air inlet for diesel heater, burner side

[simonfraser]

the standard package for a D2 comes with a short inlet.

i always assumed the air inlet would have to come from outside the boat ?

 

[pvb]

Combustion air can be drawn from the boat. It's better for the heated air to be drawn from outside, as this reduces condensation in the boat.

 

[ghostlymoron]

Dear

Combustion air can be drawn from the boat. It's better for the heated air to be drawn from outside, as this reduces condensation in the boat.

But it also increases the run time due to heating cold air instead of warm. In your house you try to avoid drawing in too much external air in winter - why is a boat different?

 

[pvb]

But it also increases the run time due to heating cold air instead of warm. In your house you try to avoid drawing in too much external air in winter - why is a boat different?

Much smaller volume, poor insulation on outer surfaces, humidity builds rapidly leading to condensation.

 

[JimC]

... It's better for the heated air to be drawn from outside, as this reduces condensation in the boat.

I agree with this. I've tried both ways and drawing in fresh air keeps the boat drier and fresher than re-circulating stale air. OK you'll burn a bit more diesel but it's worth it IMHO. I spend quite a lot of time aboard in Winter and heat a 31ft boat with an Eberspacher D4.

 

[salar]

+1. Draw in air from outside otherwise you will have walls and windows dripping.

 

[lw395]

Dear But it also increases the run time due to heating cold air instead of warm. In your house you try to avoid drawing in too much external air in winter - why is a boat different?

It's more like your car. Do you default to recirculated air or fresh?
Particular if the aircon's broken

 

[ghostlymoron]

It's more like your car. Do you default to recirculated air or fresh?
Particular if the aircon's broken

✓

 

[Porthandbuoy]

My D2 draws the combustion air from the engine bay; no problems.

The heated air is drawn from the foot of the notoriously difficult to ventilate coffin berth running under the cockpit seat. The first time I fired the system up was in a February a few years ago, it was -5degC in the shed. For a few hours the windows were running with water as the boat dried out. Since then there has been very little condensation.

Hot air rises, so I reckon the dorade vents and the hatch open a crack is enough to dispel the humid air and keep everything dry and comfortable. Been running like that for 5 or 6 years now without a problem.

 

[FWB]

The COMBUSTION air can be drawn from anywhere since it is exhausted outside.
The HEATED air is a different thing altogether. Some recommend drawing from inside the cabin, I prefer to draw from a cockpit locker. This air should be drawn from somewhere free from smells, eg not from the engine bay.

 

[ghostlymoron]

My D2 draws the combustion air from the engine bay; no problems.

The heated air is drawn from the foot of the notoriously difficult to ventilate coffin berth running under the cockpit seat. The first time I fired the system up was in a February a few years ago, it was -5degC in the shed. For a few hours the windows were running with water as the boat dried out. Since then there has been very little condensation.

Hot air rises, so I reckon the dorade vents and the hatch open a crack is enough to dispel the humid air and keep everything dry and comfortable. Been running like that for 5 or 6 years now without a problem.

My Eber, when I had one, was set up like this too. I didn't notice any condensation problems or oxygen depletion.

 

[Porthandbuoy]

The HEATED air is a different thing altogether. Some recommend drawing from inside the cabin, I prefer to draw from a cockpit locker. This air should be drawn from somewhere free from smells, eg not from the engine bay.

Good point! Chili-con-carne and a few beers make for some unwelcome recirculation.