PNW - Winter heating options

Hello,

Did some searching on this with lots of results on heating options, but nothing specific to recommendations for a non-liveaboard winter boat heating.

I have a new-to-me 1981 42' CHB that I've relocated to Seattle and I'm looking to prepare for the winter rain and cold season. The boat is moored in an open slip with standard 30amp shore power and I won't be living aboard. Mostly looking for how to keep the boat dry and secure with reasonable electrical expenses.

Am currently installing a Dickinson Newport diesel cabin heater in the salon and also looking to purchase a mid-sized de-humidifier. Also thinking about installing a 5KW forced air diesel furnace to heat the forward and aft cabins. Diesel makes great sense for winter cruising, but probably don't want to have the diesel heaters running at the dock unattended.

I'm new to Seattle and also these older antique wooden interior trawlers and looking for suggestions on the quickly approaching rain and cold season.

I was also considering a ductless mini-split heat pump. They have great efficiency, but the units are really big and I'm not thrilled about cutting big holes in the cabin to run the coolant lines. Might be nice to have AC, but in Seattle, and later Alaska, that's really not a big consideration.

What are other folks using to keep their boats snug and cozy at the dock in the winter?

Thanks!
-Rusty

Welcome aboard, sorry I can’t help you with the Seattle heating issue.

For unattended operation at the dock with 30A power, I would go with a 16,000 btu/hr heat pump, sea water cooled/heated permanently installed unit. I don't think Seattle area sea water temps get too low (35-40F) to stop heat pumps from working. And if they do, just switch to plain resistance heat for a few days to a week until it warms up enough to keep let the heat pump work again.

A heat pump will produce 2-3 times the btu/hr as resistance heat so it is decently efficient. You could set the inside temp to 50 F or so and monthly power costs wouldn't be too bad.

When you want to spend a night on board, just turn up the heat to 70 F and maybe fire up a portable space heater at 1,000 watts to stay within your 30A limit.

Some are fine with leaving a permanently installed hydronic diesel system unattended. We do it at home all of the winter. A hydronic system will probably be more expensive than a heat pump to install though.

Considering operating costs, the equivalent heat of the heat pump,16,000 btu/hr will use about 0.2 gph of diesel. At $3.50 per gallon that is $.70 per hour. The heat pump "moving" the same 16,000 btu/hr of heat will require 15 amps or 1,800 watts. At 20 cents per kw that is only $.36 per hour, about half of the diesel cost.

So look seriously at the heat pump.

David

I don't think most people in Seattle heat their boats if they are in the water. Or winterize them either. A dehumidifier is almost essential if you don't like cleaning up mold and mildew. Don't set it too low in a wooden boat, 55% is fine but no lower.

No way I'd leave a diesel heater on unattended.

Use a dehumidifier.

Many marinas have rules about not leaving resistant heating units that have a fan. Something like this.
https://www.westmarine.com/buy/west...BGkfQRhuGqXUwyy2olnfK6A6gbx53LhAaAqsTEALw_wcB

The reason is that if the fan fails, the heater can overheat and cause a fire. Fine to use while attended, but not unattended.

There are some other units that you can use to help keep the boat dry.

This one works well and has a low speed fan to circulate the air. Low enough wattage that is the fan stops there is no risk of overheating.
https://www.westmarine.com/buy/west...fan-dehumidifier-120v-ac--7867518?recordNum=1

https://www.defender.com/product3.jsp?path=-1|6880|2061076|2061081&id=1558066
This is similar but with the fan.

I use both types in my boat. The idea is to keep the moisture in the air so the dehumidifier can work.

Finally, I have used an oil pan heater on the engine. This keeps the engine warm enough to eliminate condensation on the engine and the low heat radiates throughout the ER. It doesnt want the boat, none of these do. It simply keep the boat from getting too damp and keep the boat from freezing in the rare cold snaps we get.

Don't run a diesel furnace unattended. Just warm the boat up when you get there. Not a big deal to leave your jacket on for a half hour when getting to the boat in the winter.

When we are not at the boat, we use a large household dehumidifier set at 50% humidity and a couple of oil radiators (no moving parts) at low setting (600W) with thermostat set to around 40 degrees. The dehumidifier is on an internet timer to come on only during the day in winter. I can turn off the dehumidifier remotely should the temps plunge below freezing during the day (Dehumidifiers don't like to run when it is below 35 deg F). This setup has worked great for us in the PNW.

Although our boat is kept on a trailer the same could apply. I use a home oil heater/radiator connected via one of these https://www.amazon.com/Farm-Innovat...57948&sprefix=Thermostat+plug,aps,243&sr=8-41

A Caframo low wattage Stor-Dry is on full time to move the dry warm air around. We generally don’t get brutal temps but an occasional freeze is not uncommon. It is more cold, damp air and the assorted issues with mold etc.

You would or may need more than one based on cubic feet and bulkheads etc.

I leave an oil filled heater and a dehumidifier on inside the boat from October to May. The heater is set on 55 degrees to prevent the humidifier from shutting down during low temp.

I also place a Davis Air Dryer in the engine compartment.

Insulating the hull and cabin sides will reduce winter heating requirements, prevent condensation from forming on the inside of hull and keep the boat cooler in the summer.

The oil filled radiators work well, can be set to low wattage, and turn off if they tip over.

Again, I just don't think you need to worry about hear on the boat. The point about the dehumidifiers not working when it is cold is a good one, but the dehumidifiers that I have used just quit running if it gets too cold. Not a problem because at those temps there isn't a lot of moisture in the air anyway.

>> So look seriously at the heat pump.

Great suggestions -- thank you @davidm.

Something like this?
https://www.marinaire.com/Marine-air-conditioner-16000-btu-110V-p/msba16k2.htm

16,000 BTU/H SELF CONTAINED MARINE AIR CONDITIONER AND HEAT PUMP 110-120V/60HZ

You don’t need to heat the boat when you are not on it, unless your moorage is in fresh water. Then all you need is any low watt radiant heater for the engine room. Wile Seattle does occasionally dip into the teens the ocean is always 48 degrees or warmer.

Winter boating in the PNW has an ideal heat source. An oil stove .. diesel.

Run it medium-low and open the windows or/and doors. Run it higher at sub-freezing temps. You will be as toasty warm all the time as you wish.
The most popular stove is the Dickenson brand stove. I don’t know if boats exist in SE Alsska w/o an oil stove.

Summertime of course the stoves are turned off. Too much heat.

Rusty,
Agree with all the others regarding not a great need for heat when you are not on board in the PNW in the winter.

I do support the use of a dehumidifier, but you will have to ensure that the on board humidity does not get too low (wooden boat). I would aim for 50-60% humidity. You can use a "home use' "weather station" to obtain readings, and some models of dehumidifiers can be set for a user determined humidity.
I also support the engine oil pan heater (about 250 watts so no big draw). It is left on all the time at dock. It keeps the engine warm and dry, helps with circulating warm air in the ER and basically eliminates rust and moisture in the ER. Also, the engine will fire up quickly with "pre-warmed oil" for less wear and tear on start up (it flows easier when warm).
You can use some heat appliances and small fans to move air around to supplement the dehumidifier and reduce any chance of mold/mildew. Heat sources could include oil filled radiators, the small round (some are square) about 100 watt heaters, etc. to "keep the chill off" if desired. Leave cupboards, interior doors and hatches open, and close up windows and exterior hatches.
Keep track of your amperage draw, and ensure you are not above 20 amps (for 30 amp service) for any sustained period (not just for your pocketbook), but using the above methods, you should not be anywhere near 20 amps draw.
I like a diesel furnace for keeping the boat warm when on board. Espar, Webasto, etc. There are a few options.

Good luck and enjoy your boat.

I don't have any heat on in the winter but run a big compressor-type dehumidifier. I also blow out the potable waterlines with compressed air and run the engine block heaters when it's sub-freezing.

I leave my diesel heater running all winter, often unattended, and have little to no concern over it. I think any form of electric resistance heat is much more of a hazard than a diesel furnace.

Thank you for the great suggestions everyone:

Winter boat environment control
====================
* Use a de-humidifier
* Use an engine crankcase heater
* Only use minimal heat needed to keep above freezing
* Consider heat-pump system for efficient heating
* Don't run diesel heaters unattended
* Don't use fan-based electric resistance heaters
* Use electric air-dryer to push moisture to de-humidifier
* Consider Kanberra Gel for mold mildew control

Sounds like winter weather isn't super serious in Seattle so basic measures to keep the boat interior dry and above freezing should be plenty.

Thanks again,
-Rusty

Rusty,

Just a clarification. Fan based resistance heat is fine, just not unattended. We use them at the dock so we don’t have to run the diesel furnace. It is quieter and more friendly to our neighbors. However, when it gets really cold, the diesel furnace is much better at keeping the boat nice and toasty.

twistedtree said:

I leave my diesel heater running all winter, often unattended, and have little to no concern over it. I think any form of electric resistance heat is much more of a hazard than a diesel furnace.

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Leaving a diesel heater going for a day or two, OK. But longer term unattended, a diesel heater has many more failure modes than resistance electric heat. Even a fan electric heater (good UL listed one anyway) will not burn if the fan fails. If you leave the boat plugged in (going to have to for the dehumidifier) all the electric fault hazards are already present. The only admonition I'd have is don't run so many electric heaters than your shore cord is anywhere near capacity. That is what causes many of the problems.

I've had steel, wood, and glass boats in Seattle, the first two liveaboards. Never needed a dehumidifier. My present boat had 3 Camframo (used to be Happy's) style dehumidifiers and 2 Goldenrod dehumidifiers. These are the type that heat a tiny bit and keep air moving. Junk in my opinion. I've pulled them all off sold them on Ebay. Two years without them and the interior is dryer and fresher smelling than when I bought.

The "secret" that isn't a secret is fresh air. Especially with cooking. Even more so if cooking with propane or alcohol. Most trawlers aren't designed to have sufficient air circulation when unattended. Leaving the windows open allows rain to get in, a non-starter in Seattle. But Dorade vents and solar powered mushroom vents can keep a boat dry. They need screens if you have rats (and you might be surprised). I never needed screens and never had anything bigger than a spider come aboard. A small price to pay for a fresh smelling boat with no mildew in the lockers.

I've had several different types of wood and diesel heaters, including cook stoves. The diesel cook stoves were great for liveaboard or week-long cruises. Just leave them on idle all the time. Dickenson is one of the last ones standing in this category and really nice if you have the money and space. A Peltier fan on the stove heats the main cabin evenly, but not much else.

My last couple of remote diesel heaters have been Espar ($700), Webasto ($1,200), and Brand X ($140) type heaters. The best is Brand X. My Brand X has a superior thermostat that even has a timer to come on in the morning. Size isn't that important because they are cheap enough that it would be possible to have two or more on a larger boat. All I needed to heat was the main salon, V berth, and head. Easily done with simple ductwork. The heater moves a lot of air and can heat the boat up from freezing in 30 minutes.

Visiting the boat every couple of weeks in the winter and having the heat on for several hours undoubtedly helps with any humidity issues.

Thanks Marco,

Yes, locking the boat up for a season with no air circulation can't be good.

Also, very interesting about the remote diesel heaters. Have been trying to decide between Brand X, as well as the Wallas Spartan, or even the MarinAire Integra. Obviously the MarinAire is 120v electric heat pump, but may cost less in the long run although the power draw of 10A/hr may be a challenge when cruising.

Really like the Wallas Spartan with the low power draw and very quiet operation, but ouch, the price tag. Brand X looks attractive, however have heard people go crazy with the ticking sound from the pump and no sure how loud the exhaust is in consideration of my neighbors in the marina.

Have to do a lot more research on these options.

Thanks again,
-R

Marco, even though the Davis and Camofro units (and even Goldenrods) are described as dehumidifiers, they are simply something to move air around a little bit.

When I speak of using a dehumidifier I’m talking about a compressor type or a Peltier type. They will actually remove water from the air instead of just trying to keep the moisture suspended in the air.

DDW said:

Leaving a diesel heater going for a day or two, OK. But longer term unattended, a diesel heater has many more failure modes than resistance electric heat. Even a fan electric heater (good UL listed one anyway) will not burn if the fan fails. If you leave the boat plugged in (going to have to for the dehumidifier) all the electric fault hazards are already present. The only admonition I'd have is don't run so many electric heaters than your shore cord is anywhere near capacity. That is what causes many of the problems.

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I think you and Twistedtree live in two different worlds. TT is probably running something like an Olympia or Kobala furnace. These designs are similar to home oil furnaces and they run perfectly well 24/7.

dhays said:

When I speak of using a dehumidifier I’m talking about a compressor type or a Peltier type. They will actually remove water from the air instead of just trying to keep the moisture suspended in the air.

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Probably uses more electricity, so for me, that means that there is yet another type that is totally unnecessary in Seattle.

I'm learning from TF that I am some kind of odd minimalist in the boating world. And here I thought I was normal.

When I lived in Seattle (which was long ago), I never winterized. If we got a real cold snap, I'd grab a 6-pack and a book (smartphones weren't a thing yet), and head down to the boat. Run the engine for 30 min, turn on the space heaters, and hang out for a few hours. I loved it. Sometimes I'd clean, but I didn't love that as much.

I was, however, always prepared to winterize, if it looked like the cold would be severe and long.

I have for the last 11 winters kept my boat in Seward Alaska.

I am on the boat and off of it all winter. On for a week, off for a few days. On the boat for a few days, off the boat for a week or two.

I run my diesel furnaces full time. They typically turn on in October and run full time from then until mid April when I can start shutting them off during the day.

I have only had a couple furnace failures while they are running in all that time.

Tens of thousands of hours on each of two main furnaces and something a bit less on the pilothouse furnace.

My opinion based on that experience is that you can leave a quality diesel furnace running while you are away.

Just like the furnace in your land based home.

tiltrider1 said:

I think you and Twistedtree live in two different worlds. TT is probably running something like an Olympia or Kobala furnace. These designs are similar to home oil furnaces and they run perfectly well 24/7.

Click to expand...

I'd certainly rather leave a Kobala unattended than a Webasto.

DDW said:

I'd certainly rather leave a Kobala unattended than a Webasto.

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Actually most of the furnaces operate very similarly.

A webasto, espar, even the Kabola, furnaces use a gun type combustion process.
This works by spraying a fine mist of diesel oil into a air stream.

The challenge is with the furnaces that originate from the over the road market. They are designed to use a "winter grade" of diesel that is mized down to reduce it's jell point.

We buy #2 diesel for our boats which tends to soot up the furnaces designed for over the road use. I have seen this time and time again with the ESPAR units. They will accumulate a hard soot that will start a chain reaction of sooting, reduced efficiency, more sooting until they flame out.

The good thing with a home or marine furnace is that it is designed for #2 diesel, so it does not soot up under normal operating conditions.

ksanders said:

Actually most of the furnaces operate very similarly.

A webasto, espar, even the Kabola, furnaces use a gun type combustion process.
This works by spraying a fine mist of diesel oil into a air stream.

The challenge is with the furnaces that originate from the over the road market. They are designed to use a "winter grade" of diesel that is mized down to reduce it's jell point.

We buy #2 diesel for our boats which tends to soot up the furnaces designed for over the road use. I have seen this time and time again with the ESPAR units. They will accumulate a hard soot that will start a chain reaction of sooting, reduced efficiency, more sooting until they flame out.

The good thing with a home or marine furnace is that it is designed for #2 diesel, so it does not soot up under normal operating conditions.

Click to expand...

Can't edit but need to correct. Home furnaces are designed for #1 fuel and marine furnaces are designed for #2 fuel oil

Towards the beginning and end of the season on Lake Ontario I just leave one of my A/C units on in reverse cycle heat mode. Makes sure the boat doesn't get too cold inside if we get an overnight cold snap while it's not winterized. And keeps it warm enough to keep humidity from being an issue as well. If the boat is at a dock with shore power and water temps of 40+, that's probably the route I'd go.

DDW said:

Leaving a diesel heater going for a day or two, OK. But longer term unattended, a diesel heater has many more failure modes than resistance electric heat. Even a fan electric heater (good UL listed one anyway) will not burn if the fan fails. If you leave the boat plugged in (going to have to for the dehumidifier) all the electric fault hazards are already present. The only admonition I'd have is don't run so many electric heaters than your shore cord is anywhere near capacity. That is what causes many of the problems.

Click to expand...

This, to me, is the big concern, with shore cords and dock/boat inlets as the weak points. It's something where at best I have control over only half of it.



All across the country thousands of oil burners run 24x7, unattended, for decades. Lots of safeties are built in, and they are super reliable. I don't see running it on a boat as any different.