Reverse cycle heater
- Thread starter NYSail
- Start date
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 24,521
NY Sail. Yes and no... Wouldn't factors like
- how cold is it
- How long is it running
- How much space you are heating
- How warm you want it to be inside the boat
It uses a little more power on heat cycle.. not a lot .. the reversing solenoid, which is de-energized in cooling, is energized for reversing the refrigerant when heating.. Usually 30 watts or so .. some as high as 100 watts..
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- Capacity: 16,000 BTU / hour
- Power:
- Voltage: 115 or 230 Volt AC
- Frequency: 60 Hz
- Full Load Amps - Cool: 10.5 @ 115 Volts
- Full Load Amps - Heat: 13.7 @ 115 Volts
- Locked Rotor Amps: 62.0 @ 115 Volts
- Refrigerant: R-410A
- Control type: Compact digital display
- Raw water Inlet/Outlet: 5/8"
- Ducting Collar: 6" dia.
- Dimensions: 13.50" H x 20.00" W x 11.25" D *
- Net weight: 64 lbs
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 24,521
Claude.
They work like a heat pump don't they. Heating is limited to the ability of the compressor to exchange the temp of the ambient air for the temp of the coolant. The differential is what is providing heat to the boat. This only works to a certain temp then the unit can not produce enough heat to change the air temp in the boat. Unless... Is there a heating coil as well as the pump? Then the heating coil provides electrical heat. At that point very expensive heat source.
They work like a heat pump don't they. Heating is limited to the ability of the compressor to exchange the temp of the ambient air for the temp of the coolant. The differential is what is providing heat to the boat. This only works to a certain temp then the unit can not produce enough heat to change the air temp in the boat. Unless... Is there a heating coil as well as the pump? Then the heating coil provides electrical heat. At that point very expensive heat source.
John.. exactly.. Your first answer is correct, but I thought he was asking a kind of general question..
Daydreamer's specs look like 300 watts more.. probably an artifact of the standard rating conditions.. I know that my unit in heat mode does not pull that much more .. probably because my water temperature rarely gets below 65F
Daydreamer's specs look like 300 watts more.. probably an artifact of the standard rating conditions.. I know that my unit in heat mode does not pull that much more .. probably because my water temperature rarely gets below 65F
A cautionary tale.
It's really scary when the Cruiseair unit you were counting on for your heat for the upcoming winter stops heating at all. Thankfully, the first person I mentioned it to knew that once the water temp got cool enough, the unit would no longer heat, period! Saved me tearing the system down trying to figure out why it wasn't cooling.
It's really scary when the Cruiseair unit you were counting on for your heat for the upcoming winter stops heating at all. Thankfully, the first person I mentioned it to knew that once the water temp got cool enough, the unit would no longer heat, period! Saved me tearing the system down trying to figure out why it wasn't cooling.
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I've got a much better solution. Sail down and cruise the West Indies. No need for heat down here!
LOL I'm a few years out from full time cruising and I hate being cold on the water. Might just do a Webasto diesel heater which would include a vent into the cockpit.
Never used the cool side of our MarineAir heat pumps, does not get that warm around these precincts. The main cabin unit is 16K BTU and the aft cabin 9K. A Little Giant sea water pump feeds both units and when running just the main cabin for heat combined will draw about 12 amperes total at 120VAC.
Sea water temperature in the winter around our boat can be in the low to mid 40 degrees yet these amazing units can extract enough heat to warm the cabin to a comfortable condition.
MarineAire warns that operating the reverse cycle heating in water temperatures below 40° F. The compressor doesn't like the low pressure of the gas below that level.
The efficiency is difficult to measure: You have have to deal with the "delta T" of the discharge temperature of the air to get the conditioned environment from where it wants to be. With our AC units on reverse cycle, the units run a lot longer when you're in very cold water -- but the AC panel doesn't seem to be much different when the compressor is running -- an amp here or there. The TIME that the units are on varys a lot more depending on the temp, how much the dorades are pumping cold air into the boat, etc.
The efficiency is difficult to measure: You have have to deal with the "delta T" of the discharge temperature of the air to get the conditioned environment from where it wants to be. With our AC units on reverse cycle, the units run a lot longer when you're in very cold water -- but the AC panel doesn't seem to be much different when the compressor is running -- an amp here or there. The TIME that the units are on varys a lot more depending on the temp, how much the dorades are pumping cold air into the boat, etc.