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Variables Affecting Performance |
by John F. Robbins, CEM
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| johnfrobbins@insightbb.com |
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| I. Record Current Annual Usage |
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| II. State Reasons for Change & Commit to GOALS |
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| .....Cut first-costs of new supplies or equipment? |
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| .....Cut current operation costs? |
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| .....Save money in the future? |
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| .....Invest now for savings in the future? |
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| .....Reduce need for expanding supplies? |
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| .....Manage resources better? |
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| .....Reduce uncertainties? |
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| .....Improve reliability and/or supply adequacies? |
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| .....Improve individual control of this responsibility? |
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| .....Reduce responsibility for pollution? |
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| .....Preservation or restoration? |
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| Ethics, Preferences & Politics |
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| III. Optimize Site & Landscape |
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| .....How well does building geometry access winter sun to the southeast, south and southwest? |
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| .....How is the building amply shaded in summer to the east and west? |
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| .....Are vents and least airtight assemblies in living spaces sheltered from winter winds? |
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| .....Do overall design and individual rooms have layouts for good natural ventilation? |
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| .....Are high-moisture room windows and exhaust vents directed downwind? |
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| .....Are there south-facing angled roofs or other surfaces for solar collectors now or in the future? |
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| .....Are perimeter grades, pavements and building surfaces sloped & positioned for natural drainage? |
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| .....Is rainwater collected, stored or used? |
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| .....Are toxics or wastes stored or processed optimally? |
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| .....How Is recycling of common disposables & compostables accomplished? |
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| .....Is a structure being built, remodeled and improved with minimal negative construction impacts? |
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| .....Is a natural site being restored to health, or a healthy ecosystem protected? |
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| .....Is efficient transportation available to most-traveled locations (work, stores, schools, etc.)? |
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| .....Is firewood from local deadwood or waste? |
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| .....Are there limitations on how this site or structure can be modified? |
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| .....Do laws, local associations or programs offer special opportunities or protections for this site or its structures? |
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| Opaque Assemblies (good targets): |
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| .....Ceilings (R-38 to 50) and airtight |
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| .....Attic-access doors (R-10+) and weather-stripped |
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| .....Wall & floor edge (R-19 to 25) and airtight |
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| .....Near-grade slab (R-10-20) and airtight |
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| .....Basement wall (R-10 to 20) and airtight at top |
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| .....Basement slabedge (R-5 to 10) |
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| .....Total unit R (2.5 or higher) |
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| .....Air leakage no higher than 0.10 cfm/sf @ 25mph |
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| .....Less solar-transmittant glass or shading for summer sun |
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| .....Full screens w/ dbl-hungs operable top-down |
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| .....Able to be latched tight |
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| .....Weather-stripping verified in good shape |
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| .....If glazed, at least double pane w/ low-E |
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| .....If opaque, either solid wood or foam-core |
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| .....Air leakage no higher than 0.10 cfm/sf @ 25mph |
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| .....Weather-stripping verified in good shape |
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| V. Is HVAC system Efficient & Adequate? |
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| Are the systems sized and installed correctly? |
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| .....heating sized to hold 65F when it's the lowest probable temperature outside? |
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| .....no more than 20 Btuh/sf should be adequate for well insulated airtight home? |
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| .....combustion supplied with adequate outside air? |
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| .....combustion chambers sealed from living space? |
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| .....airtight ductwork, both supply and return? |
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| .....ducts inside conditioned space or well insulated if outside it? |
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| .....AC system sized conservatively, never oversized? |
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| .....insulated water heater and hot water pipes? |
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| Are heaters most efficient and least polluting? |
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| .....efficient furnace combustion (90% min. AFUE)? |
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| .....heatpump with HSPF 8 minimum? |
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| .....pellet stoves & fireplaces with firebox airtight to living space? |
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| .....most efficient (70% or higher) wood fires with lowest emissions (< 3 grams/hr)? |
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| Are cooling systems most efficient and least environmental impact? |
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| .....SEER 12 or 13 minimum? |
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| .....outside units located in shady areas? |
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| .....reasonably short refrigerant lines? |
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| .....refrigerant line insulation in good shape? |
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| .....outdoor unit access to plenty of free airflow? |
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| .....non-CFC refrigerant? |
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| .....user-adjustable room fans to increase local air movement as desired to allow higher t-stat setting? |
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| Are heating & cooling systems operated efficiently and appropriately? |
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| .....turned down or off when not needed for long times? |
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| .....electric water heater timer? |
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| .....use of manual switches? |
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| VI. Take Advantage of Solar |
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| Is there a sunspace or greenhouse attached to the house with south-facing glass? |
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| .....Are there winter vent paths to and from the solar-heated areas of the house? |
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| .....Does it have summer ventilation separate from conditioned spaces? |
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| Do most windows face south (i.e., 8-12% of the conditioned floor area)? |
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| Do interior design and window treatments allow good daylighting? |
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| Are summer sunbeams adequately shaded from entering windows and doors? |
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| .....special building geometry? |
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| .....low solar heat-transmitting glazings to east and west? |
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| .....windows and shades managed optimally? |
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| .....avoidance of skylights, especially facing east, south or west? |
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| .....trees, shrubs and vines to shade summer sun around common structures and activities? |
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| .....Solar panels to heat water? |
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| .....Solar panels to heat air during winter? |
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| .....Blowers or pumps moving solar heated fluids to remote locations or to thermal storage? |
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| .....Solar panels to produce electricity or charge small batteries? |
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| .....Solar energy used for cooking or food drying? |
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| VII. Improve Indoor Air Quality |
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| Are low pollution materials used in construction and operation? |
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| .....no or few exposed particle boards? |
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| .....no or few carpeted floors? |
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| .....no and low VOC paints and finishes? |
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| .....no exposed loose insulation? |
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| .....measures to control and minimize dust & pet dander? |
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| Are paints and finishes applied when windows can be open for maximum ventilation? |
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| .....can living spaces be "baked" before occupancy to permit accelerated offgassing? |
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| Are envelope surfaces typically warmer than dewpoint to prevent condensation when air is humid? |
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| .....no indoor concrete directly on the ground? |
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| .....foam exterior wall sheaths over wood or metal framing? |
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| .....high-R windows without metal framing? |
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| Is there ample air exhaust, fresh air supplies, air filtering and dehumidification? |
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| .....air-to-air heat exchanger? |
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| .....efficient vacuum cleaning? |
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| Do occupants know to shut windows when outdoor dewpoint exceeds 65-70F? |
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| Are smoking & use of toxics done inside only with maximum ventilation? |
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| VIII. Use Most-Efficient Appliances, Equipment & Devices |
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| .....minimized hot water use, water conserving showerheads and faucets? |
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| .....well-insulated pipes and tank with least exterior surface areas? |
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| .....shortest runs from tank to points of most use? |
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| .....solar-thermal assist if electric resistance water heater? |
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| .....smallest acceptable size with least energy-using special features? |
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| .....top-bottom refrigerator door style, chest-type freezers? |
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| ....."most efficient" according to ACEEE "Consumer Guide to Home Energy Savings" (www.ACEEE.org) |
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| .....not exposed to direct sun or next to ovens? |
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| .....lids and doors close tightly? |
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| .....front-loading washers (horizontal axis) or other low-water-using type? |
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| .....cold or coolest wash & rinse? |
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| .....outdoor hang-drying when above 50F and not too humid, indoor hang-drying with ventilation? |
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| .....electric dryer only when no other choice? |
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| .....machine used to wash only full loads, cold rinse, air dry without heat? |
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| .....hand-wash small loads, cold rinse, air dry? |
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| .....fluorescent and LED electric lamps? |
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| .....dimmer general lighting, brighter task lights close to light-demanding tasks? |
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| .....outdoor lamps lowest-watt, aimed down, shielded from direct view and kept off during daylight? |
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| Computers & Small Electronics |
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| .....notebooks models instead of desktop models, flat screens instead of tube monitors? |
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| .....computers, TVs, entertainment centers, etc., positively "off" when not in active use for one or more hours? |
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| .....solar electric as possible for landscape lights, pumps, small battery chargers, calculators, wrist watches? |
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| Copyright 1996 - 2005 by: |
John F. Robbins, CEM CSDP
3519 Moffett Road
Morningview, KY 41063-8748
Phone: (859) 363-0376
E-mail: johnfrobbins@insightbb.com