Calorifiers, Dickinson, heating coils etc.

[StellaBorealis]

Okay so my Seaward Hot water heater has died, the heat exchanger still works but the tank has sprung a leak and the AC element no longer heats. As I have no desire for AC water heating I dont want to replace the seaward. Also I am poor so trying to engineer a solution.

Been trying to figure out what Dickinson water coils are meant to do and I think have it figured. I think its a copper coil that goes over the heater and sits in the hot water tank so that when the diesel bulkhead mounted heater produces heat the coil in the tank heats the water. I have a pretty good understanding of how the heat exchanger for the diesel engine in the seaward system works (in principle). So im thinking that I should be able to install a tank in my vee berth run the heat exchanger hose through the bilges and into that tank, then add a coil from the bulkhead heater into that tank and just move the existing hot water plumbing to that tank.

anyway I would be very interested in hearing what people think on this subject, right now the leak in the HW tank is precluding any pressure water usage.

 

[squidge]

Hi , it sounds like a lot of work to install a new tank. If you were happy with the system before the leak why not fix it, if the tank is copper it could be soldered?
Your AC heater is likely to be the same type as you home heating immersion heater , cheep and easy to replace. It might come in handy one day & for the few pounds they cost it would be worth it .

 

[pvb]

Dickinson coils...

In theory that's possible, Adam. You probably know that the heating coils used with Dickinson heaters are designed for what's called a "gravity" system - in which the less dense hot water rises up from the coil to the tank, and the more dense cold water flows down from the tank into the heating coil. This means that the hot water tank needs to be higher than the heating coil. The drawback of this is that it will take up valuable space in your V-berth, and its weight will be quite high up (which doesn't help stability). It could be possible to add an electric circulating pump, but I haven't heard of anyone doing that. You'd probably need to insulate the pipes from your engine to the hot water tank (and you might need to use larger diameter pipes to minimise back pressure and ensure good circulation).

If cost is an issue, why not try fixing the Seaward first? These usually have an aluminium tank, and it might be possible to have it welded.

 

[Trevethan]

I have Dickinsons Newport diesel sans coils and a 2 coil calorifer, where only the one coil is used. Spoke to Dickinsons about getting coil fitted and seems a pain -- the heater has to be drilled and welded, etc etc and they said the heat output was not great.

Now looking at the chimney -- gets very hot and thinking about putting a few coils of copper pipe around that, connected to a header tank and a circulatiion pump.

Need to do some experiments or calculations about how many turns given a certain flow rate, but I reckon if I form a second tube that fits over the chimney the coils can sit in there not touching the chimney so the air temperature should stay around 200 celsiius. I think I will fabricate that then test with temp probe.

Then hook that up to 12 volt circulating pump. Through calorfier and then a couple of rads or heater matrices.

 

[Simes]

Hi Stella,

We are in the pracess of designing our heating system. We are having similar thoughts to yours. However having looked at the amp draw and cost of purchase and reliability of 12v circulation pumps, I am considering putting in a small inverter, cost £20.00 and a Grundfos domestic circulating pump cost £20.00. amp draw is not really worth discussing and the cost reliability factor makes this worthwhile.
PM if you need more help.

Simes

 

[chops_uk]

if it's af any use in your design process, i noticed a similar system whilst looking for a picture of a water iron ..
http://www.marinestove.com/Accessories.htm