Who provides the best 12 volt refrigeration systems?

[john61ct]

And ColdEh TXV but evaporators.

But the holding plate + TXV I've only come across Rich so far.

[Richard Kollmann]

Originally Posted by a64pilot

It would seem Pete’s system is the odd ball operating with hold over plates, but without a TXV?

Changing condenser fan speed might work on a RV installation but not when condensing unit is in a compartment without prevision or means to discharge heat somewhere other than in that compartment.

[Richard Kollmann]

Originally Posted by john61ct

And ColdEh TXV but evaporators.

But the holding plate + TXV I've only come across Rich so far.

Rich does use the TXV on holding plates and John has an improved extra large air cooled condenser and copper evaporator with refrigerant super heat controlled by a TXV and refrigerant receiver.

When I started selling holding plates for hybrid systems the TXV's were all too large for the Danfoss BD compressor output limits. I contacted the senior engineer at Parker valves division for help and came up with the solution using a short cap tube 400 btu orifice inline with a 1/4 ton Parker TXV. This worked so well I was able to run three holding plates with each having its own TXV connected to one BD2.5 condensing unit.

[Typhoon]

Originally Posted by Richard Kollmann

Rich does use the TXV on holding plates and John has an improved extra large air cooled condenser and copper evaporator with refrigerant super heat controlled by a TXV and refrigerant receiver.

When I started selling holding plates for hybrid systems the TXV's were all too large for the Danfoss BD compressor output limits. I contacted the senior engineer at Parker valves division for help and came up with the solution using a short cap tube 400 btu orifice inline with a 1/4 ton Parker TXV. This worked so well I was able to run three holding plates with each having its own TXV connected to one BD2.5 condensing unit.

Once you you use a TXV or TEV you are now able to super size the condenser . This insures that the condensate will always be at ambient air temperatures. Actually a TXV donsn't really care what temperature the refrigerant is, at the valve as long as it is liquid. The orifice in the (Danfoss) TXV is also not prone at all to blockages. They have a large filter just ahead of the orifice that will trap anything that the filter/receiver/drier missed. The main reason manufacturers use Cap tube designs, is cost .

[john61ct]

So just to confirm, CruiseRO/CoolBlue is indeed the only holding plate system to use TXV?

Someone said all of them do, didn't sound right to me.

[newhaul]

Originally Posted by john61ct

So just to confirm, CruiseRO/CoolBlue is indeed the only holding plate system to use TXV?

Someone said all of them do, didn't sound right to me.

yep as far as I know he is the only one that uses the txv

Kollman said it back in post 133
http://www.cruisersforum.com/forums/...ml#post2695205
in the last paragraph

[a64pilot]

If you look at home heat pumps that have been mandated to become very efficient in the US since 2006 (min 13 SEER) you’ll notice the biggest immediate difference between them and the ones of old is the condenser size, where they used to be one side of a small box, they are now huge circular coils three feet across and four feet tall, the condenser is the whole circumference, they are many times more surface area than they used it be, and they have different cooling fins etc to further boost heat removal. The more heat you can remove at the condenser, the more efficient it becomes.
Cause of course there is no such thing as cold, only the absence of heat, we aren’t making things cold, we are removing the heat. So you need two things to do that of course, an efficient way in the box to absorb that heat, and an efficient way outside of the box to remove it.
I know the Cool blue has an oversized condenser, cause he can fit a BD80 compressor on the same condenser, run the same fan and it works, so there is obviously excess capacity there for the more normal 35 and 50 sized compressors.

[OzePete]

Response in BLUE!

Originally Posted by ColdEh Marine

Once you you use a TXV or TEV you are now able to super size the condenser .Whether a TX valve or capillary, makes little difference to issues related to engineering condenser capacity! This insures that the condensate will always be at ambient air temperatures. John, I believe you are only new to the industry but engineering a system to deliver liquid refrigerant to the throttling device (in your case a TX valve) at ambient temperature is not correct! It will see inefficiency issues like over condensing for one.

Chasing the lowest compressor A/H rate assuming this will be more efficient, is misleading. The lower evaporator temperature (and related suction pressure) sees the COP also considerably lower causing the system to be considerably less efficient. Actually a TXV donsn't really care what temperature the refrigerant is, at the valve as long as it is liquid. Same for a capillary system but liquid temperature (pressure) outside engineered parameters is detrimental to both types.

The orifice in the (Danfoss) TXV is also not prone at all to blockages. They have a large filter Actually a small strainer and in time although rare as previously stated, you will come across a blocked TX valve strainer or clocked orifice!! A proper filter dryer that has a secondary felt pad is the answer for these micro systems. just ahead of the orifice that will trap anything that the filter/receiver/drier missed.

The main reason manufacturers use Cap tube designs, is cost .The 99+% of the millions of small fridge or freezers manufactured worldwide each year are capillary fed because it is simpler, less problems and provides virtually the same performance.
A TX valve costs a fridge manufacturer approx $15, a receiver/ filter with sight-glass less than $12 while a capillary costs about $6 so cost may be a minor part of the issue.

BTW, I had emailed John several times offering to assist with his new venture, apparently as Rich Boren had kindly done previously. My offer was not accepted!

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[Richard Kollmann]

Originally Posted by OzePete

Response in BLUE!

BTW, I had emailed John several times offering to assist with his new venture, apparently as Rich Boren had kindly done previously. My offer was not accepted!

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

John, If you are smart you will not respond to this distorted game of facts. Your designs are far more appealing than his. STAY COOL

[OzePete]

Originally Posted by Richard Kollmann

John, If you are smart you will not respond to this distorted game of facts. Your designs are far more appealing than his. STAY COOL

Perhaps instead of your usual muckraking towards me, you might like to explain what were the distorted facts in my post. But explain with fact not just puffery!

And could you also explain how you come to the conclusion stated in the second part of your post, when you have no idea regards our system! ESP perhaps?

Cheers OzePete

[Richard Kollmann]

Originally Posted by OzePete

Perhaps instead of your usual muckraking towards me, you might like to explain what were the distorted facts in my post. But explain with fact not just puffery!

And could you also explain how you come to the conclusion stated in the second part of your post, when you have no idea regards our system! ESP perhaps?

Cheers OzePete

John, of Cold Eh marine has produced a marine mobile refrigeration system addressing the normal problems with simple very efficient solutions. There are no secrets or hidden proprietary gadgets in Johns designs that will compromise reliability and longevity. It takes a boat owner like John or Rich of Technautics to understand how to design a boat’s refrigeration system.
John needs respect for his Cold ED Marine achievements in the marine industry not petty insults in BLUE INK.

[john61ct]

No matter the "truth" one way or the other, directly sniping at a (what should be) well-respected colleague in a public forum

to say leaves a bad taste in my mouth is a gross understatement.

Personality and character count for a lot in business.

And never mind with "the what about?s", two wrongs don't make it right.

[weavis]

Gentle people

If you cant be nice, then you should not post. One more outburst and the thread is toast and infractions will be issued as you both are contravening CF rules of conduct.

Please.!

[OzePete]

Originally Posted by Richard Kollmann

John, of Cold Eh marine has produced a marine mobile refrigeration system addressing the normal problems with simple very efficient solutions. There are no secrets or hidden proprietary gadgets in Johns designs that will compromise reliability and longevity. It takes a boat owner like John or Rich of Technautics to understand how to design a boat’s refrigeration system.
John needs respect for his Cold ED Marine achievements in the marine industry not petty insults in BLUE INK.

I have nothing but respect for John and Andrea specially as they are entering the industry at such a difficult time.

Richard, you may not be aware but when John and Andrea started we had several private communications discussing our industry, we also discussed an offer we proposed for possible joint activity between Ozefridge and ColdEh , and at that time I offered any assistance I could.

At all times and as of now, I have wished them every success as this cut and paste from an email I sent to John and Andrea a year ago indicates...
"Let me know if you are interested and we can discuss things further in a lot more detail, otherwise I wish you and your family all the best with you project and hope we can always remain on a friendly professional basis"

I consider them as friends I have yet to meet, and as with any friend I will do / say anything that I truly believe will help them.

Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[rgleason]

My experience with the ozifridge eutectic system and some informal testing to get the right solutuon of antifreeze/water is that the solution does not all freeze at exactlty the same temperature. You might think it should but it doesn't. There as if freezes there will be a range of a couple of degreesC and I forget exactly how much.

Since doing this many years ago there have been new companies specializing in eutectic solutions. Has anyone tried discussing our particular needs to come up with a better solution that might be more efficient, precise, or hold motre btus?