The Antarctic Floor Mounted Heater is ideal for boats 35' - 40'. Size of this heater produces greater heat output than the smaller heaters although fuel consumption is the same. This model is round in design and has a large viewing window. In sailboat installations, this unit must face fore or aft, if facing port or starboard is desired, the valve would need to be mounted to the side of the unit so the gravity fed valve won't starve the burner on heels up to 15°. Requires 3" diameter chimney partsMinimum 4' or maximum 8' of chimney is required, a straight run with no elbows work bestChimneys 6' or longer we highly recommend a barometric damperPermanent fresh air vent needed in area of the unitCreates a dry heat to dry out moisture inside the vesselThis model has a larger combustion chamber so more heat is produced than the Alaska and Newport heaters12v draft assist fan included (can be converted to 24v and 32v). Used for start up and draft assistance on high fireValve is calibrated for diesel but can be re-calibrated for kerosene or stove oil1 turn hot water coil for 5-10 gal or a 2 turn hot water coil for 15-20 gal can be installed for water heating