Hi Dennis These are all double walled to protect the hull. Just google heater exhaust thru hull or heater exhaust transom thru hull and you will find plenty of examples to look at. Typical installation has approx. ¼ inch of space between the pipe portion that travels thru the hull and the hull itself. On top of that as is standard practice the balsa is dug out in the opening and replaced with thickened epoxy to prevent water intrusion into the hull.
Very good question though. FWIW this entire project presents interesting challenges all along the progression of installation. 1. Where do I locate the heater unit? 2. What do I mount the heater to? 3. How do I route the ducting to the cabin? 4. How do I route the exhaust? 5. The Chinese versions are reputed to have lesser quality exhaust components and no thru hull so these must be sourced and replaced. (the fresh air to heat is in cockpit locker same as where exhaust components live – vs when installed in truck or camper) 6. Once all of the above is complete electrical gets looked at. I suspect a boat has longer electrical runs than a camper due to location of heater in cockpit locker All of this in very cramped locations inside the nether regions of a sailboat. If all comes together then hopefully will have a cozy boat to overnight on earlier and later in the season. Especially important when there is nothing else and nowhere else to go these days Mike Hoyt Persistence Halifax, NS www.hoytsailing.com From: Dennis C. via CnC-List <cnc-list@cnc-list.com> Sent: May 6, 2021 10:03 AM To: Stus-List <cnc-list@cnc-list.com> Cc: Dennis C. <capt...@gmail.com> Subject: Stus-List Re: Question re heater transom exhaust thru hull Being from the south where we're more concerned about air conditioners, I'm not familiar with heater exhausts at all. If one goes through a balsa cored portion of the hull or deck, is there concern about heat and the balsa? Or is a heater exhaust fitting designed to protect the core from excessive heat? Just curious. -- Dennis C. Touche' 35-1 #83 Mandeville, LA
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