Vent covers, why bother ? (1 Viewer)

Affiliate links here may earn MHF compensation

ymfb

Free Member
Jun 16, 2017
798
6,347
Salisbury
Funster No
49,040
MH
AS Kingham
Exp
Since 2009
Could someone explain the benefits of fitting vent covers, also any reasons to not fit them.

Thanks
 
Jun 29, 2015
3,551
59,106
Southampton
Funster No
36,999
MH
caravan (for now)
Exp
on and off since 1984
We don't use the MO HO in the winter apart from as a car, so don't fit the covers, the more air circulation the better. But if sleeping in it when it's cold we do fit them.
 
Apr 27, 2008
11,880
14,154
Eastbourne East Sussex
Funster No
2,327
MH
Hymer low profile
Exp
Since 1972
I fit the vent cover on the oven in the winter but don't bother with the fridge as it still seems to work fine. Unlike the fridge which is sealed the oven vent lets in a draught.
Perhaps in constant sub zero temperatures the fridge vent might help.
 

DuxDeluxe

LIFE MEMBER
Jul 10, 2008
14,691
73,610
Planet Zog
Funster No
3,243
MH
A woosh bang van
Exp
since 2008
My vent covers sit in the MH garage. Never used them but use the van all year round

Subscribers  do not see these advertisements

 

Theonlysue

LIFE MEMBER
Sep 14, 2009
6,111
7,411
Essex
Funster No
8,456
MH
As Executive 50th an
Exp
Not long enough!
Handy when its windy. Stops blowing the flame out.
I've camped in minus 15 and fridge worked better without covers than with.
Perhaps it's trial and error?
 

Shrimp

Funster
May 27, 2015
4,044
34,611
Bedfordshire, UK
Funster No
36,573
MH
Hymer B584
Exp
Long time
We put the covers on the other week when it was very cold and after a short time the fan was running, so we took them off again & it’s been fine.
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
54,455
154,794
On the coast in West Sussex
Funster No
658
MH
Carthago Compactline
Exp
Since 2008 & many years tugging
Use them all the time when the van is not in use, stops all the crap getting in behind the fridge. When the van is in use I fit them when it's cold but if running on gas I only fit the bottom vent.
I take them off when travelling as the have been known to come off and at over 40 quid a pair I don't want to loose them.
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
54,455
154,794
On the coast in West Sussex
Funster No
658
MH
Carthago Compactline
Exp
Since 2008 & many years tugging
We don't use the MO HO in the winter apart from as a car, so don't fit the covers, the more air circulation the better. But if sleeping in it when it's cold we do fit them.
Sounds like you have a very dangerous fridge installation, the back of the fridge must be completely sealed from the habitation area for safety. If there are any draughts it needs sorting.

Subscribers  do not see these advertisements

 

TerryL

LIFE MEMBER
Mar 5, 2010
6,248
8,303
North East
Funster No
10,511
MH
Low Profile
Exp
2009
This was covered in a thread a couple of weeks ago, but here is the real reason.

Your fridge has heating elements which are used to heat an evaporator, the cooling of which then cools the refrigerant liquid - sounds stupid but that's the physics of it, we all know evaporation results in cooling. Ordinarily the heating elements are able to provide enough warmth for the works to do it's job but if the outside temperature falls below a certain point insufficient heat is generated thus there is insufficient cooling. This in turn may* result in the temperature sensor inside the fridge demanding more cooling so the heating elements stay on longer - if you're on gas you may notice the gas burner running longer than usual. The point of the covers is to reduce the flow of outside air thus giving the heating elements a chance of doing a proper job and the manufacturers have specified a temperature at which point you should use covers. Incidentally you should never completely blank the vents off.

This also the reason you may be advised to turn the fridge controls down (i.e. less cooling) if you fridge doesn't appear to be working properly - again it sounds daft but it's true when you understand the physics.

*You note I say may. Some installations manage quite well without covers but it's also quite possible you never notice the fact that the heating elements are on longer than usual.

Tried to put it into basic language, but I only managed a "D" in O-level physics - at the third attempt!

As for reducing drafts, yes they're good at that too although that shouldn't be necessary in a properly installed fridge..........................

Subscribers  do not see these advertisements

 
Last edited:

Geo

Trader - Funster
Jul 29, 2007
11,757
14,566
Mansfield,Notts
Funster No
35
MH
Autotrail Tracker FB
Exp
45 +years with breaks
I think I did well in my O levels

Moths 0
Engrish 0
Histerry 0
Scyence 0
Woodwok, Nailed that:xThumb:
I was so good they said i didnt have to go back as i was excrement:xThumb:
 

pappajohn

LIFE MEMBER
Aug 26, 2007
43,515
51,033
Dark side of the moon
Funster No
172
Exp
Since 2005
The exhaust vent on my RV fridge was roof mounted, which most American RVs are, and on inspection the mesh insect guard had rotted through in places.
Removed the outer rain cover to replace the simple mesh guard and found an active bees nest.
It worth fitting the covers during none use/storage even in summer.
 
Feb 28, 2013
188
297
Carterton, Oxfordshire
Funster No
24,893
MH
Coachbuilt
Exp
Since 2012
Beware using the covers as recomended, up to plus 8C, I believe. I followed this instruction, the outside air temp was around plus 4C, and running on gas, anyway after getting a whiff of scorching, I found the top cover and slatted piece underneath warped. I can only assume it was due to heat build up. I now fit the top cover leaving a one slat space at the top. The covers are of the full width type and came with the van.
 

TerryL

LIFE MEMBER
Mar 5, 2010
6,248
8,303
North East
Funster No
10,511
MH
Low Profile
Exp
2009
Beware using the covers as recomended, up to plus 8C, I believe. I followed this instruction, the outside air temp was around plus 4C, and running on gas, anyway after getting a whiff of scorching, I found the top cover and slatted piece underneath warped. I can only assume it was due to heat build up. I now fit the top cover leaving a one slat space at the top. The covers are of the full width type and came with the van.

It should never get hot enough to damage the vent cover - I think there might be a diffuser of some sort (there is on my Swift) but I'm no expert. Methinks a proper inspection might be called for. Anybody else ever suffered this fault?
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
54,455
154,794
On the coast in West Sussex
Funster No
658
MH
Carthago Compactline
Exp
Since 2008 & many years tugging
Beware using the covers as recomended, up to plus 8C, I believe. I followed this instruction, the outside air temp was around plus 4C, and running on gas, anyway after getting a whiff of scorching, I found the top cover and slatted piece underneath warped. I can only assume it was due to heat build up. I now fit the top cover leaving a one slat space at the top. The covers are of the full width type and came with the van.
On the big fridge/freezers the top vent gets very hot on gas, I just fit the bottom one when running on gas.

Subscribers  do not see these advertisements

 

DBK

LIFE MEMBER
Jan 9, 2013
18,144
48,639
Plympton, Devon
Funster No
24,219
MH
PVC, Murvi Morocco
Exp
2013
This was covered in a thread a couple of weeks ago, but here is the real reason.

Your fridge has heating elements which are used to heat an evaporator, the cooling of which then cools the refrigerant liquid - sounds stupid but that's the physics of it, we all know evaporation results in cooling. Ordinarily the heating elements are able to provide enough warmth for the works to do it's job but if the outside temperature falls below a certain point insufficient heat is generated thus there is insufficient cooling. This in turn may* result in the temperature sensor inside the fridge demanding more cooling so the heating elements stay on longer - if you're on gas you may notice the gas burner running longer than usual. The point of the covers is to reduce the flow of outside air thus giving the heating elements a chance of doing a proper job and the manufacturers have specified a temperature at which point you should use covers. Incidentally you should never completely blank the vents off.

This also the reason you may be advised to turn the fridge controls down (i.e. less cooling) if you fridge doesn't appear to be working properly - again it sounds daft but it's true when you understand the physics.

*You note I say may. Some installations manage quite well without covers but it's also quite possible you never notice the fact that the heating elements are on longer than usual.

Tried to put it into basic language, but I only managed a "D" in O-level physics - at the third attempt!

As for reducing drafts, yes they're good at that too although that shouldn't be necessary in a properly installed fridge..........................
This is quite a good description of how these type of 'fridges work. :)

https://www.arprv.com/how-dometic-norcold-fridge-works.php
 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Latest journal entries

Funsters who are viewing this thread

Back
Top