Webasto diesel heater - sizing of radiators

[stuart]

I'm looking to fit a Webasto diesel heater, but struggling to find information about what size/output to make the radiators in side the boat.

 

 

The heater outputs about 5kw on full and 2.5kw on half power, understand that these units are best operated without them cycling on/off like a gas boiler does/can do.

 

 

What's best with regard to fitting correct BTU/Wattage radiators?

 

 

(PS: Aware that TRV's are a no-no!)

[granddad]

The webasto figures are self-explanatory regarding load except with their webasto 2010 unit.

That load configuration is not easy to understand - This isn’t verbatim but there must be 10 litres in circulation and it must all be in a 22 mm pipe. The load must not be in a feed and return bridged by normal radiators but the feed and return must be

coupled with a 22 mm end pipe connected to the feed and return. The output will then cycle this body of water increasing

the temperature and turn off the burn in the unit momentarily (say 1 minute at a time) until the entire load is at the required

temperature.

Don’t bother with 90s/t versions as the heated evaporation system no longer works with marina red diesel. The webasto

2010 is a pressurised atomised fuel fired through an electric igniter.

The above is the result of 6 years’ experience with webastos.

ken

[NMEA]

5kw? more likely a TTE 5.2kw unless a vehicle unit, in which case it may be 5kw. Anyway, back to the radiator sizing question, the Webasto recommended loading is boiler kw + 10% and ignore the calorifier, this is all clearly explained in the TTC marine install factory manual along with many other requirements, if you want a PDF copy of that document just PM me an email address and I will be happy to send you one.

Edited March 16, 2015 by NMEA

[stuart]

Thanks for the help.