Last spring, while visiting new friends aboard their catamaran, we learned of a new, super quiet (and efficient) range of compressors by Marine Air. Based on prior experience we would not have believed the noise claims, but as we were sitting right on top of the compressor pallet and could not hear it run, we knew something good was going on.

With a major decision looming in the not-too-distant future for the 97 air con system, we figured we’d better replace what we had on Wind Horse and give the new approach a real world test.

Chris Martin is holding the compressor sound shield in the photo above. This fits over the compressor on the Marine Air vector pallets. The vector rotary compressors, fans, and ducting have all been redesigned to make them much quieter. The optional sound shields reduce sound levels even further.

The system is quiet enough now that you hear no mechanical noise, just the air blowing through the ducts.

We also modified the cooling system, so that it now pumps fresh water from the aft fresh water tank through the air conditioning condenser coil and back into the fresh water tanks. To illustrate the the efficiency of this heat exchange system consider that before we launched a few weeks ago, when afternoon temperatures warmed into the 80s, we ran the air con for several hours, with just the tank cooling the hauled-out Wind Horse. The return point for the cooling water was 4 degrees F/two degrees C warmer than the surrounding area. Move 3 meters/10 feet, and we measured just two degrees F/ one C warmer.

The advantages of using fresh water for cooling are numerous. Reduced pump and condenser maintenance (and longer life) plus the elimination of a major flooding risk (why we never ran the air conditioning if we were off the boat with sea water cooling).

When we get back aboard in May we’ll give the new air conditioning system a thorough test.