Heating with Wood

Part 2

AdvancedCombustion

WoodburningFIREPLACE

Advanced Combustion

WoodburningFireplace

Fireplace & Woodstove Emissions

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Conventional Fireplace

Dirty Woodstove

Advanced CombustionFireplace

Air Requirements of Furnaces & Fireplaces

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ConventionalFireplaceConv Gas/OilFurnaceHi-Effic Gas/OilFurnaceAdv CombustWoodstove

Efficiencies of Advanced Combustion Fireplace & Stoves vs

Conventional Fireplace

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Adv Stove AdvFireplace

ConventionalFireplace

Room AirOutside Air

Characteristics of Efficient, Safe,

Advanced Wood Fireplace

• Tested to EPA 1990• Preheated prim & sec air• Ceramic glass door• Insulated comb. chamber

& baffle• Air wash for door• Good circulating fan• Insulated outer casing• Extremely attractive fire

Advanced Combustion Fireplace Insert

Advanced Combustion Insert for Existing Fireplace

MasonryHeaters

Masonry (Fireplace) Heater• Concept common in Europe• Large mass with convoluted flue path to extract

heat• Short periods of high burn to generate heat, which

is stored in masonry for slow later release• May or may not be clean burning and efficient,

depending on system - simple combustion air flow changes nearly doubled efficiency

Masonry Heater

Characteristics ofGood Masonry Heater

• Should follow MHA guidelines for design and installation

• Installed inside house envelope, usually in centre with most/all sides exposed

• Dampered outside air supply• Operates at high burn for relatively short

period, potentially with good excess air, storing heat for slow release into house

However, with evening burn, uncontrolled release of heat into house overnight may counter potential savings of thermostat cutback

What combustion systems offer the greatest potential for renewable energyin new and existing homes ?

The Advanced Combustion woodburning appliances of today !

If harvesting is done properly,forests can be self-sustaining.

Wood heating can be considered a truly renewable resource and greenhouse gas-neutral !

For an advanced combustionwoodstove or fireplace

to be trulyefficient & effective,

it must beproperly sized & located !

LocationLocation

Location

If not properly sized & located,efficient woodstoves & fireplaces can

• Be ineffective in supplying heat to house

• Result in significant local overheating• Cause sig. client dissatisfaction

Advanced Combustion woodstoves & fireplaces are primarily a localized

space heaters, releasing significant amounts of heat by radiation

To be effective, and to prevent overheating,

the fireplaceshould be properly size, and

locatedin a major living area

which “sees”other parts of the house

Good Fireplace Layout

Where to Install:

• On inside wall, or• On outside wall, but inside house

envelope, or• If unavoidable, on outside wall, but

having significant insulation on fireplace outer casing

Fireplace/Furnace:

Integrated Gas Fireplacewith

Zoned Air Ducting

On-Going Advances inFireplace Technology

• Inc. input modulation with good EA• Minimal-to-zero pilot energy• Minimized air requirement• Powered exhaust, no dilution (sealed or not)• Ducted systems with modulation/zoning

Potential for Next Generation

Fireplace

As houses are getting lower and lower heat demands, people will become increasingly unwilling to pay $$$ for a high-efficiency furnace.

Yet they will demand to have a fireplace.

As it’s going to be there in any case, why not have the next generation fireplace satisfy all the house energy demands, efficiently ?

Condensing Fireplace-Based Integrated Space-Water

Ventilating System

Next Generation IntegratedCondensing Fireplace

• High Efficiency > 90%• Local space heating - Flame radiant• Central heating - fan coil or hydronic

baseboard/radiant floor• Tap water heating• Second burner behind for summer operation• Ventilation with heat recovery• Pleasure of a flame

Summary• Advanced Combustion Woodstoves and Fireplaces ( EPA

1990) have the potential to be clean-burning and efficient• The above should be properly sized and located• Pellet stoves which have been tested for emissions (<3gph)

and efficiency (>78%), offer more automation• Masonry heaters built according to MHA Guidelines can be

suitable for some applications• Wood-burning central furnaces are generally problematic at

this time• Some advanced-combustion wood boilers, particularly

coupled with water storage, have good potential, but require significant user understanding and monitoring

• All wood burning appliances require good venting systems, properly sized and ideally located inside the house envelope

• Outdoor wood boilers should be avoided until properly certified and tested for emissions and efficiency by recognized agencies

Review of Objectives• Understand performance advantages with advanced

woodstoves and pellet stoves• Appreciate the technology limitations and

installation/operating requirements of central wood-fired boilers and furnaces

• Understand why you should be wary of outdoor boilers• Appreciate air supply, venting, IAQ problems, drawbacks

with conventional fireplaces• Recognize why advanced combustion fireplaces and

inserts can allow the fireplace to return to Vermont homes• See how wood can be an efficient, low emissions (including

Greenhouse gases) heat source, while providing comfort and even pleasure

The potential is there.The pleasure is there.The comfort is there.

The efficiency is there.The environmental benefits are there

Take it !!!

Fireplace & Other HeatingPublicationson the “net”

http://energy-publications.nrcan.gc.ca/index_e.cfm

“Heating with Wood”“All about Wood Fireplaces”“All about Gas Fireplaces”

If you wish more information, or wish to discuss specific problems,

please don’t hesitate to contact Skip Hayden, at

(613) 996 3186or e-mail at

skip.hayden@nrcan.gc.ca