Installing an Electric Fridge

[captjeanette]

We are looking at replacing our refrigeration system with an electric fridge. Having to run the engine several times a day to keep the fridge cold just isn't an efficient way to handle this and I keep losing food out of the fridge and freezer since they won't get cold enough or stay cold enough. Have had 3 different refrigeration mechanics on board who have 'fixed' leaks in the coolant system but still have trouble.

Anyway, anyone have any experience with installing an electric fridge? Appreciate any advice/information.

Thanks!

CJ

[belizesailor]

What kind of system do you have now? An engine driven compressor?

And, by "electric" do you mean AC or DC?

Note the current DC driven compressors are amazingly efficient. Household grade AC driven compressors have gotten better in recent years, but are still typically far less efficient than DC compressors.

[bobofthenorth]

We went to Best Buy on the day after Christmas and paid $200 for an apartment sized refrigerator. Then we hired a dirt carpenter to build an enclosure for it out of teak. All in we've got less than 25% of what it would have cost to fix our "marine" Norcolds. The fridge runs just fine off our inverter for days at a time and it has tons of space. The only thing remotely like a problem was that it didn't come with any way to latch the doors. I solved that with a couple of pieces of black velcro (the fridge is black too). The velcro is pretty well worn out now, two years later but its a small price to pay for what we ended up with.

[captjeanette]

belizesailor: yes, we have an engine driven compressor. I would ideally like one that could run on either a/c or d/c, but would settle for a/c and run it off the inverter. We currently bought a small dorm style fridge which we have been using while the main refrigeration hasn't been working and it works fine off the inverter.

bobofthenorth: thanks! I think that is along the lines of what I am looking for. We are currently live aboards in a marina with ready access to shore power. I think one would run fine off the inverter (we may need a larger one). We have already spent $$$ trying to fix the marine refrigeration system and I believe we could easily do with something like what you did.

cj

[Sumner]

If you are in a marina with shore power the majority of the time then I see no problem with the 110 volt fridge. If at some point you aren't and are generating electricity to run a fridge either by running the ship's power or adding solar and/or wind power then I think a very well insulated 12 volt fridge will quickly pay for itself.

Here is what we did...

Endeavour 37 Interion Mods Index

bobofthenorth on your install does the teak enclosure have more insulation or is it just a decorative enclosure with a space to circulate air around the box and the openings for the compressor/condenser?

Sum

[captjeanette]

Thanks everyone for all the ideas. We are lucky that we have a perfect spot for a new upright fridge as our marine model is already an upright. Takes up about 60" tall by 24" wide and 24" deep. Problem is removing it as it is built in. Oh, well, that's what sawsalls are for!

CJ

[captjeanette]

Sumner: I checked out your web page--wow! you are quite the handyman!~ Nice retrofits on that endeavor! We have an Irwin 45s. Small galley but I am hoping that I can add a small box as a platform for the new fridge with a drop down door for extra storage.
Are you still on the west coast? We are on the east coast.

[landonshaw]

I just replaced our 12V DC refrig with a new one. It was very easy to do and took maybe 3 hours. There is a lot of information on the manufacturers web site on matching the correct size plates and condensors. We have refrig only with no freezer, although that is possible if I make a few changes. I never have shore power and run off of solar and wind.

[sushirama]

i posted the other day on the power req for my HD chest freezer. The same applies to a mini-fridge. A friends boat took out their shoulder high freezer on a Corinthian trimaran and installed 2 mini freezer/fridge combos. Like with mine they dont have to run all the time. Though a little more than my freezer at15-30 minutes every 6 hours. More like 4 hours. You can mitigate that with thermal mass like bottles of water iced up. The pull is about the same at 60-70 watts with a little more needed for startup. But still way better that any thing that was installed. Alos we took into account the advances in refrigeration and insulating technology since the original install 40 years ago. The also charge(or run directly) when under way with a cheap 900 watt 2 cycle generator from Harbor Freight. About 175 i think. Spend the extra 10 and you can replace no questions asked every year or two. oh one thing - make sure you have vent space for the mechanicals.

[Sumner]

Originally Posted by captjeanette

Sumner: I checked out your web page--wow! you are quite the handyman!~ Nice retrofits on that endeavor! We have an Irwin 45s. Small galley but I am hoping that I can add a small box as a platform for the new fridge with a drop down door for extra storage.
Are you still on the west coast? We are on the east coast.

Thanks, we live in SE Utah (canyon country). The Endeavour is in Charlotte Harbor Boat Storage (SW Florida).

Does the current fridge have good insulation or could that be added? If so you might be able to add an evaporator to it and install a 12 volt compress/condenser near it. I noticed you said fridge and freezer. Is it all one unit? Front loading door?

Sum

[janice142]

Hello CJ. I would respectfully suggest that you go to Amazon and purchase a weather station. Yes -- for your refrigerator. Mine is by Ambient Weather (brand) and was about $25. What's great about it is (in addition to the barometer, atomic time, et al) is there is a remote outdoor sensor. I put that inside my refrigerator away from the freezer section.

The monitor displays both temperature and humidity (mine removes humidity first, then the temp goes down) -- and with it you'll be able to check how cold things are inside the reefer. I went into a dock for a couple days and have determined Setting 3 (1 thru 7 on dial) is the right balance between too warm and too cold for my $70 a/c powered Haier from Walmart.

Would I like an Engle? Sure... but it's out of my price range and this works. I suspect the Ambient Weather station would help you insure the inside is keeping cool enough.
Aside: I bought an Accurite weather station ($20 or so) and could not see the doggone numbers unless right exactly in front of the thing.. Make sure the numbers show up -- much to my chagrin I discovered they are not all the same.

Good luck, and happy cruising.

[belizesailor]

Originally Posted by captjeanette

belizesailor: yes, we have an engine driven compressor. I would ideally like one that could run on either a/c or d/c, but would settle for a/c and run it off the inverter. We currently bought a small dorm style fridge which we have been using while the main refrigeration hasn't been working and it works fine off the inverter.
...

Given that you are living aboard and plugged into shore power running the fridge off the inverter should work fine, but you may be a bit shocked when you disconnect the shore power.

Most residential grade AC driven fridges that I have tested with a multimeter draw many times more than a similar sized DC driven fridge. To add insult to injury you will probably lose at least 10% going through the inverter (depends on the inverter, so look up the specs if available).

Also, don't trust what the labels say on electrical devices. I have tested some that are not even close to what they claim. If I have a moment today I will clamp a meter on one here and post the numbers.

The AC/DC switching is no big deal. Waeco for example advertises this as a feature, but it really has nothing to do with the fridge (the compressor is DC driven). They just use a third party switching unit which can in fact be used to drive any DC fridge or device.

[Irish rambler]

I have an Isotherm 80 litre DC unit and power it by Solar panels in the summer months and through a Waeco switching unit when on shore power over the winter, would I have the same again ? Absolutely Not ! the Isotherm is very power hungry and it's cheaper for me to ship spares from the States than buy direct. The most power efficient DC fridge and freezer units that only use half the current of the Isotherm I have found are manufactured in the UK by shoreline.co.uk who specialize and manufacture only DC powered units and ship worlwide. Having said that I must say that the service I recieved for Isotherm spare parts from Great Water in the States has been exemplary and I would highly recommend their service..

[belizesailor]

Originally Posted by Irish rambler

I have an Isotherm 80 litre DC unit and power it by Solar panels in the summer months and through a Waeco switching unit when on shore power over the winter, would I have the same again ? Absolutely Not ! the Isotherm is very power hungry...

Haven't owned an Isotherm fridge, but the Waeco and Danfoss based systems I have owned have been amazingly efficient and reliable.

Although even with an efficient system, refrigeration is still one of the major loads.

[Weyalan]

Originally Posted by Irish rambler

I have an Isotherm 80 litre DC unit and power it by Solar panels in the summer months and through a Waeco switching unit when on shore power over the winter, would I have the same again ? Absolutely Not ! the Isotherm is very power hungry and it's cheaper for me to ship spares from the States than buy direct. The most power efficient DC fridge and freezer units that only use half the current of the Isotherm I have found are manufactured in the UK by shoreline.co.uk who specialize and manufacture only DC powered units and ship worlwide. Having said that I must say that the service I recieved for Isotherm spare parts from Great Water in the States has been exemplary and I would highly recommend their service..

The main "power hungry" component of any 12v DC fridge is the compressor, and since pretty much all 12v DC refrigeration systems use either the Danfoss DB35 or DB50 compressors (depending on size of cold space), they should all, broadly, use similar power. If your system is particularly power hungry, perhaps the culprit is poor insulation?