Cockpit diesel heating - downstairs too?

[PooleBoater]

I’m looking for some advice from anyone with experience in these matters. I have a new to me hardtop sports cruiser which has reverse cycle air con installed. Three units in total, one in the saloon, and one in each of the two cabins. She seems to heat up fairly well in current UK conditions considering the water temperature is already fairly low. The downside is that it does work fairly hard and subsequently makes more noise than the diesel heating I had on my last boat. The requirement for 240v to run the air con also means running the genny at anchor which I’m not keen on overnight.

I intend to add diesel heating in the cockpit as we like to sit upstairs as long as possible throughout the year. If anything, I would like this cockpit heating over spec as we also like to have the aft cover off whenever possible which lets the heat escape.

I think I have the following options:

1. Fit diesel heating upstairs in the cockpit. Ideally a powerful unit so it can cope for as long as possible with the aft cover off. In this situation would I need only one outlet or is more better?

2. Fit one diesel heating unit with outlets throughout the boat. This will give quicker/quieter heating without needing to run the genny downstairs but will it give me the performance I’m looking for in the cockpit? Incidentally this is the setup I had on my previous boat.

3. Go all out and fit two diesel heaters. One with outlets in the saloon and cabins. The other with one or more outlets in the cockpit. This sound like it might add extra expense and complexity?

Any advice gratefully received on these options or any others you can think of.

Many Thanks!

 

[Hot Property]

I would go for two outlets in the cockpit to distribute the available heat. I have a 5 kw heater in my cockpit but it's a relatively small space. Search for threads on diesel heaters on the forum. You could buy about 10 Chinese versions for the price of one Eberspacher so apart from fitting costs/time it's a no brainer!

 

[snowbird30ds]

You could do the planet a favour and buy a coat, never got to grips with folk that expect outside heating.

 

[zt260]

Check where you can run your heating pipes downstairs as the aircon may have taken up the best and easiest route

 

[Simi]

make sure what ever you fit you put insulation on the ducting it makes a great difference especially on a long run of ducting
i woule fit 2 heaters one to feed the main saloon and any easily adjacent rooms / heads the other for the bow cabin and head
but it depends on the length of you boat

 

[BruceK]

One also needs to watch for pressure differentiation between inlet and outlet on longer runs / enclosed cabin spaces as IIRC the max is 16kPa or the controller shuts down. 16kPa sounds a lot but I found 1x 5m run of heated ducting enough to be on the limit.

 

[rlw]

I installed a 5KW heater on my 52 with insulated ducts and is sufficient for heating in and out. If it is middle winter cold it does take the boat a few hours to warm up but is fine then.
With the benefit of hindsight I would probably now opt for a water heater as it would have been easier to run the smaller piping to a heat exchanger under the cabin floor. I was always told heaters prefer to run hard as running low soots them up quicker. Have had many good years out of a webasto units but might consider planar next time as a halfway house between the big brands and the chines versions in price but decent support.