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heating gizmo

I want to know what fitting is used to heat my rads from calorifier whilst engine is running and webasto is not on (hope this makes sense)

Asked by: Bayliss Brown  | 10.36am, Thursday 8 September

WW says:

Its not easy to give you a simple answer since there are many methods of installing the pipework for the calorifier and radiator system. I'm also not clear if you are asking how your existing system operates or if it can be modified to provide internal heating from the engine. I don't know of a particular gismo that is designed to do the job, but the use of waste heat to keep the boat warm has featured in boat tests recently and can obviously be achieved. If two coils are used in your calorifier it's possible for a restricted about of heat to be transfered to the internal heating circuit via the second coil, it may be this effect that you have noticed. The current high cost of fuel has made us all look for methods of using waste heat which presently goes to warm up the cut.
I'm hoping to complete an article shortly showing a method suitable for retro fitting to boats with water cooled engines, I hope this will be of interest to you.

Mike Jordan  | 12.44PM, Friday 9 September

The simplest answer is to use the ready-made Adle heat exchanger. It can be plumbed into the return feed from the calorifier to the engine- and then fed into the heating system. Alternatively, as it uses 22mm feed and is low flow resistant, can be placed in the main pipe outlet towards the keel tank, which would reduce any chance of overcooling the engine.
Otherwise, you can easily fit a seperate heating system- maybe also using mini fin-rads, with a small low-current draw fan, to spread the heat- again, Alde make some off the shelf- only a seperate circulation pump would be needed, with a small header tank- by not using conventional convectors (radiators!), the volume of the solution is low, so expansion room needed limited.
The mini fan assisted convectors are quite small, and can transfer around 250 to 800W of heat each, depending on the temperature of the circulating liquid and the ambient temperature. They easily fit into units/lockers/wardrobe bases, and are quiet in operation.
You could also add heated towel rails to these circuits- very useful in bathrooms/galleys, as well as easily distriuting more heat.
It is very easy to convert heating systems from engine heat- WW have published articles in the past on this topic. People have also used car heaters salvaged from a scrapyard- and there are also matrix units
(from people like Webasto)which can have the calorifier return plumbed in, and then ducted hot-air pipework pushed to places needed.
As a rule of thumb, for every 1kW of engine power produced, you get the same amount in waste thermal load. Heat exchangers like the Alde allow you to measure the heat output you can transfer, but previous tests have shown that, at idle on a warm engine, you can obtain at least 2kW of output- possibly up to 5kW when running hard and the calorifier is hot- easily enough to heat a narrowboat- a 60ft boat only needs around 2 to 2.5kW of heat to maintain a comfortable temperature of 21degC when externally it is below freezing.
Hope that helps

Mark Langley  | 10.16PM, Sunday 11 September

And I was assuming that you meant how to install a system- if it is an existing one, my money would be on an Alde heat exchanger. The manual, etc, can be found at www.alde.co.uk

Mark Langley  | 10.23PM, Sunday 11 September

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