Air conditioning, heating and ventilation are at the heart of all systems decisions. With the FPB 78 we are designing for the most efficient and comfortable environment yet.

In the lead photo you are looking at a locker which is centered in the great room. This has four 12,000 BTU evaporators, as well as a heater (which is plumbed to a Webatso boiler). The light colored “Y” shapes are plenums connected to each evaporator. We then have a choice of using one, two or all four units. Much of the time a single air evaporator will be sufficient to dehumidify the air and drop the temperature a touch. Occasionally we think that two units might be required. The four are there for unusually hot and humid conditions where it would be nice to get the boat chilled in a hurry – think tied to a dock with no breeze. In addition to housing the great room air conditioning system, this locker will also provide substantial storage.

The back side of this locker, showing where the return air grills go. These provide access to the service points on the evaporators.

Staying with the HVAC theme, this is the engine room air inlet. There are three Delta-T 11”/275mm  fans pulling air into the engine room (one of the three fans is shown). Above the fans is a fire dampener. The fan/dampener assembly is hinged for service access, which also allows the engine room to be passively ventilated if this becomes desirable. These three 1400 CFM fans are intended to be run at half speed in most conditions (fan noise is thereby reduced or eliminated).

At the forward end of the engine room, on each side, are another pair of openings to the outside world, these can be used as passive intakes or exhausts when the fans are running. The mechanism we are looking it here is the fire dampener. We don’t think these will be required in temperate or higher latitude environments, in which case the fire dampeners can be closed.

The aft port corner of the engine room is a bit crowded but we still have reasonable access. The partially shown white barrel overhead is the secondary engine muffler (after the aqua lift), and bottom right you can see the shutoff valve for the engine exhaust, connected to the muffler with a pair of high temp silicone rubber fittings (hose clamps not yet installed).

The Webasto diesel boiler is upper left in the photo above. The key maintenance item here is the power head, which is easily accessed for maintenance or R and R should there be a malfunction (we will carry a complete Webasto heater in the spares department).

One of the eight Dorade vents into the lower deck, this one ventilates the electrical cabinet outboard of the stairs between great room and lower deck. Each of these Dorades includes a 9”/225mm Delta-T fan, either blowing into or extracting ( in this case). To minimize the drip risk onto electrical components, the bottom of this Dorade pipe is sealed with a drain line (although we do not expect to ever have anything coming through the water shedding grill and baffle between this opening and the exterior). With the rest of these vents the bottom is open.