Wintering livaboard

[Bentwings]

This will be my first winter living aboard. We are in Minnesota so it gets real cold. -25 to -30 F at times.

I’m about a week away from finishing my winter heater install.

So for the time being I’m using my new Cruisaire AC on reverse flow as a heat pump. So far it been perfect for my boat. It will freeze you in the summer and roast you for now. I know there is a limit on how cold the water can be. It’s said 38-40 deg F. At some point there is no longer enough heat in the water and it will lose efficiency. The instructions say 40 deg. I measured the water today at 46 deg. I’m told it won’t go much below this for another month. That remains to be seen. The river is in beginning flood stage now some 10 feet higher than normal. It’s a record year for high water levels.

I just measured the output air at 107 deg F. It’s heating us nicely. The unit runs a bit longer than usual but it down in the 30’s to low 40’s at night. It was 50 most of the day today and will be like this for the week.

I’m trying to get the heater installed and running even if the ducting isn’t complete as soon as possible. It’s a diesel air heater. All the other liveaboards use propane except one that heats with wood. I’m scared of using propane in this small of space in a gasoline boat. Plus the moisture they give off is huge. Some use thru hull furnaces like RV’s. But even this is scary in my mind.

I monitor the water temp every day and output temp frequently.

So how cold can we go? Maybe I’ll set a record but I’d rather not ruin my new AC.

[Nicholson58]

We are about to start our winter season leaving Trinidad in November. No heater, no parka, no shoes. My wife thinks you are insane. I say just a bit off. We considered mast down indoor heated storage live aboard before we headed south from the Michigan side.

Stay warm.

[GordMay]

Originally Posted by Bentwings

... I just measured the output air at 107 deg F. It’s heating us nicely. The unit runs a bit longer than usual ...

That's good (for now).
The supply air temperature, at a room supply heating register is typically 100°F - 110°F.
Measured near the furnace, the supply air temperature typically ranges 40 - 70 °F above the return air temperature. (Residential furnaces generally specify a supply air temperature rise on their data tag)
You might find the Titus tutorial, “Designing for Comfort” useful:
➥ http://www.airex.ca/wp-content/uploa...-55-and-62.pdf

[Bentwings]

That was an informative article.
Our boats are very confined spaces compared to even a small home. Where we can even install a heating system is pretty limited. The reverse flow AC allows a very compact heating an cooling unit. Adding this winter heater is much more difficult. I found some butterfly gates that will allow me to use the AC ducts for about 1/2 of the system.

If the HVAC system were designed from the start it would have been possible to install both units together
Under the cabin seats. It would take some tricky fabrication and insulation to keep the heating system temps within boat guidelines. IE nothing too hot to touch.

As it is I’m going to make a heat exchanger out of the heater exhaust. This will be used to keep the engine room above freezing. Double walling the exhaust line this is beyond the average boat owner but I did this type of fabrication for a living and have equipment to build to have these parts made would probably double the cost of the unit. Compare a car motor to the same motor in a boat.

I did look into installing the heater under the cabin seat but the exhaust run was just too long. If done while building the boat it would have been much easier.

My biggest concern is the difference in flow ratings. My AC heat pump has nearly 5 times the cu.ft per minute of the heater yet the heater has about 20% greater btu capacity.

Well, we will see how it works in a month or so when it gets really cold.

[Spot]

BW-Is the boat on the hard or in the water?

[Bentwings]

I’m in the water, Mississippi River.

[Spot]

Thanks BW. Do you stay in all winter? My boats are trailered so I know nothing of these things.

[Bentwings]

My boat is too big for practical trailering. I just got it last year. I had it hauled and shrink wrapped last winter as there just was not enough time to install the winter heater.

He is just starting to haul boats out this week. There are a few 40 footers that will come out and about 30 that are under 32 feet. He just cleared the storage lot last week. We had ta big flood last year and the water is in low flood stage now so it’s possible we could have another big flood. He leaves the drain plugs out. It better to get a foot of water in the boats than have them floating around.
I’ll probably have to get a dingy of some sort as the flood water gets high enough you can’t wade to shore. A cheap old duck boat is fine. A small trolling motor is what most use.
The water temp is right at 50 deg F today so my AC heat pump is working fine. The mgr told me the water temp stays above 40 deg way into Dec. we’ll see. I measure it every day. We use bubblers to prevent the boats getting iced in. It was like a small lake around the live aboards last year even at -20 deg.

Some don’t winterize at all others winterize the motors and water systems. I’ll check the bilge and engine room today.

[Dignity too]

having done some 10 years living aboard in winter, all over the UK and Sweden, its easy and comfortable. plenty ventilation, a good diesel heater. occasionally a dehumidifier. keeping the temp around 18c inside, outside temps range from -10c to 5c.

[Smokeys Kitchen]

Originally Posted by Bentwings

I’m in the water, Mississippi River.

We spent 5 years in Mpls/St Paul going to grad school. We owned a house just 2 blocks off the Mississippi. I'm not sure that I would want my boat in the water over the winter.

Check out Alvah Simon

https://www.amazon.com/North-Night-S.../dp/076790446X

[Lepke]

You need ventilation. Even in the coldest weather. All the cooking, showering and moisture in your breath stays in the boat. If it stays in the boat you get mold, mildew, rust, and bad smelling clothes. A heat pump doesn't change the air and is expensive to run unless you own the power company. To get 107° output, the electric heat strips are probably on. The most expensive heat I know of.
You should have some way of powering the heater if shore power goes out. What about water when it's below zero?