Clearly Third Day has this worked out. The important point is that the question is not just holding plate or not, but the system design. His holding plate system is nothing like the jacket-around-the-evaporator "improvement" sold by his competitors. His TXV system is an improvement on the capillary systems typically sold.
Some basic points: the amount of heat that needs to be extracted every day by the refrigeration
is ALWAYS going to be equal to the amount of heat that gets conducted or convected into the space (not including cooling
down new additions). Holding plates per se don't change this. Better insulation
and sealing, top loading instead of side loading, unsealed drains, do have a major impact, so fix them first.
A holding plate, other things being equal, will result in fewer and longer compressor runs. This can result in some efficiency improvement, but ultimately the amount of heat removed is the same. As Third Day noted, the fewer starts should improve product life.
Personally I have a custom system installed in Turkey
. It is a basic Danfoss BD35F capillary system with air and keel cooling
, and (due to mistaken communication) a holding plate. It works well, but note that the guys who did it knew their stuff. As Third Day pointed out these systems are very critical as far as internal volume, quantity of refrigerant, and pressure drop across the capillary - not really for amateurs. I originally had a problem with the capillary, probably from contamination, so had new tubing installed with a larger/longer capillary (to maintain the pressure drop). Even for an experienced professional (not me), getting the charging
right took a bit of time, and an added high pressure port for better instrumentation. The dual condensers added to the confusion. I'm happy with the result, but it was a unique situation. Next time I'll be looking at a packaged system.
BTW my previous system was an Isotherm
seawater cooled one. It was complicated without much benefit and in the end very unreliable due to the seawater cooling design. In the future I will stick with keel cooling if at all possible.
For those that are using the Danfoss systems with the Danfoss basic controllers, you should be aware that the compressor speed can be manually adjusted by adding resistance into the thermostat loop. Without resistors the compressor runs at 2000rpm, but can also be set to run at 2500, 3000, and 3500 rpm
. So adding a resistor can significantly improve the capacity/reduce run time for those with high duty cycles. The advanced controllers control the speed automatically, which is a benefit. Perhaps Third Day could comment on this.