Ozefridge systems are a result of scientific calculations directly from your gathered data. Each system has a calculated heat loss data sheet that is generated off the conditions in which it is expected to operate, these conditions are directly related to your refrigerator/freeze box make up. In the end when you choose an Ozefridge system you have done your best to ensure functional success and the best energy efficiency available. At Ozefridge there is no guessing – “Its All In The Science”.

When it comes to quality components Ozefridge will definitely meet and exceed your expectations. From dual cooling fans to optional fresh water cooling the Ozefridge is the refrigeration product that will go the distance. Stainless enclosures and panels are corrosion resistant. Digital controls and surge protected electronics make the Ozefridge system stand out. Builtin voltage/spike suppressor protection and extra MDM aka compressor control module supplied with every system gives you added confidence when your miles at sea.

“Rich’s Thoughts”

After over a decade in the Marine Refrigeration Business, I often get asked by New Cruisers and Cruisers in Planning:

“Hey Rich, what is the No 1 failure you see in Marine Refrigeration Systems”

The answer is pretty easy and that is Dead Compressor Power Modules and without that…well friends…there is no cold beer!

Many Cruisers my not realize this, but your 12v compressor really isn’t a 12v compressor. The MDM or Motor Driving Module mounted on the side of your compressor is taking the ships DC Power and converting it into 3-phase AC Power to run the compressor. That is how the controller goes about changing the compressor RPMs and enabling a soft start-up on some models. But ALL of your “DC” compressors are really running on 3-phase AC Power.

The MDM is the weak link, designed to be so in some ways to protect the compressor. It’s susceptible to voltage spike and surges. It’s also an electronic part stuffed away on a boat that’s susceptible to the crimes of heat and the corrosive nature of the Sea. Some refrigeration units come standard with voltage spike/surge suppressors on the inlet power side, while others leave that to the installer to provide.

So when folks are getting ready to cast off on their Cruise, the one spare I recommend carrying for their Marine Refrigeration is a Spare MDM or Compressor Control Module.

After all, if you can’t have Cold Beer and Ice Cream at anchor, then you are Camping, not Cruising in my book!

Rich Boren-Owner Cruiser Services
Schenker Watermakers, Frigomar Air Conditioning
and OzeFridgeUSA Marine Refrigeration

Condenser Temperature Control:

The OzeFridge Compressor/Condensing units are designed to maintain a condensing temperature as close as possible to the optimum design specs to prevent both over-condensing in cold environments and more commonly, to prevent under-condensing in hotter environments. Properly controlling the Condenser temperature is a major factor in OzeFridge system’s industry leading efficiency. Something no other marine refrigeration system has, the condensing temperature on the OzeFridge Condenser can be easily checked by pressing the “up” button on the digital temperature controller.
The Condenser temperature is first controlled using air and for units operating in enclosed spaces or in the tropics, with optional Fresh Water cooling. Looking first at the air cooling control details, the OzeFridge is equipped with two cooling fans. The Compressor unit starts the Condenser cooling with one fan and then switches to twin fans as required based on Condenser temperature. When the Condenser temperature lowers sufficiently it will automatically revert back to one fan operation to maintain optimum condensing.
The Compressor/Condensing unit also comes equipped with power terminals set-up to run an additional 12v cooling fan. These power terminals are energized when the Compressor/Condenser unit is running. This comes in useful for installation that have the Compressor/Condensing unit mounted in a closed locker or space to help with air flow through the locker.
For most projects air only is adequate. Air and Fresh Water cooling is recommended for large refrigeration boxes, especially if the condensing unit is placed in an air-restricted, hot area or sailing in the tropics is planned. For systems with the optional Fresh Water cooling, the compressor unit starts the Condenser cooling with the single fan and when the temperature of the condenser reaches 43C (109F) bot the second cooling fan and the Fresh Water cooling pump are turn on. Once the Condenser temperature go below 43C (109F), the system automatically reverts to the single fan cooling.
In hot environments, Fresh Water cooling leads to a decrease in compressor high side pressures and lower the net overall power draw. For example, an air-only system operating in a 40C (104F) environment will see typical compressor high side pressures approaching 200psi. However, adding fresh water-cooling can lower the compressor high side pressures to about 155psi, for a 22.5% decrease. The lower high side compressor pressures, results in a decreased Amp usage for the same level of Refrigeration Box cooling.

Understanding Ozefridge Fresh Water Cooling:

Fresh Water Cooling Option:
OzeFridge approaches the use of water cooling of the refrigerant gas condenser differently than other systems on the market, which contributes to the industry leading technical design and efficiency. First, it’s important to note that the water cooling on OzeFridge units is done by Fresh Water from your ships water tank rather than dealing with the corrosive nature of sea water! Right away, the No 1 maintenance issue with a water cooled refrigerant condenser goes away, and that is fouling and scaling of the raw water heat exchanger.

Using the ships fresh water tank for condenser cooling raises two common questions:

1) Will it make my tank water hot?

2) Is there a risk of contaminating my tank water?

1- To address warming your tank water, the BTUs of heat being transferred to your tank water are minimal and in tanks over 10Gallons, you won’t even notice a warming of the fresh water.

2- In terms of the risk of Fresh Water Contamination, the configuration of the fresh water cooling loop on the condenser eliminates the risk of Refrigerant Gas to Water contamination. The Water Loop on the condenser is also high quality and food safe.

A second important feature of the OzeFridge fresh water cooling feature is it’s control.
On systems equipped with Fresh Water Cooling, it only turns on when the Condensing unit reaches 110 degrees F or higher.
So energy is not used when it’s not needed.

Concerning Energy, the ultra low amp draw micro-pump, only uses 0.5 Amp-Hours or power to the overall daily power usage, but that is off-set by the 1.0Amp-Hours of overall energy savings of the compressor. So adding the fresh water cooling option, can actually use Less Daily Power when the compressor unit is operating in Hot or Enclosed spaces without good dissipation of condenser heat.

Lastly and something to consider first, would be to understand why and when the Ozefridge system would benefit from adding fresh water cooling. Which is, when the compressor unit is going to be mounted in an enclosed space without the ability to have adequate exchange of the space air.