 |
|
28-01-2025, 10:30
|
#46
|
Registered User
Join Date: Mar 2003
Location: Currently on the boat, somewhere on the ocean, living the dream
Boat: Morgan 461 S/Y Flying Pig
Posts: 2,302
|
Re: Surprising results with a spill-over fridge.
Quote:
Originally Posted by hzcruiser
Hello again,
I take it that your evaporator was/is in the freezer section and you used the fan as required to cool down the fridge?
I'm wondering how much ice build-up you got in the freezer, or how often you had the defrost it, as I'm considering a very similar spill-over solution myself?
|
It was, both in the first iteration (Frigoboat water cooled) and after that packed up, a SeaFrost air and water cooled, with 3 separate evaporators built like cold plates but just having copper piping looped around inside, enter and exit at the top and accordion folding copper pipe inside the protective (and sealed) SS evaporator box.
As to condensation, that's a product of local humidity and how often you let the outside in. Our front-load reefer no doubt contributed, but we spent most of our time in, either, the Abacos or SE FL (Vero Beach), both hot and humid most of the time.
So, we wound up defrosting about once a month. We'd turn off the power as we went to bed, then got up and packed all the frozen stuff into a cooler. I used a heat gun at the edges, and with the plates warmed a bit by not having any cooling overnight, for the most part, the ice slid offf readily, or with the encouragement of a plastic spatula (putty knife). Behind (3/8" standoff washers) the plates, I blew warm air with the crevice tool on our stinger mini shop vac to loosen it up. That which didn't readily fall off I encouraged with a long SS spatula handle (flat) which I put the business end opposite of where I was introducing the handle, and then swiped it back and forth a bit.
Because it was ice, for the most part it came off in sheets or sections of sheet ice, easily collected. I used the heat gun to make sure it was no longer cold enough to collect condensation, blew off the surfaces, and called it good.
Water cleanup was relatively minimal; I could have used the shop vac, but I never did, instead just taking a tupperware container and swiping it along the floor, picking up much of the water and nearly all the ice; the remaining I used a drywall sponge to pick up, and the same bucket for squeezing it out, followed by a towel to thoroughly dry it.
All the frozen stuff went back in, immediately cooling it down, and, of course, repowered, the plates got cold quickly; generally speaking, my box went from the 75-80 ambient to (with the frozen goodies helping) to the set temp of 4 degrees in a couple of hours. In the meantime, as the reefer hadn't been opened, it had stayed relatively cool, so it contributed little to the heat load.
So, that was a very long answer to a very simple question, but might have answered a lot of potential other questions
|
|
|
28-01-2025, 18:01
|
#47
|
Registered User
Join Date: Aug 2008
Location: Sydney, Australia
Boat: Roberts 45
Posts: 1,044
|
Re: Surprising results with a spill-over fridge.
Quote:
Originally Posted by skipgundlach
[...]
So, we wound up defrosting about once a month. We'd turn off the power as we went to bed, then got up and packed all the frozen stuff into a cooler. I used a heat gun at the edges, and with the plates warmed a bit by not having any cooling overnight, for the most part, the ice slid offf readily, or with the encouragement of a plastic spatula (putty knife). Behind (3/8" standoff
[...]
|
Hello Skip and thanks a lot for the detailed answer! I agree, this should be helpful for future readers as well!
Your procedure confirms my expectations or concerns as it sounds rather involved, even if you only have to do it once a month.
That's why I kept thinking about alternatives or easier/quicker ways of getting rid of the ice. So far, I haven't been able to come up with a better solution.
My initial thoughts are around a way to force the ice build-up onto a surface that is easier to defrost, e.g. a silicone or rubber membrane wrapped over the evaporator plate. Then you only need to bend the membrane and shake off the ice.
I also read somewhere that installing a small fan that continuously blows air across the evaporator plate would help significantly in reducing ice build-up.
I will let you and this forum know as soon as I found a workable option.
|
|
|
29-01-2025, 05:35
|
#48
|
Registered User
Join Date: Mar 2003
Location: Currently on the boat, somewhere on the ocean, living the dream
Boat: Morgan 461 S/Y Flying Pig
Posts: 2,302
|
Re: Surprising results with a spill-over fridge.
Quote:
Originally Posted by hzcruiser
Hello Skip and thanks a lot for the detailed answer! I agree, this should be helpful for future readers as well!
Your procedure confirms my expectations or concerns as it sounds rather involved, even if you only have to do it once a month.
That's why I kept thinking about alternatives or easier/quicker ways of getting rid of the ice. So far, I haven't been able to come up with a better solution.
My initial thoughts are around a way to force the ice build-up onto a surface that is easier to defrost, e.g. a silicone or rubber membrane wrapped over the evaporator plate. Then you only need to bend the membrane and shake off the ice.
I also read somewhere that installing a small fan that continuously blows air across the evaporator plate would help significantly in reducing ice build-up.
I will let you and this forum know as soon as I found a workable option.
|
About the only way you're going to achieve that is to do as household reefers do and have a separate cold box to cool the freezer, thence move freezer air on demand to the reefer (and back, with the route I described - taking reefer air from the bottom and blowing the now-colder air out the top of the spillover space - as more elegant than the ducting we've been discussing).
That cold box would be isolated by a flapper valve (to keep any loss of cold air from the freezer - there's another flapper which isolates the reefer from the freezer, preventing the reefer from getting too cold, and opening only on cooling demand from the reefer thermostat), and a reverse cycle initiated on a schedule (ignorant as to how much frost had formed), melting the ice (that's what the hose and the drip pan under the reefer/freezer is for - letting the melted frost evaporate naturally), and then returning to normal cooling cycles after having chilled the previously hot (from the melting cycle) tubing or plate, however it was done.
I suspect the drop-in/slide-in units commercially available may do something similar, but am ignorant on the subject. If you're really that concerned about a monthly less-than-an-hour routine, that might be a better route.
And, in point of fact, given the cost of marine refrigeration, and the reliability of residential refrigeration (so long as it's not encumbered with a bunch of electronics!), were I in the same position today (buying a boat with ancient and minimal insulation in an icebox), I believe I would buy a chest freezer and adapt it to a spillover-style reefer/freezer, and adapt the lid to become a countertop section.
Orders of magnitude less expensive, no defrost issues, and at the cost of it vs marine refrigeration, worth just swapping out if and when it or the box, due to rust, failed.
Are you at that position? That is, in the process of a massive refit, and able to do something of that nature?
|
|
|
04-02-2025, 02:55
|
#49
|
Registered User
Join Date: Aug 2008
Location: Sydney, Australia
Boat: Roberts 45
Posts: 1,044
|
Re: Surprising results with a spill-over fridge.
Quote:
Originally Posted by skipgundlach
About the only way you're going to achieve that is to do as household reefers do and have a separate cold box to cool the freezer, thence move freezer air on demand to the reefer (and back, with the route I described - taking reefer air from the bottom and blowing the now-colder air out the top of the spillover space - as more elegant than the ducting we've been discussing).
|
Thanks again for your detailed response, Skip!
And no, it's not about a one hour duty once a month, I thought it would be required much more frequently.
Quote:
And, in point of fact, given the cost of marine refrigeration, and the reliability of residential refrigeration (so long as it's not encumbered with a bunch of electronics!), were I in the same position today (buying a boat with ancient and minimal insulation in an icebox), I believe I would buy a chest freezer and adapt it to a spillover-style reefer/freezer, and adapt the lid to become a countertop section.
Orders of magnitude less expensive, no defrost issues, and at the cost of it vs marine refrigeration, worth just swapping out if and when it or the box, due to rust, failed.
|
That's definitely an interesting option which I've considered, but my concerns were:
- a pre-made chest freezer would not fit in the space left by the previous fridge
- a residential freezer needs 240V, which means the inverter has to be on 24/7
- the residential and camping fridge/freezer combos I've looked at have fairly limited insulation and to make matters worse: the compressor sits at the bottom of the chest with its heat radiating upwards
From some other really good threads in this forum I gathered that one can bring down the runtime of the compressor significantly (as in: from about 60% on to 30-40% on) with proper insulation.
Quote:
Are you at that position? That is, in the process of a massive refit, and able to do something of that nature?
|
I need to replace the failed fridge, yes, and I've bought the Danfoss BD50 compressor/evaporator combo plus different insulation material (XPS and Aerogel/Spaceloft). The challenge is to install it in the space provided: fibreglass it in while keeping the compressor out of the way yet still accessible for maintenance or replacement down the track. Then I need to fabricate a good lid that seals properly without being too heavy or bulky.
The YT channel Sail Life - refitting Athena has also given me some very good ideas and inspiration.
It always looks fairly easy when someone else is doing the jobs and summarizes a week of sweat and blood in 20 mins
|
|
|
04-02-2025, 02:57
|
#50
|
Registered User
Join Date: Aug 2008
Location: Sydney, Australia
Boat: Roberts 45
Posts: 1,044
|
Re: Surprising results with a spill-over fridge.
Here is the their one minute YT reel with a very unusual fridge lid:
|
|
|
 |
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|