Cooling fan installation for Thetford fridge

[wildebus]

No, the fans are at the top, and you'd get far more airflow when driving, plus the burner has a cover to keep it out of any wind.

You have to make sure the fans are pointing the right way

If at the top, you want them extracting the air to the outside, but if at the bottom, you want the fans pulling in air.
This is where and how my fans are setup, to push outside air onto the compressor of my fridge, but on the 3-way, fans up top for sure.

 

[Pudsey Bear]

I debated with myself about the positioning of the fans David, and I selected at the top, drawing the hot air out. This made access to the burner easier, and I couldn't find any data on which was best, pushing in or drawing out, at the time.

I surmised that it probably wouldn't make much, if any difference, as any air going out would suck a similar volume in.


I also fitted a PC in the fridge, blowing off the fins. I didn't take any pics of the final fitment.

I did inform the shopping and fridge filling elf that there needed to be some space between things for the air to flow, but braking etc tended not to help in that attempt.

 

[Wooie1958]

They need to push air out from the top and not pull air in from the bottom. This will pull debris in and towards the burner.

 

[wildebus]

They need to push air out from the top and not pull air in from the bottom. This will pull debris in and towards the burner.

Should have filters on the fan wherever they are.

 

[Pudsey Bear]

In the bottom or out at the top, only so much air can flow; regardless, I didn't fit a filter, not that much flow, so I didn't want to restrict it further

 

[wildebus]

In the bottom or out at the top, only so much air can flow; regardless, I didn't fit a filter, not that much flow, so I didn't want to restrict it further

When I say "filter", didn't mean some kind of pollen filter but more a protection against larger things being sucked in.
So in my case, I made sure to have the fans behind the original filter/grill

 

[MERL]

Theoretically the amount of air flow would be the same whether you installed them pulling or pushing. BUT putting them in the top in a pulling fashion would ensure a slightly negative pressure on the fridge burner system, putting them on the bottom inlet side 'pushing' would create a slightly positive pressure on the burner.
If your fridge rear wasn't perfectly sealed from the habitation area (which it should be) then the positive system would tend to drive burner fumes or worse still leaking propane gas INTO the hab area. For this reason I think fans in the upper section would be preferred.

 

[Pudsey Bear]

When I say "filter", didn't mean some kind of pollen filter but more a protection against larger things being sucked in.
So in my case, I made sure to have the fans behind the original filter/grill

Ah, both of the vents had a sort of gauze on them

 

[MERL]

Though this appears to raise concerns about using a PWM type speed controller with brushless motor fans.

I take it you missed putting a link in your post Chris?
Most PC cooling fans use a 3 or 4 wire system to operated a PWM speed control system, this is because reducing the voltage to the fan by either analogue or PWM can lead to a voltage selection that lets the fan run nice and slow once it's actually running but the fan won't actually start at this voltage and sits stalled and generating heat and possibly burning it's self out. If you're intending to fit a speed controller to a standard 2 wire fan then it's maybe best to ensure the fan starts reliably at its minimum setting OR install a 2nd timer module that bypasses the speed controller momentarily at switch on.

 

[wildebus]

Ah, both of the vents had a sort of gauze on them

yeah, it was my bad saying 'filter'

 

[TJBi]

Is it a Thetford 3-way fridge? If so, where is the flue?

 

[Geek]

Please can you tell me where the speed controller came from?

It was many years ago that I fitted it. At that point it came from my 'bits and pieces' drawer, but it almost certainly originally came from China on the slow boat, probably via ebay.

 

[Geek]

One question.
If the fridge is running on gas , is the extra air flow likely to cause any issues with the burner?

No, absolutely not.
The burner is in a box at the bottom. The vent fans suck outwards at the top, where there is supposed to be strong convection current anyway.
The burner is supposed to stay lit where there is literally a gale blowing in through the bottom vent.

 

[Canalsman]

Is it a Thetford 3-way fridge? If so, where is the flue?

Yes.

On the right hand side looking from the back.

 

[Canalsman]

I take it you missed putting a link in your post Chris?
Most PC cooling fans use a 3 or 4 wire system to operated a PWM speed control system, this is because reducing the voltage to the fan by either analogue or PWM can lead to a voltage selection that lets the fan run nice and slow once it's actually running but the fan won't actually start at this voltage and sits stalled and generating heat and possibly burning it's self out. If you're intending to fit a speed controller to a standard 2 wire fan then it's maybe best to ensure the fan starts reliably at its minimum setting OR install a 2nd timer module that bypasses the speed controller momentarily at switch on.

I didn't omit a link.

However this is what I'm considering:

DEWIN DC Motor Speed Controller, 0-100% Adjustable Wireless Remote Control DC Motor Speed Controller DC 6.5-55V 30A LCD Smart Display Timing Control : Amazon.co.uk: Business, Industry & Science

DEWIN DC Motor Speed Controller, 0-100% Adjustable Wireless Remote Control DC Motor Speed Controller DC 6.5-55V 30A LCD Smart Display Timing Control : Amazon.co.uk: Business, Industry & Science

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