Portable Fridge Bags - Work or Not?
Submitted: Tuesday, Jan 19, 2016 at 14:49
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975
I have owned a Waeco CF-45 for years now and purchased a protective insulated bag for it.
I have read many posts claiming the benefits of the Fridge once in a bag.
Today it's 39 degrees here (In
Griffith NSW)
The fridge is mounted in the back of a Black AWD (not ideal i know)
After 2 hours in the direct sunlight, the cabin temp is off the charts
But more alarming is the "Heat Soak" the Black OEM Waeco bag his induced with the sun through the window.
Sliding your hand in under the cover between the cover the fridge it is hot as hell.
I would think the fridge would be running cooler without a cover at all in this situation.
What are peoples thoughts on this?
Are these covers any use in High Temp, Direct Sun situations?
Seems to me, the Black Waeco cover just attracts more heat to the surrounds of the fridge.
Thank You
Reply By: Rob K (VIC) - Tuesday, Jan 19, 2016 at 16:52
Tuesday, Jan 19, 2016 at 16:52
Hi 975,
I think the bags are designed to keep the cold in, not keep the heat out. That's why the silver insulation is on the inside (I reckon). I agree the black cover is not a good idea if you want to keep the fridge as cool as possible.
When I find myself in a hot environment like you described, I do a number of things:
1. get as much ventilation going around the fridge's heat exchanger by removing things that might prevent air flow (open car windows and/or doors near the fridge if you can - even just a small gap to let the heat out of the car would help);
2. try and park in the shade or keep the direct sun away from the fridge;
3. provide more insulating material around the fridge, for example, I often place a woollen blanket over the fridge lid and sides (but not the motor area of vents) and find this helps keep the cold inside the fridge better than no blanket.
I'm sure others will tell you about reflective screens on the windows etc. and I'm sure they work. From my experience, it's all about trying to make the insulating layer around the fridge as thick as possible to keep the "cool in". The very thing fridge bags are useless at doing in high temperatures.
Not telling you what to do, just my thoughts on your query.
Cheers
Rob K
AnswerID:
595162
Follow Up By: 975 - Tuesday, Jan 19, 2016 at 22:46
Tuesday, Jan 19, 2016 at 22:46
Thanks Rob
Yes, i follow everything you suggest.
Most i find just common sense.
But i find the OEM Black topped insulated cover to attract far more heat that its concept protects from.
Yep, where possible i park in shade
Leave a door open... etc
But when in town, parked in a busy area, with no shade, i have little of those options.
FollowupID:
863829
Reply By: Les - PK Ranger - Tuesday, Jan 19, 2016 at 18:58
Tuesday, Jan 19, 2016 at 18:58
I think you're right mate, in that circumstance it might be better for the fridge to be out of the cover, or leave the top cover lid open ??
You only have to be in the sun driving in black shorts and feel the heat when the black attracts heat to know how bad it can be.
Black probably heats up more in the hot enclosed back, but moreso if it's in the sun.
Use some alfoil builders insulation over the window and keep the sun off it if that's happening.
AnswerID:
595168
Reply By: Malcom M - Wednesday, Jan 20, 2016 at 06:55
Wednesday, Jan 20, 2016 at 06:55
My experience with the bags has resulted in their being sold off.
Point to remember. The fridge can only drop the internal temperature relative to external temps.
ie if it can manage say a 40 degree difference then in a 50 degree closed vehicle, it can only ever drop to 10 degrees. Reducing ambient temperatures is key to cooling.
Have a fridge in the back of the 100 in a drawers setup. The fridge is surrounded by wood. Found that the bag restricted any cooling air from the sides resulting in a hot fridge. Fitted reflectors to the rear windows instead and the whole truck is cooler, therefore so is the fridge.
Have an 80 litre in the camper. Similar experience as it created a false ambient temp around the fridge. Tossed the cover and the fridge is now operating relative to the campers inside temp.
Where the bags do
well is in outside of vehicle conditions where the bag is acting as a sun shade. In an enclosed environment, I feel they are bad news.
AnswerID:
595178
Reply By: 671 - Wednesday, Jan 20, 2016 at 12:00
Wednesday, Jan 20, 2016 at 12:00
I have been using a 40 L Engel with an Engel bag on it in the back of a fully enclosed permanent camper body on the back of a ute for the last nine years without many trouble at all. Our travels have included two week long VHC trips in heat wave conditions in January.
Inside the closed camper is like an oven in those conditions but the fridge has worked perfectly with the temperature setting dial just a fraction above the lowest of the five positions. That is the five refrigeration settings, not the cool only position.
I don't know if the bag is helping or not but it does not appear to be doing any harm.
When I bought the fridge I thought some of them are going to be used in the open back of a ute in over 50 degree full sun in the Outback so inside the camper should not worry them.
The easiest way to get the correct information on this is to ring the fridge manufacturer and ask them
AnswerID:
595188
Reply By: CSeaJay - Wednesday, Jan 20, 2016 at 15:45
Wednesday, Jan 20, 2016 at 15:45
There are several replies above of individuals who has bags and used them for x years without a problem, other means of insulation and the like.
Personal experience is that I disagree with Waeco's advertising statement that it provides protection against moisture. It actually traps condensation and moisture between the bag and the fridge when used in humid tropical conditions.
Which brings me to my point that it is mainly advertising and money making. "do you want fries with that?"
My personal experience is that with or without the bag I do not see any real difference. Whilst I am sure it will make some difference, it is not noticeable and questionable whether it is worth its money as an insulator only. This statement is based only on me being observant and interested in monitoring the voltage and operation of the fridge through the remote indicator.
I have one, and use it but more as protector rather than insulator.
CJ
AnswerID:
595191
Reply By: Shaker - Wednesday, Jan 20, 2016 at 16:28
Wednesday, Jan 20, 2016 at 16:28
I lifted this from a physics website, it explains why desert Bedouin tribes wear black & also why Volkswagen air cooled engines have black tinware!
"We're all encouraged to wear white in summer, since white clothing is supposed to keep us cool — but it doesn't. In fact, black clothing is the best way to keep cool in the heat. It's basic physics. And biology. Find out why cool people will wear black this summer.
Generally in summer, we're treated to lines of loose summery white clothing. Not only is the white supposed to look nice floating around the edges of a picnic — until a few seconds into the event, when it has its first grass stain — people claim that white is the ideal way to keep cool in the summer. When we see white, we're seeing the combination of all possible visible light. This means that white clothing reflects a great deal of wavelengths of energy coming in. This means it should reflect the sun's rays back, instead of letting them
cook us. And that's perfectly correct.
Except that this explanation is also incomplete. Heat is not just coming in off of the sun. It's also coming off a person's own, sweating, warm-blooded, mammalian body, which is a lot closer than the sun is. When all that body heat hits the white clothing covering it, it gets reflected right back towards the body. When we wear white, we
cook ourselves.
The best color to keep cool in the heat, it turns out, is to wear black. Black absorbs everything coming in from the sun, sure. But black also absorbs energy from the body instead of reflecting it back. Now, the helpfulness of black clothes depends on finding black clothes that are the same thickness and looseness as those summery white clothes. Black clothing also needs a little help from atmospheric conditions. Once it has absorbed heat, it has to have some way to radiate it away. If there's even a little wind, black clothing is the better choice for those who want to keep cool, like goths who understandably don't like sweating through their make-up. So find something black to wear this summer.
And if people ask you what you're in mourning for, tell them you mourn their limited grasp of physics."
AnswerID:
595194
Follow Up By: Allan B (Member, SunCoast) - Thursday, Jan 21, 2016 at 00:36
Thursday, Jan 21, 2016 at 00:36
.
Shaker, that's a very interesting, and doubtful, yarn.
It also has no bearing whatsoever on the discussion of blankets over fridges. Read on.........
......."But black also absorbs energy from the body instead of reflecting it back".......
In the case of the fridge there is no heat being radiated from the fridge to be absorbed or reflected back. The fridge outer skin is cooler than the ambient due to the cold within the fridge, = no "heat". The aim of the insulation, be it within the fridge walls or of the (black) overcoat is to reduce the heat from the ambient entering the fridge.
Then there is...... "Once it has absorbed heat, it has to have some way to radiate it away."........
So now that the black overcoat has absorbed heat from the ambient, some of it will "radiate away" into the outer walls of the fridge and then be conducted through the insulation to the fridge chamber? That's just what we are trying to minimise.
The exposition that you have "lifted from a physics website" reads more like a Hiclone advertising spiel.
The whole function of fridges is to a) transfer heat out of the fridge chamber by refrigeration and b) surround the chamber with insulation to impede the transfer of ambient heat into the fridge. Any additional insulation will assist, white or black.
FollowupID:
863869
Follow Up By: Shaker - Thursday, Jan 21, 2016 at 13:08
Thursday, Jan 21, 2016 at 13:08
You obviously have a very poor understanding of refrigeration, of course heat is generated to enable cooling, how do you think a gas or kero fridge works?
Why do you think putting a fan behind a struggling Waeco upright fridge helps its performance, because it helps to dissipate the generated heat.
I know when I was racing Formula Vee that when people tried chrome plating or painting the engine tinware a light colour instead of the factory black, it caused problems with overheating.
As far as having no bearing on the discussion, weren't people criticising the black colour of the cover?.
FollowupID:
863893
Follow Up By: Allan B (Member, SunCoast) - Thursday, Jan 21, 2016 at 14:39
Thursday, Jan 21, 2016 at 14:39
.
Actually Shaker, I do have a qualification in refrigeration mechanics together with qualifications and long experience in process control of chemical plants where heat transfer and refrigeration processes form a major component. That should give me a fair understanding of the subject being discussed.
Take a look at the photo below of refrigerated LNG storage tanks. They and other such vessels are always clad in shiny aluminium or painted white to minimise heat absorption. I would think that the design engineers would know what they are doing. And have you ever seen a black milk tanker?
Your exposition of black clothing "has no bearing" as it was relating to..."But black also absorbs energy from the body instead of reflecting it back."
Well there is no heat energy being radiated from a refrigerator housing as it is below ambient temperature. The exercise is the other way, to minimise heat transfer into the refrigerated chamber.

Refrigerated LNG tanks

Refrigerated Milk Tanker
FollowupID:
863897
Reply By: Salty Dog - Friday, Jan 22, 2016 at 09:44
Friday, Jan 22, 2016 at 09:44
Thanks everyone
As a trial, i opened the top of the cover and folded out of the way, that made a difference.
I then did as one member suggested and put a white towel over the unit, that made a remarkable difference (it wasn't wet or damp though, just a dry white towel)
Now, onto the strange posts about Black being a good colour to wear or use to repel heat or direct sunlight.
Bahahaha, i have never laughed so hard.
You may need to explain that to all the Solar Hot water panel manufacturers.
Or stand outside on a hot sunny day in a Black T-shirt
Or get in my partner's Black BMW X5 in a 39 degree day in
Griffith!!!
There is a reason that 90% of the Cars in
Griffith are White or Metallic Silver, good luck trying to sell a Black car up there!
I renamed the Missus car the X5 Webber, as it made a great slow cooker.
Someone else that replied had also missed the point, with his Weaco in a fully enclosed camper, how does direct sunlight get to react to the Black Fridge Cover in that situation??
Yes, my fridge seemed to work better with the cover removed or partially removed in the environment i explained.
So as a consequence of this, i have no idea why Waeco made their covers with a Black top and ends.
I see the newer covers are NOT Black anymore.
AnswerID:
595255
Follow Up By: Shaker - Friday, Jan 22, 2016 at 17:33
Friday, Jan 22, 2016 at 17:33
So why do desert nomads wear black robes, why are radiators black & more to the point, why are fridge motors black?
Because it dissipates generated heat!
FollowupID:
863936
Follow Up By: Allan B (Member, SunCoast) - Friday, Jan 22, 2016 at 19:30
Friday, Jan 22, 2016 at 19:30
Shaker, I could spend hours explaining it all to you, but I won't.
Instead, just
read this which will explain the Bedouin clothing for you.
FollowupID:
863941
Follow Up By: Salty Dog - Friday, Jan 22, 2016 at 23:02
Friday, Jan 22, 2016 at 23:02
Show me a Black surfboard and i'll show you a Surfboard with no wax on it :)
And how many fridge motors see direct sunlight?
And i haven't seen too many Mobile Cool Rooms painted black in the passed 40 years.
But i have seen plenty of White Cool Rooms :)
FollowupID:
863947