Fridge Optimizer

[windmist]

A few weeks back I mentioned on another thread that I ordered a Fridge Optimizer unit for my NovaKool to improve its performance and a few people asked me to post my observations.

Well it was a very easy installation except running the one small cable into the interior of the fridge. I ran the cable with the other wires so had to remove the sealant around the existing wires. That was the hard part. I used butyl sealant to seal the new holes I made.

This product claims to keep the fridge defrosted and that seems to work well as I never see ice buildup on the cold plate at the top of the fridge. Better performance is hard for me to attest to as we've only used the fridge for a few weekends but I came across a review of the Fridge Optimizer that goes into great detail that you may be interested in.

http://threesheetsnw.com/blog/2016/...-with-the-stainless-lobster-fridge-optimizer/

Here are a few more links that may be of interest:

SLFO-ACDC-122401 Fridge Optimizer - Programmable Thermostatic Control & Monitor AC/DC

Fridge Optimizer | Stainless Lobster | Creative Marine Products

One caution I would suggest is that you look at your compressor and note the model number before ordering to be sure the Fridge Optimizer is compatible. In my case, I have a AC/DC fridge but because my NovaKool was manufactured (12/03) before a AC/DC compressor was available I initially ordered the wrong model - a AC/DC rather than a DC only model.

 

[C lectric]

Good Info,
Thank you.
It will go on the list.

 

[dhays]

Thanks Ron for the update. Looks like it may work out pretty well.

 

[Pgitug]

Like the features. A happy fridge usually means a happy first mate. ?

 

[ranger58sb]

One caution I would suggest is that you look at your compressor and note the model number before ordering to be sure the Fridge Optimizer is compatible. In my case, I have a AC/DC fridge but because my NovaKool was manufactured (12/03) before a AC/DC compressor was available I initially ordered the wrong model - a AC/DC rather than a DC only model.

??

Our AC/DC NovaKools were manufactured on or before 2002, and NovaKool told me they have DC-only compressors. (When running on AC, there's a small power supply converting AC to DC.)

Where does condensation go when the Optimizer defrosts the fridge?

-Chris

 

[MurrayM]

Where does condensation go when the Optimizer defrosts the fridge?

-Chris

From link above;

When the fridge is defrosting, what should I do with the water?

The process of defrosting is turning the frost that has built up on the coldplate/holding plate/evaporator into water. To minimize new frost build up and to avoid wet groceries, you should remove this water. ​​If your system has a drain, we recommend leading the water to the drain so it can drip out instead of accumulating. For a closed system we recommend a placing a sponge under the evaporator. This collects the water in once place. Squeeze it out over the sink now and then to keep it absorbant.

 

[ranger58sb]

Ah. Thanks, I didn't go through all three links... should have...


-Chris

 

[FF]

The RV folks have battery powered units that operate quite a while on a couple of C cells.

About $15 or so, Seconds to install.

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Fridge Airator
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CampingWo

 

[Nimble1]

I have used the small RV type air mover in my fridge for years. Seems to help.

 

[ranger58sb]

Quick glance at some of the FF links.. they all seem to emphasize air circulation, even cooling, etc... but I don't see where any address the frost build-up issue. Or does air circulation do that anyway?


-Chris

 

[FlyWright]

Love my NovaKool, but it needs to be defrosted every other month.

This Fridge Optimizer will be my next fridge efficiency mod! Its claims are to drop my NK consumption from ~65AH/day to ~20AH/day!

 

[DavidM]

None of those devices seem to use the variable speed capability of the Danfoss compressor installed on virtually all marine refrigerators. A fridge is most efficient when the compressor runs at the slowest speed necessary to keep up with the heat load. The Danfoss compressor has the capability of running between 2,000 and 3,500 rpm

This Merlin device is a small circuit board that plugs into the back of the Danfoss compressor and does just that: See Frigoboat, Merlin II Automatic Smart Speed Controller for Danfoss 12v

I had a previous version on my former boat. With it plugged in. the fridge would first run at about 6 amps, the maximum. After a few hours the on period would extend and the current would drop, finally settling to about 70% on and less than 3 amps as the algorithm learned what speed it takes to keep up with the heat load.

Why does this work? Well its a combination of thermodynamics and mechanics that keeps the condensor delta T at an optimum point and also relies on the lower parasitic losses as a compressor runs slower, even doing the same work.

It works and is dead simple to install, just plug in to the appropriate terminals on the back of your compressor.

David

 

[FlyWright]

That's very interesting, David. I like the simplicity of the installation.

Does it have an effect on the defrosting on your unit? That's a significant reason for me wanting to upgrade...well, that and saving electrons.

 

[DavidM]

That's very interesting, David. I like the simplicity of the installation.

Does it have an effect on the defrosting on your unit? That's a significant reason for me wanting to upgrade...well, that and saving electrons.

No, it doesn't manage defrosting. I have never understood automatic defrosting as it just seems an unnecessary luxury that uses energy when it does defrost. When I was cruising full time, I shut down the unit once a month, scraped out the frost/ice and turned it back on.

David

 

[ranger58sb]

I could learn to love auto-defrost. Maybe.

OTOH, would think it could be on a switch, so it could become optional for periods when the user decides it's too much of a hit on the energy budget.

-Chris

 

[FlyWright]

The apparent beauty of this optimizer is that it cuts energy consumption by 1/2 to 1/3 my present ~65AH load while also providing auto-defrost operation. Almost seems too good to be true, but our late friend and OP, Windmist, installed it and confirmed to me its promised function.

 

[fryedaze]

The 3rd and 4th connectors are doubled up with the comp and fan power.

 

[DavidM]

The apparent beauty of this optimizer is that it cuts energy consumption by 1/2 to 1/3 my present ~65AH load while also providing auto-defrost operation. Almost seems too good to be true, but our late friend and OP, Windmist, installed it and confirmed to me its promised function.

How does it cut energy usage? The website says nothing meaningful about how it does it.

It is the opposite of climate change which has both a sound theoretical basis (greenhouse gasses collect in the atmosphere and hold in heat) and a sound empirical basis (measurements of those greenhouse gasses in the atmosphere and measurements of global temperature warming). So without both to support this device, I am skeptical.

David

 

[foggysail]

My Summit apartment size (8.3cu ft) came equipped with self defrost feature. Even has an interior light. And better still, it cost less than 1/2 the bucks demanded by marine refrigerator manufacturers for their products. It replaced an overrated Norcold.

 

[FlyWright]

I thought the same, David. I can't explain how it works but this guy installed one in his boat and reports 50% reduction in power
in his 5/10/16 comments here. He appears to be very satisfied with this upgrade after months of using it and Windmist was equally pleased after installing his on his NT.

 

[DavidM]

Flywright:

Placebos used in drug trials often show significant benefits. User anecdotal evidence is almost worthless IMO, without corroborating science.

David

 

[dhays]

Flywright:

Placebos used in drug trials often show significant benefits. User anecdotal evidence is almost worthless IMO, without corroborating science.

David

I agree. In healthcare we call that "evidence based medicine". OTOH, there still is a place for "clinical experience".

I would like to see someone like Practical Sailor do some tests. Still, if enough smart boaters report good results, that isn't something to completely discount. Even if a placebo works for one person it doesn't mean that the placebo won't work for another.

 

[DavidM]

Dave:

I will sell you a placebo for $200 and you too can enjoy the benefits of that device.

David

 

[FlyWright]

OK, I agree that the claims sound fantastic...almost too good to be true. But if that's a placebo, where are all the bad product reports? I've searched for other reports but cannot find a single one. Seems we'd have one or two reports with empirical data from folks who know it doesn't work.

I have first hand confirmation that it worked well from conversations with Windmist (the OP), a man I've met, respected and boated with in his Helmsman 37. Ron made his success in Microsoft and really knew his stuff. Unfortunately, he passed away and cannot provide the proof you need.

I figure that for $200, if it only defrosts and maintains the same high efficiency I now enjoy, it's a winner. If it can also save energy, that's a win-win.

 

[OldDan1943]

No, it doesn't manage defrosting. I have never understood automatic defrosting as it just seems an unnecessary luxury that uses energy when it does defrost. When I was cruising full time, I shut down the unit once a month, scraped out the frost/ice and turned it back on.

David

A hair dryer will speed up the chore.

 

[foggysail]

A hair dryer will speed up the chore.

And self defrost beats a hair dryer.

 

[Simi 60]

Our 240v 550litre/20cf Samsung has a plate in the fridge that freezes every few days reducing cooling effectiveness and its an issue with all in this model so says google.

Simply turning it off around 8pm and back on at 7am seems to have solved the problem for us.

Added bonus is batteries are at about 90% and solar has us back at 100% by about 10am.

 

[DDW]

This device does not defrost with a heating element like many "frostless" refrigerators. That is inherently energy inefficient. It does so simply by periodically turning off the compressor until the evaporator rises to above freezing, allowing the water to drain away, then restarting the compressor. That does not waste any energy at all. It needs to be done frequently, before a lot of ice has built up, or it will take too long to melt and your beer gets warm.

I am also skeptical of the energy savings claims, but there is some sound science as to why it might be: varying the speed of the compressor, keeping ice off the plate, and ability to supercool the box when charging current is available. The latter doesn't save energy in the strict sense, but saves energy out of your batteries, which is all you care about. On a cold plate system it could result in 100% savings in that sense.

 

[tnltracy]

This device does not defrost with a heating element like many "frostless" refrigerators. That is inherently energy inefficient. It does so simply by periodically turning off the compressor until the evaporator rises to above freezing, allowing the water to drain away, then restarting the compressor. That does not waste any energy at all. It needs to be done frequently, before a lot of ice has built up, or it will take too long to melt and your beer gets warm.

I am also skeptical of the energy savings claims, but there is some sound science as to why it might be: varying the speed of the compressor, keeping ice off the plate, and ability to supercool the box when charging current is available. The latter doesn't save energy in the strict sense, but saves energy out of your batteries, which is all you care about. On a cold plate system it could result in 100% savings in that sense.

We installed one this summer with a new NovaKool 5812, and are very happy with it. The thermostat and built in fan circulate the air to both help defrost, and more quickly cool down. Our usage varies from 8% currently as it’s quite cool here in RI to mid 60% range mid summer. We wipe down the cold plate once a week, and have not had to manually defrost.

Well worth the $$ compared to the effort and frustration with defrosting, and warm beer.

 

[SCOTTEDAVIS]

I have had one of these SL units for 2 years just about.

It indeed has reduced the energy used by the 2500 series Vitrifrigo unit I have it attached to

It reduces the frost to such a degree that it is near frost free depending on your operating condition and door open time. Here in muggy Florida it reduces the summer defrost time from every 2 to 3 weeks to perhaps every 6 or so.

It is extremely programmable and I find the super cool with abundant power to work well and after a day of running have nearly frozen milk but a greatly reduced run time on the hook during the night.

Great folks, great product, if you dont have one fine but I can tell you as a owner of one and someone with a great degree of medical training it's not a placebo.

Buy a 4 dollar fan if you think it's the same thing and relax and have fun, see you on the hook.