Fridge freezer performance in hot summer ambient conditions

[cookie]

I did read somewhere that fridges are made for different levels of outside temperatures and countries , and it won't make a major difference what you do.
Also heard that moving the temperature sensor in the fridge on the fins can have a reasonable effect.

 

[tonyysue]

First step would be install fans with an electronic temperature control. If that doesn't work check out my infamous fridge saga thread..

Our 3 way fridge saga

My story just might help someone with 3 way fridge trouble so here goes; We've had our motorhome 3 years now and the fridge was always ok even in Spain's high ambient temperatures, until suddenly about a year ago we were in Spain, temperatures were the usual high twenties and I noticed the...

www.motorhomefun.co.uk

I made my own fridge fan controller and it works very well with only a tiny power standby usage, the posh controllers with a LED readout will use about 150ma continuously and even more when the relay pulls in.

Here's mine:

View attachment 401035
There's an on/off switch and 2 status LED's. The sensor is on a 1m long cable and it's just pushed into the fridge condenser fins, you can vary the on off setting by moving the sensor to the left or right in the fins. I can make you one at cost if you want, £5 plus postage.

I’ve asked this already, but against the wrong answer I think!. Ballpark cost and postage to Spain (Postcode 17480 Roses)? Presumably the box slots into the void behind the fridge?

 

[Two on Tour]

I did read somewhere that fridges are made for different levels of outside temperatures and countries

You probably read it on this thread, post number #39.

 

[Richard n Ann]

I’ve asked this already, but against the wrong answer I think!. Ballpark cost and postage to Spain (Postcode 17480 Roses)? Presumably the box slots into the void behind the fridge?

Going away today for a few days but I'll look into it when I get back

 

[Richard n Ann]

I am going to ask a daft question, I have a Thetford T1090 fridge 12v only compressor. What temp should I expect in the freezer section ? And would providing better air circulation ( fans ) make it more effective? Currently Freezer section doesn’t get below -5%. If I turn the setting to their highest the fridge section freezes at the back so I don’t switch to move the half way.
I also switch it off when we are not staying in the van, should I be keeping it switched on (solar should help with power drain) ?

To see if more ventilation would help, you need to note the temperature of the liquid pipe off the condenser, it's OK for it to be warm, but if hot it needs more ventilation.

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[Lenny HB]

I was quite surprised to find markings on the back of the fridge, roughly where I have mounted my fans labelled Fan 1 and Fan 2 ?. So I know for sure its where the manufacturer intends fans to be placed.
Can't understand why the manufacturers don't fit external ( and internal fans to circulate cold air ) when they know full well that they are needed in hot ambient temperatures.
Cost and reliability I suppose, but these fridges aren't cheap appliances to skimp on.

They probably supply an option with the fans for sales to hot climates, which doesn't mean they are in the best position. With commercial products they will choose the most cost effective option they can get away with.

 

[Borsuk]

We were in Tabernas the other week with temps in the 40’s, the site is new so not much shade on the van and our Theford Tek Tower had the freezer down to -5 ish and our fridge never got below 15. It never got there for long either before bouncing back up. We stuck a small fan we have for the dogs in the cavity and both temps came down a bit more though the fridge was still around 10 degrees. Our Mobicool box was looking after the perishibles with the fridge looking after the liquids. The coolbox was around 6.
We are back in the UK for a visit and both fridge and freezer are working fine now. I received 3 computer fans yesterday so they will be getting tie wrapped in with an on off switch for the run back to Spain next week or so. We initially thought the unit was fritzed but reading on here we learnt that this is normalish.
Probably replace it with a compressor at some point in the future once I get the van 12v system upgraded.

 

[MartinandBev]

Hi All,

Been reading through with keen interest as also residing in Spain am struggling to keep the fridge cool. Have fitted Titan fans both bottom and top of the fridge, and this last week even removed the fridge and tipped it upside down ( a work of art as the fridge would not fit through the hab door )

i also cleaned out the gas flue while it was out, and cleaned the gas burner and then lit the fridge on gas, I was told by a local dealer not to put on max as this works in the opposite way creating too much heat, so set it on No 2 and left it

After 12 hours my freezer was at -25 ( started at +31.9) and the fridge dropped to 10 ( started at 30.6) the ambient temperatures outside are +33 at the moment here in southern Spain, so wondering what peoples views are, is this the best I can expect? I was hoping the fridge would move more towards the 5-8 degree range?

thankyou

Martin

PS our fridge is a Thetford N3175

 

[John Barrett]

I found that a Waeco 35L portable compressor fridge was a useful cockpit accessory on my last boat - a 13m Dutch steel monster. Minus 19C was possible in 38C outside!

 

[Richard n Ann]

Hi All,

Been reading through with keen interest as also residing in Spain am struggling to keep the fridge cool. Have fitted Titan fans both bottom and top of the fridge, and this last week even removed the fridge and tipped it upside down ( a work of art as the fridge would not fit through the hab door )

i also cleaned out the gas flue while it was out, and cleaned the gas burner and then lit the fridge on gas, I was told by a local dealer not to put on max as this works in the opposite way creating too much heat, so set it on No 2 and left it

After 12 hours my freezer was at -25 ( started at +31.9) and the fridge dropped to 10 ( started at 30.6) the ambient temperatures outside are +33 at the moment here in southern Spain, so wondering what peoples views are, is this the best I can expect? I was hoping the fridge would move more towards the 5-8 degree range?

thankyou

Martin

PS our fridge is a Thetford N3175

They are the symptoms of our 3 way fridge saga...

Our 3 way fridge saga

My story just might help someone with 3 way fridge trouble so here goes; We've had our motorhome 3 years now and the fridge was always ok even in Spain's high ambient temperatures, until suddenly about a year ago we were in Spain, temperatures were the usual high twenties and I noticed the...

www.motorhomefun.co.uk

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[Richard n Ann]

do you you just slot the box in the cavity behind the fridge?

Screwed ours up under the bench seat next to the fridge, but it can go anywhere that's convenient really

 

[gus-lopez]

I was hoping the fridge would move more towards the 5-8 degree range?

I would expect it too also ,especially with a freezer at -25º? Maybe it now needs the evaporator paste renewed?
Mine,which is fridge only, can maintain 5º during the day on the shaded side whilst on ehu or gas. With overnight temps still in the mid 20's it easily gets below zero if you do not watch it.

**I used to install fly screen on both upper & lower fridge vents to prevent the flies getting inside .I have to remove it in springtime to allow unrestricted air flow.
You would not believe how much air flow is restricted by a net full of holes**

 

[AndyVW]

It does make a huge difference , sucks in from the bottom blows out the top Auto. operation Dometic temp sensor on the Tube,

 

[MartinandBev]

They are the symptoms of our 3 way fridge saga...

Our 3 way fridge saga

My story just might help someone with 3 way fridge trouble so here goes; We've had our motorhome 3 years now and the fridge was always ok even in Spain's high ambient temperatures, until suddenly about a year ago we were in Spain, temperatures were the usual high twenties and I noticed the...

www.motorhomefun.co.uk

Thanks, just read that and removed the fins, not a lot of paste on here so time for a renew I think, for the cost of it not worth not trying it really

is this the same stuff, trying to order here in Spain, so Amazon looks best bet for quick delivery

Amazon product ASIN B0009PTBZ6

 

[MartinandBev]

I would expect it too also ,especially with a freezer at -25º? Maybe it now needs the evaporator paste renewed?
Mine,which is fridge only, can maintain 5º during the day on the shaded side whilst on ehu or gas. With overnight temps still in the mid 20's it easily gets below zero if you do not watch it.

**I used to install fly screen on both upper & lower fridge vents to prevent the flies getting inside .I have to remove it in springtime to allow unrestricted air flow.
You would not believe how much air flow is restricted by a net full of holes**

Interesting point about the fly screens, as I have just fitted some over the grilles for the obvious reasons, but now you have me thinking

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[Bucket]

So it looks like fans are the way to go. I've seen many different options but what I frequently notice is that people have to fabricate mounts to fit the top vent. Does it have to be difficult ?

I just used a couple of cable ties on each one.

 

[Richard n Ann]

Thanks, just read that and removed the fins, not a lot of paste on here so time for a renew I think, for the cost of it not worth not trying it really

is this the same stuff, trying to order here in Spain, so Amazon looks best bet for quick delivery

Amazon product ASIN B0009PTBZ6

Yes as long as there's enough. It's just the same paste as is advertised for processor heatsinks. Mine was golden and I think 30g tubes x2

 

[MartinandBev]

Thankyou, well the pipe behind is freezing so I’m optimistic that when I reassemble it all works fingers crossed

 

[Otter Spotter]

To see if more ventilation would help, you need to note the temperature of the liquid pipe off the condenser, it's OK for it to be warm, but if hot it needs more ventilation.

I cannot get around the back of the fridge, it is screwed in place and there are no vents at the back

 

[Borsuk]

Just in the process of fitting 3 cheap 12v computer cooling fans to the upper vent screen of my fridge freezer with cable ties. Ordered some heat transfer paste as well so I will renew that when it arrives.
At the moment the fans are always on, waiting on some switches to arrive. The supply coming off a 12v socket at the door. If this works I will see about a better more efficient arrangement but I am an admirer of the KISS principle so it may stay like this forever.

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[2657]

I am an admirer of the KISS principle so it may stay like this forever.

As am I

 

[JohnH17]

An add-on to JFD's reply about the mesh behind the grilles - a few years ago I spoke to the Dometic tech support chap at the NEC show, who said:
- use the winter covers below about 8degC (ok, so this is for future reference in about 6mths!)
- for the fridge fan (the Dometic kit), the thermal switch is set to 62degC for an ambient of about 35degC
- remove the mesh behind the grilles - it cuts airflow by 50%; insects don't go in there anyway as it's too hot!
It surprised me, but it does work
John

 

[TerryL]

Have just fitted an MCV-2 fan kit I ordered from Italy. Looked at the Brunner offerings but the reviews suggested a high proportion of units had to be returned for replacement whereas the MCV-2 had nothing but good reports.
BUT IT WAS QUITE EXPENSIVE! However I'm a numpty when it comes to stuff like this so I'd rather spend a bit more to get a professional setup - although upon inspection it is just a couple of computer fans in a frame with an electronic control box.

I fabricated a mount out of some alloy angle attached to the metal shroud as there was virtually nowhere else to attach the fan unit. The control unit fits neatly on the side of the fridge housing and the cable to the fans through the bulkhead. Power from a nearby 12v socket and Robert is your fathers brother! It has an automatic setting which cuts the fan in at low speed above a variable temperature then switches to high fan speed when the temperature exceeds 50°C - it can also be manually set to the high speed if required. Very quiet in operation and there is a significant flow of warm air being extracted (yes I DID manage to fit it the right way round first time - very unlike me!)

I did this because on our last couple of trips the gas burner was running almost constantly, I believe trying to cool the fridge down. I have replaced the internal sensor and redone the thermal paste. I also only operate it at around half the control setting which generally keeps everything cool.

Off to Stratford tomorrow and the forecast is for hot hot hot - let's see if this helps.

 

[Jim and Louise]

As you say, each persons experience is different, so I very much doubt you will find a definitive answer as there so many variables with different fridges and the fan setup used.

This is our fridge fan setup, 3 x 140mm fans that can be individually switched on or off at the fans, and internal fan to move air around and digital temperature controllers.
Probably a bit over the top for what you have in mind.

View attachment 401019

View attachment 401020

View attachment 401021

May sound silly but what is the direction of the airflow inward or outward ?

 

[Two on Tour]

May sound silly but what is the direction of the airflow inward or outward ?

Draw cool air in through the bottom vent which then passes up taking heat away from the cooling fins on the condenser pipework near the top of the fridge and out through the top vent.

The fans on the top vent are drawing hot air out.

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[JohnH17]

if you fit them at the bottom, inward, at the top, outward. you need airflow over the fins at the top - oh see previous answer!

 

[MartinandBev]

Well just as an update, stripped mine back and removed the evaporator fins, and cleaned the pipe and applied loads of new thermal paste, but alas freezer performance is good. -25, but the fridge will only just scrape 10 degrees and that’s with a fan on the bottom drawing in air and a fan at the top exhausting air - my only conclusion now is the fridge is knackered (it’s only 4 years old) and time for a new one - ouch

 

[Landy Andy]

Well just as an update, stripped mine back and removed the evaporator fins, and cleaned the pipe and applied loads of new thermal paste, but alas freezer performance is good. -25, but the fridge will only just scrape 10 degrees and that’s with a fan on the bottom drawing in air and a fan at the top exhausting air - my only conclusion now is the fridge is knackered (it’s only 4 years old) and time for a new one - ouch

I’m not an expert, but I don’t think it can be knackered as if the freezer is working so well, the fridge should be as they use the same system. It’s not fridge system, and freezer, it’s shared. Maybe just needs more time to sort freezer, then fridge gets going?
I'm sure an adult will be along in a bit to give info.

 

[Graham of Madrid]

Before any adult arrives, is the fridge door pushed firmly shut (my N3000 series needs a firm push sometimes) and are the rubber seals in good condition. I agree - the freezer is working too well to condemn the fridge.

 

[MartinandBev]

in the absence of adults ha ha .

I have had it running for 24 hours now since applying thermal paste, and the fridge is cooling, as when I started it was 32 degrees inside, and I can get it to 10.9, but agree the freezer works well, so am confused yes fridge door closes well, seals look good, no splits or anything, I am going to put a light in it when dark to check there are no leaks but confident on that one……

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