Installing diesel heater in centre cockpit yacht

[sealily]

Ive recently bought a Webasto type diesel heater (Chinese brand) and am trying to figure out the best place to install it. The ideal situation appears to be to have the exhaust coming out of the transom which means the heater itself needs to be at the aft end of the boat as to keep the exhaust run short. With my centre cockpit yacht the whole aft space is a sleeping cabin with the deepest bilge spaces taken up by water tanks and batteries - so no space for the heater - unless I put it aft and under the deck which will look kinda ugly.
My other option is to put under a seat in the saloon with a stainless pipe exhaust up the bulkhead and out the cabin roof near to where my previous solid fuel stove was.
Reading though the manual (and the Webasto manual) it says NOT to install in accommodation spaces! Obviously you wouldnt do this without running the exhaust outside though?
I would love to hear from others who have installed their Webasto, Espar or other with the exhaust out of the cabin roof and how they have found this. Im planning on having the combustion air intake from the bilge space. Also hopeing to be able to take the heating air from the cockpit but not sure how long this duct can be? And how to take from cockpit without the potential of getting water down it?
Sorry this is rather long winded!

[leftbrainstuff]

Ours is installed in the engine room. Our Espar recently passed the 10,000 hour mark and has a fan failure.

We bought a cheap replacement ($400 versus $4300) but am yet to install it.

The replacement unit has identical castings as the Espar and the controller is much better than the clunky espar unit and wiring.

A new espar was incompatible with all our spares and this lack of backward compatibility helped our decision.

I wouldn't install the unit or exhaust in any interior space. Even with good CO monitoring the risk of a fatality is too great imho.

Mounting it in the engine room of our center cockpit is ideal from a hot air distribution. It alao keeps all the diesel supply in one place. Engine, generator and heater.

[hpeer]

I did the same thing, it’s hung over the engine in a bracket I made and with safety chains. I ran the exhaust out of the engine compartment, up through a closet, and out a cockpit locker. It exists the coaming above the side deck, no issues at all. Well once a light wind blew some exhaust into the open companionway and set of the alarm, but that was really weird.

I have a single short piece of hose that vents out under the companionway ladder. It heats the main saloon nicely. We have lived in the boat in the wonder, a few nights into the teens and one to the single digits. Ice on the hatches but in to 60’s below. I close off the forpeak and act cabin in these circumstances as we have only a small D4.

[sealily]

Apologies for my delayed reply! Many thanks for your thoughts / suggestions.

Ive come across many instances of heater installations inside RVs and boats - under seats etc. I dont have much choice with my boat. If in the engine 'room' this is still connected to the rest of the boat.

Cant route exhaust out of cockpit coming as this is solid plywood at deck level.

Anyone out there put an exhaust out of cabin roof?