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Fridge insulation


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#1 Nzgrant

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Posted 12 July 2019 - 12:33 PM

Im going to have go at building a fridge but cant seem to find what to insulate it with(google has not been my friend).

Figured someone in crewland will have done this and could point me in the right direction.
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#2 mattm

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Posted 12 July 2019 - 12:43 PM

Talk to Fridgetech Marine in Auckland. They can sell you the correctly rated insulation, in a variety of thicknesses. They can also supply it with a plastic layer on one or both sides, which can be used as the inside liner of the box, just cut insulation/plastic sheets to shape, glue together, seal edges, box made.
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#3 wheels

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Posted 12 July 2019 - 01:04 PM

There is also one that has a heavy aluminium foil on it as well.
The insulation material is Polyurathane Foam. It has the highest R rating of pretty much anything. Normally minimum of 25mm thick it used for fridge and 50mm for freezer. Please note that being minimum. The thicker you can make it, the better, but space is always going to be your limiting issue.
 


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#4 Island Time

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Posted 12 July 2019 - 01:28 PM

Im going to have go at building a fridge but cant seem to find what to insulate it with(google has not been my friend).

Figured someone in crewland will have done this and could point me in the right direction.

In the interests of full disclosure, I'm the NZ Ozefridge agent. Have a look here, http://www.ozefridge....au/?page_id=28  then scroll down a bit for on that page for cabinet ideas. If you make one like this, it will be as efficient as possible. I'm happy to help with any questions or issues


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#5 tuffyluffy

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Posted 12 July 2019 - 02:58 PM

I bought a sheet of 25mm insulation foam from Forman Insulation and cut it to fit the box. I put two layers in then glassed over the top and painted it with two pot.

Im not sure how it compares to other cool boxes, but it seems to do a good job 


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#6 Nzgrant

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Posted 12 July 2019 - 03:17 PM

What sort of R value shd I be aiming for?
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#7 harrytom

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Posted 12 July 2019 - 05:09 PM

Im going to have go at building a fridge but cant seem to find what to insulate it with(google has not been my friend).

Figured someone in crewland will have done this and could point me in the right direction.

If you are in Auckland,Give fairfax or maxitrans truck builders a ring. Trailer or truck refrigerated bodies are no longer 50 mm. There is a new product they are using and is only 25mm,we had a new fleet built and fridge plants ,once at temp,no longer running as hard as the use to.


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#8 Island Time

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Posted 12 July 2019 - 05:46 PM

The R-value, also called the R-factor in some cases, is a way of quantifying the resistance (the R in the name) a material has to the transfer of heat in a specific application. The higher the R-value, the greater the resistance to temperature transfer. Because R-value takes the material being used and its thickness into account, the measurement refers to a specific usage, rather than the material itself. For example, a 2-inch-thick sheet of polyurethane would have a higher R-value than a 1-inch-thick sheet of polyurethane, so the material itself cannot have an R-value until its intended use is considered.

To determine R-value, we must know the material's thermal conductivity, also known as K-value or K-factor, as well as the thickness of the material. The K-factor is the ability of a material to conduct heat – the lower the number, the less heat it conducts and therefore the better an insulator it is. Most materials used as insulation have a K-value of less than one. To get the R-value, you would divide the thickness of the material (in inches) by its K-factor.

As an example, we will use an insulation material that has a K-value of 0.035. Using the formula of R-value = inches of thickness0.035:

Thickness: 0.5 in., 1 in., 1.5 in., 2 in. results in R-Values: 14.29, 28.57, 42.86, 57.14

 

Importance in Refrigeration

R-value is typically more prominent in specs for walk-in coolers and freezers, referring to both the wall panels and the floor, but the R-value of a reach-in refrigerator or freezer is also often noted on the model's spec sheet or is available upon request. Knowing this figure can help you establish how well your equipment will maintain internal temperatures.

The higher the R-value of a refrigerator’s or freezer's insulation, the more it is capable of keeping ambient heat out of the box. This means that the compressor will not have to run as often in units that are able to better maintain internal temperature, which can affect both energy efficiency and the longevity of the unit. A refrigerator or freezer with a higher R-value can, over time, save you money in both maintenance and utility costs.

 

So, higher is better. Like on the Ozefridge site above, 50mm min on sides and top, 100mm on bottom. 


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#9 ynot

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Posted 12 July 2019 - 07:47 PM

If ya want some urethane sheet call me.
I got plenty around 50mm 75mm 100mm 150mm big bits small bits
All off cuts just tell me size bits ya want... free for crew.org peoples.
I can leave outside in kumeu or catch me up somewhere

We build commercial coolroom freezers.
Tony
0212760498

We normally dump it
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#10 Island Time

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Posted 12 July 2019 - 07:50 PM

Great offer Tony, Thx!!!


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