Mahe 36: Refrigerator and Freezer

[Cotemar]

Scott,

Did you say FREEZER. Nice upgrade !!! Can you give me more details on the model and maybe a pic. of it installed. First Mate would love one of those.

We charge with the Honda 2000 watt generator for 1 hour in the morning and 1 hour before bed which works well.

My plan would be to install only sealed batteries in the back of the port bunk storage compartment and only use the existing conduit raceways or tie into that 12 volt high amp fuse box under there already.

Solar panels on the davits is one of my winter projects, so we can get rid of the generator noise all together, but we will need more battery capacity to hold all that juice.

Mark

[Scott730]

Mark
The Freezer is a portable 35 quart unit. It can be operated on 12 DC or 110 VAC. It is made by Waeco. You can find them at Defender.com. It worked great. We placed it at the foot of the Nav station and added a 12 Volt outlet to accomodate it. Uses around 3 amps when it is running, which is a function of ambient temp., On average it was on 35% of the time when cruising the Bahamas last winter. I'm also looking at adding a solar panel on the davits, we should compare notes.

Scott

[jean1146]

Very nice Cotemar! thanks for showing us all the improuvements you made on your Mahe. Our next thing will be to buy a portable freezer for our extended trips,Scott I looked at the same one you have but the larger model,also I think we want to buy a portable ice maker,the only drawback is that they are 110 volts,but I think this is when our little Honda 2000 comes in handy so we don,t have to run the big noisy generator.We just had the bottom done and a waxing job on the hulls so the boat looks great....
Good sailing to you all.
JC.

[lstyles]

I want to improve the efficiency of my existing refrigerator (it is the stock model of indel I think). There is not much room for insulation around it though. Any ideas or has anyone added/changed anything to improve efficiency?
thanks,
Lori
Venti

[Cotemar]

Lori,

Glade you brought this up.

For our Factory Isotherm you can easily add a few inches to the back of the Refrigerator which may help, but that is about it for this set up.

For us cruisers it is important to have Refrigeration that works in
paradise which is warm & tropical.
Our Factory Isotherm is nice, but a cruising Refrigerator & Freezer
should have 6" of closed cell foam of either sprayed or in sheets.

Polyurethane Foam board or Spray are very similar, closed-cell foam
insulation materials. Because both materials offer high R-values (R 5.6 to R 8) per Inch (25.4 mm) of thickness Cruisers should have R30 > or better insulation around the Refrigerator & Freezer to
1) Minimize battery use and battery bank size
2) Keep the saloon from getting hot because of the constant
Refrigerator & Freezer cycling
3) Keep your food lasting longer

I will be working on a solution to this cruising problem in the future
and will post some real world examples

Mark

[lstyles]

Hi Mark,
I look forward to hearing what you do to improve things! I have considered changing out the existing fridge for something better. Have you looked into this?
Lori

[Cotemar]

Energy Efficient Cruising Refrigerator Requirements

1) Top loading Chest fridge/freezer consumes less battery power per day. When we open a chest freezer the cold air stays inside, just because it’s heavy. Even if we leave the chest freezer door wide open, the heavy cool air will still remain inside. Shouldn’t we cooperate with Nature rather than work against it like using a vertical door which when opened puts all our hard earned cold air on the floor?

2) R30 > insulation all around

3) Holding Plate contains a solution that freezes at a low temperature storing a large amount of cooling energy instead of a thin evaporator, so compressor cycles less.

4)The Isotherm (SP) self pumping refrigeration system uses a special self pumping thru-hull fitting with a built in condenser/heat exchanger. The SP fitting is similar in principle to a keel cooler through which heat is conducted into the water outside the hull. To increase efficiency, the SP design takes advantage of every movement of the boat to produce the self pumping cooling action. The SP fitting replaces an existing thru-hull requiring no extra holes in the hull for installation. The sp system consists of three components: the compressor, the thru hull fitting, and the holding plate.
This will take the heat out of the boat instead of adding heat into the Saloon

[colemj]

Hi Mark,

We have used both a holding plate system and a thin evaporator in the same reefer/freezer on the same boat. For cruising, the thin plate evaporator is a much better system than the holding plate. The holding plate system experienced wide temperature swings and hot/cold spots within the box. Holding plates on 12V systems tend to be small and don't work well for freezers - especially ones with spill over reefers. They will use more electricity than evaporators, even though the compressor cycles are further apart. The important measure is not the compressor cycles, but the amount of time the compressor is running. Holding plates will cycle less, but run more than evaporators.

If you have a relatively small reefer with no freezer, a 12Vdc holding plate system will work well. If you have a very large reefer and freezer, you will need a 120V holding plate system. Anything in between will be better served by a thin plate evaporator system.

Our system is a 4cf freezer with a 6cf spill-over reefer. 6" of polyurethane insulation. The 120V holding plate system required two large holding plates in the freezer and one large holding plate in the reefer to get the performance of a single freezer evaporator plate and a Danfoss BD50 compressor.

Mark

[Cotemar]

Colemj,

Can you post some pictures of your refrigerator/ Freezer.
1) Your is top loading ?
2) 6" of insulation "Perfect"
3) Is yours air or water cooled?

I know they put a very good system on your boat, but I have never seen it up close.

Mark

[colemj]

Hi Mark,

1. It is top loading.
2. 6" works well, but I guess more would be better.
3. air cooled standard Adler Barbour Cold Machine with custom-formed evaporator plate (AB will readily do this for you and charge it to match your system even though it isn't typically shown in their catalogs).

The pictures show the location of the reefer/freezer and the inside of it. The freezer is the smaller compartment and has a custom formed evaporator plate completely surrounding the compartment and attached to the freezer walls with 1/2" standoffs. The divider is 1.5" urethane foam with a 1.25" spillover fan at one end and an air return hole at the other. There are separate thermostats for controlling the reefer through the spill over fan and the freezer through the compressor.

Mark

[LexLocal]

Thanks for the information on improvements to existing boxes--the vessel has a Norcold upright-120volt/12 volt power supply--Freezer top and frige on the bottom--

Mission statement is to add insulation--

2.5 Centimeters from the factory box to Wood enclosure--

How about removing the middle section of the factory box--leaving the fore and aft sections--with the evporator-doors etc --??

This would free up space 6 to 8 centimeters to add R 30 insulation --

or the spray foam --not recieved good ratings for the actual insulation value of Spray Foam???

[Cotemar]

Colemj,

WOW, Very nice Energy Efficient Cruising Refrigerator.
Looks like you really dialed in the right combinations to make a very nice system.

We currently have a Isotherm/Indel Marine 4.6 cu/ft vertical door Refrigerator /Freezer
Which does work well, but is not insulated enough or large enough for long cruising

There are a couple of ways I can up grade to what you have.
I could purchase the parts and build a custom box with 6 inchs of (152.4 millimeters) insulation and lid similar to yours.

I could purchase a box already made.

Isotherm/Indel Marine
Top Loaded Refrigerators, Freezer boxes
BI 92 a built-in refrigeration box with stainless steel inner liner, plastic bottom section and three wire baskets. Insulations with double rubber seal for the lid in two parts, divided 50/50, inner light. Fan cooled compressor mounted below, easily repositioned up to 1.5 m away.
3092CB2B00000 Refrigeration- freezer box with couplings, 2.5 meters pip and SP self pumping
Technical Specifications:
Volume 92 L = 3.24894 ft³
Dimensions HxWxD (mm) 615x485x805
Weight 28 kg
Power consumption, Avg/Max (12V) 1,0/5,2 A
Danfoss compressor type BD50F

Mark

[colemj]

Hi Mark,

That looks like a good system with one reservation: it is difficult to install a keel cooler system on a catamaran with a bridgedeck galley. The tubing run to the hull is a long way. Is your galley down in a hull?

Personally, if it fit I would buy a pre-made box like you show instead of building one myself.

Mark

[Cotemar]

Colemj,

They call it a keel cooler, but it is just a thru hull fitting with a heat exchanger built in. I would just replace a current thru hull down in my Stb. hull.

We have A Galley up setup, but this thru hull is just about 3 or 4 feet away from where I would mount the compressor unit.

I am thinking really hard about just buying the pre-made box. It would be hard to make a box that nice. I can just add more insulation around that box instead of a scratch build.

Mark

[Scott730]

Mark
I have used a Waeco/Dometic CF-40 portable freezer/refrig for the past 2 seasons in the Bahamas. It worked great as our freezer, fits nicely under the nav station.
The freezer allowed us to turn up the temp on the Isotherm unit thus saving power. The unit runs on both 12 volt DC as well as 120 AC. The heat released into the salon is not a problem.

Scott