at dawn. Shocked

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

Last time I was in Edmonton, a Feb. about 10 or so years ago, it never made it to 0℉. It was especially entertaining watching cars trying to go up a moderately steep hill and slide back down to the bottom to try once more. I think I'd rather winter in Vancouver or Victoria. Wink

Never leave footprints behind.
Fred & Maria Kearney
Sonoma 167RB
Our Pod 172
2019 Ford F-150 4x4 2.7 EcoBoost

I didn't think you needed fridges in Canada? Big smile

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

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marwayne Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 25 Oct 2011 Location: Edmonton AB Can Online Status: Offline Posts: 1002	Topic: Fridge not cooling Posted: 03 Jul 2020 at 11:00am
	Try and shield the fridge vents from the heat of the sun By the way my pod is a 2011 and it works just fine
	If you want something done right, do it yourself. 2011 RP172, 2016 Tundra 5.7 Litre, Ltd.

jato Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Feb 2012 Location: Kewadin, MI Online Status: Offline Posts: 3219	Posted: 03 Jul 2020 at 11:15am
	That is most impressive marwayne, like everything else you do on your R-Pod! My temp has not changed inside the fridge although outside it is up to 94. I have the fridge side facing north so the sun only hits it until 10:30 so now it will reside in shade the rest of the day.
	God's pod '11 model 177 '17 Ford F-150 4WD 3.5 Ecoboost Jim and Diane by beautiful Torch Lake "...and you will know the Truth and the Truth will set you free."

StephenH Members Profile Send Private Message Find Members Posts Add to Buddy List podders Helping podders - pHp Joined: 29 Nov 2015 Location: Wake Forest, NC Online Status: Offline Posts: 6288	Posted: 03 Jul 2020 at 1:13pm
	I can't find a chart to show the relationship between ambient temperature and refrigerator temperatures for absorption refrigerators. At this point, I would blow out the LP line and see if it makes a difference. On our recent trip to the coast, we were maintaining temps in the 30's in ambient temperatures in the high 80's while set to 4 bars.
	StephenH Happy is the man that findeth wisdom,... ouR escaPOD mods Former RPod 179 Current Cherokee Grey Wolf 24 JS

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 03 Jul 2020 at 5:15pm
	Haven't seen such a chart either, probably because an RV absorption fridge is a a pretty complex device thermodynamically. Check out this slide presentation: https://www.slideshare.net/IanLouiseCelestino/simple-vapor-absorption-refrigeration-system If you go to around slides 17-20 you can see that the COP of an absorption fridge is related to three temps (To-condenser/absorber), Te -evaporator, and Tg -generator). I didn't run the numbers, but since To (essentially the ambient temp) is showing up twice, in the denominator in one case and subtracted in the numerator in another) COP is going to fall off quickly with higher ambient temps. And if COP drops cooling capacity drops along with it. To run the numbers you would need Tg, essentially the hot air from the propane flame or electric element. I found one reference for that which is around 350F. Note that you would need to do this calc in degrees above absolute zero (Rankine or Kelvin degrees), not in F or C. The reference with the Tg of 350 was this, which is an interesting discussion of what causes damage to RV fridges and how to prevent it. https://myamericancoach.com/wp-content/uploads/2018/02/ARPRV-Absorption-Fridges.pdf
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

marwayne Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 25 Oct 2011 Location: Edmonton AB Can Online Status: Offline Posts: 1002	Posted: 03 Jul 2020 at 5:27pm
	Jato, Cleaned up the fridge outside and turned it on, went from 23* C to 6* C in about 4 hours on LP
	If you want something done right, do it yourself. 2011 RP172, 2016 Tundra 5.7 Litre, Ltd.

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2587	Posted: 03 Jul 2020 at 6:50pm
	Marwayne, that sounds like our weather here in NV last week. 23℃ in the afternoon and down to near 0℃ at dawn.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

marwayne Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 25 Oct 2011 Location: Edmonton AB Can Online Status: Offline Posts: 1002	Posted: 03 Jul 2020 at 7:02pm
	It's been cool and wet.
	If you want something done right, do it yourself. 2011 RP172, 2016 Tundra 5.7 Litre, Ltd.

lostagain Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2587	Posted: 03 Jul 2020 at 7:53pm
	Last time I was in Edmonton, a Feb. about 10 or so years ago, it never made it to 0℉. It was especially entertaining watching cars trying to go up a moderately steep hill and slide back down to the bottom to try once more. I think I'd rather winter in Vancouver or Victoria.
	Never leave footprints behind. Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost

marwayne Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 25 Oct 2011 Location: Edmonton AB Can Online Status: Offline Posts: 1002	Posted: 03 Jul 2020 at 8:12pm
	If you can afford to live there, and I couldn't stand the grey rainy weather in the winter
	If you want something done right, do it yourself. 2011 RP172, 2016 Tundra 5.7 Litre, Ltd.

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 04 Jul 2020 at 5:54am
	I didn't think you needed fridges in Canada?
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold