Kedel Pellet Boiler

I have a PB105 at home and a Kedel at the office. I like the Kedel better. I use the PB105 for hot water all year but the Kedel is better at it. It has options for scaling down output just for hot water use, while keeping it's efficiency high. The new Kedel's have ash compaction, automatic blowdown cleaning of the heat exchanger and the burn pot. I don't have any direct experience with the OkoFEN other than just seeing them.

The Boiler Room is probably a better place to discuss this.
It's a boiler, not a pellet stove

I have a PB105 and considered how to produce DHW efficiently. I don't have the coil in the boiler, but I do have a 100 gallon DHW tank that I use as a buffer. Both the oil boiler and the pellet boiler are connected to the tank and are separated by weighted check valves. The pellet boiler has priority and if it's running will heat the tank to 185 degrees. Then I use a thermostatic valve to temper the water to about 125 degrees. In the summer I set the low temp on the PB to 140 and the boiler will auto start and stop. That hot water will last for about three days without a call for heat. Then on a cool June morning it will provide heat when the thermostat calls. At half the price for pellets over fuel oil, my DHW is the same.

LTDAN said:

Probably like a lot of folks, we are seriously considering a pellet boiler to replace our wholly inefficient oil furnance in our 2200 sf home. With a technology that is relatively new to the marketplace, I am anxious about the switch. Clearly the goal is the best cost/efficiency ratio. What, of course, we don't want is to purchase and install a system at great expense only to have serious issues with the heating of the house.

I'm gathering a couple quotes, for the Kedel and a OkoFEN. I've learned from this forum that the OkoFEN/Froling(s) will generally have a much higher price tag, and I guess what I'm most curious about is the added cost have enough real value to justify it?

Also, are people running their pellet boilers all year to heat DHW? It would seem to me more practical to heat hot water (at least in the warmer months) seperately. Is that accurate? What ways are compatable with a pellet boiler?

What kind of square footage does each of these btu outputs generally cover?

Thanks!

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I don't know much about the Kedel pellet boiler.
I do know a lot about Windhager, Fröling and Oköfen pellet boilers.
All quality heating appliances, made in Austria, the leader in automatic pellet boilers.
Disclosure: we sell Windhager BioWIN

You have plenty of time to figure out which one to put in.
GO AND SEE, FEEL, TOUCH AND SMELL EACH ONE OF THE ABOVE!
Go see 2 or 3 installed boilers and talk to the home owners

For what concerns sizing:
DO NOT GO BY SQUARE FOOTAGE OF YOUR HOME, and DO NOT OVERSIZE.
A pellet boiler needs to run, not start and stop, start and stop, .... .
Check your oil usage per year for the last 3 years.
With the oil usage and Heating Degree Days for your location we can determine the maximum size of the pellet boiler.
See example of heat load calculation.

Quite happy with my Kedel thus far. Take Marc's advise and do not oversize! Do not go by the size of your old boiler either. Do a calculation based on oil usage, or if you have baseboard in the house you can measure it up and multiply roughly 600btu/ft to find how much heat rejection you have available. I can't remember the rule of thumb for DHW... another 20,000-30,000btu/hr? Anyway, I did a heat balance calc on my 2200 ft2 house and came up with 60,000btu/hr at -10*F (thin 2x4 walls) and assumed 1 air exchange/hr. I bought the K102 (102,000btu/hr) Kedel since I was tying in my 24x40 workshop as well.

The workshop was not hooked up this winter so I only heated my house alone. I had 2-3 design temperature days and my Kedel averaged 35-40% firing rate for the 24 hour periods.... so roughly 35-40,000btu/hr. This was keeping the downstairs at 50-55 and the upstairs at 71*F. I really wish I bought the K68 like I originally planned so my boiler could modulate more and not be at idle so much. Perhaps next winter will be different when I finish plumbing in the shop.


As for DHW, I am still using the Kedel and I can set up a timer on it for the heel season so it will only start twice a day. So when my wife does dishes or uses a little hot water the boiler does not short cycle. I have it set to make water in the morning and evening for showers. The timers are built right into the controller and are handy for the heel season.

Don't forget Maine has a $5000 incentive for pellet boilers from efficiency Maine. I would encourage you to take a look at a geothermal system with the 30% tax credit and the $5000 rebate from efficiency Maine it may come in about the same cost.

LTDAN said:

Thanks for the advise! When you say 600btu per foot, do you mean linear foot of existing baseboard?

I have a 2300 sf house. Late 1800s construction, but insulated again in the 1990s.

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What was your oil consumption the last year?