Eberspacher heater

[Rod_vw]

Derek Uzzell - 2012-12-02 6:26 PM

 

An Eberspacher Airtronic D4, correctly installed, should be plenty adequate to heat a motorhome the size of a Flash S2.

 

Installation/Operating instructions can be downloaded from the Eberspacher website

 

http://www.eberspacher.com/support-and-downloads/technical-documents.html

 

and there's a large amount of information here (NB. some of the website links may be out of date)

 

http://letonkinoisvarnish.co.uk/Eberspacher_Intro_1.html

 

(It may be worth noting the section about fitting a remote sensor.)

 

Thanks for the links Derek very worth adding to the favourites list.

[mikejkay]

Thanks for the links Derek. I had found and read the one from Eberspacher and the one from Le Tonkinois was interesting. I moved on to the article on repairing battery chargers to see if I could pick up any useful information.

[mikejkay]

"If a more efficient heat exchanger was employed it would consume more fuel. You need more energy to push the exhaust past a larger resistance" - not sure about this. If I remember my lectures on thermodynamics, energy in = energy out. Any increase in energy required would be offset by an increase in temperature inside the van. I envisage something like a finned pipe through which the exhaust gas would flow on its way to the outside.

[Derek Uzzell]

If Eberspacher's data for the Airtronic D2, D3 and D5 heaters are compared, it will be noticed that, for a similar heat-output wattage, the air throughput, electrical power requirement and fuel consumption vary, but not necessarily in the manner one might think.

 

For example, an Airtronic D2 (maximum heat-output = 2200W) at low setting produces 850W of heat, with an air throughput of 36meters-cubed/hour demanding 8W of 12V power and using 0.10litres/hour of diesel fuel, whereas an Airtronic D4 (maximum heat-output = 4000W) at low setting produces 900W of heat, with an air throughput of 55meters-cubed/hour demanding 7W of 12V power and using 0.13litres/hour of diesel fuel. So, at the low setting, compared to a D2 a D4 produces a bit more heat, uses more fuel but less 12V power, and can move a lot more air.

 

What constrains the heating power of an Airtronic heater is its physical dimensions - the bigger the appliance the bigger the blown-air fan and heat exchanger can be. When an Airtronic heater is fitted within a motorhome (I think Chausson fit the heater externally) the heater's size will be important, as will its price. A D5 costs about twice as much as a D2 and about 50% more than a D4, so one should anticipate that motorhome manufacturers will fit the smallest, cheapest Airtronic model they can get away with. A D2 should be fine for a panel-van conversion or a sub-5.5m-long coachbuilt design; a D4 should be suitable for motorhomes up to 6.5m long, and a D5 for up to 7.5m in length.

 

While it might be practicable to increase an Airtronic's efficiency by using an 'afterburning' principle (as mikejay is suggesting) where exhaust heat is exploited, it's questionable whether the gain would offset the additional design complication. If the amount of diesel-fuel used by an Airtronic heater were compared with the appliance's heat-output, it wouldn't surprise me if the efficiency was well above 90%. There's no reason for Eberspacher (or Webasto) to market inefficient heaters and, if there were a simple way to increase efficiency that didn't compromise other factors (eg. size, cost, safety) it should be expected that they would have done it.

[Derek Uzzell]

Derek Uzzell - 2012-12-02 6:54 PM

 

Curtisden - 2012-12-02 5:52 PM

 

...But I have a question.

Mine heats a self container heat exchanger full of Antifreeze as found in a truck. This in turn heats the water and the fan blows out the heat from mini rads in each outlet.

Having drained down the water tank and piping but not the heat exchanger can I safely run the heater?

P

 

I believe you own an East Neuk Fifer L with a Webasto Thermo-Top C300 heating system that provides blown-air heating and heating of 'domestic' water.

 

I THINK you should be able to run your heating system safely when it's drained of water. This would then provide blown-air heating but (obviously) no hot water.

 

I strongly suggest you confirm this with East Neuk and/or Webasto.

 

(I would have thought you should have Operating Instructions that would cover this, as it's plainly something that a motorhome owner is likely to want to know.)

 

A follow up...

 

I haven't been able to find on-line Operating Instructions for a Webasto Thermo-Top C300 system, but the instructions for the Webasto Dual-Top (which is essentially a Thermo-Top C300 in a single box) state categorically that blown-air heating operation remains available when the Dual-Top's water storage reservoir has been drained. I'd expect there to be a similar statement somewhere in the Operating Instructions I assume you have.

 

Webasto(UK)'s technical-advice contact details are here:

 

http://www.webasto.co.uk/Mailer/content/webasto_co_uk/en/jsp/contact.jsp

[Curtisden]

 

 

A follow up...

 

I haven't been able to find on-line Operating Instructions for a Webasto Thermo-Top C300 system, but the instructions for the Webasto Dual-Top (which is essentially a Thermo-Top C300 in a single box) state categorically that blown-air heating operation remains available when the Dual-Top's water storage reservoir has been drained. I'd expect there to be a similar statement somewhere in the Operating Instructions I assume you have.

 

Webasto(UK)'s technical-advice contact details are here:

 

http://www.webasto.co.uk/Mailer/content/webasto_co_uk/en/jsp/contact.jsp

 

Thankyou for that.

No this was not covered in the information EN supplied and a E Mail reply from Darren this morning confirms your views. It can be used without the water system pressurised.

 

Are you the chap who had a Fifer M and put the pictures on Flicker?

 

We are frankly delighted with are van, it ticks all the boxes and some.

Thanks.

 

Peter

 

[JasmineAnders]

If you live in the south you can get excellent Eberspacher servicing from

Krueger Ltd

Unit 16, Queensway

Stem Lane Industrial Estate

New Milton

Hants

BH25 5NN

 

01425 619869

 

When we arrived at the Peterborough Show this year Rosie said " something is hanging down and swinging under the van like a donkey's appendage"

I climbed down to have a look and as I watched the Eberspacher exhaust pipe fell to the ground.

The metal had completely rotted through by the silencer outlet.

 

I managed to obtain a long length of replacement piping and fitted it without any trouble.

[Derek Uzzell]

Curtisden - 2012-12-03 10:20 AM

 

...Are you the chap who had a Fifer M and put the pictures on Flicker?

 

We are frankly delighted with are van, it ticks all the boxes and some.

Thanks.

 

Peter

 

Not me.

 

When I get the time I'll see if I can prise from Webasto some Thermo Top C300 instructions that cover the type of system you've got. There's operating advice on-line about the basic Thermo Top system but (apparently) no advice about the system when it has been expanded to include RV 'domestic' water heating.

[HymerVan]

Peter/Derek

I am not the man with the pictures on Flickr either (they are of an older Ducato Based Fifer) Mine is a 2012 130bhp Euro 5 Citroen. "M"

I am also delighted with my Van.

Derek if you do manage to get more info from Webasto could you post it here or PM it if you prefer.

I remain very very indebted to you and the other gurus on this forum

This is my tenth year as a motorhomer and I am still learning every day !!

[Derek Uzzell]

OK - with any luck there'll be an appropriate .pdf file Webasto can either direct me to (and I can provide the link here) or can e-mail to me (in which case I'll PM you and curtisden and can then forward the file to an e-mail address if you provide me with one).

 

I think East Neuk install a Webasto system similar to the one shown on Webasto's Australian website, so one might reasonably expect there to be operating instructions for the various bits:

 

http://www.webasto.com.au/products-and-markets/graphics/WEBASTO-COM-AU_Caravan_TTSeries_PS.pdf

[Curtisden]

Hi

I find the heater puzzling. Its no doubt a good bit of kit.

But while away last night in sub 0 I left the heater on on 15/20% to provide background heat.

Woke in the middle of the night to a fan running at some speed and blowing out cold air?

Turned it of and back on 30 seconds later and it started to warm up and the fan returned to cycling when needed.

Any Ideas?

Peter

[Derek Uzzell]

How about this?

 

Despite the outside temperature being freezing, the temperature inside your motorhome became sufficiently warm for air-heating to cease operation. When the heater started up again it woke you up and, because the heater had been shut down for while and the coolant that's circulated to your radiator/fan unit was cold, when you checked what the heater was doing it was still in the warming-up stage and the fan was running quickly and blowing out cold air. Obviously, you didn't much like what the system was doing, so you 'rebooted' it, when it then began to behave as you expected it should do. Perhaps, if you had left it alone rather than switched it off, it would have warmed up inthe way that it did after you'd switched it back on.

 

I suspect there's a flaw in that scenario, as it's probable that you did give the heater the chance to warm up (as that's what I'd have done) and it refused to do so.

 

Dunno - motorhome heaters sometimes seem to have minds of their own. If it keeps doing this it would be wise to ask East Neuk about it in case it's a known characteristic, or in case there's something wrong.

[crinklystarfish]

Curtisden - 2012-12-05 6:12 PM

 

Hi

I find the heater puzzling. Its no doubt a good bit of kit.

But while away last night in sub 0 I left the heater on on 15/20% to provide background heat.

Woke in the middle of the night to a fan running at some speed and blowing out cold air?

Turned it of and back on 30 seconds later and it started to warm up and the fan returned to cycling when needed.

Any Ideas?

Peter

 

Constant modulation is the term they use, and may be what you encountered. Basically the heater will heat the 'van to the temp set on the thermostat and then will stop burning diesel. The fan, however, will keep running, usually at a much reduced rate. There can sometimes be a pretty considerable lag before the room sensor / control / ecu combination (depending on spec) indicates to the heater that it needs to start burning fuel again to re-attain the initial set temperature. While the fan is running but the heater not burning diesel then the emitted air will feel cool.

 

Turning off and back on, as said, is likely to have 'tricked' the control unit into re-firing.

 

I find the trait slightly irritating so use the gas heater for background heat overnight.

 

 

[HymerVan]

Topic slightly highjacked by Webasto !!

I have checked the papers I got with my Fifer and it is indeed an Air Top C300. (see Guarantee etc).

Like Derek I have not been able to find comprehensive user instructions and i think that this is due to the relatively "bespoke" nature of the installation.

What I did did come across though was an instruction to run the system for at least 20mins each month, something I will now do while the Van is in Winter storage.

[Birder]

Hmm! Someone not reading/remembering what was posted 1st December:- "We were also encouraged to ensure the heater was switched on for at least 20 minutes per month to ensure everything keeps ticking over nicely. They are very good 'workhorses'. "

Perhaps like me you have a 'Good Forgettery' :D

[Derek Uzzell]

Birder - 2012-12-06 2:00 PM

 

Hmm! Someone not reading/remembering what was posted 1st December:- "We were also encouraged to ensure the heater was switched on for at least 20 minutes per month to ensure everything keeps ticking over nicely. They are very good 'workhorses'. "

Perhaps like me you have a 'Good Forgettery' :D

 

Your Avondale motorhome has an Eberspacher Airtronic D2 blown-air-only heater, whereas HymerVan's East Neuk Fifer M and curtisden's Fifer L have much more complex Webasto ThermoTop C300E-based systems able to heat both air and domestic water. The scope of a TT-C300E system is covered here:

 

http://www.webasto.co.uk/service/en/html/9199.html

 

HymerVan's heating system differs from yours in terms of manufacturer and concept, so there would have been no particular reason to expect your 1st December "20 minutes per month" Eberspacher-related comment to be relevant to his Webasto system. That Eberspacher and Webasto both provide similar advice is coincidental, though it's likely to be applicable to all vehicle heaters fuelled by diesel.