Eberspacher D3L Airtronic Heat output temperature

[lenseman]

Can anyone advise the output temperature of an Eberspacher? As the 75mm pipework is so expensive I am considering starting with conventional Eberspacher flexible pipe due to the extreme heat exiting and then run into 75mm circular plastic tubing that is supplied to the ground heat pump market.

This pipe is polyethylene and will melt at 154°C and a 6 metre length would become slightly 'saggy' from +90°C upwards.

Has anyone else used this or any other cheaper form of ducting to get the warm air around a yacht. We are talking about less than £25 for a 6 metre length of 75mm? My yacht requires about 22 metres of 75mm pipe!

http://www.ebay.co.uk/itm/HDPE-GEOT...DIY_Materials_Plumbing_MJ&hash=item19d8bb5f67

Answers please before I freeze to death or have to burn the woodwork to stay warm.



.

 

[pvb]

Firstly, I didn't think there was a "D3L Airtronic". However, if there is such a thing, it certainly won't work properly with 22 metres of 75mm ducting. If you have to use that length of ducting, you need to increase the diameter to 90mm or 100mm.

Eberspacher's Marine Installation Guide has a useful section on ducting sizes - see http://www.eberspacher.com/download...ebuk/airtronic_d2-4-5_marine_heater_22278.pdf

 

[pcatterall]

When I needed insulation I was given the figure of 175C so you may be ok half way along the pipe. As stated 22m is a massive duct run And a D3L(C?) is a very small heater ( for that sort of size)

 

[David2452]

Any duct material used in forced air systems requires materials capable of constant withstanding of 140c without effect. As has been said even a properly lagged air distribution system with a 3kw heater will not work to any decent degree at 22m even using 90 or 100mm duct, you would need something like a HL 90 to cope with that. I have used thin wall ali tubing on some long runs, properly insulated it is very good but obviously needs a completely straight path.

 

[lenseman]

Thanks for all the replies about the ducting.

I bought a working D3L from a friend and I thought that all the forced air heaters were Airtronic and the radiator models were called Hydronic?

When I was working my way through my little ship, to see where I could mount the unit and run the pipework/ducting, I discovered two more D3L units with a number of very useful extras, exhaust pipes and lagging and mufflers, thermostats, 3 x diesel pumps and a load of wiring, etc, etc.

The problem I have is the fact that the yacht is 50 foot and has steel 5mm bulkheads every two feet which makes installing an air duct a difficult challenge. The 22 meters takes into account the forepeak to cockpit run and includes the branches off to the various outlets.

I had considered a 100mm duct reducing for each branch but cutting large round holes every two feet would be difficult. I have also considered using one of the other units midships (port side) so that the blown air could somehow heat the hot water cylinder for the shower and hot water taps plus heating the forepeak? Suggestions anyone??

I appreciate that the air temperature leaving the outlet of the Eberspacher is going to be very, very hot probably in the hundreds of degrees C but somewhere this temperature has to drop down to 40°C to 80°C which is well withing the design parameters of the plastic pipe (154°C)?



.

 

[David2452]

Really sorry but you are wasting your time, 3kw will never heat a vessel of that size or even close, however installed. From your description of the install I would be looking to fit a 9kw liquid system, a 9kw blown air system or two 3.5kw blown air units. I do sympathise, I recently did wet based system on a 97 footer and even cutting the holes for 22mm pipe (28mm including protection) was a complete PITA and wore out several hole saws.

 

[oldgit]

Or you could drastically reduce the cabins you wish to heat to a decent temperature.Perhaps just heat one or twn my boat we have a single outlet to main cabin to get comfortable when sitting down and just allow convection to heat wheel box above perfectly OK when we are on move.The forecabin with bunks is right next to the main cabin and so small it gets sufficiantly warm by the time bedtime arrives purely by leaving door open.Purchased my ducting from a caravan company up on the Broads somewhere via ebay.Lagged all the ducting via some stuff from Wickes.Worst job is running ducting and/or stat wiring through all nooks and crannies and trying to keep runs as straight as possible .
We are fibreglass so perhaps a bit less heat lossy than you.

 

[lenseman]

Thank you everyone for constructive replies.

I have decided to install 100mm ducting throughout the yacht and as and when I have the time, add a branch and vent to each and every area that requires heating.

I appreciate that I can zone the various cabins as I have been doing that in winter for three years and more but when you have crew visiting and requiring a berth in winter, forepeak and other berths require a few BTU's to change them from a fridge to a warm area.

As I have three D3L units onboard, I will run with one or more of these units this year and upgrade to different maker with a larger heat output and sell on the Eberspachers.

Like all planning, incorporating a water heating system at the same time as installing a cabin heating system seems a prudent move as it is such a problem with steel bulkheads everywhere!

Thanks again for all your help.



.

 

[pcatterall]

Before starting I would seriously consider going for a hydronic type heater, at least a D5 but a D7 or bigger would be better. Plumbing runs in your boat would be vastly simplified, you could also get hot water and even engine preheating if required.

 

[David2452]

Before starting I would seriously consider going for a hydronic type heater, at least a D5 but a D7 or bigger would be better. Plumbing runs in your boat would be vastly simplified, you could also get hot water and even engine preheating if required.

Absolutely agree, but d D5 or 7 will not cut the mustard on a vessel that size (well, not one anyway)