Diesel Heater - Air Intake

[Slipperman]

My diesel heater is situated in my cockpit locker. If I run it with the cockpit locker lid closed I find that I get a smell in the boat which seems to result from wet ropes etc (made worse by the heat generated by the heater!) If I run the heater with the lid open, I get nice warm air without any noticeable smell. However, it is not always practicable or desirable to have the locker lid open, so my question is whether any form of 'air fliter' could be fitted to the air intake, similar to the one fitted to the engine (which is essentially just a piece of foam rubber in a box)? Would the heater be likely to work with such a device, and if so would it be likely to eliminate the smells?

 

[pvb]

A simple filter won't remove smells. The answer is to duct the intake air from somewhere else. Some people recirculate cabin air, but I don't like this idea as it tends to build up humidity. My Eberspacher takes intake air from the cockpit coaming, which is vented to the cockpit.

 

[vyv_cox]

Can you take the air from the interior of the boat? It's more efficient to recycle warm heating air than to pull in cold from outside. The photo shows mine, the lower hose just in the picture is the air being drawn from the aft cabin.

 

[pvb]

It's more efficient to recycle warm heating air than to pull in cold from outside.

Might be "more efficient", but it builds up a fug, and increases humidity. I like fresh heated air in my boat.

 

[vyv_cox]

Might be "more efficient", but it builds up a fug, and increases humidity. I like fresh heated air in my boat.

I can't say I have noticed that. It's what Eberspacher recommend.

 

[pvb]

I can't say I have noticed that. It's what Eberspacher recommend.

It's not what Eberspacher recommend - their Installation Guide says "The heater air supply must consist of fresh air or circulated air and be sucked in from a clean area not contaminated by exhaust fumes of the drive machine, the combustion heater or any other source..."

 

[aquaplane]

My Wallas is in the saloon so the air is recirculated to some extent. We tend to get the boat warm and then open the hatches to let the warm wet air out, it works for us for now.
I may add some vents to outside near the unit so the heater can draw in some fresh air at some point but after one seasons use it seems OK without.

I would have preferred to mount the heater outside so that when it's hot I could circulate cool air but access and mounting was not easy so I compromised and put it where it is down the Stbd ¼ berth.

The OP's locker mounting may not be ideal for now but sucking all that wet air out is going to dry out the locker isn't it?

 

[alahol2]

Our Eber is similarly sited to the OPs, in the cockpit locker. We don't suffer from any smelly hot air. What we have found is that, with the lid closed, the locker gets to such a warm temperature that the sensor in the air intake shuts it down. So we have to prop the lid open an inch or two to allow the hot air to exit. I would recirculate but the pipe run would be too long and complex to bother with. I may try to fit a vent into the locker but can't think how to do it without risking water ingress, if pooped for example.

 

[vyv_cox]

It's not what Eberspacher recommend - their Installation Guide says "The heater air supply must consist of fresh air or circulated air and be sucked in from a clean area not contaminated by exhaust fumes of the drive machine, the combustion heater or any other source..."

Mine (Eberspacher D3LCC December 1998) says 'use return air ducting for best efficiency'

 

[lw395]

Perhaps one day our £60k boats will have a little switch allowing us to choose fresh or recirc air, like on our £6k cars?

 

[Deleted member 36384]

Dyson "HEPA Bactisafe" Filter

Perhaps one day our £60k boats will have a little switch allowing us to choose fresh or recirc air, like on our £6k cars?

Ha Ha. I'll guess they will charge us another £6k for the optional extra.

I have a Mikuni heater and it states that the air should be drawn from within a well ventilated locker and specifically states that if the heater is mounted in an engine space, for example, then ducting should be run to draw air from an another area to stop the transfer of engine smells and fumes. This extension ducting should be kept as small as possible; but read on.

You can buy filter material from HVAC suppliers that eliminates certain smells and while it may be possible to fabricate a filter housing the pressure drop is likely to be too high and the cost prohibitive. Most odour control systems are quite bulky but they all have filter elements within. You can always investigate via Google "odour control air filters"; lots of UK based stuff.

An idea that springs to mind is the HEPA (High Efficiency Particulate Air) filter that is fitted to Vacuum Cleaners i.e. the Dyson Model DC14 Animal (marketed for allergy sufferers) which is a combined HEPA and bacterial filter. That filter does reduce the smell of the air coming out of the unit, is low cost and of a diameter that lends itself to a relatively easy installation solution e.g. Gaffa Tape it over the inlet!

I would try this before buying and fitting further ducting as it is likely to be a lot cheaper solution if it works. The filters are also washable.

 

[Slipperman]

Many thanks for replies so far. I like the idea of using a Dyson particulate filter - must be worth a try, so I will try to obtain one and have a go.! I will also look to see if I could route some ducting to draw air from the cabin, but I have a feeling it might be too far.

 

[SimbaDog]

Interesting! I have no idea where my webasto draws air from
Think I will be delving down below tomorrow to have a look

 

[NormanS]

It seems terribly inefficient to draw in cold damp air from outside. My Eber is installed in a large locker under a settee in the deck saloon. The locker face is louvred, so all the air used for both combustion, and ducted heated air, is drawn from the deck saloon. The doors from the cockpit into the deck saloon have permanently open vents.

When the Eber is on, the volume of air required for combustion is drawn in, ensuring a constant supply of fresh air passing into, and through the deck saloon.