36’ Aft Cabin Trawler/MY LPG Question

[GordMay]

Originally Posted by twistedtree

... Granted, ABYC are guidelines, not laws ...

Certain ABYC Standards, including those for LPG & others, have been incorporated by reference into law (CFR). Thus, they are not merely “recommendations”, but carry the force of law.
See ➥ 46 CFR 175.600 - Incorporation by reference. | LII / Legal Information Institute

From 46 CFR 121.240 - Gas systems
➥ 46 CFR 121.240 - Gas systems. - Code of Federal Regulations - Title 46: Shipping - Subpart B: Cooking and Heating - Id 19854503 - vLex

“Cooking systems using liquefied petroleum gas (LPG) and compressed natural gas (CNG) must meet the following requirements:
(a) The design, installation and testing of each LPG system must meet ABYC A-1, “Marine Liquefied Petroleum Gas (LPG) Systems,” Chapter 6 of NFPA 302, or other standard specified by the Commandant...”

[GordMay]

ABYC Standards dealing with LPG:
A-1 ➥ http://www.abycinc.org/committees/A-01.pdf
A-3 ➥ http://www.abycinc.org/committees/A-03.pdf

[DSDman]

Thanks Gord,
I hear alot about the standard but have never been able to find it. This is great and will ensure that I get it right. I'm going to have to change my plans a bit as I didn't know the locker had to be dedicated for LP storage only. Just added another 300 bucks to the tab! vent has to be 20 inches from any opening into the boat....thats going to be tough.

[Pblais]

I have not yet had the opportunity to look at one of these units live.
I assume if you installed it in the shower thay are waterproof?

Well sort of waterproof. Ours is installed about a foot down from the overhead with a stainless plate that goes up the bulkhead and across the overhead just above the vent. It deflects the heat and prevents any problems with the overhead. The shield never gets too hot to touch. The very top of the unit does get quite hot. The unit vents straight up. If you look down into it you'll see the burner flames. It's not water tight but when you use our shower you pretty much just use the hand spray that is removable from a wall mount below the top of the heater and to the right. There is a seat in the shower. It's not like a stall shower in a house but the shower area has it's own floor to contain the water but has no door it takes up about half the space inside the head. The shower is not totally enclosed but the head isn't all that big either. It does have a solar vent in the overhead and an operable port. The solar vent is in the shower as well. The ODS has never shut off the burner or tripped the CO detector. Even to old one that wasn't that well adjusted never did that either.

If you need to install it in a tight space with no venting to the area then you'll need a flue. It's pretty hard to find a place on a boat for a flue. We have one for the diesel heater but I have a cap that fits on top when we travel. That would not be totally bad for a water heater except you won't have any under way.

The PO installed a Bosche ventless unit 20 years ago and they lived on the boat for 7 years. It worked well but did have a standing pilot light you had to light. The newer Excel unit is not as deep so mounts closer to the wall than the old one did. I love the electronic ignition with no pilot light required. It's very quick and avoids pilot light issues. It means you just turn on the solenoid for the propane tank and your hot water heater is automatically ready. I do have a shut off just before the propane inlet that I can manually keep it off. If the propane is off it just flows cold water.

I suppose I would not have picked the location as being there but I really can't find a better place for it. Inside the head means it helps dry it out when showering and it is warm in cold weather too.

You have to deal with condensation from the propane burning and there is no escape from that. You need some way to vent the heat and moisture but I don't feel a flue is mandatory if you have an alternative method. You can NOT install a ventless unit inside a locker. You could install in the galley as they are usually open and can be vented by ports or hatches.

[Tony B]

I plan on using two 40# bottles. Is there any kind of rack I can buy to keep them from moving around?
When I retire in 6 months, I am thinking of buying a small welder and learn to weld stainless and aluminum so I can make my own stuff. If I cant buy a rack, I will have to make one - but prefer to buy.

[Pblais]

I plan on using two 40# bottles.

Have you ever tried to heft a 40# on and off the boat? It;'s not so easy on land but really not easy on and off the boat. Personally, I use one 20# tank and it's fiberglass not steel. Steel tanks won't last more than 2 years if you are lucky before they rust bad. You can get 30# fiberglass tanks and the good ones have NO steel at all. The cheap ones have a steel ring where the valve stem goes in. Nice aluminium tanks will cost a LOT of money. With two 20# tanks you have a lot of time when the first one goes empty to refill it. You just don't use propane that much unless you are heating the boat in the winter. Two 10# tanks would probably do you just fine! Your wife can carry those! Hauling a 40# tank for someone retired sounds like too much work to me and I'm 58.

If you need to haul 40# tanks then you'll need to build something pretty strong. They don't need to even wiggle! It would need to be in a vented locker overboard not connected to the inside else some place on the rear deck outside. I really can't see needing 80# of propane. Steel tanks will be a nightmare! This is not a good idea!

Learning to weld stainless would be like learning surgery by doing brain surgery. Stainless is clearly one of the hardest metals to weld properly and finsih.

[Tony B]

"Have you ever tried to heft a 40# on and off the boat?'

I know what they weigh. They are NOT light. I load them on and off my P/U all winter long for heat in an uninsulated steel shop with 20' + roof. I have a crane on my boat which will make it quite easy. I used the crane yesterday to get my old 15HP O/B off the boat and onto the dock. Used the crane again today to get some batteries on and off the boat. Not AAA batteries. LOL
I thought about getting 20 pounders but I already own two 40's. Even living aboard I know that a tank will last several months for hot water, stove/oven and BBQ.
More than likely, I will probably end up taking your advice and get smaller tanks.

I plan on leaving the tanks outside on the Sun Deck under the hard top.
It will be enclosed during the winter months but plenty of ventillation along the floor.
It is not a current priority of mine yet but will be in about 2 months so I am investigating all possibilities and thanks all for the info.