BD50 compressor for a 80 liter freezer/fridge combo - is it overkill

[rotorman]

Hi, I am replacing my refrigeration system. The only compressor I can get quickly and locally (Singapore) is the BD50 (Frigoboat Capri 50F).

Is it overkill for my 80 l (60 l fridge and 20 l freezer) combo?

Any downsides to buy this instead of finding a BD35 (other then price)?

Kind regards
Geza

[rotorman]

I have already found that the BD50 run at 2000 consumes 4.3A. The smaller unit BD35 only consumes 3.0A.
But on the other hand maybe this translates to shorter runs of the BD50 compared to BD35?

[ErikFinn]

We have a few pros here on the forum mostly based in the US, if you can wait a few hours for the daylight over there Im sure you'll get some good answers.
Sorry I can't offer better help for now..

[OzePete]

Provided the BD50 is matched to the system then the daily power consumption will be much the same as a system with a BD35 matched to it. A system with a smaller compressor may have a lower hourly consumption rate but it has to run proportionately longer to perform the same task so its half a dozen of one and six of the other.
Believing a BD35 uses less power because it is rated at 3.0A is not correct. Go for the BD50 and your system will have a bit of grunt for coping with extreme conditions.
Cheers OzePete Ozefridge | 12 Volt Refrigeration Systems

[El Pinguino]

I recently replaced a 35 with a 50.

I often tend to run the fridge only when I run the engine.

Its a lot faster bringing the temp down and takes it a lot lower in the same period time.

To my simple mind that equates to it being more efficient...

[fallingeggs]

That's a small fridge/freezer you got there! No offense. (For Americans, I think his fridge is about 1.3 sq ft and freezer is 0.7.)

I just installed (or still finishing) a DB50 for a combo twice as large, which I thought was boarder line for the DB50. The smallest evaporator plate recommended by my maker for my DB50 just nearly fit into my freezer.

If you install the DB50 with too small of a evaporator plate, you lose efficiency, I believe. You'll have to ask your maker what the smallest recommended evaporator plate is. Or, maybe, if the system is recharged by a good professional, they can fill it with just the right amount of refrigerant.

And yes, wait for EhCold and ThirdDay to chime in!

[Typhoon]

For a 2.8 cubic foot box or there about . A BD50 would be large . But that really depends on your insulation and your intended cruising grounds . If you have just 2 inches of good foam or R10 insulation you could probably go with a BD35 . The smaller compressor would be more efficient in this case , as it would cycle less . On a thin plate capillary tube system it is essential to match the box to the systems capacity for maximum efficiency. Your goal would be a 50% duty cycle of the compressor . Remember a compressor that cycles on and off to often wastes energy .

Regards John

[rotorman]

Thanks guys. I was looking at evaporators, Frigoboat H160 would be available here (which has a small freezer part only). The rest of the box would be fridge. How can I figure out if it is a good match with the BD50?

(The current insulation is not too good I believe so I am thinking of redoing it. Cruising grounds is tropics, full time.)

[Typhoon]

Originally Posted by rotorman

Thanks guys. I was looking at evaporators, Frigoboat H160 would be available here (which has a small freezer part only). The rest of the box would be fridge. How can I figure out if it is a good match with the BD50?

(The current insulation is not too good I believe so I am thinking of redoing it. Cruising grounds is tropics, full time.)

Not knowing the state of your insulation , taking into account the size of your box , I would still go with a BD35 for that bin evaporator.

Just a note , the systems we design are not sensitive to this balancing act to achieve maximum efficiency . The compressor is not controlled by evaporator temperatures .

Regards John.

[ALLAN WARD]

If you are going to be cruising permanently in the tropics and want to keep things frozen , l would lean towards the BD50 . I chose the BD50 over the BD35 even though it appeared at the time to be a little overkill but the system has worked well .

[stormalong]

If you want to keep meat and ice cream frozen go with the BD50.

I have two separate systems - for a 2.5 cf freezer and a 5 cf refer. They are adjacent separate boxes. The freezer draws double the power (run time) for half the space. As long as the evaporator plate is large enough the larger compressor will run less time.

Are you aware that you can set the compressor speed by changing the resistor in series with the thermostat. That can save power or extend/reduce run time to suit your needs. With air cooled units it can be advantageous to run longer at lower speed. Be sure you have good airflow over the condenser coil.

[Richard Kollmann]

Singapore is near the Equator and has an average tropical temperature of 80 degrees F (27 C). With a small 80 liter (2.8 cu ft ) box the BD35 could perform OK but with little room for error and maybe less efficient than the BD50. You can not compare amperage per hour at minimum compressor speed between a BD35 and BD50 compressor because to satisfy your desired box temperatures you do not know what compressor speeds it will take. Depending on quality of insulation and drinking liquid habits it may require the BD35 to operate longer at higher less efficient speeds to maintain desired box temperatures.

The Capri BD50 F air cooled would be my first choice as it has out performed most other systems. When it comes to small icebox conversions the choice of evaporators are generally limited. I would first make a facsimile of evaporator out of cardboard to see if it will fit inside box. If you select a Frigoboat BD50 system they may not have the size and type evaporator you require.

Keep the refrigeration simple without added gadgets if you want extended reliable service.

[KWISPEL]

This one have a little fan in it, so have you a good circulation from the cold air in the fridge. Works very well.

https://www.svb24.com/en/dometic-vd-...vaporator.html

[patprice]

I recently replaced my total BD35 system.

Why? The seam which joins the two halves of the compressor developed a rust spot, goodby gas and oil and all.

I have an arrangement that should suck cooler air from the bilge. I notice the new unit is blowing into the fridge.

Can I reverse the fan?

[Typhoon]

Originally Posted by patprice

I recently replaced my total BD35 system.

Why? The seam which joins the two halves of the compressor developed a rust spot, goodby gas and oil and all.

I have an arrangement that should suck cooler air from the bilge. I notice the new unit is blowing into the fridge.

Can I reverse the fan?

Yes you can reverse the fan but you can't simply do it by changing the wires , you have to physically turn the fan around .

Regards John