How to Balance Power in Winter

[rgano]

To the OP, what do you mean by "space heater?" Hopefully not exposed element heaters with fans because those are just dangerous aboard boats. I use an oil-filled radiator style heater with a tilt switch and a thermostatic power source when I need to keep my boat's innards from freezing.

 

[Pete Meisinger]

In any climate which is considered to be "northern" you should not use space heaters. Your reverse heat pump will work but still draws a lot of power. You you need to go diesel or propane heat.

pete

 

[catalinajack]

Reverse cycle generally works with water temps down to forty degrees. I have two units aboard, an older Domestic split system and a brand new all-in-one. The split unit is still putting out heat in excess of forty degrees above input air temp with the water temp at 36 degrees. The new unit quit at 38 degrees.

In any climate which is considered to be "northern" you should not use space heaters. Your reverse heat pump will work but still draws a lot of power. You you need to go diesel or propane heat.

pete

 

[Rob]

Most people would agree that I’m fairly experienced with dealing with keeping warm and dry on a boat. We have owned a couple of trawlers and have spent several hundred nights aboard when heat was required. Our experience on the boats consists of twenty years of cruising Alaska and about ten years here in the Northern Puget Sound area. Our most recent adventure of living aboard full time was just that, living aboard full time for 18 months. I think that I’ve tried every method of heat, from ceramic, heaters, oil filled radiator, circulating hydronic and forced air Wabasto heaters and then there the good old reliable “Dickinson”. We’ve owned three boats where we’ve had a Dickinson heater and now I’m in the process of installing another in our current boat. Our new Dickinson Alaskan heater will be installed with a heat robber on the exhaust stack and a heat coil to circulate water into a radiator type forced air system in the pilot house. There are so many advantages to the Dickinson! For starters it’s a nice dry heat that simply sucks the humidity out of your boat, it’s absolutely quiet, doesn’t require any power if installed with a gravity fed fuel tank or at the least very little +12 volt power. As far as the amount of fuel required, it’s truly minimal. We have run our Dickinson heaters for over thirty days at a time several times with out any problems! Last winter we heated our boat exclusively with a Wabasto hydronic system, it used a lot fuel and made to much noise for me. Did I mention that maintenance is a bit expensive as well. I know that I sound a bit like a salesman, but I promise you I’m not. Just an avid boater. In the event that you might be interested in installing a Dickinson heater I do have a good contact for a Dickinson Lofoten unit. My son purchase on
e but has never fired it up, to install in his cabin up in Alaska. I tried to talk him out of purchasing it because it simply couldn’t provide enough heat in his cabin in the bush. He instead opted to use a Renia sp? If you’d be interested I’m sure that he would cut you a VERY decent deal. I can put you in contact with him. Rob

 

[OldDan1943]

To the OP, what do you mean by "space heater?" Hopefully not exposed element heaters with fans because those are just dangerous aboard boats. I use an oil-filled radiator style heater with a tilt switch and a thermostatic power source when I need to keep my boat's innards from freezing.

Two built-in resistant heaters (with fans) are standard equipment on the AT34.
Maybe larger ATs have more?
Yes, the reverse cycle A/Cs do put out heat but, you have to plan ahead. The heat is not instantaneous, not like other forms of heat producing thingies.
Sometimes my feet get cold so I turn on one of the evil built-in resistant heater with fan, stand in front and presto, my feet get warm.

 

[Transaxial]

As Rob says in post 34 these little Dickinson Newport diesel heaters are really simple and put out 16,000 btu which heats my 40’ trawler pretty well. As a supplement to some engine heat or some electric heat while on shore power it keeps the boat warm and dry. As Rob says it requires no 12 power unless you need a little 12 v pulse fuel pump to flow 1 gal/day on low or 3.2 gal/day on high. It can have a tiny 12 v fan to assist combustion. Not as even heat as ducted or hydronic. You can add a heat exchanger to the 3” chimney and duct that heat to a cool corner of the boat. They are on sale at Steveston marine right now for $780, about 35% off the reg $1200. These are a great little heater for the price.

 

[ksanders]

Most people would agree that I’m fairly experienced with dealing with keeping warm and dry on a boat. We have owned a couple of trawlers and have spent several hundred nights aboard when heat was required. Our experience on the boats consists of twenty years of cruising Alaska and about ten years here in the Northern Puget Sound area. Our most recent adventure of living aboard full time was just that, living aboard full time for 18 months. I think that I’ve tried every method of heat, from ceramic, heaters, oil filled radiator, circulating hydronic and forced air Wabasto heaters and then there the good old reliable “Dickinson”. We’ve owned three boats where we’ve had a Dickinson heater and now I’m in the process of installing another in our current boat. Our new Dickinson Alaskan heater will be installed with a heat robber on the exhaust stack and a heat coil to circulate water into a radiator type forced air system in the pilot house. There are so many advantages to the Dickinson! For starters it’s a nice dry heat that simply sucks the humidity out of your boat, it’s absolutely quiet, doesn’t require any power if installed with a gravity fed fuel tank or at the least very little +12 volt power. As far as the amount of fuel required, it’s truly minimal. We have run our Dickinson heaters for over thirty days at a time several times with out any problems! Last winter we heated our boat exclusively with a Wabasto hydronic system, it used a lot fuel and made to much noise for me. Did I mention that maintenance is a bit expensive as well. I know that I sound a bit like a salesman, but I promise you I’m not. Just an avid boater. In the event that you might be interested in installing a Dickinson heater I do have a good contact for a Dickinson Lofoten unit. My son purchase on
e but has never fired it up, to install in his cabin up in Alaska. I tried to talk him out of purchasing it because it simply couldn’t provide enough heat in his cabin in the bush. He instead opted to use a Renia sp? If you’d be interested I’m sure that he would cut you a VERY decent deal. I can put you in contact with him. Rob

All the fish boats that are operated year round in Seward have Dickinson heaters.

Probably because they work!

 

[tozz]

Before we installed our Wallas forced air diesel heater we referred to the constant turning on/off of electric heaters/devices the "30-amp dance".

Echoing what others have said, 50-amps (or a second 30) would be a good move in addition to having a diesel heat source.

I’ll also echo the echo. We are at EBM down the dock from you. We have 50A power and run two espar D8LC forced air diesel heaters as primary heat source. They are about 27k BTU each. We don’t expect 50A or good power everywhere, especially up north, so we carry a number of power cord adapters to use 30A service when available. We also have two generators (13.5kW and 18.5kW).

For “backup” we do have 240vac cadet perfectoe toe kick heaters in most of our rooms. Most are 750W. I think one is 1000W. Last year we did install an Ocean Breeze reverse cycle unit but primarily for AC use. It can be used as a tertiary heat source but it pulls a ton of power and we’ve never used it for heat.

We do run block heaters that keep the engine room warm when on shore power but as others have said it’s not necessary with our water temps. On our previous boat we just ran an Xtreme heater in the lazerette space for some heat above the waterline in the most severe of our cold snaps (ex: several days in a row in the 30s).

Good luck and will look for you on the dock!

-tozz

 

[thataway]

I had a Cal 46 which I kept in the PNW for 4 winters. We put in a 45,000 BTU diesel fired hydronic heating system, using 3/4" hose for the water circulation, small radiators with computer fans pushing the air and a thermostat on the fans in each discrete area of the boat, plus copper pipes under the floor in the main head, in hanging lockers and towel racks in the main head. In my opinion the only way to heat a larger boat...

 

[catalinajack]

Yes, the heat on reverse cycle is not instantaneous. My unit takes about five minutes to produce heat that is 45 degrees warmer than the room temperature.

Two built-in resistant heaters (with fans) are standard equipment on the AT34.
Maybe larger ATs have more?
Yes, the reverse cycle A/Cs do put out heat but, you have to plan ahead. The heat is not instantaneous, not like other forms of heat producing thingies.
Sometimes my feet get cold so I turn on one of the evil built-in resistant heater with fan, stand in front and presto, my feet get warm.

 

[FF]

"Your reverse heat pump will work but still draws a lot of power. You you need to go diesel or propane heat."

Till the water gets cold , then no heat.

The only source of reverse cycle heat at cold 0F and below is a mini split .

Problem is finding outside space for the external unit.
In Euroland many are simply bolted to the hand rail, not pretty , but effective summer and winter.

The Dickinson with a coil of tubing on the exhaust pipe will make water hot enough for instant coffee or chocolate , sometimes for tea.

The recovery is too slow for showering or dish washers.

 

[caltexflanc]

Has the OP tried using the reverse cycle? The water usually doesn't get all that cold in Seattle. Our CruiseAirs ran all winter here in NC even with several days of sub freezing temps that prompted the marina to turn off the fresh water. We kept a couple of them running virtually all the time, which a very good tech said helped (vs trying to cold start).

Due to the design of our boat, internal boat temp, especially the lower level, was also aided greatly by the engine block heaters.

 

[rslifkin]

"Your reverse heat pump will work but still draws a lot of power. You you need to go diesel or propane heat."

Till the water gets cold , then no heat.

It's a concern, but it depends on where you live. In some places, the water never really gets below 40. And in others where it does (like where I live), the boats aren't in the water at that point. Regardless of how cold it gets here, by the time the water gets below 38 - 40, the boats are all hauled. And it's usually at 40+ by launch time in the spring.



For places where water temps are suitable for reverse cycle, the biggest issue is the power draw. No problem when at the dock, but it means constant genset use when away from the dock for heat.