Heat Excahnger Sizing for a KA 6 Keystoker Boiler

Heat Excahnger Sizing for a Ka 6 Keystoker Boiler

PostBy: jeb2235 On: Wed Mar 02, 2011 8:37 am

Hello. I have been trying to decide on the Harman VF3000 boiler or a Keystoker boiler. I have forced hot air and want to put in a heat exchanger for heat and heat my hotwater. I started to make a few calls and Harman said that there unit would not work (not sure why). So I called a Keystoker dealer and then called Keystoker and talked to Jim he was great answered all my questions and assured me that a KA 6 would work for my application asked him about a heat exchanger size but he told me to contact a HVAC contractor in my area for the sizing so I guess I will. I wish I could figure that on my own there has got to be a chart on BTU's and square footage that I could figure out myself I have duct work sizes. But I will contact somebody if I have to. Any help would be great! Thanks Jason
Stove/Furnace Make: Woodchuck
Stove/Furnace Model: 2900

Re: KA 6 Keystoker Hopefully Order Soon!

PostBy: Rob R. On: Wed Mar 02, 2011 9:10 am

Hi Jason - You can do a heat loss calculation on your home and base the heat exchanger and boiler size off that number. There are a number of programs that you can use to do this, and even a few websites.

e.g. http://www.warmlyyours.com/hlc/room/room_general

How do well does your current system heat your home? Do you know how many BTU's per hour the furnace is rated at?

Rob R.
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy

Re: KA 6 Keystoker Hopefully Order Soon!

PostBy: watkinsdr On: Wed Mar 02, 2011 10:19 am

Please check your existing FHA furnace for its BTU capacity; assuming, your existing furnace heats your home without problems... I realize assuming is never good...

I'm in the process of doing the same upgrade. I love my Keystoker Koker; but, I want to generate unlimited DHW year 'round. My furnace has a data plate on the inside which states its capacity on either natural gas; or, propane---with propane being significantly less.

I'm assuming you're going the creative route and installing your own heat exchanger in your hot air plenum. I plan on buying a heat exchanger with slightly more capacity than my existing furnace. I believe my existing furnace has approx. 110K BTU net with propane; so, I'm going with an exchanger with approx. 130K BTU capacity.

Please keep us updated on your progress.
Stoker Coal Boiler: AHS S260 Boiler

Re: KA 6 Keystoker Hopefully Order Soon!

PostBy: jrn8265 On: Thu Mar 24, 2011 7:38 am

Watkinsdr, why not just use the hot water coil option in the Koker for your hot water instead of switching to the boiler solution? Love my Koker also, performing better that I ever imagined. Keeping the house at 74 and using about 5 tons a year. Your help a while back was priceless!
Stove/Furnace Make: Keystoker Koker
Stove/Furnace Model: Koker 160

Re: KA 6 Keystoker Hopefully Order Soon!

PostBy: watkinsdr On: Thu Mar 24, 2011 12:19 pm

Hey jrn8265:

I have a DHW coil in my Koker; and, it works great! But running the Koker 24/7/365 is unrealistic to generate DHW; so, I'm upgrading to an AHS S-130 Coal Gun boiler. I plan on running the Coal Gun year 'round heating the house (with a heat exchanger in my FHA plenum, using my existing furnace as an air handler), heating my DHW, and heating my in-ground pool.

The boiler arrives tomorrow, Friday 3/25. I plan on installing everything (except the new coal bin...) Saturday 4/2. I hope to have detailed digital pictures of the whole thing... My wife is the official photogragher!!

Best Regards
Stoker Coal Boiler: AHS S260 Boiler