diesel heater throughhull

[paulga]

is this 316L exhaust through put 24mm compatible with exhaust hose of ID 25mm?

is this compatible with generally all Chinese diesel heaters that usually has 25mm exhaust hose?

what is the hole saw diameter required?

 

[janice142]

I bought this one
https://www.amazon.com/dp/B097MSLTS6 for my heater. Dry fits together tight. Mine is angled up with the exhaust looping down into the unit. It was/is tight. Waiting for the exhaust wrap and Webaso muffler (thanks to advice picked up in the Chinese diesel heater thread) to complete that part.

But yes, the one I linked does fit without issue. There were two thru hulls available. I liked this one better for my space constraints.

 

[paulga]

I bought this one
https://www.amazon.com/dp/B097MSLTS6 for my heater. Dry fits together tight. Mine is angled up with the exhaust looping down into the unit. It was/is tight. Waiting for the exhaust wrap and Webaso muffler (thanks to advice picked up in the Chinese diesel heater thread) to complete that part.

But yes, the one I linked does fit without issue. There were two thru hulls available. I liked this one better for my space constraints.

I read somewhere that there is maximum fuel line requirement, is that 6 ft?
the manual is quite abstract. the heater has only one hot air output, I would need 4 "Wye" to arrange the hot air ducts throughout the boat. The supplied air duct is too short. do you know where to buy compatible Wye fitting and air ducts?

 

[janice142]

Wye are available on Amazon, along with Tee configuration. I did not check for the ducting hose though suspect it is offered too. To find the wye, check under any of the diesel heaters offered. That is where I found my thru hull fitting.

I have read that insulating the ducting makes a big difference especially in long runs. That came from a Sweedish sailor with a 35' sailboat. His heater was mounted aft and his runs were long.

Currently I am pondering the fuel supply issue. I am not certain which HDPE tank would be best AND fit in the small area I have available. Definitely not a plastic tank though.

I do like checking fuel levels of that 10 liter tank however I do not like the longevity when using with diesel. And I have to get fuel to the day tank without making a mess. It would be much easier to mount the fuel tank in the bilge. :/

 

[Marco Flamingo]

heater has only one hot air output, I would need 4 "Weye" to arrange the hot air ducts throughout the boat. The supplied air duct is too short. do you know where to buy compatible Wye fitting and air ducts?

There is a reason why the heaters come with a short duct and maybe a T. The little fans in them might not be able to push through 20 feet of ducting and 4 Ys. My owner's manual for the Espar D2 had a diagram that showed the suggested limits on ductwork. Total length and number of elbows, Ts, and Ys. It was surprisingly short, like two Ys, three registers, not to exceed 12 feet total. The reason is that the little fan has to effectively cool off the heat exchanger. Too much resistance and you'll get overheat errors, sooting, and short fan life.

You are most likely to be happy with Ys instead of Ts (much less resistance). Don't get the Ys that have internal dampers used to control the air direction. Too much constriction. Make your most important register your first register (usually the main cabin). My final run is about 6 feet. Instead of using the aluminum/paper duct that is generally purchased, I spliced in 3 inch PVC pipe. Cheaper, smooth wall, and good to 160 degrees when used for water plumbing. For hot air, PVC pipe can deform above 210F. Should never be a problem with the heater. Elbows and Ys are available at any hardware store.

Bottom line, it could be that instead of 4 Ys and longer ducting you need two heaters.

 

[paulga]

6ft air duct would be barely enough. The required length from heater to the aft cabin easily exceeds 6 ft. just wonder if a high end heater like $4,000 Wallace Spatan powerful enough to support 25+ft and multiple Y?

so the compatible air duct is 75mm (3in)? and you substitute with 3in PVC. are these ID or OD? for the entire install how many hole saw sizes were required?

There is a reason why the heaters come with a short duct and maybe a T. The little fans in them might not be able to push through 20 feet of ducting and 4 Ys. My owner's manual for the Espar D2 had a diagram that showed the suggested limits on ductwork. Total length and number of elbows, Ts, and Ys. It was surprisingly short, like two Ys, three registers, not to exceed 12 feet total. The reason is that the little fan has to effectively cool off the heat exchanger. Too much resistance and you'll get overheat errors, sooting, and short fan life.

You are most likely to be happy with Ys instead of Ts (much less resistance). Don't get the Ys that have internal dampers used to control the air direction. Too much constriction. Make your most important register your first register (usually the main cabin). My final run is about 6 feet. Instead of using the aluminum/paper duct that is generally purchased, I spliced in 3 inch PVC pipe. Cheaper, smooth wall, and good to 160 degrees when used for water plumbing. For hot air, PVC pipe can deform above 210F. Should never be a problem with the heater. Elbows and Ys are available at any hardware store.

Bottom line, it could be that instead of 4 Ys and longer ducting you need two heaters.

 

[paulga]

Is this through hull fitting sealed to the hull using Bed-It tape, or heat resistant tube-type sealant like sika 221 (on top of the rubber gasket supplied)?