Fridge that uses little, if any, of your battery!

[OzeLouie]

Originally Posted by rgleason

Just to help move this along, I forget what size Danfoss Unit our Ozifridge Model C150/ T45-30 with 9 litres of eutectic solution mixed to freeze at 23 degF or -5degC with polypropylene glycol with the controls set for cut out temp+-7c and cut in temp= -2c but in thinking about how to improve the system, I considered the possibility of a more powerful compressor to take advantage of the times when we have plentiful power (ICE powered alternator in/out of harbor, or 1-2 hours power battery (initially 140 FLA amp-hr later changed to 214 ah fla) charging when voyaging.

Compressor: Danfoss BD50, Capacity 934 btu/hr (274 watts) <--there it is! If the manuf. wrote w/hr that would help
3.41 btuh/watt x 274watts (watt-hr or watt/hr) = 934

Our box is top entry, reasonably insulated but old insulation, fairly large 4.55 cu.ft. 2634 sq.in. surface area with an R-value=9 and delta T of about 53f and is not a freezer, but we can keep steaks somewhat frozen against the eutectic tank for a several days, but that is not the intent.

Would a larger Danfoss Compressor be advantageous to faster drawdown, or would it be impaired too much by requiring greater power during the longer periods when we are dependent on our battery?

Louie, I have no doubt that I have used confused or wrong units at times. Your points were completely clear to me, regardless. I think this units thing it beaten to death now.

I have also considered getting some of the more advanced premixed food industry eutectic solutions which phase change less gradually and over a smaller temp range than the polyprop glycol. I think that might be an improvement.

I have considered removing the counter top and fiberglass chest and rebuilding (big job) using
Aerogel - Pyrogel XTE Blanket 5mm x 5= 25mm= 1 inch, Pyrogel XTE - 0.14 BTU-in/hr-ft2-°F

Your condensing unit has a speed selector switch on the front panel. There are two resistors (one for each switch position) Change the higher value resistor to 1700 ohms to cause the compressor to run at maximum speed when 'Hi speed' is selected. You will also need to increase air over the condenser and suggest changing the internally mounted 120-120-25mm fan for a 120-120-37 mounted externally. (Must be rated less than 6 watts) You may need to add a little R134a refrigerant also.
You could automate the system using a voltage switch to monitor voltage available and once a voltage that indicates batteries are topped up is achieved, have this switch put 300k ohms across the probe circuit and at the same time the 1700 ohms for maximum speed. This will cause your system to switch on prematurely and run harder removing more heat when power is abundant.

Also suggest talking to Rich Boren at Technautics before getting involved with vacuum panels.

[Uncle Bob]

Originally Posted by StuM

Sigh!
As pointed out, Raymond was incorrect - as any competent engineer would realise. The Watts he quoted in his reference was correct; and no reputable publication would use the meaningless Watt/Hr.
You however have consistently misused these units.
You apparently still don't "get it"

Stu, I respect your yearning for the correct use of units and terminology, I have to wonder if your desire for the correct use of the language would extend to one that claims to be an author who however cannot apparently master the correct use of the tools of the English language, grammar, punctuation and the correct terminology for the topic being discussed. Not to mention the age old craft of proof reading prior to posting.

[AndyEss]

[weavis]

Now that we have established that everyone partaking in this thread cannot spell, has no idea what they are talking about and and doesn't know what a Watt is from a when, can we please get back on track and discuss the subject at hand?

I confess to being in the position of no longer knowing what the subject is and am rapidly losing the will to live in reading this thread.

oh... and please be nice. Refrigeration is turning into the new anchor discussions..

[OzeLouie]

Originally Posted by weavis

Now that we have established that everyone partaking in this thread cannot spell, has no idea what they are talking about and and doesn't know what a Watt is from a when, can we please get back on track and discuss the subject at hand?

I confess to being in the position of no longer knowing what the subject is and am rapidly losing the will to live in reading this thread.

oh... and please be nice. Refrigeration is turning into the new anchor discussions..

Thank you Weavis, unfortunately this thread has been diverted from its objective which many want to focus on. An interesting topic.

[JPA Cate]

This thread will now be closed for moderator discussion. There are procedural difficulties.

Ann