Diesel heater out or in?

[fizzy]

Webasto extract from interwebs:

View attachment 525810

It would make some sense in a very well sealed room so if you are using it in a caravan or boat then fair enough. But for normal use I still can't see the problem logically.
I mean it will suck in air from the room and push it outside - so you get a slight loss of efficiency as outside air will be dragged into the room.
But what is the danger? I can see none at all if you have good ventilation.
Of course in a totally sealed room it will suck air out and you may find oxygen levels dropping. Then you can't open a door or window to escape as you are living in a vacuum

 

[fizzy]

Also with the air intake pipe inside a minor detail is that you are therefore losing that heated space air to outside. And depending on how well sealed the buiding fabric is, it could create a small negative pressure bringing in even more cold air.

Lol I just typed that!

 

[Bullet2012]

Then you can't open a door or window to escape as you are living in a vacuum

Unless they open inwards , then you may get squidged, a bit

 

[fizzy]

I am installing into a dusty work area so regardless of the combustion NEED would PREFER to run the pipe out through a timber shed wall. Does anyone have experience of suitable glands/grommets/whatever for making it a neat job!
I also want some type of filter for the heating input as I suspect large quantities of sawdust won’t do it any good. Again- thoughts please?

Yes they do suck in large amounts of dust. Something large to go over the end of the pipe. Perhaps one of these modified.

Pack of 2 Foam Cover, Foam Filter Mat Wet Filter, Foam Filter Vacuum Cleaner Round, Wet Filter for Vacuum Cleaners, Reusable Water Washable Foam Filter for Shop-Vac Vacuum Cleaners : Amazon.co.uk: DIY & Tools

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The kind of things that go over the float cage in a wet vac.

 

[Shiny Steve]

I’m wondering if a k&n style air filter might work on the heating air inlet to reduce throughput of dust.

 

[fizzy]

I’m wondering if a k&n style air filter might work on the heating air inlet to reduce throughput of dust.

Yes as long as it's big and doesn't restrict volume they do suck through a fair bit.

 

[JOEPRO]

Lets do the pros and cons of combustion air inlet being inside:

Pros:

Saves coring holes.
Saves pipework extensions should they have been required length wise.
No risk of water ingress

Cons:

Holes to drill and pipe to route as part of install.
Small loss of efficency + neg pressure in the space.
Potential for airborne contamination - saw dust etc inside the combustion chamber.
Potential for leakage of combustion products and.... death. (Minor detail)

I think there are more cons, and serious ones than pros for not taking the combustion air intake to outside. Save one 'ole, worth it? Really?

And... for clarity I have already spent too much time on this!!! Trying to help is all and be safe. But you can do what you want to do of course- just be safe.

And at that - I'm out of this diesel heater thread.

 

[zzr1200]

Webasto extract from interwebs:

View attachment 525810

I can understand that being as most (modern)vehicle are fairly sealed boxes on wheels (except true Land Rovers...) and most Webasto Heaters are fitted in vehicles that potentially have people sleeping in them in cold climates, also it's cheaper than running an engine all night.

I can assure you my garage/workshop is anything but airtight, more like a wind tunnel..

What about log burners, another source of workshop heating???

 

[Bullet2012]

And at that - I'm out of this diesel heater thread.

bye, missing you already.

 

[Misterg]

Just for 8hits and giggles:

AI Overview


Yes, the combustion air intake for a 12-volt diesel heater
must be routed outside the vehicle or heated space for safety, preventing carbon monoxide and fumes from entering due to potential flameouts or backdrafts, ensuring proper fresh air for complete combustion, and maintaining optimal efficiency by not using already heated cabin air. While some systems draw from the cabin (which is less ideal), standard practice for safety involves routing both the combustion intake and exhaust outside, separated and positioned correctly.

Key Reasons to Route Combustion Air Outside:

• Safety: Prevents dangerous carbon monoxide and unburned fuel fumes from entering your living space, especially if the heater malfunctions (flameout) or backdrafts occur.
• Performance: Ensures a steady supply of fresh, oxygen-rich air for efficient and complete combustion, improving heater performance and reducing soot buildup.
• Pressure Balance: Stops the heater from creating negative pressure in the cabin, which can pull exhaust fumes in through tiny gaps or cause drafts of cold air.
• Efficiency: Using pre-heated cabin air for combustion can slightly reduce efficiency and requires the heater to work harder to bring the cabin temperature up.

Installation Best Practices:

• Intake & Exhaust: Both the combustion air intake and exhaust should be routed to the outside.
• Separation: Keep the intake and exhaust tips as far apart as possible and positioned so the intake isn't drawing in exhaust gases.
• Orientation: Point the intake away from oncoming air (towards the rear of the vehicle) to avoid obstructions, and ensure it's not near the exhaust.

 

[Bullet2012]

more like a wind tunnel..

blame the christmas sprouts.

 

[skotl]

I can understand that being as most (modern)vehicle are fairly sealed boxes on wheels (except true Land Rovers...) and most Webasto Heaters are fitted in vehicles that potentially have people sleeping in them in cold climates, also it's cheaper than running an engine all night.

I can assure you my garage/workshop is anything but airtight, more like a wind tunnel..

What about log burners, another source of workshop heating???

That was my initial thought. I'd do it differently (i.e. outside) in a vehicle, but seems overkill for a draughty garage. That's why I need the heater!

 

[zzr1200]

blame the christmas sprouts.

That wind ades heating, with a source of ignition..........

 

[oldbikedavey]

Yes i would love one. I don't think my staff could cope with the starting procedure though

They'd get the message ....