Advice on Top Loading FREEZER Materials

[Pelagic]

I need advice on materials/ insulation thickness/ compressor/ size of cooling plates and any recommended sources for a stand-alone top loading freezer for continual tropical conditions.

The inside dimension of cabinet space is H31” x W20” x D22”

The Compressor can be mounted directly below cabinet in a large ventilated upper bilge area (steel boat) as I would like to make Freezer as deep as possible to carry as much hard frozen stuff as I can.

Lid will need to be flush as part of counter top and lift off as there is a Microwave overhang that prevents a hinge.
How thick should the Lid be?

Photo shows location, and where kettle sits is a top loading fridge with remote compressor

Thanks again and all suggestions welcome.

[Terra Nova]

That location looks too crowded for a reefer/freezer, with not enough space all around for a minimum of 4" insulation. Besides the overhanging microwave problem. Your 31"x20"x22" will become less than 23"x12"x14" of refrigerated space, about 2 square feet!

[Pelagic]

Yes it is limited to about 2 m3....but convenient

I was considering using 1" Vac Panel t but concerned about Rich's warning.

Originally Posted by SV THIRD DAY

Just make sure they commit to a delivery time....there have been reports of people waiting for months for orders to fill from Rparts (for box hatch opening).


At the price shown....WOW...those are blow out prices.
RPARTS.COM - Vacuum Insulation Panels - www.rparts.com

The only thing "worrying" with Vac pannel insulation is that if the panels ever get damaged....ka paw...you have Zero insulation now from that panel. And now your box is designed and built for 1" of insulation...so how are you going to re-do it for 4-6" of old school foam?

[Terra Nova]

It may seem convenient but there isn't enough space to build a worthwhile reefer/freezer. It's hard for me to believe that there aren't better locations for it in that galley. Perhaps if you used the entire corner space, too, expanding it outboard, you could have decent enough volume.

[Pelagic]

Yeah it is very limited... Boat was built in the early 80's in Holland when refrigeration was not a priority.

That Corner area already has a top load refrigerator (Isotherm) but I am wanting a separate freezer for frozen meats and ice tray

When i bought the boat... They had a portable freezer box in my hanging locker.... Not exactly ergonomic

Still pondering options but does using more efficient insulation seem plausible?

[Cotemar]

You may want to use 3.3 inches of aerogel which will give you an R33. Do a search here in the CF as their are a few here that have done it already.

[Terra Nova]

Use the thinnest, most efficient insulation you can afford, if you must. It just means running the compressor longer. Seriously, though, if that's the best space you can come up with, it will have to do.

What is the machine just inboard of that location? Can it be moved, a little, to add insulation?

[Pelagic]

It is an old Isotherm with remote compressor that we keep vegetables in.

You gave me an idea though to remove it and build something more efficient within the combined space.

I will go to boat tomorrow, measure and take some photos.

[bstreep]

We have friends cruising in the South Pacific. She is a retired NASA engineer. They experimented with and tested all sorts of materials before rebuilding their refrigeration system. They concluded that the "pink stuff" from Home Depot/Lowes is the best material for insulation. There are products with slightly higher R values per inch. But they all take in significantly more water than the pink foam insulation. Water - even a little bit - quickly reduces R values.

[Pelagic]

Hi Cotemar, I have been researching all the built in fridge and freezer threads.

As usual…. the best advice and opinions are specific to a particular site applications…

This will be my first time doing this, so I need to define the design criteria and options available to get specific advice

Was delayed taking photos at boat because of tree damage (at our house) after the last Typhoon passed over Subic…
FYI SBYC was perfectly protected with just a 1ft wind chop, no swell in 90 knot winds

Terra Nova, sorry I misunderstood your last question… that machine inboard is a small Isotherm day fridge
Photo shows it under our main galley drawer, which my SO refuses to give up.

I will post these photos first together with my first post to give an overview.
I will then post sketches with my thoughts and questions for those who have done similar projects and know the materials available.
(which I will need to import)
Cheers!

[Pelagic]

Ok here are my ideas:

1/..Shift stove top (there is no oven) 6” Forward so I can square off refrigeration Cabinet
2/..Remove existing Isotherm and design a new cool box/freezer for whole space.
3/..Remote the new Compressor(s) in the large storage area under the Galley Floor but not directly under new cool box.
(This large area is very well ventilated and is naturally cool)
4/..Keep Day fridge and the ventilation system only for that area, but seal off the 2 “ vent under new cool box and install bottom Insulation under Galley Floor (C) so as to achieve maximum height for new cool box/freezer
5/.. Insulate Riser Area (E)) for new cool box/freezer area to minimize (B) thickness.
6/.. At hull Side…. Take advantage of 3” frames to install best materials to improve heat insulation (especially above waterline for the new Freezer Area) and determine required insulation thickness needed above and below waterline? (F & G ?)

Questions:
Is it more space efficient to design a spill over system from Freezer to Cool Box or is it better to have 2 separate thermostatically controlled systems with 2 remote compressors? Pros and Cons?

My uninsulated Inside Dimension for Combined Freezer/Cool Box is 36.5” x 22” s 35” = 28,105 cubic inches or 16.3 cu ft.

From sketches you can see that I am trying to insulate wherever I can outside that box so will that idea work?
And if yes…
…Recommended Insulation Material and Thickness for
(A)
(B)
(C)
(D)
(E)
(F)
(G)

Obviously I will also loose space from cooling plates etc…
Those who have experience doing this before…. What do you guestimate will be my final insulated volume?

[Terra Nova]

Nominally 4" is considered minimum insulation thickness--much more is better, wherever possible. That's 4 uninterrupted inches, not with a galley floor stuck in between layers. Typically urethane foam is used with an exterior vapor barrier of aluminized Mylar. There are other ways to go about it and I would suggest reading Grunert's refrigeration box building book.

Best installation would be two independent systems, reefer and freezer, using Frigoboat keel-cooled units. I did one like this, side by side boxes, either one could be set as a freezer or reefer. Both freezers or both reefers. The owner claimed 1 amp/hour per box in SoCal summer. Done right, they will be much more efficient than your free-standing Isotherm.

[dohenyboy]

I used 5 inches of aerogel to insulate my refrigerator and freezer. A little expensive but i believe it saves money in the long term.
If you have air cooled compressors then seems to me the air intake for the compressors should be different than the exhaust. Otherwise you are re cycling the same hot air through the compressor. In mine, the exhaust is inside the cabin and in hot weather the interior can get toasty by morning. The intake must be from the interior-salt air ruins the compressors. I installed the Sea Frost units. So if i were you i would have the compressor intake from the galley and the exhaust under the floor.
However, on another boat I used the glacier bay system with one compressor and solenoid to switch it between plates and it saved having two compressors.



Sent from an undisclosed location on the high seas or from the lounge chair by the pool, you decide.

[Pelagic]

Thanks Terra Nova for the explanation.

I will get hold of that book and study some more.

Seems like the solution will need to be some sort of compromise between better than Freestanding units and creating enough usable freezer space and cool box in the available space.... While accepting a higher energy bill.

I do want to stay with air cooled compressors as they will continue to work if we are living aboard on the hard.

[Pelagic]

Originally Posted by dohenyboy

If you have air cooled compressors then seems to me the air intake for the compressors should be different than the exhaust. Otherwise you are re cycling the same hot air through the compressor. In mine, the exhaust is inside the cabin and in hot weather the interior can get toasty by morning. The intake must be from the interior-salt air ruins the compressors. I installed the Sea Frost units. So if i were you i would have the compressor intake from the galley and the exhaust under the floor.

I have space to install 5" of Aerogel under the galley floor and hull sides, but not all the way around.

Thought about the air circulation... That area under the galley has a massive amount of volume that carries about 35 ft forward to collision bulkhead.
There is also another 3ft of empty bilge depth under that sub floor going to 5ft depth just forward of Freshwater and grey Water holding tanks.

So good cool circulation that dissipates out on hull sides to salon portholes and also rises up into Pilothouse where we have massive circulation and exit out if things get toasty warm

I will study the Glacier Bay system.... Thanks for the advice