Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: kenhat on October 20, 2019, 08:32:06 pm

Title: Ammonia Refrigerator Hot Weather Mod
Post by: kenhat on October 20, 2019, 08:32:06 pm
As all you ammonia refrigerator owners know when the weather gets hot so does the fridge. It was pretty common for my fridge to be in the high 40ºs during the hot part of the day.

I tried the urban myth thing of pulling the fridge and turning it upside down overnight then back upright for another 12 hours. Did that 4 or 5 times. Reinstalled with no appreciable improvement in performance.

Relined the fridge compartment with hardy boy while I had the refrigerator out. Thanks for the idea Pierce!

I did this mod back in June and have been very satisfied with it. Installed an 8" radiator fan from Amazon.

Amazon.com: cciyu 8" Inch Push Pull Slim Electric Radiator Cooling Fan Mount... (http://www.amazon.com/gp/product/B07MV28P6G/)

Wired the fan directly in and it sounded like a hurricane! Wired in a DC motor controller and turned the fan down so that I can just hear it. Just have the adjustment knob hanging out the vent for now. Not sure how or where I'll mount it. Went on the roof and can feel the heat pouring out the fridge vent.

Installed an extra long cable to power the fan so I could pull the cover easily. Also used Anderson PowerPole quick connects to ease pulling the cover off.

Fridge has been working great all summer. Today in Southern California temps hit  90º. Fridge is at 36º during the hottest part of the day.

see ya
ken
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: John Morales on October 20, 2019, 08:52:01 pm
Ken,
Is that fan pulling air in or out ?
John M.
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: kenhat on October 20, 2019, 08:58:35 pm
Ken,
Is that fan pulling air in or out ?
John M.
Pushing air in and up the stack.

see ya
ken
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: Pierce & Gaylie Stewart on October 20, 2019, 09:11:16 pm
Looks great! Lower speed probably uses a lot less juice and won't extend the time much to float on solar systems. . How about a thermostat to turn the fan off each night after the weather cools? Interior fridge thermostat would be really cool. ;)  ;)  ;)

Pierce
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: bbeane on October 20, 2019, 09:23:19 pm
Mine still has the little pancake computer fan that JC Refrigeration installed over a year ago works great. I just think it comes on at 130 degrees. When it dies I'll replace it with something like ken has done. 
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: MarkC on October 20, 2019, 09:24:51 pm
We have had very good results with the Titan fan system:
Amazon.com: TITAN- 12V DC Double Rack Mount Ventilation Cooling fan for... (https://www.amazon.com/Ventilation-Cooling-Refrigerator-Controller-TTC-SC22/dp/B077TJCL3F/ref=sr_1_4?crid=8NNZW3RXPZF4&keywords=refrigerator+fans+for+rvs&qid=1571620994&sprefix=refrigerator+fan%2Celectronics%2C262&sr=8)
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: kenhat on October 21, 2019, 12:58:22 am
Looks great! Lower speed probably uses a lot less juice and won't extend the time much to float on solar systems. . How about a thermostat to turn the fan off each night after the weather cools? Interior fridge thermostat would be really cool. ;)  ;)  ;)
With the speed controller it uses less than an amp. About .4 or .5 IIRC. For now I just go out and adjust the speed depending on the temperature. I crank it a little bit for higher temps. Forgot to mention the fridge is set on 4 out of 5 and is usually 33º in the morning. As soon as the temps drop I'll probably turn it off for the winter.

see ya
ken
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: kenhat on October 21, 2019, 01:00:48 am
We have had very good results with the Titan fan system:
Amazon.com: TITAN- 12V DC Double Rack Mount Ventilation Cooling fan for... (https://www.amazon.com/Ventilation-Cooling-Refrigerator-Controller-TTC-SC22/dp/B077TJCL3F/ref=sr_1_4?crid=8NNZW3RXPZF4&keywords=refrigerator+fans+for+rvs&qid=1571620994&sprefix=refrigerator+fan%2Celectronics%2C262&sr=8)
That looks like it would work but it's kinda pricy...

see ya
ken
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: kenhat on October 21, 2019, 01:03:15 am
Mine still has the little pancake computer fan that JC Refrigeration installed over a year ago works great. I just think it comes on at 130 degrees. When it dies I'll replace it with something like ken has done. 
Mine has 2 of the pancake fans but those didn't cut it for mine. The radiator fan made a huge difference.

see ya
ken
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: kenhat on October 21, 2019, 01:06:03 am
Forgot to post the link for the DC motor controller.

6-30V 20A 600W Max PWM HHO DC Motor Variable Speed Controller Switch... (http://www.ebay.com/itm/6-30V-20A-600W-Max-PWM-HHO-DC-Motor-Variable-Speed-Controller-Switch-Regulator/162431679351)

There are a ton of these on ebay look around for best price.

see ya
ken
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: wolfe10 on October 21, 2019, 09:43:23 am
Ken,

Only issue I see with that large fan pushing from the bottom is less linear flow/higher possibility of turbulence over the condenser (fined area at the top). And, laminar flow over the condenser is important to removing the heat.

Two small 12 VDC muffin fans installed on top of the condenser exhausting UP maintains laminar flow.

Accessing/installing from the roof is the way to install them unless you have the refrigerator out for some other reason.
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: kenhat on October 21, 2019, 09:55:23 am
Only issue I see with that large fan pushing from the bottom is less linear flow/higher possibility of turbulence over the condenser (fined area at the top). And, laminar flow over the condenser is important to removing the heat.
Don't doubt that that is happening but doesn't seem to matter. Fridge has been working great all summer. Working a little too well now with 50º nights. Was at 29º this morning on 4 setting. I've moved the thermistor down a little to warm it up a bit. (I think that's the right direction?) :)

My redneck solution is easy, cheap and effective as far as I can tell. For a total of $26 worth a try.

see ya
ken
Title: Re: Ammonia Refrigerator Hot Weather Mod
Post by: Pierce & Gaylie Stewart on October 21, 2019, 07:04:30 pm
Ken,

What do you think of the idea to put four of them across the radiator and wire them to a switch to be able to be turned on in case of a pump/motor failure? If a belt fails or any one of the other components, there is zero air passing through the radiator. This happened to us on a cross country trip three years ago. Ground was level but we could only go about a half mile at a time and then had to wait. While the fans would not cool enough to zip up grades, at least you would be able to drive slowly to a place to do the repair. That and driving with the heater on high could do the trick.

I've seen a big tour bus with an air cooled diesel with the only cooling a large electric fan blowing down on the engine. The fan never came on at idle.

Pierce