Webasto Heating

[NMEA]

Your builder (as usual) has got it upside down, first plan what the boat needs to heat it in terms of BTUs then plan your radiators to suit and only then then specify the unit to suit, it may even be a 4.2 kw. Do not fit an evaporator heater at all if it is your sole form of heating unless you are happy with frequent service bills. These things are suited to two or three hours in the morning to heat water and take the chill off until you go to work or light the stove, same in the evening. If you want CH as a primary heat source then get a P.J. boiler like a Kabola Compact 7 which will stand constant cycling, can use TRVs and or a room stat and is built looke a brick outhouse.

[ditchcrawler]

Your builder (as usual) has got it upside down, first plan what the boat needs to heat it in terms of BTUs then plan your radiators to suit and only then then specify the unit to suit, it may even be a 4.2 kw. Do not fit an evaporator heater at all if it is your sole form of heating unless you are happy with frequent service bills. These things are suited to two or three hours in the morning to heat water and take the chill off until you go to work or light the stove, same in the evening. If you want CH as a primary heat source then get a P.J. boiler like a Kabola Compact 7 which will stand constant cycling, can use TRVs and or a room stat and is built looke a brick outhouse.

NMEA what is the effect of putting say 7KW of rads on a 5.2KW heat source. I am not a heating engineer but the way I see it, the unit would run constantly as the heat would dissipate faster than it could be generated until the boat starts to warm up when the radiators wouldn't be able to push out so much heat as the differential would be much less.

[NMEA]

NMEA what is the effect of putting say 7KW of rads on a 5.2KW heat source. I am not a heating engineer but the way I see it, the unit would run constantly as the heat would dissipate faster than it could be generated until the boat starts to warm up when the radiators wouldn't be able to push out so much heat as the differential would be much less.

You surmise correctly, the ideal for a 5.2 kw is around 5.5 to 6kw to make it work hard. even that is a huge amout of rads on a narrowboat thats 5 off 800 x 600 double panel type 22 rads, for single panel a lot more. Acheiving a temperature differential is very important and why I ignore calorifiers as they soon have almost zero differential. it s also worth realising that quoted outputs for radiators are based on a fluid temperature higher than evaporator heaters run at.

[NMEA]

Ok thanks for all that, so in summary the 3 rads and towel rail I'm having fitted should add up to 5.2kw or there abouts for the 5.2kw webasto to work properly/efficiently? Well that makes perfect sense!!!

 

Cheers!

Not unless they are double panel, double finned type 22s and even then they would need to be 1200 x 600 to properly load a TTC.

Thanks, I know a little bit about BTU and radiators as Iv'e fit quite a few and had this little clever device that when you put in how many windows, outside walls, room size, etc it told you the BTU and radiator you need, different kettle of fish on a boat as the calculations wouldn't work the same as it's sat in cold water.

 

But yes I'll be going for 3 doubles.

That clever little device would be totally uselless as it's designed for known and specified thermal losses in buildings which are entirely different from boats,

[Richard X]

Not unless they are double panel, double finned type 22s and even then they would need to be 1200 x 600 to properly load a TTC.

That clever little device would be totally uselless as it's designed for known and specified thermal losses in buildings which are entirely different from boats,

Yes that's what I said, the devise I used to tell me the size of radiators for each room in a house won't work in a boat, completely different perimeters

[Bee]

Just a couple of thoughts and I freely admit to being a dinosaur as far as boat heating is concerned but keeping things simple and being able to fix things is actually a) cheaper and b)more reliable. I worked on mobile libraries for 20 odd years and spent the majority of most winters freezing with no heating because the Eber or Webasto had bust. Eventually all the vans were fitted with two, expensive, identical units and even then there were problems, nice clean fuel, well charged batteries. I suggested storage heaters, plug in overnight and be warm in the day but it didn't happen but in a marina with shore power, why not? Or just use a reliable, gravity heating system and save a stack of money on the technology. As with lots of delicate and expensive stuff its expensive and prone to giving up and unfixable when its 10 degrees below and the spanners are frozen to the deck.

[widebeamboy]

Just a couple of thoughts and I freely admit to being a dinosaur as far as boat heating is concerned but keeping things simple and being able to fix things is actually a) cheaper and b)more reliable. I worked on mobile libraries for 20 odd years and spent the majority of most winters freezing with no heating because the Eber or Webasto had bust. Eventually all the vans were fitted with two, expensive, identical units and even then there were problems, nice clean fuel, well charged batteries. I suggested storage heaters, plug in overnight and be warm in the day but it didn't happen but in a marina with shore power, why not? Or just use a reliable, gravity heating system and save a stack of money on the technology. As with lots of delicate and expensive stuff its expensive and prone to giving up and unfixable when its 10 degrees below and the spanners are frozen to the deck.

 

Storage heaters are useful IF you are home during the day, however by evening in a well insulated flat they were hardly of any benefit (plus you don't get economy 7/ over night rate electric in a marina).

 

Most flats in or around London have them as gas is expensive to install. My experience is they are rubbish, however maybe that was the dinosaurs that had been installed in the block and its of course possible that advances in technology have made similar items more effective.

ps in your mobile library example it would have been excellent and quite cheap too. Clearly the people who made the decision were not that clued up.

[mross]

Storage heaters without the benefit of the Economy 7 tariff would be horrendously expensive. 4kW on for 12 hours a day would be £50 a week. Unless you have Economy 7 it would be cheaper to use the electricity only at the times you needed warmth, so plain fan heaters.

[Sue]

We have a Collingwood wide beam 12ft and found that the Webasto 5.2 kw supplied is adequate along with the morso stove. The timer supplied by them is totally useless.. Well not useless but difficult to set up. Upgrade to the better controller as suggested.

 

These stock wide beams produced are really built for living aboard in a marina so some upgrades for continuous cruising will be required.

[ditchcrawler]

We have a Collingwood wide beam 12ft and found that the Webasto 5.2 kw supplied is adequate along with the morso stove. The timer supplied by them is totally useless.. Well not useless but difficult to set up. Upgrade to the better controller as suggested.

 

These stock wide beams produced are really built for living aboard in a marina so some upgrades for continuous cruising will be required.

Like a water tank?

[Sue]

Like a water tank?

 

Yes absolutely Brian as you know by reading the blog. Our stupid water tank on this stock wide beam is a ridiculous 375 litres. My error.. I just presumed it would be bigger on a big fat boat!! Same for the black tank, very small too.

 

I thought I would just point out one of two things to Richard X that I didnt think about and should have.

[Richard X]

 

Yes absolutely Brian as you know by reading the blog. Our stupid water tank on this stock wide beam is a ridiculous 375 litres. My error.. I just presumed it would be bigger on a big fat boat!! Same for the black tank, very small too.

 

I thought I would just point out one of two things to Richard X that I didnt think about and should have.

It says on the spec that they're putting in a 200 Gallon water tank which is approximately 900 litres. It will be a stock 70' x 12' Eurocruiser but only part fit, so only the Main bedroom will be complete to get it within budget.

[Neil Smith]

Yes absolutely Brian as you know by reading the blog. Our stupid water tank on this stock wide beam is a ridiculous 375 litres. My error.. I just presumed it would be bigger on a big fat boat!! Same for the black tank, very small too.

 

I thought I would just point out one of two things to Richard X that I didnt think about and should have.

You probably thought it was 375 gallons.

 

Neil