Reefer Design

[colemj]

Rich, do you have any data on the drawer style fridge/freezers? These seem like the ideal solution to me - much less cold air spill out than front loading and much more convenient than top loading.

Mark

[Roy M]

I don't have any data on the drawer types, but I have installed one and can make an informed comment. Since the drawers are relatively closed (not water tight), a small amount of dense, cold air will pass out, and also be warming when the door is open. CLICK ON THE PICTURE, SEVERAL TIMES, TO ENLARGE THE IMAGE. I think the greatest advantage of the drawer types is that they are so accessible from above that the drawer is open a shorter time than with a front opening door. It's quicker to stare into the fridge before selecting what you are looking for, then remove it and close up. Nothing comes close to a top opening reefer, though. That's why I designed my own box to be single layered and top opening. I don't have any figures yet on its efficiency as I am still finishing off the details (water pump, electrical hookup and charging the system). Soon, I keep promising myself.

[SV THIRD DAY]

Originally Posted by colemj

Rich, do you have any data on the drawer style fridge/freezers? These seem like the ideal solution to me - much less cold air spill out than front loading and much more convenient than top loading.

Mark

Unfortunately I don't Mark.
The drawer units I have seen locate their evaporation plates either on the back wall or top of the box, so they would still have issues of the air spilling out when they are opened, but perhaps the drawes themselves act as a barrier to slow down the exchange of air?

The cruisers I know with these drawer type of boxes love them. No more ballancing on your gut like a teeter-totter to dig through the conventional top open box. But I'm sure they take a bit more power than the top sytle boxes. Would you trade amps for convienience...we do it every day, so it's not a "wrong" choice if you have the power for it.

We get back to the standard boat compromise of convienince vs maximum efficiency. I know some cruisers that limit the opening of their boxes to save Amp by planning out their meals and make it a point of pride that their box only gets opened 6 times per day unless loading provisions from the store. Heck, I'm as bad as my kids opening the box and staring in there hoping to find some scrap of food that I didn't see 15 minutes earlier that someone excaped the eyes of my teenage kids! So far I can report no success with that by the way...they are like locus devouring everything in their paths that I haven't hid in my room!

[Boatguy30]

Hard to have top loaders on most cats, unless they are under the bunks which is inconvenient. I was thinking of a top loading freezer accessed from "up" in the saloon as the galley is "down" in the hull. The fridge would then be under the freezer and a front loader with perhaps a split plastic flap.

The moisture in the air exchanging is a good point. My daughter is nearly vegan due to food allergies so I'm tempted to try this boat sans fridge, but I have a ton of cubic volume available for a well insulated fridge freezer.

[bobconnie]

When we bilt our Colvin we made room for the largest freezer spill over system I could fit aboard ! But then we had 6 of us aboard, and were planing for long range cruiseing ! Back then we ran the engine at least once a day to keep things cool and frozen. Today with the solar avaiable and the much more better refer systems out there it would have ran without any engine at all! But it had good insulation and thats what it takes in the tropics! no matter what you install for a system if you
don't have good insulation your just wasteing time!! Im Impressed with the bild in systems shown above, those pull out drawers are cool !! (pun intended) If I was doing a galley over I would sure be looking at them !!!

[Cheechako]

I love the drawer concept, but it's hard to believe they arent real inefficient... between leaking at the gaskets, not much insulation to start with and the open door loss issue noted regarding front door refrig's... hmmmm
Some of you guy's amp hour numbers are amazing... are these real or theorhetical? Got anyone who'se given you real results? My , admittedly poorly insulated (2-3" foam), 2 cu ft topdoor box in the Caribe (not summer) seemed to soak up 80-90 amp hours a day. The slightly smaller one in my other boat with vacuum panels didnt do that much better.

[SV THIRD DAY]

Originally Posted by Cheechako

Some of you guy's amp hour numbers are amazing... are these real or theorhetical? Got anyone who'se given you real results?

Like a poster said above...
1. Insulation
2. insulation
3. An efficient system

But without 1 and 2...there is NO WAY that No 3 can really get you there, no matter what system you buy!

Here are some real life cruiser feedback emails documenting the low amp usage in tropical cruising climates

CoolBlue Client Feedback

"Their advertised amp consumption is pretty much on the money with a properly insulated box (I think it was 24 amp-hours daily - about half the competing product's specs). I was suspicious of that since it was so low, but even in the heat of El Salvador it only drew 30-35 amp-hours. It is also air cooled, so does not bring seawater on board for cooling,

Rich & Jan

s.v. Slip Away

[Boatguy30]

Originally Posted by Cheechako

I love the drawer concept, but it's hard to believe they arent real inefficient... between leaking at the gaskets, not much insulation to start with and the open door loss issue noted regarding front door refrig's... hmmmm
Some of you guy's amp hour numbers are amazing... are these real or theorhetical? Got anyone who'se given you real results? My , admittedly poorly insulated (2-3" foam), 2 cu ft topdoor box in the Caribe (not summer) seemed to soak up 80-90 amp hours a day. The slightly smaller one in my other boat with vacuum panels didnt do that much better.

I ran a 2.5 cu ft DEEP freezer (kept meat for 9 months) and 4.5 cu fridge in the tropics on about 80 amp/hrs. Had 6" of blueboard 4" on the top. That system had 2 air cooled compressors

Other system was a 1.25 ish freezer with about 4 cu ft reefer. Had a custom made Nova kook split plate system. That used about 50. Had only about 4" foam due to space constraints in an 8' bigger boat!

[colemj]

Originally Posted by Cheechako

I love the drawer concept, but it's hard to believe they arent real inefficient... between leaking at the gaskets, not much insulation to start with and the open door loss issue noted regarding front door refrig's... hmmmm
Some of you guy's amp hour numbers are amazing... are these real or theorhetical? Got anyone who'se given you real results? My , admittedly poorly insulated (2-3" foam), 2 cu ft topdoor box in the Caribe (not summer) seemed to soak up 80-90 amp hours a day. The slightly smaller one in my other boat with vacuum panels didnt do that much better.

Do you know that the drawer units do not have much insulation? I haven't been able to find any info on how much insulation they have. I found a FAQ that said adding another inch of insulation to their product would only result in an additional 4Ahr less power use per day.

We have an air-cooled AB Cold Machine BD50 running a 4cf freezer with an evaporator plate surrounding 85% of it. There is an active (fan on thermostat) spillover system through a 1" foam barrier to a 6cf reefer. The entire system is top loading and is insulated with 6" of poured polyurethane foam. The freezer is kept at 10F and the reefer 36F. In the tropics, we use 45-55Ahrs/day depending on usage (I have a meter on it).

Insulation is key, but so is location. Many boats have their boxes located against the hull or engine room, which works against them even with good insulation.

Mark

[Boatguy30]

You have a meter so I'm forced to believe you, but you would no doubt qualify for a CF record with that 10 cu ft in the tropics on just 50 amps!

Where in the boat is the system if it's not touching the hulls side anywhere and has 6" of insulation?

[robert sailor]

Flag goes up with 10 cu feet, half of it on freezer at 50 amp hours per day!!

[Boatguy30]

He has a meter......

I had a look at Manta pics online. See the fridge is on bridgedeck up forward there. Nice layout. Maybe when I remodel.

[colemj]

I doubt it is a record since the numbers presented by Frigoboat and CoolBlue for similar systems seem to be much better than ours. Frigoboat has claimed 25-30Ahr for a similar sized system. Yes, I have hour and amp meters on the system so I know exactly how much time it is running and how many amps it has drawn. It is split 40% freezer / 60% reefer, not 50/50. To be honest, the evaporator plate surrounding the freezer probably reduces the usable size of it to 3cf, since it has 1/2-3/4" standoffs.

The box is located in the bridgedeck saloon of a catamaran, so it is not near a hull side or engine compartment. This helps a lot, as does 6" of insulation on all sides. The box itself is formed from 1/2" Nidacore, so that has some additional insulation quality. Also, the compressor has the AEO controller, which automatically adjusts compressor speed and runtime to be most efficient. Another thing that probably helps a lot is that the compressor condensor has a shroud on it with a duct bringing it fresh cool air from another location and a vent on it removing the hot air to a different location. So the compressor system is not sitting in its own heat recycling its hot air.

Right now the boat is on the hard in Guatemala and we are not living on it, so not using the box. The system is only using ~25Ahr/day now even though the interior is 90F - so I guess that attests to the insulation and seals. And I did not have to set up a Rube Goldberg water drip system to run it on the hard!

Mark

[Noreastern]

Mark, I like this setup. Thanks for sharing.

I would like to down size it for about 2cf freezer and 2cf reefer. If I am reading this correctly you have a fan moving cold air from freezer to the reefer that is separated by 1 inch and that both boxes are insulated with 6 inches?

Brian

[SV THIRD DAY]

Mark,
The more photos of I see of your boat and the well laid out systems, the more envious I become, so I can't wait to see the length extensions you are planning!

That is a dream box set-up in terms of insulation, location, and daily Amp hour usage. I know many cruisers that have a much smaller total box volume but with no exaggeration use 150AH for their refrigeration and are cryin the blues trying to keep up with the daily power usage.

It goes to show a real life example of just what Insulation along with a good box design can do for you! Thanks for sharing.