PNW Heating System

You'll need to ask a specialist for a quote on what it would take to ad "Aux Heat" to your system. My boat had a pair of Cruise-Air air handlers that feed the Salon with AC and reverse-cycle heat. Problem is that when the water temperature is below 60 f , the reverse cycle heat doesn't do much and once the water temp hits 40 f, the unit needs to be turned off as it will turn the water to ice inside the system.

I replaced the 2 air-handlers in my salon with units that have Aux-Heat. It's very convenient and works well.

It's also fine to run electric (oil based) space heaters ... they just don't provide instant heat like the aux-heat does and cannot really be used easily while under way.

Mike

Heating systems

Would recommend a Webasto diesel furnace , 12 v dc with individual blower coils in each area to be heated, all 12 v dc with individual speed controls, piping can be regular heater type hose and double clamped connections. No idea of the cost today, but we did our 70 ft MY for 7500 quite a few years ago, works like a hot ****

Keep the fuel clean and dry...

I too would recommend a Webasto diesel furnace, and go with the hot water, not the hot air. It is an independent system and would be separate from your HVAC. We have both, but to run the CruiseAire you have to start the gen set. The Webasto is 12 VDC, and, installed correctly, is a very quiet and efficient system. We use it as a back-up to space heaters during the winter while tied to the dock, with the thermostat set at about 40 degrees. With the hot water and the related plumbing, you end up with residual heat in the plumbing that keeps the whole vessel toasty. Talk to Sure Marine in Seattle to find the best installer in your area.

If this is an original equipment installation (OEM), Marine Air or the local Technical Sales Rep would have approved the size of the HVAC System based on the regional criteria required by the boat manufacturer, either Southern California or some other location. They most likely were more concerned with cooling requirements than heating, and the mutual goal of equipment supplier and boat builder would have been to mitigate potential warranty issues on the cooling side.

With the cooler waters up in PNW, you will most likely NOT get the kind of "dry" (less humid) heat that you are looking for. The HVAC units efficiency will significantly drop in colder sea water. That is why so many go to an independent heating system like Webasto, etc.

You could supplement the existing HVAC System with in-line boosters but this will only increase your electrical load demand and the HVAC units will still struggle in the PNW climate.

Diesel furnace is the way to go.......

heating system

Here in Vancouver BC we run our reverse cycle system all winter, even works when a skiff of ice on the water, we also have built in electric BB and only use the diesel if a really cold snap comes in or at anchor when the gen set is off.

If you are reasonably handy you can do a lot of the piping runs etc yourself.

On some boats the BB heat and the reverse cycle heat, when run at the same time, will overload the electric service.

You may be able to run one or the other only and not use the BB as a suppliment.

A few years back a local decided to live on board his 50' Sundancer. He had a diesel system installed, and I seem to recall it costing him about 30K. He lasted one winter. DK if that's because of the cold or the divorce.

I would suggest installing a Webasto 2010 (diesel heater with water cicuit) or for continous duty even a Kabola. With the Kabola you could have the system running virtually nonstop throughout the whole winter.
Or if your requirements are not that extreme you could choose the slightly smaller bu more economic Webasto with electronic controll unit.
For installation one coil of epdm rubber hose should be sufficient. You can combine that with blower type heat exchangers or conventional home standard radiators.
Just keep in mind that the 2010 for example needs a water circuit of about at least 6 gallons and an expansion tank to work fine.

Forget Webasto, go with Hurricane. Local manufacturer, quiet, efficient, not a modified truck heater.

Webasto

Installed 1992..repair expense to date...one exhaust hose 35.00...replace one nozzle, spare came with unit..no charge...failures ...none...
YMMV