Webasto Thermo Top C

[Roger Gunkel]

Nice idea about the air tube. I am puzzled how you are using a step-down transformer to decrease the speed of a computer fan as these are 12v DC devices not AC and a step-down transformer will only work on AC. I suspect you mean a DC voltage converter so it may only be nomenclature.

 

I built a 12v pulse-width modulated "dimmer" circuit for a computer fan which gives total control from nothing to full chat without wasting any power (unlike a simple resistor speed control). I'd be happy to pass the circuit diagram on to you if you could use it.

 

Chris

 

You are probably correct about the nomenclature, I referred to it as a stepdown transformer as it gives a lower output voltage than goes into it, but then my electrical knowledge is very limited. It was a simple 12v car socket adapter with 4 preset output voltages selected from a switch on the side. Came from Wilkinsons for abou £3 or so. I took it apart and wired it into the fan supply. Your "dimmer" circuit sounds like a great idea and would certainly give more control than a fixed voltage and anything that avoids wasting power has got to be useful.

 

Thanks

 

Roger

[kayDee]

I'm a great believer in trying the simplest things first and have been thinking about your problem. Firstly, my own situation is on a 57ft widebeam with a solid fuel stove in the lounge at the front. We have a side corridor running down the boat with the back bedroom doorless to the corridor. Our heat is moved very gently down the corridor by a 4" computer case fan on the ceiling at the warmest point where the corridor joins the lounge.

 

In your case, it seems that the main heat source, the stove, is producing all its heat in the lounge, and the interuption to the airflow by doors and obstructions would be the main problem. How about trying the same system as us , but sending a gentle flow of warm air through a suitable diameter tube, to the point where it is needed.

As the air would be warm rather than hot, any tubing of the right size would do. You could even make up a square tube from thin expanded rigid foam. We run our fan at half power through a very simple stepdown transformer, which makes it totally silent and the slower airflow stops draught from the moving air. The power consumption on the fan is minute, probably about 0.1 amps.

 

The idea is purely speculation based on our own success, but providing the fan is fitted tightly into the tube, I don't see why it shouldn't work. It would cost very little to make, with no skill neccessary. Others may well think the idea is ridiculous, but there is nothing to lose in trying it.

 

You can also considerably reduce your heat loss with simple double glazing on the windows. We used thin film and double sided tape and the difference was amazing.

 

You could of course try both methods for very little outlay or disruption, before laying out money on radiators, plumbing and back boiler.

 

Hope it at least gives some alternative ideas,

 

Roger

 

Thanks for that Roger - I like the sound of the tube. I thought about some of that flat extraction fan pipe rather than a round pipe. It would be an absolute nightmare to run it as it would go through the galley - so through all the floor level cupboards and behind the fridge! Gawd! I really do need to have a think about what is going to be the best way. We're not really talking the requirement for a lot of heat - just enough to keep the chill off really.

Thanks again Roger for taking the time to explain all that for me, its given me a few ideas!

Kay

x

[kayDee]

Hi all... x

I was searching a few threads and came across the Kabola heating system - which I've presumed is more suited to the live aboard boat? Is this right? Is there a massive price difference or is the difference in the amount of fuel it drinks? Its just another option I thought I'd explore!

 

 

Oh, off topic I know but at midnight last night, something VERY loud and VERY fast flew down the canal and almost unpinned me! It took about ten minutes for the water to calm down again. It REALLY scared me, I thought the boat was going to tip over, I've never experienced anything like that before! Very spooky! I couldn't see any lights either and it was obviously pitch black at that time of night. Anyway, thought I'd mention it! x

Kay

x

[magnetman]

there's a nice Kabola heater for sale here:

 

http://cgi.ebay.co.uk/boat-diesel-heater-K...id=p3286.c0.m14

[kayDee]

there's a nice Kabola heater for sale here:

 

http://cgi.ebay.co.uk/boat-diesel-heater-K...id=p3286.c0.m14

 

Oh, I thought they were purely diesel fired heating units - my mistake... There must be something out there that can cope with about 9 hours use through the night in winter without too many problems? I just don't think the back boiler idea and one rad (nice and cheap) will be able to heat something so far away from the stove - its practically the other end of the boat :-(

Frustrated Kay

x

[magnetman]

If I was wanting to heat a small cabin with a diesel fired heating system I would definitely consider a Refleks heater. a lot of yachts have them and they are very well respected. They do a nice small one:

 

http://cgi.ebay.co.uk/Refleks-Diesel-Heate...id=p3286.c0.m14

[Colin Smith]

Oh, I thought they were purely diesel fired heating units - my mistake... There must be something out there that can cope with about 9 hours use through the night in winter without too many problems? I just don't think the back boiler idea and one rad (nice and cheap) will be able to heat something so far away from the stove - its practically the other end of the boat :-(

Frustrated Kay

x

 

Hi Kay,

Have you looked at the Alde 3010 compact? We've spent a lot of time looking into heating systems for a new 57ft x 11ft barge. There won't be any other form of heating (no stove) so reliability and running costs were important in finding the best solution. I was put off the Webasto, Mikuni and the like because of the problems that seem to crop up with anything other than occasional use - something that I've not only read about on here but also through talking to owners up and down the cut.

Cost was another issue. Although the product prices are similar, the Alde worked out cheaper to run at current fuel prices and all the indications are that diesel will increase in cost over the long term faster than LPG. The 3010 is a lot more economical than the previous/other models they do and are pretty easy to fit. I also found Alde to be very helpful and honest about realistic service intervals/costs. The downside (possibly) for you would be the need to change the calorifier to a stainless steel one (you can't use copper in the system). If you need any more info, costings etc, drop me a PM. I'd be happy to share!

 

Regards,

Colin

[chris w]

Cost was another issue. Although the product prices are similar, the Alde worked out cheaper to run at current fuel prices..........

How are you working this out Colin?

 

If one runs the maths based on current prices and assuming a typical 5KW heater, the running cost per hour for propane works out to be 60 pence per hour based on £22 per 13kg canister of gas.

 

For diesel, running a 5KW heater, it would be 37.5 pence per hour based on diesel at 75 ppl. Heating diesel would have to rise to £1.20 a litre for the costs to be identical. So the ratio means that running a gas heater is about 1.6 times more expensive than running an equivalent diesel heater.

 

This agrees with users of Alde heaters in my marina who complain bitterly about the running costs of their Aldes.

 

My calculations based on:

 

Calorific value of Propane = 50MJ/kg; Density of Propane = 583kg.m^-3

 

Calorific value of Diesel = 43MJ/kg; Density of Diesel = 840kg.m^-3

 

Chris

[magnetman]

apparently you can get refillable bottles which you fill up with Autogas at BP filling stations. That'd make it a bit cheaper per kilo but I don't know if its actually propane or not. it is described as LPG so it should be either Propane or Butane

 

Another heating system I'd definitely consider for heating a small room in a narrow boat would be an Eberspacher D1LC (compact) AIR heater (rather than water) apparently these are a bit more reliable than the water type as they burn a bit warmer and don't coke up so much and they are a bit easier to install because of no plumbing.

[Marc Harris]

If I was wanting to heat a small cabin with a diesel fired heating system I would definitely consider a Refleks heater. a lot of yachts have them and they are very well respected. They do a nice small one:

 

http://cgi.ebay.co.uk/Refleks-Diesel-Heate...id=p3286.c0.m14

 

We've just had one of those removed this weekend from our boat. While it was very good when the cost of diesel was low (30p /litre few years ago), it was becoming very expensive to run as a main heating system.

 

We've now had a solid fuel stove with back boiler fitted in its place (will be running 3 rads, furthest one is 60 foot away).

 

If the OP is interested in our Refleks, then send me a pm in the next few days before it goes on Ebay. It's got all the flue and chimney bits included, as well as pipework for running radiators.

 

Good luck in your search for heating!

 

 

*edit to include piccy of fire*

Edited October 20, 2008 by Marc Harris

[chris w]

apparently you can get refillable bottles which you fill up with Autogas at BP filling stations. That'd make it a bit cheaper per kilo but I don't know if its actually propane or not. it is described as LPG so it should be either Propane or Butane

 

Another heating system I'd definitely consider for heating a small room in a narrow boat would be an Eberspacher D1LC (compact) AIR heater (rather than water) apparently these are a bit more reliable than the water type as they burn a bit warmer and don't coke up so much and they are a bit easier to install because of no plumbing.

The problem with air heaters (and I talk from previous personal experience) is that they take a very long time to get the boat warm and that heat is easily lost when someone goes in or out of the cabin doors to the outside.

 

Chris

[magnetman]

The problem with air heaters (and I talk from previous personal experience) is that they take a very long time to get the boat warm and that heat is easily lost when someone goes in or out of the cabin doors to the outside.

 

Chris

 

what size cabin were you trying to heat?

 

I've got one in my boat, the main cabin is approximately 9ftx8ft and it gets warm quickly and is well cozy. To be fair the coldest outdoor temperature I've used it with so far is about 5 degrees C. Opening the door to outside does lose heat quickly, as you say.

 

The OP was wanting to heat a baby's bedroom which to me suggests a small space which would be quite self contained with access from the main cabin, which would have its own heating system so there would be no direct link between the cabin itself and outside, cold air.

 

(except that there should of course be access from both sides but not as an everyday entrance just as an egress route in the event of fire or other problems)

 

This kind of setup would give a thermostatically controlled warmth for a single cabin and is easy to switch on and off and runs on diesel so you would be able to get cheap fuel for it by making a suitable declaration.

[Berty]

Hi,

 

We have a solid fuel stove (Morso Squirrel) with a backboiler on a 57ft narrowboat. The boiler feeds two radiators (bathroom and bedroom) and also heats up a tank full of water.

 

Our system is gravity fed, so it doesn't require a pump, and the water still manages to circulate nicely. (Retrofitting a gravity system to an already fitted-out boat will be disruptive, as you have to ensure that the pipe from the top of the boiler runs uphill to the radiators along the entire length of the pipe run.)

 

With a water pump, I'm can't see any reason why a single radiator in the back cabin would be particularly difficult to heat up.

 

Also, do the doors to the back cabin have vents in them? That might be an easy way to provide sufficient airflow to keep the chill off? Or would that lead to too much noise disturbance?

 

Cheers,

Berty

[Orca]

I have a Webasto Thermo 90 fitted - many boaters/'experts' say this unit is absolute overkill for a Narrowboat @ 9kw output, but I've never had any problems with it and the fierce nature of the burn cycle guarantees getting rid of any carbon/soot deposits. I also have the 7-day timer that allows 8 different on/off times per day - worth the money!! The mistake most people make with these types of systems burning Gas Oil (Eberspacher or Webasto), is that they should not be allowed to 'slow burn' after the heating/water system has come up to temperature.....imho

 

Edited to say: The only drawback imho is the fact it costs almost £2k new (without installation)

Edited October 20, 2008 by Orca

[chris w]

The mistake most people make with these types of systems burning Gas Oil (Eberspacher or Webasto), is that they should not be allowed to 'slow burn' after the heating/water system has come up to temperature.....imho

The user doesn't get a choice. It's part of the software that when the water gets up to 72C the burner switches off and the Webasto just runs the water pump until the water cools to 62C and then the unit automatically switches back on at half power. It will only come on again at full power if the water temperature drops to 56C (eg: you switch on an additional rad) at which point it will stay on full power only until the water reaches 62C and so on etc as above again.

 

(My knowledge based on a Webasto Thermo Top C)

 

Chris

[Orca]

The 90 is different and doesn't actually switch off, but will burn slowly, until said temperature drops/extra rad put on etc as you say. Very similar principle, but the 90's burner keeps going very gently and that's when the problems start (I know of two other's with these fitted and any prob's with fire up/excess smoke or vapour has been remedied by simple de-coking)

[chris w]

I have just fitted an hour meter to my Webasto and over last weekend (I am not a liveaboard) I was amazed that I had notched up 18 hours running time. This will all be good data when it comes to the red diesel split decision.

 

Chris