Another look at Solar Powered refrigeration on sailboats

[newhaul]

Originally Posted by ramblinrod

The following statements are always true:

1. Everything on a boat is a compromise.

2. Any solution to a problem necessarily creates another problem.

That one may consider the new problem "more desirable", another may not.

number 1 usually true
Number 2
Not necessarily and IME actually incorrect if the solution is properly engineered and executed .

[rramsden]

I bought my boat with these already installed. A high efficiency marine DC refrigerator freezer, and a 640 watt solar panel. The panel charges the house battery. The refrigerator is connected to the battery.
In reasonable sunlight, the battery is fully charged by sundown.
The fridge and panel were recent upgrades by the previous owner.
Rich
S/V Fleur de Lis

Fountaine Pajot Bahia

[ramblinrod]

Originally Posted by newhaul

number 1 usually true
Number 2
Not necessarily and IME actually incorrect if the solution is properly engineered and executed .

Number 2: One cannot solve a problem that does not introduce another problem.

Incorrect.

Every issue has its pros and cons.

Correspondingly, every solution has its problems.

These are undeniable truths that shall exist for all eternity.

A true engineer knows this.

[newhaul]

Originally Posted by ramblinrod

Number 2: One cannot solve a problem that does not introduce another problem.

Incorrect.

Every issue has its pros and cons.

Correspondingly, every solution has its problems.

These are undeniable truths that shall exist for all eternity.

A true engineer knows this.

ok then explain to everyone if I have 3 inches of spray foam insulating my ice box .
I remove that wet stuff and replace it with 3 inches ( estimated replacement of r5 to7 insulation ) of foil lined Cryogel ( Estimated r value R45 to 47)
how have I created another problem wrt increasing the efficiency of a refrigeration system .( doesn't matter what is installed)


what new problem have I created?

[Uncle Bob]

Originally Posted by newhaul

ok then explain to everyone if I have 3 inches of spray foam insulating my ice box .
I remove that wet stuff and replace it with 3 inches ( estimated replacement of r5 to7 insulation ) of foil lined Cryogel ( Estimated r value R45 to 47)
how have I created another problem wrt increasing the efficiency of a refrigeration system .( doesn't matter what is installed)


what new problem have I created?

Newhaul, stop it I say stop it.. You are being so damn logical and sensible here that you are depriving the needy of an ongoing opportunity to ramble and debate pointless postures.

[Richard Kollmann]

This has been an informative review of solar powering pleasure boat refrigeration. This subject thread has covered both sides of the refrigeration hardware energy efficiencies so each forum viewer can be encouraged to spend time upgrading or selecting his icebox conversion refrigeration system. This thread drifted at the end to what was defined as a very large issue that everyone is aware of, Insulation the real elephant in the room. I think it is time to start a new thread subject how much insulation is required and which insulation is the most reliable in a marine environment?

A simple unanswered question about boat refrigeration insulation might be, Is open cell insulation that is used to hold heat in and cold out suitable for boat refrigeration?

[newhaul]

Originally Posted by Richard Kollmann

This has been an informative review of solar powering pleasure boat refrigeration. This subject thread has covered both sides of the refrigeration hardware energy efficiencies so each forum viewer can be encouraged to spend time upgrading or selecting his icebox conversion refrigeration system. This thread drifted at the end to what was defined as a very large issue that everyone is aware of, Insulation the real elephant in the room. I think it is time to start a new thread subject how much insulation is required and which insulation is the most reliable in a marine environment?

A simple unanswered question about boat refrigeration insulation might be, Is open cell insulation that is used to hold heat in and cold out suitable for boat refrigeration?

simple answer to that question
It depends on its hydroscopic rating.

[Richard Kollmann]

Originally Posted by newhaul

simple answer to that question
It depends on its hydroscopic rating.

Hygroscopic rating is the attraction and holding of water molecules from the surrounding environment at normal standard day ambient temperature. Conditions surrounding a boat’s refrigerator are far from normal as moist air interring and leaving insulation does act as a dehydrator trapping moisture in any open area or insulation cell. Moisture destroying R value of any insulation or its protect barrier takes sometimes years. You have to admit this is an open question looking for debate. Even VIP panels popular a few years back lost their open cell insulation R value do to moist air leaking in.

[newhaul]

Originally Posted by Richard Kollmann

Hygroscopic rating is the attraction and holding of water molecules from the surrounding environment at normal standard day ambient temperature. Conditions surrounding a boat’s refrigerator are far from normal as moist air interring and leaving insulation does act as a dehydrator trapping moisture in any open area or insulation cell. Moisture destroying R value of any insulation or its protect barrier takes sometimes years. You have to admit this is an open question looking for debate. Even VIP panels popular a few years back lost their open cell insulation R value do to moist air leaking in.

true but you did ask a specific question and in true forum form I answered with the standard answer
" it depends"
That is one reason I chose Cryogel with the foil backing . High r value ( r8 per 10 mm)
and hydroscopic rating of <5% ( by weight) in refrigeration installations.
Then there is the I only have 3 inches on 2 sides without losing volume.

[senormechanico]

Originally Posted by ramblinrod

I doubt any more effort on my part will be fruitful. Higher priorities await.

With baited breath, we all await your Golden Words of Wisdom...

[ramblinrod]

Originally Posted by senormechanico

With baited breath, we all await your Golden Words of Wisdom...

Well it is is good to know that at least some appreciate my help.

Thanx.

[RaymondR]

Originally Posted by Richard Kollmann

I totally disagree with the above. The TX valve quoted is most likely a Danfoss T2 or TE2 using a OX orifice as these are the smallest they have available. They are Danfoss rated with a nominal 1/3 ton at MBP and 1/8 ton at LBP, far far too big for the BD35 specialy at low RPM used on a cold plate. It is akin to fitting a four barrel Holley carburetor to a motor scooter!!

This is why flood back (super-heat Hunting) was reported at some earlier post and described as a compressor cooling feature!!! lol

TX valves, especially oversized ones, have no place on theses micro or similar systems, as 99.?% (est) of the worlds makers seem to understand.

Cheers OzePete

Interesting opinion. But I have even run three TXV T2 Danfoss valves supplying refrigerant to three holding plates at the same time with one single BD2.5 compressor in the hybrid system in my boat.

Hi Richard,

I was re-reading this very interesting thread in preparation for another refrigeration adventure when the bit in red caught my attention. I'd be interested in learning a little more about the arrangement.