COP
Peter, I have been involved in non marine heat pumps most of my 30 year career. We have a 376 with only (1) reverse cycle. We are located in the Chesapeake area and it has been doing a very acceptable job thusfar. Last year we were in the water into December and were toasty every weekend. Although, you have (2) on your 430, it is easily justified that the 430 has twice the exposed surface and therfore twice the heating requirement. The water sourde heat pump or reverse cyle AC unit is VERY efficient. It does have some baisc needs and understanding though. How old is your 430 and have you ever pulled and cleaned the filters? Is the water flow through the unit adequate and have the inlet strainers been washed? Both proper air flow and water are critical. Never close an outlet or inlet vent entirely. Never obstruct the vents with anything placed directly in front of them. Air flow and efficiencly can be greatly impeded by the extra resistance imposed by closed or blocked vents. If you and yours are used to the very warm delvery air temperature of a gas or oil fired system, a reverse cyle can NOT deliver that. Since air movement has a cooling effect on the human body, your best bet is to aim your vents to supply air flow along the outside perimeter of the boat, i.e. the bulkheads. Because the delivery air temperature is cooler it becomes very important not to cool your crew with a direct blast of air. In the summer time, it is a good feeling to have air wisk past your body since it creates skin surface evaporation and cooling. You do not want this to happen with a heat pump. The output of the reverse cycle more than likely exceeds the heating requirement of your boat. The addition of an oil fired is a drastic step and seems very unlikely to be necessary. Let me know how you make out! I am on the HOW directory if you would like to send email. Heat pumps carry an unpoplular stigma. They are said to work wll only in the sunbelt. Take it from me, you don't need a heat pump in the sunbelt. They work best right where you and I sail. I would have a pro make an independent evaluation before proceeding with another system. Mike DiMario Media, PA s/v Serenity H376
