heating with wood · review of objectives • understand performance advantages with advanced...
TRANSCRIPT
Heating with Wood
Part 2
AdvancedCombustion
WoodburningFIREPLACE
Advanced Combustion
WoodburningFireplace
Fireplace & Woodstove Emissions
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101520253035404550
Conventional Fireplace
Dirty Woodstove
Advanced CombustionFireplace
Air Requirements of Furnaces & Fireplaces
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0.6
0.8
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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