Archive for September, 2009

Domestic hot water from summer pellet burning

Monday, September 14th, 2009

In the interest of full disclosure the author is a Director of Maine Energy Systems.

I am often asked what I do about domestic hot water in the summer since my house is heated with a MESys pellet-fired boiler system. The answer is, “I burn some pellets” just as I have burned some oil to create hot water for decades.

The follow-on question is always, “how many pellets does it take?” In a single case sample, my own, I have found an answer. Three adults live in my house full-time, one a college-aged son who loves long showers. We have frequent overnight company, including the families of four of our older son and our daughter. We use a washing machine and dishwasher as anyone does, and we’ve made no particular water reduction modifications to our house so our hot water consumption is probably typical for Americans like us.

My system contains an indirect hot water tank, which I keep adjusted to 180F during the heating months. During the non-heating months, I’ve reduced that setting to 120F, so the boiler fires at low level or in “keep alive” mode most of the time.

This summer, since the end of the heating season, I have averaged 20 pounds of pellets/day for the heating of water using my MESys 4000/Janfire system. At $270/ton that places my average daily hot water costs at $2.70, or the cost of a bit more than a gallon of #2 heating oil.

Ideally, I would have solar panels on my barn roof to further reduce combustion of any sort for the production of domestic hot water, but that will have to wait a bit.

Dutch Dresser

OkoFEN Training

Friday, September 11th, 2009

In the interest of full disclosure, the author is a principal of Maine Energy Systems

MESys has become the first importer of the renown OkoFEN pellet boiler systems from Niederkappel, Austria. The boilers are marketed by MESys as their AutoPellet line and come in capacities ranging from 41,000 BTU/hour to 191,000 BTU/hour for stand-alone boilers and for capacities up to, and beyond, 764,000 BTU/hour for staged units.

AutoPellet boiler system

AutoPellet boiler system

Herbert Ortner, owner of OkoFEN and Maine Eco Pellet Heating LLC, was the first to produce a pellet boiler in Europe in 1997. Since that time, he has refined and improved his line of pellet boilers to be the most sophisticated in Europe with the deepest penetration in the European market.

During the last week in August, Herbert came to MESys headquarters in Bethel, Maine, to train regional contractors on the installation and maintenance of the OkoFEN boilers. The two day training sessions were filled to capacity. During the sessions contractors learned about the use of biomass as a residential heating fuel, began to understand global efforts to replace fossil fuels with renewable fuels, and had plenty of time with the boilers. The three demonstration boilers were disassembled and reassembled by all present and ample time was spent configuring and adjusting boilers using control box simulators created by OkoFEN for the task.

Training sessions will be held regularly to ensure there is an adequate workforce to install and service these systems.

I enjoyed the session and was stricken by the greatly increased user-friendliness of this system over those I’ve been familiar with, including my own MESys 4000. The burning technology in these systems is a bottom-fed design, which has pellets burning on a “blade,” or plate that feeds secondary air to support the combustion. Ash and other combustion by-products simply fall off the blade into the bottom of the boiler as new fuel emerges from the center of the blade to be burned. This feed system reduces burner sensitivity to unwanted combustion by-products like clinkers and slag.

Bottom fed burner design

Bottom fed burner design

Once in the bottom of the boiler, the ash is compressed into a removable container for easy user cleaning on infrequent bases determined by fuel consumption rates.

That these systems approach liquid fuel burning systems in their ease of use should help the US market find adoption easy for the economic and environmental benefits realized by conversion to regionally produced, renewable fuels.

Dutch Dresser