Insulating fridge.

Jeppo · Veteran Member

Insulating fridge.

Leshill · Veteran Member

I have just added fan & insulation with a shroud as well...fan running right now on the river Murray.
I just used the flat sides of a broccoli foam box.this fitted the sides & top nicely.For the top of the shroud I used the silver backed house insulation as that was easier to cut and fit in.
I hope what we have done helps the overall cooling of the fridge.
Later I will add a thermal switch to the fan but at the moment I just have an on /off isolating switch.

Whenarewethere · Guru

Some info in this thread https://thegreynomads.activeboard.com/t65059593/extra-fridge-insulation-wattage-test/

Extruded polystyrene you can get in 30 & 50 mm from _unnings, it is less messy to cut than white foam boxes, or layer up Kingspan Aircell, it works really well, I have 3 layers around our ancient home fridge.

Hold everything together with foil tape, 75 mm works best, 50 mm is too narrow to be useful. Do not forget to do under the fridge! It is hard work this bit, but the more sides you can do, the better.

Whenarewethere · Guru

Also we have added a layer of Air-cell to the front of the fridge door & covered that.

erad · Guru

It is important to have the fridge 'sealed' into place. Just putting slabs of polystyrene foam will not totally stop airflow from getting from the hot (rear) area to say the top of the fridge. If you have some domestic roof type fibreglass insulation, it can squeeze in and seal the area and hopefully no warm air will get to the area in contact with the fridge external surfaces. I tried to fit insulation to the sides as well, but the gap was too small, so the fridge just has it on the top only. We had no insulation at all on our Jayco caravan fridge. The adjacent cupboard used to get damned hot in summer. I fitted two 12 V computer fans just inside the top fridge vent, and they kept most of the heat from the cupboard. Last trip, I had some ordinary domestic fibreglass insulation pushed in on top of the fridge body, and the difference was remarkable. We still use the 12 V fan (one only now) and the fridge seems to work a lot better.

It isn't a difficult job to fit the insulation to the top of the fridge - just remove the top vent and you can see where the fibreglass has to go. Make sure that it is clear of the chimney and doesn't foul any electrical wiring and it will be fine.

Peter_n_Margaret · Guru

Jeppo wrote:
. im questioning a suitable iinsulation.

The best insulation are vacuum panels, but expensive and hard to get.

Next best and easily available would be closed cell rigid polyurethane foam which is the same stuff used in 90% of commercial fridges and freezers made.

It can be purchased in sheets cut to any thickness. In Adelaide the place to get it is Coolfoam, they are a national company.

Urethane foam is almost twice as good as polystyrene foam the same thickness.

Cheers,

Peter

erad · Guru

The big problem with any rigid type insulation is the fact that you cannot easily seal against the fridge and warm air can leak past the slab of insulation. For example, the top if the fridge is not flat - there are gas pipes and electrical wires running across the top surface. This where your slab of domestic fibreglass insulation comes into its own it absorbs the uneven variations in the surface.

Jeppo · Veteran Member

Thanks to all for your helpful advice. Will investigate my options based on your replies By the way I ended up getting the fridge in through the window. Easy as. Thanks again for your replies.

Whenarewethere · Guru

Polyurethane foam is better in the first few years but extruded styrene is better in the longer term as it takes on less moisture.

We have about R8 in our home ceiling, using batts & Air-cell in various combinations. Multiple layers of Air-cell around the fridge will probably do a better job than batts.

If you use batts enclose that in Air-cell, but the batts will take on a bit of moisture.

At the end of the day it boils down to thickness, 100mm if you can find the room which is the minimum the people install on yachts, 150mm is what people try to do. Also chuck out the front opening fridge for a top opening cool box while at it. You will stop loosing cold air everytime you open the fridge.

Peter_n_Margaret · Guru

erad wrote:
The big problem with any rigid type insulation is the fact that you cannot easily seal against the fridge and warm air can leak past the slab of insulation. For example, the top if the fridge is not flat - there are gas pipes and electrical wires running across the top surface. This where your slab of domestic fibreglass insulation comes into its own it absorbs the uneven variations in the surface.

Easy to seal with Sikaflex Pro or similar. It can still be added as smaller pieces too.

Alternatively it is available in a can and can be injected as an expanding liquid that then sets to the shape available, which is how all commercial fridges are insulated.

Cheers,

Peter