custom water coil setup for Channing III

Did you manifold your tubes or run the whole length in one series loop? Your best heat transfer will be manifolds on the inlet end and the outlet end (all of the tubes between each manifold), with inlet feed being on one corner and the outlet on the opposite diagonal corner.

Dallas yes you are right a manifold coil is much more efficient spacially. I toyed with making a box shaped coil and welding in passsages like in an auto tranny. However the design of the channing III with the clean glass would make such an install challenging at best. This summer I may tear the coil out and put in a small box coil on the side of the stove to get just a little more out of the coil. I am getting fairly respectable results but I didn't quite get the calculations right for the amount of thermal loss I recieve via my chimney on the boiler. I figured it on the draft loss when the boiler water was at 135* and failed to realize that the amount of heat going up the chimney exponentially increases as the boiler temp rises. once you hit that 150* mark the baro damper will even hang open about 15 to 20 percent. I am getting about 110* on the surface where it enters the chimney at that boiler temp which is resulting in a huge draft loss.

I had an epiphany or I was bored . Not sure but I just increased the surface area by 54% by adding the manifold portion of the coil pictured in the attachments. So far so good on the temps they are running about 180* in the boiler for the past few hours so it seems to be enough so far.

More pics

Here is the coil I had made. I'm waiting for a warm day to do the install.

where can i get a coil at a decent price?

PM me.

The addition has been quite successful today. It runs from 150* to 180* all the time and recovers nicely after showers laundry etc. The boiler has been off all day and I seem to have more than adequate hot water . So bottom line is if you are using a boiler to heat your hot water and are attempting to use a stove coil the coil needs to needs to be much larger than one used to heat a hot water tank. This is do to the draft loss up the chimney. Between the boiler and the coil there is approx 20-22 gallons and I have around 465 sqin ( 3.12 sq ft) of surface area on the coil which is close to 2X the size of the small Hiloil coil which claims to heat a small hot water heater up to 35 gallons.

Reading this good info has given me inspiration to do a similar project. I just ordered a 20' piece of 316l, 3/4", .065 wall stainless and I intend to make a "spring- like- coil" in my Alaskan. I am going to stray slightly and utilize the coil in a closed loop radiant heat system. I have 3 zones already plumbed with tubing that are resisting connection to the fuel oil boiler. I will keep you posted.