Loft insulation for fridge insulation - stupid idea ?

affinite

affinite

Well-Known Member
Joined
2 Feb 2005
Messages
1,239
Location
Eastern Med
Visit site
I am opening myself up to be shot at but here goes ...

I want to improve the insulation on my top loading coolbox/fridge.

Trouble is the boat is in Turkey and
a) I'm not sure I will be able to source Celotex boards locally in Turkey
b) Celotex boards are too bulky to try and carry them on the plane

so I wondered if I could take a roll of loft insulation in hold luggage and lag the fridge with it (a bit like a hot water cylinder jacket)

Any thoughts ?

Good idea or muppetry ?

Happy Christmas and Happy New Year to all.

Steve
 
A heat flow researcher writes ...

Whatever you use (my only worry about loft insulation would be escaping fibres), make sure you add lots of reflective material.

People almost always forget radiation as a source of heat, and it's a very important one. Space blankets work well: if you are going to use loft insulation I'd suggest a layer of space blanket (bright side out), 2" of loft insulation, another layer of space blanket, another 2" of loft insulation and a final layer of space blanket.
 
affinite said:
... a bit like a hot water cylinder jacket ...
Click to expand...

Well I'm a muppet, as I actually used hot water cylinder jacket panels around and beneath our top loading cool box, because I did not fancy the potential problems of loose fill or expanding foam, and Celotex board would have been difficult to get into the gaps. For me the advantages were that they could be relatively easily manipulated into the spaces (of varying width) without mess, they are protected against water ingress, and they can be easily and cleanly replaced. Doubtless they are not particularly efficient, but they are certainly better than nothing.
 
John the kiwi said:
... sorry, just couldnt resist! ...
Click to expand...

No apology needed - very good indeed! :) :encouragement:

(As I wrote, I was a bit concerned that I could not put a figure on how much 'better than nothing' it is. You have just shown me that that was just another example of baseless worry! :()
 
With access difficulties to the outside of our fridge box and the worry of expandable foam doing damage by expanding to much, i am thinking of Celotex sheets on the inside.

its a big box that we never completely fill???

Your thoughts please
 
Rogershaw said:
This table shows the U- value of various insulation configurations of fibre glass blankets

http://www.combustionresearch.com/Infra-Spec/infra-spec/uvalue.html

Compare with the U-value for Celotex for your answer.

I used spray in foam the same as I used to insulate my whole boat.
Click to expand...

Roger - thanks for the link
Re Spray-in foam, were you concerned about moisture absorption in open-cell foam?
Builders spray foam does seem like a good idea wrt application in confined spaces, but I know this idea has been discussed on here before and concerns raised over water absorption.
 
Ribtecer said:
With access difficulties to the outside of our fridge box and the worry of expandable foam doing damage by expanding to much, i am thinking of Celotex sheets on the inside.

its a big box that we never completely fill???

Your thoughts please
Click to expand...

Toby, this is a job I'll soon be embarking on, for similar reasons (along with fitting a new evaporator, pump and keel-cooler). One of the main issues as I see it is sealing the insert, so that the new interior is waterproof...and vapour-proof: obviously I don't want any voids between the new interior and old to become damp and pongy.

Happy to chat in detail by PM if you wish.
 
Has anyone got experience of Cryogel® Z? (Claimed to have "... lowest k-value of any cryogenic (cold work) insulation material in the world".)

http://www.aidirect.co.uk/insulatio...-cryogenic-cold-work-insulation-material.html

It's £108 for 1.45x1.0m, but I reckon that amount would just cover the outside of our ca. 70 litre coolbox, assuming it can be cut and the edges taped (?) - and its just 10mm thick.
 
Last edited:
Hydrozoan said:
Has anyone got experience of Cryogel® Z?

http://www.aidirect.co.uk/insulatio...-cryogenic-cold-work-insulation-material.html

It's £108 for 1.45x1.0m, but I reckon that amount would just cover the outside of our ca. 70 litre coolbox, assuming it can be cut and the edges taped (?) - and its just 10mm thick.
Click to expand...

It's a brand name for aerogel. If you search by that name you'll get a broader range of information.
It's very space age (originally from NASA...the American one ;)) It's often claimed to be 'up to 5 times more effective than conventional insuating materials', but from what I've discerned it's only about 1.5 to 2 x better than products such as Celotex. And a whole lot more expensive. Still, where space is tight, it could be very useful.

'Basic' aerogel is hygroscopic, but most is treated to make it hydrophobic. As well as blankets, it's also available in rigid boards, sometimes with a foil vapour barrier. There's also a fireproof version, but IIRC it doesn't burn, anyway.
 
macd said:
It's a brand name for aerogel. ...
Click to expand...

Thanks, Mac - I had a quick look years ago at Aerogel, but was not sure if/how Cryogel Z was differently structured for cryogenic work. So, as it's in 'blanket' form, my specific follow-up questions (which I appreciate you may not be able to answer) would be: Is Cryogel Z (specifically) hygroscopic? Can one cut and tape it? (The photos on that link show a valve (?) lagged with it and what appear to be foil taped ends.)

It is expensive, but as you say it could be very useful where space is tight (as it certainly is for our coolbox) - and the P&P to me in the UK would be £12 I find (for a total of £120 - sometimes it adds a prohibitive amount to a small order!). So it is a possibility to think about. I wonder what happens to the offcuts from a large job like that 'I'm green' spherical tank in the photo ... :)
 
Hydrozoan said:
1. Is Cryogel Z (specifically) hygroscopic?
2. Can one cut and tape it?
Click to expand...

These are off the top of my head, although I have read up on the subject:
1. It's probably treated not to be, but I'd double-check with the supplier.
2. I see no reason why not, but I'd be inclined to bond it, too. Aerogel seems not to like many solvents, but I can't see any problem applying adhesive (Sika or similar?) direct to the foil barrier.
 
Why not just get some closed cell foam mat and glue it on.

Camping bedrolls are cheap and light.
 
The thing to realise is. there is no such thing as loft insulation, or fridge insulation, or cylinder insulation. It is all just insulation and the important thing is the properties, both thermal and moisture resistance. Just look and see if the properties suit your application.
 
affinite said:
Roger - thanks for the link
Re Spray-in foam, were you concerned about moisture absorption in open-cell foam?
Builders spray foam does seem like a good idea wrt application in confined spaces, but I know this idea has been discussed on here before and concerns raised over water absorption.
Click to expand...

I used both spray in foam from a company whose main business is insulated containers and refrigerated trucks. I also used the same foam in sheet form. I found the guy who fitted my stainless steel fridge box left a section out that caused the fridge to take too long to cool down. When I found the void the open section had been creating condensation. that was lying on top of some of the foam but did not soak into it so must be closed cell.. The void I did fill with spray in foam can from a local supplier and would stick to the stainless steel case and thus prevent condensation. The spray in foam uses moisture in the air to expand and set so any condensation around would help the foam to expand and set.
 
All fridges if not properly indsulated will get condensation outside which would make the loft insulation wet. This is why it is never used for that task and it's usually polystyrene.You can get loft insuation in foil but when you cut it to fit the insualation would be uncovered.
 
You must log in or register to reply here.

Share this page

Top