Refrigeration Refit Challenge

[OzePete]

[QUOTE=Exile;2836219]

I'm not on the boat right now and don't have exact measurements, but my best guesstimate is that the refrig is ~11 cu.ft. and the freezer ~7 cu.ft. I could be off. From talking with the gurus over the years, I know I would need, at a minimum, one BD50 for each box. There are differing opinions on whether it's advisable to use the same holding plates. Cleave @SF for one recommends sticking with water cooling, but CoolBlue & ColdEH said I'd be fine with air cooled units.

Hi Exile, firstly your cabinets are a decent size and each would require separate systems. I agree with Cleve that water cooling should be considered especially if operating in the tropics or the unit location has ventilation issues, but am strongly against raw water cooling for several reasons, lack of condenser control and electrolysis being the main ones. We have a hybrid system (model AW480) that is air cooled but with fresh water re-cycled on demand to assist automatically as needed. This maintains optimum condenser temperature and eliminates the raw water electrolysis issue.

Also the Ozefridge compressor is 3.5cc and of course proportionately more powerful than the BD50 which is only a 2.5cc compressor. (The BD35 is only 2.0cc) This means that more refrigeration of eutectic plates occurs for each hour of running, especially important when 'abundant power is available, and greater ability to cope with extreme heat loads like when adding warm products to the fridge. BTW: Using a larger capacity compressor does not increase daily power consumption. It will use more watts / hr but runs for proportionately less hours

Questions Re: Insulation:

1. When beefing up insulation, why is it recommended to remove the stainless steel liners?
Metal conducts heat and is specially an issue if the cabinets interior or the lid / door liners don't have a proper thermal break, that is where the lining metal has access to the outside and therefore heat that can be transmitted into the cabinet. Sounds a bit pedantic but it does effect efficiency.

2. Is the blue board closed cell, i.e. resistant to water saturation?[Yes somewhat, but still vapour seal the insulation.
/QUOTE]


Cheers OzePete

[Richard Kollmann]

Exile;2836219]

I'm not on the boat right now and don't have exact measurements, but my best guesstimate is that the refrig is ~11 cu.ft. and the freezer ~7 cu.ft. I could be off. From talking with the gurus over the years, I know I would need, at a minimum, one BD50 for each box. There are differing opinions on whether it's advisable to use the same holding plates. Cleave @SF for one recommends sticking with water cooling, but CoolBlue & ColdEH said I'd be fine with air cooled units.

Do you homework like DHooper.
Do not let anyone tell you a BD 50 or other small 12 volt compressor system can equal the performance of your present SeaFrost Engine drive system

Cold Ed and Coolblue people are correct because of their more reliable air cooled condenser designs.

[Uncle Bob]

Hi, if it were me I would search out as many reputable refrigeration suppliers as possible,(four have been identified here), seek their opinions and then search for reviews of their product from previous customers. When happy with one or two then obtain quotes to supply a complete system. I would limit my research to those businesses that have a proven track record in design and manufacturing these types of refrigeration, not those that just talk about it.

[OzePete]

Originally Posted by Uncle Bob

Hi, if it were me I would search out as many reputable refrigeration suppliers as possible,(four have been identified here), seek their opinions and then search for reviews of their product from previous customers. When happy with one or two then obtain quotes to supply a complete system. I would limit my research to those businesses that have a proven track record in design and manufacturing these types of refrigeration, not those that just talk about it.

Great advise Uncle Bob.... Here are a couple of links to CF member comments about our products. Hopefully others will follow..

http://www.cruisersforum.com/forums/...-136455-3.html
http://www.cruisersforum.com/forums/...or-107093.html

We also have lots of data and photos of our manufacture and stock areas etc., available at our web site and elsewhere. Would be good to see pictures of other makers manufacture facilities and stock areas!

Also worth noting is that Ozefridge have both an air cooled only condensing unit model A480, (the only one with twin, two speed, thermostatically controlled fans for best possible air cooled condensing) AND an air / water cooled unit model AW480 also condenser temperature controlled.
No others have condenser temperature control which prevents over or under condensing automatically ensuring optimum condenser performance.

We can advise which suits each application best without prejudice because we manufacture both air and air/water cooled, not just the one type!

Cheers OzePete

[rbk]

[QUOTE=OzePete;2836257]

Originally Posted by Exile

[/B]
2. Is the blue board closed cell, i.e. resistant to water saturation?[Yes somewhat, but still vapour seal the insulation.
/QUOTE]


Cheers OzePete

Ensure your vapor barrier goes to the warm side and not to the cold side. This can be fudged slightly say half way (middle) on fridge, and say 1/3 on the freezer (in three inches of insulation "warm/1"/ VB/2"/Cold" but if unsure keep it completely to the warm side or you'll end up with moisture and ultimately mold in the refer walls. If using a vapor impermeable insulation you can seal the seams (detail this very, very well).

[Exile]

Thanks for all the helpful advice here.

Ozefridge - the other obvious benefit I see going from water to air cooling is the ability to run the fridge while away from the boat without worrying about the sea strainer packing up. It sounds like your hybrid system offers this as an option, and so maybe the best of both worlds.

Richard K - yes, I'm reluctant to remove systems on the boat that have performed well and proved durable. I'm also looking at it with a broader view than just upgrading individual components, since switching to 12v compressors will require commensurate upgrades to battery & charging systems.

DHooper - you may want to take note of some explanation & pics on the ColdEH site re: insulation. Those guys personally own a Bristol 45.5 with boxes identical to mine, and possibly laid out similar to yours (albeit smaller). I was particularly interested in how they upgraded the old insulation in their standalone freezer box lid using Aerogel insulation and vapor barrier tape.

RBK - thanks for the insulation tips. Your advice is consistent with earlier threads which suggested using polyiso (sp?) on the warm side (outside I assume) and blue board on the cold side (inside?). As for sealing seams & gaps, a two-part closed cell insulation product was recommended. One such product is called 'Tiger Foam'.

https://tigerfoam.com/sprayfoaminsul...D_BwE<br /> -

[Richard Kollmann]

Exile, I have been waiting on someone who understands sailboat refrigeration for boats with more interest than just drink cooler refrigeration. Engine driven or better yet Hybrid refrigeration has always proven to be the best choice for true cruising boats. I bought a new sailboat in 1983 and installed an engine driven compressor removed from a wreaked 78 Dodge. Thirty five years and two Yanmar engines later it was still ticking. It was a completely automatic three holding plate system that ran when engine started and each box temperature was controlled by a thermostat and solenoid. My boat charted out 182 weeks while I owned it crossing Gulf Stream many times. At 15 years I added a single standard Adler Barbour Cold machine condensing unit to supply refrigerant flow to each of the three holding plates so I would not need to run engine compressor at the dock, once plates were frozen by engine compressor.

Holding eutectic plates can rarely be justified unless there is surplus energy and no place to use or to store it. Engine driven refrigerant compressors from automobiles theoretically can freeze several hundred pounds of eutectic ice in on hour. Fractional three cubic inch horse power 12 volt compressors do not produce surplus energy nor does the refrigeration process generate additional energy.

DHooper after you are convinced that you really need those two oversize boxes and understand you can not support the electrical energy to maintain adequate box temperatures. I offer the following suggestions:
1. Install a new or remanufactures York or identical Climate Control compressor on the old system. This model compressor was used on 1975 Granada Ford Cars. Most engine drive compressors today use the Sanden Swashplate 5 cyclinder compressor but if your unit is Grunert the York or new climate control is a perfect bolt hole match. The reason these compressors fail is because of rapped speed just after start up causes slugging. If possible change the drive pulley to limit compressor to less than 1600 rpm at max engine cruise range. I know there were those that believe if it was OK to run compressor at 3000 Rpm in a car but not as low temp refrigerant flow in a boat.
2. The existing engine drive system and its tiny holding plates were never even 30 years ago adequate enough to provide much more than beer cooler temperatures in a warm climate.
3. I also recommend two air cooled 12 volt BD50 systems with box shaped (Bin) evaporators similar to Adler Barbour one in each box. With this engine driven system and dual 12 volt hybrid combination redundancy you can be satisfied with box temperatures. I would consider the Nova Cool machines at $900 each that are as energy efficient and reliable as any other name brand unit.
4. Refrigeration is still only one half of your problem solved the complete electrical power grid needs upgrading before venturing farther South.

I know every one investigation energy consumption as you are will be confused with the equipment marketing charts provide by different companies. All companies and even technical books in the boat business start out using two charts. There is one chart for selecting size of refrigeration unit based on box size and amount of insulation. This first chart is generally straight forward little trickery involved.

The other chart containing energy consumption and may not be a true representation of what you might expect in your boats energy needs. Let me use as an example refrigerator energy performance chart calculator from a company no longer in business so I will not step on anyone’s ego trip lets say Glacier Bay refrigeration.
When I was asked why my design Slide Show calculation for energy use far greater than that of GB’s and others charts? My answer was I was establishing a worst case energy need it boat were ever operated in a tropical climate. Anyone who follow my slide show math can adjust final totals Btu and amperage by reducing them two percent per warmer degree in ambient temperature down from 98 degrees F.

Refrigeration manufacturers no longer offer energy performance charts because of customer complaints after purchasing their units. These energy charts generally mean they refer to standard day temperatures and relative humidity at 69 degree F. This means the bottom line figures of Btu and amperage required do not include Mother Nature’s influence or the impact of people onboard a boat or other thermodynamics involved. So these energy charts are greatly misleading.

Here are energy consuming Btu items per day not normally considered in Sales marketing charts for mobile marine icebox conversion refrigeration operation in tropical climates:
• 300 Btu for freezing each two pounds ice cubes
• 17 Btu per inch of door or lid seal
• 1,000 additional Btu for every person onboard
• When temperatures increase charts design (standard day chart temperature) there will be a 4% per each degree of temperature rise in both amperage and Btu needed. Standard day from 69 degree to 94 degrees is going increase energy needed by 100%
• All of the above create addition sensible heat along with heat from living food product in refrigerator is ignored.

[Exile]

Originally Posted by Richard Kollmann

Exile, I have been waiting on someone who understands sailboat refrigeration for boats with more interest than just drink cooler refrigeration. Engine driven or better yet Hybrid refrigeration has always proven to be the best choice for true cruising boats. I bought a new sailboat in 1983 and installed an engine driven compressor removed from a wreaked 78 Dodge. Thirty five years and two Yanmar engines later it was still ticking. It was a completely automatic three holding plate system that ran when engine started and each box temperature was controlled by a thermostat and solenoid. My boat charted out 182 weeks while I owned it crossing Gulf Stream many times. At 15 years I added a single standard Adler Barbour Cold machine condensing unit to supply refrigerant flow to each of the three holding plates so I would not need to run engine compressor at the dock, once plates were frozen by engine compressor.

Holding eutectic plates can rarely be justified unless there is surplus energy and no place to use or to store it. Engine driven refrigerant compressors from automobiles theoretically can freeze several hundred pounds of eutectic ice in on hour. Fractional three cubic inch horse power 12 volt compressors do not produce surplus energy nor does the refrigeration process generate additional energy.

What seems to work best with my two systems (which share holding/eutectic plates) is to use the engine drive to cool the boxes initially, and then the 110v to maintain it. As you say, the engine drive is very efficient. I suspect the same would hold true for an engine drive combined with two, properly sized 12v BD systems, but then the add'l battery consumption would need to be reconciled. One upside to having a 110v system while on passage is that the AP amounts to the biggest battery draw. At anchor the battery draw is pretty minimal, and only from a few instruments, lights, and maybe a computer. I can therefore go pretty long between needing to charge batts. with my 510ah house bank. But this only makes the most sense for a boat with a genset and little or no solar.

It sounds like, whatever choices I ultimately make, you're suggesting not to dispense with my engine drive system so long as it continues to function reliably.

[DHooper]

Originally Posted by Exile

Thanks for all the helpful advice here.

Ozefridge - the other obvious benefit I see going from water to air cooling is the ability to run the fridge while away from the boat without worrying about the sea strainer packing up. It sounds like your hybrid system offers this as an option, and so maybe the best of both worlds.

Richard K - yes, I'm reluctant to remove systems on the boat that have performed well and proved durable. I'm also looking at it with a broader view than just upgrading individual components, since switching to 12v compressors will require commensurate upgrades to battery & charging systems.

DHooper - you may want to take note of some explanation & pics on the ColdEH site re: insulation. Those guys personally own a Bristol 45.5 with boxes identical to mine, and possibly laid out similar to yours (albeit smaller). I was particularly interested in how they upgraded the old insulation in their standalone freezer box lid using Aerogel insulation and vapor barrier tape.

RBK - thanks for the insulation tips. Your advice is consistent with earlier threads which suggested using polyiso (sp?) on the warm side (outside I assume) and blue board on the cold side (inside?). As for sealing seams & gaps, a two-part closed cell insulation product was recommended. One such product is called 'Tiger Foam'.

https://tigerfoam.com/sprayfoaminsul...D_BwE<br /> -

No question about the benefits of insulation. My 3" is certainly the minimum level but given the level of effort to reduce the box and reinsulate it is a level that I will live with for the foreseeable future. A nice project to be added to the project list down the road.

[DHooper]

Originally Posted by Richard Kollmann

Exile, I have been waiting on someone who understands sailboat refrigeration for boats with more interest than just drink cooler refrigeration. Engine driven or better yet Hybrid refrigeration has always proven to be the best choice for true cruising boats. I bought a new sailboat in 1983 and installed an engine driven compressor removed from a wreaked 78 Dodge. Thirty five years and two Yanmar engines later it was still ticking. It was a completely automatic three holding plate system that ran when engine started and each box temperature was controlled by a thermostat and solenoid. My boat charted out 182 weeks while I owned it crossing Gulf Stream many times. At 15 years I added a single standard Adler Barbour Cold machine condensing unit to supply refrigerant flow to each of the three holding plates so I would not need to run engine compressor at the dock, once plates were frozen by engine compressor.

Holding eutectic plates can rarely be justified unless there is surplus energy and no place to use or to store it. Engine driven refrigerant compressors from automobiles theoretically can freeze several hundred pounds of eutectic ice in on hour. Fractional three cubic inch horse power 12 volt compressors do not produce surplus energy nor does the refrigeration process generate additional energy.

DHooper after you are convinced that you really need those two oversize boxes and understand you can not support the electrical energy to maintain adequate box temperatures. I offer the following suggestions:
1. Install a new or remanufactures York or identical Climate Control compressor on the old system. This model compressor was used on 1975 Granada Ford Cars. Most engine drive compressors today use the Sanden Swashplate 5 cyclinder compressor but if your unit is Grunert the York or new climate control is a perfect bolt hole match. The reason these compressors fail is because of rapped speed just after start up causes slugging. If possible change the drive pulley to limit compressor to less than 1600 rpm at max engine cruise range. I know there were those that believe if it was OK to run compressor at 3000 Rpm in a car but not as low temp refrigerant flow in a boat.
2. The existing engine drive system and its tiny holding plates were never even 30 years ago adequate enough to provide much more than beer cooler temperatures in a warm climate.
3. I also recommend two air cooled 12 volt BD50 systems with box shaped (Bin) evaporators similar to Adler Barbour one in each box. With this engine driven system and dual 12 volt hybrid combination redundancy you can be satisfied with box temperatures. I would consider the Nova Cool machines at $900 each that are as energy efficient and reliable as any other name brand unit.
4. Refrigeration is still only one half of your problem solved the complete electrical power grid needs upgrading before venturing farther South.

I know every one investigation energy consumption as you are will be confused with the equipment marketing charts provide by different companies. All companies and even technical books in the boat business start out using two charts. There is one chart for selecting size of refrigeration unit based on box size and amount of insulation. This first chart is generally straight forward little trickery involved.

The other chart containing energy consumption and may not be a true representation of what you might expect in your boats energy needs. Let me use as an example refrigerator energy performance chart calculator from a company no longer in business so I will not step on anyone’s ego trip lets say Glacier Bay refrigeration.
When I was asked why my design Slide Show calculation for energy use far greater than that of GB’s and others charts? My answer was I was establishing a worst case energy need it boat were ever operated in a tropical climate. Anyone who follow my slide show math can adjust final totals Btu and amperage by reducing them two percent per warmer degree in ambient temperature down from 98 degrees F.

Refrigeration manufacturers no longer offer energy performance charts because of customer complaints after purchasing their units. These energy charts generally mean they refer to standard day temperatures and relative humidity at 69 degree F. This means the bottom line figures of Btu and amperage required do not include Mother Nature’s influence or the impact of people onboard a boat or other thermodynamics involved. So these energy charts are greatly misleading.

Here are energy consuming Btu items per day not normally considered in Sales marketing charts for mobile marine icebox conversion refrigeration operation in tropical climates:
• 300 Btu for freezing each two pounds ice cubes
• 17 Btu per inch of door or lid seal
• 1,000 additional Btu for every person onboard
• When temperatures increase charts design (standard day chart temperature) there will be a 4% per each degree of temperature rise in both amperage and Btu needed. Standard day from 69 degree to 94 degrees is going increase energy needed by 100%
• All of the above create addition sensible heat along with heat from living food product in refrigerator is ignored.

Yesterday I spent some time communicating with live aboards in different forums and learned that most of them have systems that parallel your suggestion. My loads would directly benefit from the engine drive as a supplement to a BD or similar compressor. However, having thin plate flat evaporators next to Eutectic plates would take up a great deal of cabinet space. My preference would be to have a similar function as Exile that shares the plates between the engine drive compressor and an air/water cooled compressor. Unfortunately the Grunert system was removed because of decay so an entire system would have to be built as compared to just replacing the compressor. I don't believe holding plates can live with flat plate evaporators with 2 drive systems or am I mistaken?

[Richard Kollmann]

Originally Posted by DHooper

Yesterday I spent some time communicating with live aboards in different forums and learned that most of them have systems that parallel your suggestion. My loads would directly benefit from the engine drive as a supplement to a BD or similar compressor. However, having thin plate flat evaporators next to Eutectic plates would take up a great deal of cabinet space. My preference would be to have a similar function as Exile that shares the plates between the engine drive compressor and an air/water cooled compressor. Unfortunately the Grunert system was removed because of decay so an entire system would have to be built as compared to just replacing the compressor. I don't believe holding plates can live with flat plate evaporators with 2 drive systems or am I mistaken?

Refrigeration is the process of removing heat and disposing of it to the outside. Whether systems evaporator coils are inside eutectic plate or one of them is a thin plate they both get the job done by extracting heat. The thin plate alone if engine drive is inoperative has shown it will remove eutectic liquid heat down to the freezing point only. Tecnautics and SeaFrost both started out in the eutectic holding plate engine drive business they both have designs for dual plate coil hybrid systems. They both also have quick to freeze holding plates you may not find elsewhere.

[DHooper]

Originally Posted by Richard Kollmann

Refrigeration is the process of removing heat and disposing of it to the outside. Whether systems evaporator coils are inside eutectic plate or one of them is a thin plate they both get the job done by extracting heat. The thin plate alone if engine drive is inoperative has shown it will remove eutectic liquid heat down to the freezing point only. Tecnautics and SeaFrost both started out in the eutectic holding plate engine drive business they both have designs for dual plate coil hybrid systems. They both also have quick to freeze holding plates you may not find elsewhere.

Good to know Richard thanks. Will investigate Technautics again...stay tuned.

[Pelagic]

Originally Posted by DHooper

Thanks for your thoughts. Yes, they are definitely large boxes with a little over 3" of insulation and a stainless steel liner. Reducing the boxes may be my only option but that is what I am attempting to learn here.

Why a stainless steel liner?
If you are going for a holding system like Ozefridge, you don't want stainless inside as it transfers the cold much quicker into the insulation

Listen to Pete! [emoji4]

[Exile]

Originally Posted by Pelagic

Why a stainless steel liner?
If you are going for a holding system like Ozefridge, you don't want stainless inside as it transfers the cold much quicker into the insulation

Listen to Pete! [emoji4]

Interesting that a number of boats, incl. mine & DHooper's, came from the factory with stainless steel liners. Wonder why?

[Pelagic]

Originally Posted by Exile

Interesting that a number of boats, incl. mine & DHooper's, came from the factory with stainless steel liners. Wonder why?

I think it was a sales tool by the builder who didn't know or care about efficiency.
Stainless interior are more suitable for commercial walk in units or land based conventional refrigerator units where power is not an issue.

Super yachts with 24 hr generators install commercial grade stainless units