Background:
I have an older model Force 10 Slimline cabin heater from a previous boat - it is a rectangular wall mount propane heater with a ceramic grid and two burners - it runs with one or both grids on (see image). It really worked great and will fit in the same location as our cozy cabin heater plus it puts out considerably more heat. Unfortunately I can't find any data on this model heater to see the actual BTU rating (there is a sticker on it that says model 12000 - possibly 12,000 BTU)- I would estimate that I bought it from West Marine about 9 or 10 years ago. If anyone has any info on this model that would be excellent.
My Question:
This heater has 3" stack pipe (which is considerably larger than the 1" pipe on the Cozy Cabin heater) and came with a low profile Charlie Nobel vent and top cap - the top cap is made to islate the pipe from the cabin top. The problem that it sticks up about 5" and will be right in the path of the headsail sheets (the heater is mounted on the STBD outboard bulkhead next to the door to the forward cabin). The Wolter vent cap is really low profile and the looks to be about the same size, I'm just not sure if it would be safe to use with this heater. We had to remove the Wolter for our insurance survey so the vent cap is not being used.
Winter is on the way - and I'd perfer to have these types of project already completed by the time cold weather arrives.
Open for any suggestions or input...
Mike
Attachments
Force 10 Slimline Heater
Force10-Slimline-12000.jpg (121.86 KiB) Viewed 15709 times
I doubt you will make 1 tack. I didn't, though I knew I wouldn't. I just didn't have the guard ready yet and wanted to go out! I duct taped over it for the day... which actually helped me decide on the angles.
I installed a newer Dickson heater (very similar) and posted a blog entry (http://sail-delmarva.blogspot.com/search?q=heat). The stock ($75?) guard should work for you, but if you wait until Monday, I will add photos of the guard I made for mine; it's just Home Depot stuff and scraps, perhaps $5.
Rather ugly, since the birds have suddenly started using my deck for bombing practice. However, the installation came out very well and I am please with the heat out put.
Looks like I'm going to put the project on hold for this season. I really like the Wolter mushroom cap - it is low profile and waterproof (it screws down tight) I'm just concerned about the proximity to the deck it would place the stack pipe (I don't think the Wolter is anywhere near 12000 BTU). I'm sure that there are 3" SS flanges around that I can create a base for the Wolter cap and leave some dead air space between the deck and the stack (I''ll probably fabricate some fins to disperse heat). If the flange were 1/4" thick the total vent height would be approx. 1 1/4".
James: Would you know anywhere that the Wolter stack parts are still available?
I think the temperatures may be a bit less than you fear; the double stack cools the exhaust to an extent. Longer pipe would help. Still, if it is as low as you describe, there are worries, no doubt.
I just found a Wolter Heater manual online - apparently it put 27K BTU to the mushroom vent cap with a silicone heat deflector. I'll have to look closer I did not notice the silicone part on mine. I wonder when PDQ stopped installing the Wolter Water heaters.
Still it will be a next year summer project when we are off the boat...
Try heating your boat with electric heaters first. Add up the watts. Multiply by ~ 3.5 and that will be the BTU output requirement. however, fueled heaters are often rated by the input firing rate, which could be as much as double. Typically, small heaters will be about 70% efficient.
My daughter did somemores on our Dickson heater yesterday - kids! Yes, I had one .
Hey Mike, PDQ installed the wolter water heaters over a period of 4 to 5 years. I believe we stopped due to them being tempermental and the risk of carbon monoxide poisoning. Unfortunately I dont have a source for parts. Mariners Hardware sells a selection of mushroom vents. You might be able to locate a replacement stack thru other cabin / water heater manufacturers. James
Thanks for the input - since we've removed the Wolter I'd like to re-use the mushroom vent for my Force 10 heater. I was just concerned about the lack of insulation\clearance between the mushroom vent through deck fitting I'd hate to get the deck too hot and damage it. Looking at the Wolter info it looks like the Wolter BTU's are considerably higher than the Force 10 Slimline (37K vs 12.5K BTU). Our existing Force 10 Cozy cabin heater works OK but on a really cold night it doesn't do much for the lower levels. I think the larger Force 10 will radiate the heat a little better.
Mike
FYI: Some info to share with other PDQ owners wintering aboard above Latitude 38.
This will be the 5th winter we've spent on II the Max in DC - and we've made it work with 5 Econo-Heat panels (they start out at about 3.5A and drop once warm). We have a 16,000 BTU Reverse cycle unit but it is costly to run and once the water temp drops is not very efficient. We have installed the 5 panels as follows 1 large panel 24"x24" in each of the forward cabins mounted on plywood on the outer hull sides (they lean against the wall one edge behind the locker). We have 2 of the smaller 18" x 24" panels in the aft cabins mounted on plywood but hanging from the side trim (we switched out 2 of of the trim screws with longer ones that go through the plywood and suspend the panels in place. The 5th panel is a 24" x 24" in the salon mounted permanent next to the companionway. With all of the panels running our load is less than 17A and it keeps the boat pretty cozy to about 30 degrees and there is almost no moisture. When the temp drops below 30 we use the propane heater as needed (we also have a mattress pad warmer to take the chill off). We also have a small portable dehumidifier - with everything on we are barely hitting a 24A load (not the reverse cycle - it is about 11A once it is running). We have dogs so we really like the panels because they are safe to leave on when we are not aboard.
My gut tells me that the water heater is far more efficient and thus has a much lower stack temperature. In one case you are trying to get the heat to go from air-to-air; neither is a very good conductor of heat. In the water heater, you are going from air-to-water, and water is a far better conductor. That is why 150F air feel good and 150F water will take your skin off.
I would like to see what the stack temperatures are on each unit, or any hot water heater with a similar cap design. If I get tot the boat this weekend I will check those temperatures on my boat (differernt models, but the water heater has a low profile cap).
Also, is the Wolter cap designed for a double pipe, like the Force 10?
From the manual the Wolter appears to use a silicon heat deflector where the Force 10 uses dead air space as the deck insulator. The through deck portion of the mushroom vent is double pipe but only about a 1/4" between layers which is my concern. Looking at the marine hardware site there are SS deck threaded plates that would allow me fabricate an insulated insert (using a 5" deck plate) to accomodate the low profile mushroom vent and have the option of capping it off completely in the summer when not in use for a flush cabin top. In the old deployment the Wolter had a horizontal run before hitting 90 and exiting the locker - the Force 10 would be about 12" with a double 45 to kick it out a little from the bulkhead - the picture shows our existing Force 10 - the Slimline will take up most of the back plate and use the 45's to make the bend away from the upper cabin side to the vent.
Mike
Attachments
Existing Force 10 Cozy Cabin heater
11theMax_PDQ_Force10heater.jpg (25.27 KiB) Viewed 15532 times
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