Window Fogging

Marin · Oct 15, 2012

skipperdude said:
Marin have you looked at the espar?

The biggest issue in a boat like ours is where to put the heater. For example, a bulkhead-mounted Dickenson propane (or oil) heater would work well in a boat our size but there is no place to mount it. And while GBs have a fair amount of stowage space, we have none that we want to give up for the installation of a heater.

So the best solution is a diesel heater mounted in the engine room with either forced air or hot water circulation sent to small outlet units in one or more cabins. Fuel would be taken from the boat's fuel tanks. While the components themselves are not all that expensive the labor to install them can be. And I don't have the time (or the desire) to do this sort of installation myself. From talking to other people who have had similar systems installed in similar-sized boats, the cost with installation hovers around $7,000 give or take.

rwidman · Oct 15, 2012

FlyWright said:
When we're underway in the winter, we sometimes use a ceramic cube heater on the low 600W (L/M/H 600/900/1500W) setting powered by the inverter, with the batts being charged by the alternators. It takes about 50A 12V to power the inverter. The alternators are easily able to keep up with this load. It takes off the chill of our moderate winter temps.

I did that once before but the thought of burning fuel to produce motion to produce electricity to charge a battery and then taking the energy from the battery to power an inverter to produce power for an electric resistance heater is pretty inefficient at best. There's probably just as much heat generated by the inverter as by the electric heater.

The heater I have is from West Marine and is designed so it's pretty impossible to tip over.

Propane heat (I could run the stove) uses up the oxygen and produces a lot of moisture. I wouldn't do that.

rwidman · Oct 15, 2012

Moonstruck said:
rwidman said:

Thanks. I know they make such a heater and the plumbing should be pretty simple. As long as it has a 12 volt blower, I could

Yep, 12 volt blower with engine coolant circulating through the coils. It would be waste heat going out the exhaust. Almost free.

Click to expand...

My mind is turning figuring out where I could put it. I already have engine coolant going to the water heater so it's just a matter of some fittings and valves.

On the other hand, my need for interior heat is so infrequent, it may not be worth the trouble.

psneeld · Oct 15, 2012

Marin said:
The biggest issue in a boat like ours is where to put the heater. For example, a bulkhead-mounted Dickenson propane (or oil) heater would work well in a boat our size but there is no place to mount it. And while GBs have a fair amount of stowage space, we have none that we want to give up for the installation of a heater.

So the best solution is a diesel heater mounted in the engine room with either forced air or hot water circulation sent to small outlet units in one or more cabins. Fuel would be taken from the boat's fuel tanks. While the components themselves are not all that expensive the labor to install them can be. And I don't have the time (or the desire) to do this sort of installation myself. From talking to other people who have had similar systems installed in similar-sized boats, the cost with installation hovers around $7,000 give or take.

I went with Wallas...super quiet and easy to install...I installed mine in a day with only a few cuts needed but depending on where you want outlets..it could turn into a quagmire...I mounted mine under the helm seat in a locker ...It's so small for a little over 15000 BTUs I only lost 1/2 the locker space. So far VERY impressed...love the concept it doesn't start and stop with a thermostat...cold starts are what usually kills a diesel setup...this is great if you are looking for supplemental liveaboard heat or enough to get you through some chilly nights at anchor.

Moonstruck · Oct 15, 2012

rwidman said:
Moonstruck said:

My mind is turning figuring out where I could put it. I already have engine coolant going to the water heater so it's just a matter of some fittings and valves.

On the other hand, my need for interior heat is so infrequent, it may not be worth the trouble.

Click to expand...

Ron, if you have an open riser set of steps into the cabin, you could mount it behind those (a box could be built for it), If risers are closed it may could be mounted in a riser. Ours was under the dinette blowing out on the feet.

rwidman · Oct 16, 2012

Moonstruck said:
rwidman said:

Ron, if you have an open riser set of steps into the cabin, you could mount it behind those (a box could be built for it), If risers are closed it may could be mounted in a riser. Ours was under the dinette blowing out on the feet.

Click to expand...

The neatest thing would be to have it blow into the existing ductwork for the reverse cycle AC. Baring that, depending on the depth, I think I have a place for it flush mounted.

But, the project may just slide by the wayside as heat is needed so seldom. We wouldn't set off on a trip if it's cold, but twice we've had to come home in the cold. And I'm talking 60 degrees so that's not all that cold, just the problem with the fogging.

ksanders · Oct 16, 2012

psneeld said:
I went with Wallas...super quiet and easy to install...I installed mine in a day with only a few cuts needed but depending on where you want outlets..it could turn into a quagmire...I mounted mine under the helm seat in a locker ...It's so small for a little over 15000 BTUs I only lost 1/2 the locker space. So far VERY impressed...love the concept it doesn't start and stop with a thermostat...cold starts are what usually kills a diesel setup...this is great if you are looking for supplemental liveaboard heat or enough to get you through some chilly nights at anchor.

I'll second the Wallas. Its the only unit I've seen that actually varies the heat output.

Al · Oct 16, 2012

Wow, the subject of the forum sure has revolved. The original inquiry on fogging has spiraled into general cabin heat. Great! makes for very interesting response which makes this site really neat. We have a 27 foot boat. the original owner installed a Espar heater. It hangs on the overhead of a floor joice. I marvel at the small amount of space it requires. All the connections are concise with ducting routed to two outlets. The exhaust which is of small diameter, outlets at the same joice level overboard far above the water line. It uses 15 amp on a short initial start then levels off at 4 amp draw. We only have two golf cart house batteries which have not been challenged during our anchor times when heat is called for. It uses nil volume of fuel.
If a unit of this size is friendly in a small craft as ours, surely larger boats have installation room.
As to the fogging, living in 150 inches of annual rain fall, moisture is always present. During running, we use the Espar on departure and cut to the Red Dot when engine heat is up. Back to the Espar on the hook.
Regards,
A.M.Johnson-Ketchikan
27 foot Marben

FlyWright · Oct 16, 2012

rwidman said:
I did that once before but the thought of burning fuel to produce motion to produce electricity to charge a battery and then taking the energy from the battery to power an inverter to produce power for an electric resistance heater is pretty inefficient at best. There's probably just as much heat generated by the inverter as by the electric heater.

The heater I have is from West Marine and is designed so it's pretty impossible to tip over.

Propane heat (I could run the stove) uses up the oxygen and produces a lot of moisture. I wouldn't do that.

Wasn't this thread about returning home, presumable under power not tow, and clearing the fog from your windows?

You're already enroute, so your engine(s) are running and you're in motion. Your alternator(s) are producing power and charging the batteries. The inverter is on and available for use. You're just plugging in the heater to generate heat from systems already operating and available. No harm, no foul, no additional cost. (BTW, if your inverter really runs as hot as a heater, I'd stop using the inverter since something's wrong there.)

I agree that heating a cabin with a propave oven or stovetop is not smart. I don't think anyone here is recommending that. Using a propane heater designed for this purpose with appropriate safeguards is safe, albeit not optimum if the goal is just to reduce the moisture. Proper venting and circulation is key to preventing windows from fogging when using propane heat.

refugio · Oct 17, 2012

I think I've tried every one of these heaters over the years, starting with a solid fuel fireplace in a Pearson 26, then a gradually increasing series of heaters in my old Romsdahl ending up with an Espar I installed myself in the dead of winter in Juneau, to a solid fuel fireplace and gasoline (!) forced air heater in my Monk, to the Hurricane hydronic I have now (plus propane fireplace for ambiance).

I also had a red-dot in a Osprey Pilothouse, a Webasto Airtop 2000 in my CD22 (in addition to the Wallas stove), and even an Espar D2 in my Arima (with a Mr Heater Big Buddy as backup).

In the PNW, I wouldn't leave the dock in anything other than a summer heatwave without at least two sources of heat. I'm not too bad with cooler ambient temperature, but my wife is from the tropics and thinks anything under 80 degrees is getting chilly.

In a smaller boat, it's hard to beat a diesel air truck furnace (Webasto or Espar) with marine fittings. About $800 on EBay plus maybe $200 in fittings from Sure Marine (local to me in Seattle) and you get 30K BTU of instant, quiet heat at your fingertips. Having installed 2 of these in my commuter boats, I think it would take me - with planning and a quality hole saw - about 2 hours to get one installed and running.

But I hired out the Hurricane installation on my trawler. It's plumbed to my potable water heater and via heat-exchanger to the engine cooling (in this case now warming) systems. I think the entire system - with installation - was under $5K and has performed flawlessly for 5 years.

The only boat that was a moisture challenge was the CD22, and that's because it wasn't insulated so it lost heat (and increased relative humidity, leading to condensation) very quickly. Even the Arima with a liner was much better in that respect.

I know that just throwing heated air at the problem isn't a workable solution in warmer climates, but I don't really have much to contribute for that particular situation.

psneeld · Oct 18, 2012

refugio said:
I think I've tried.....

cut for space

But I hired out the Hurricane installation on my trawler. It's plumbed to my potable water heater and via heat-exchanger to the engine cooling (in this case now warming) systems. I think the entire system - with installation - was under $5K and has performed flawlessly for 5 years.

The only boat that was a moisture challenge was the CD22, and that's because it wasn't insulated so it lost heat (and increased relative humidity, leading to condensation) very quickly. Even the Arima with a liner was much better in that respect.

I know that just throwing heated air at the problem isn't a workable solution in warmer climates, but I don't really have much to contribute for that particular situation.

Under 5K???? That's great...every time I called places, I couldn't find JUST the boiler for 5K...most system set ups were gonna run around 6-7K with all the pieces and parts for 3 zones.

Who was your supplier?

rwidman · Oct 18, 2012

Al said:
Wow, the subject of the forum sure has revolved. The original inquiry on fogging has spiraled into general cabin heat. Great! makes for very interesting response which makes this site really neat. ..............

A seperate thread on cabin heat would probably be better. That way, someone looking for advice on cabin heat could mre easily locate it. And those looking for advice on fogging windows would have responses and advice tailored to their question.

Anode · Oct 18, 2012

After 25-30 years exposed to salt water old glass windows get etched. They're hard to clean and no Rain-X doesn't do much good.
New glass makes a world of difference.

rwidman · Oct 18, 2012

Anode said:
After 25-30 years exposed to salt water old glass windows get etched. They're hard to clean and no Rain-X doesn't do much good.
New glass makes a world of difference.

It's not 25 - 30 years, but it's 13 years. I am suspecting the same thing. I'm trying to find a replacement for the "Glass Wax" cleaner that was so popular when I was young. It's similar to a polish in that it dries to a haze and is wiped or buffed off. There's a company on the Internet that claims their product will remove alkaline deposits that cloud glass. It's an acid so I'm thinking vinegar might be worth a try.

New glass is going to be hard to find and pretty expensive.

FlyWright · Oct 18, 2012

Here's something that might help.

Z-12 Clear-View Glass Polish: Zaino Store

I have a product at home that is a very fine powder made up of finely ground sea shells that makes a paste when mixed with water. With mild rubbing, this mildly abrasive paste removes water deposits from glass. I have long suspected that this is just repackaged diatamacious earth (pool filter medium), but it works.

rwidman · Oct 18, 2012

I'm going to try this:

No Streek® Glass Polish (NS-8) - Glass Cleaner - Ace Hardware

and see how it does. It looks to be a lot like Glass Wax.

ksanders · Oct 18, 2012

rwidman said:
A seperate thread on cabin heat would probably be better. That way, someone looking for advice on cabin heat could mre easily locate it. And those looking for advice on fogging windows would have responses and advice tailored to their question.

I would agree, but the problem is that you cannot separate heating, ventilation and window fogging. They are all interconnected, as window fogging is a direct result of a lack of ventilation, and or heat.

rwidman · Oct 18, 2012

ksanders said:
I would agree, but the problem is that you cannot separate heating, ventilation and window fogging. They are all interconnected, as window fogging is a direct result of a lack of ventilation, and or heat.

The thread has gone a long way from my original post of minor fogging a couple times a year. I'm not going to install a $6K heating system when I can just run over the glass with a squegee every few minutes.

If someone wants suggestions on heating a boat, he/she would do better by starting a thread on that subject.

refugio · Oct 18, 2012

I did have a problem with the CD22 where it seemed impossible to get the windows to stay clear even when cleaning with Windex.

So I used this formula (I think): How to Keep Salt Water Off Your Windows | eHow.com
And it seemed to help.

refugio · Oct 18, 2012

psneeld said:
Under 5K???? Who was your supplier?

Ocean Alexander Marine Center, which has now closed. I just called ITR, and he said that they sold all their Hurricane stuff to McPherson's (also in Seattle).

My records show I paid $2,374.63 for the furnace itself, and I paid the installer (Dale Pederson who's also the senior captain of the Virginia V) another $2,312.58 - all of this in 2005 (longer ago than I remembered). If I did it again I wouldn't install the engine heat exchanger (that was an expensive piece - like $800?).

The guy I called at ITR said the current list price on the furnace is $4,595, but that a "Boat Show" price of under $4,000 was certainly possible.

I have three zones, and the installer used some of the runs from the old Espar for running the hoses, but all the ductwork was new as were the thermostats, aquastat, expansion tank, all plumbing, and ducting in the pilothouse. I was able to re-use the fuel pickup from the Espar and the exhaust thru-hull, but that was about it.

psneeld · Oct 18, 2012

Thanks...more inexpensive than when I checked earlier this year with some suppliers.

Window Fogging

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