The RiteAire Marine™ Dehumidifier System
and Your Boat’s Air Conditioning –
Why You Need Both on Board
“My boat already has air conditioning – why does it need a RiteAire Marine™ Dehumidifier System too?”
If we’ve heard it once, we’ve heard it a thousand times. Many boat owners realize that high humidity inside their vessel can lead to problems like mold and mildew, discolored cabinetry and paneling, and even respiratory issues such as red eyes and scratchy throats. But they believe that their boat’s air conditioning system is capable of lowering the humidity level on board on its own.
“It’s a very popular misconception. The truth is that your boat’s air conditioner was not designed to control humidity. It was only designed to control temperature,” said RiteAire Marine™ Co-Founder Hector Escardo. “The outside air in Florida and on the Gulf Coast easily hits 80 percent relative humidity in the summer. Conventional marine air conditioning can only lower the relative humidity inside your boat to about 65 percent – maybe 60 percent, but only if it’s a newer, highly efficient unit. Some larger yachts have a marine chiller system (also known as a chilled-water air conditioning system), but it’s rare to find one that can lower the relative humidity on board below 65 percent.”
Scientific studies have shown that the “healthy zone” for relative humidity in indoor spaces is lower – 40 to 50 percent relative humidity (rh) – minimizing the presence of mold, mildew, viruses, and volatile organic compounds (VOCs) like formaldehyde in interior air.
Some owners building a new boat will specify that the builder install extra a/c units or a larger a/c system in their vessel. “There is such a thing as too much air conditioning,” Escardo said. “If you get the inside of the boat too cold, then the grills, ductwork, and other metal surfaces are going to condensate even quicker. Normally you start to see condensation form when you cool the boat down below about 68 degrees Fahrenheit.”
Some marine air conditioning systems have a “Dehumidification” button on their control panel or remote control, but it is a misnomer.
“The only thing the ‘Dehum’ feature does is to run your air conditioner for 20 minutes out of every hour at a ‘slow fan’ rate. This allows the air going through the system to have a little longer contact with the evaporator coil,” Escardo said. “It would be better named the ‘Energy Saving’ setting rather than ‘Dehumidification’. The “Dehum” setting also lets the temperature in the boat’s interior rise, so owners typically don’t use it while they are onboard.
By contrast, the air-cooled RiteAire Marine (RAM) Dehumidifier System, which operates independently of the air conditioner, works 24/7 to pump dry air through your boat’s interior, dramatically reducing the humidity on board. The RAM unit’s condenser coils are larger than the ones you would find in a conventional marine air conditioner, and the air flows through the RAM system much more slowly across those coils, giving the system more time to work efficiently. The RAM system actively removes moisture from the air inside the boat and discharges it overboard, further reducing the humidity.
Using a professional Graywolf humidity sensor, RiteAire Marine™ has demonstrated that the RAM system can take in air with a relative humidity level of 65 percent and lower its rh level to 30 percent in just one pass. Used continuously, RAM automatically maintains the relative humidity in the boat’s interior a a pre-set relative level in the “Healthy Zone” between 40 and 50 percent. All you have to do is “set it and forget it.”
“Your boat is like a fresh head of lettuce. If you don’t have temperature and humidity under control on board, your cabinetry, upholstery, headliners, and more visibly wilts,” Escardo said. “Marine air conditioning and the RiteAire Marine™ Dehumidifier system complement each other, working hand in hand to give you a more comfortable and healthier boat interior.”