It should be noted that both my Norcold and Vitrifrigo had/have more insulation installed and sit in an insulated cabinet designed to promote airflow over the condensers, decreasing their battery draw by some percentage.
I also modified my Vitrifrigo with a quieter, more efficient 120mm condenser fan which sucks cold air from the floor below and pushes it through the condenser and across the compressor, and then out a vent in the body, so it cannot recycle any preheated air, for maximum efficiency.
I have 198 watts of solar and have no issues powering the fridge, not even a concern. I consume 25 to 40 amp hours after sundown until sunrise with fans laptop TV LED lights ect including fridge.
My Norcold's condenser was passive, but I did have an silent, low cfm additional fan rigged up to blow air across it full time.
I added 40mm fans to the interior of both fridges that run continuously. These allow much more even internal temps and quicker cool downs, but do not make the fridge use less battery power. They do however allow it to use a lower t stat setting to hold sub 39f temps.
I generally keep the VF on a setting of ~2.2 out of 7 to hold sub 39f. When I remember, and have excess solar amps available, I will turn it upto ~3 afternoon, then back down to 2.2 near sundown, then the duty cycle and battery consumed is lessened overnight. The internal fan allows me to better take advantage of the solar surplus by cooling down interior contents faster. If I forget to return the dial to 2.2, the milk jug might be slushy the next morning as internal temps fall to the 30 to 32f range.
The TruckFridges, while very similar to the Italian assembled Vitrifrigo, are assembled in China. I would not have been able to do my fan modification to push air through the condenser with the TF. I think the extra C note I spent on the VF, over the TF, was well worth it.
Originally the fan pulled air through the condenser. Pushing it is quieter. The extra insulation to fridge body and cabinet interior allowed this repositioning of the fan.
The Noctua NF-f12 fan was not much quieter when pulling air through the condenser, It was designed to push it through a restriction. While it is rated at 53 cfm and the fan it came with was 72 cfm, the Noctua has a higher static pressure rating, and the duty cycle seemed to lessen with the new fan pushing. Also the Noctua only draws 0.05 amps, the provided fan pulled 0.12 amps.
The Norcold's Sawafuji compressor was a buzzsaw in comparison to the Danfoss. I believe it failed due to low refrigerant, and recharging it would have cost as much as a new fridge. The Vitrifrigo is easily rechargeable.
The sawafuji did start up smoother than the danfoss, but while the sawafuji keeps getting louder and develops harmonics, the Danfoss gets quieter after the initial start up.
The compressor controller for the danfoss allows much more options such as changing compressor speed, and wiring an additional fan to power on with the compressor, as well as add a LED light to read trouble codes, and change the low battery voltage cutouts.
Faster compressor speeds are desirable for quicker cool downs, or for larger fridges, but basically the slowest speed is most efficient as long as duty cycle remains below 50%. The faster compressor speeds do lower duty cycle, but amp draw is increased while it is running.
Danfoss is now Secop and no longer European assembled. Hoping quality did not decline with the move to asia.
