Energy Assessment

Residential Energy Assessment

Below is an evaluation format I recommend for existing and new homes. For existing, use actual energy records, including energy acquired for free like firewood. For new homes being designed, calculations can estimate heating and cooling energy as well as estimate other energy usage based on current household usage history.

I. Record and Assess Annual Usage and Cost

Compile at least 1 calendar year of usage and cost for conventional energies:

Electricity

Natural Gas (Ngas)

Liquid Propane (LP)

Oil

Kerosene

Gasoline

Firewood

Pellets

Water

Other

How do your energy usage, cost and carbon emissions compare with local and regional norms per-sf of floor area and per-person?

If you live in Southwest Ohio, Northern Kentucky or Southeast Indiana, learn more about this region's average and best home energy performance by visiting my Home Energy Surveys page. The survey has ended, but results and summaries are still available and presented.

Use the following tables to estimate raw energy content and CO2 emissions for common conventional energies. For each type of energy usage, multiply the volume times the Btu content and CO2, then add it all up to get your totals. If you don't want to do this yourself, contact Robbins for assistance!

Energy Type : Btu Content

Electricity : 3414 per kWh

Gasoline : 125,260 per gallon

Heating Oil : 139,000 per gallon

Kerosene : 137,000 per gallon

Liquid Propane : 91,600 per gallon

Natural Gas : 102,900 per CCF

Wood : 18,750,000 per mini-cord (3/4 of a full cord)

Energy Type : CO2 Emissions

Electricity : 1.156 lbs per kWh in Ohio (2022 avg)

1.567 lbs per kWh in Indiana (2022 avg)

1.720 lbs per kWh in Kentucky (2022 avg)

Gasoline : 19.6 pounds per gallon

Fuel Oil : 22.61 pounds per gallon

Diesel : 22.44 pounds per gallon

Kerosene : 21.5 pounds per gallon

Propane : 12.43 pounds per gallon

Natural Gas : 12.04 pounds per CCF

Wood: n/a

If your usage or emissions are higher than local norms, consider ways to lower your usage and/or switch to cleaner energy.

If your usage and/or emissions are average, you may feel less urgency to lower your usage or seek cleaner energy. But even average users can usually find significant cuts.

If your usage or pollution is far less than average, congratulations!

Below is an organized way to evaluate possible energy improvements:

II. Optimize Your Site and Landscape

Can windows in living spaces admit more winter sun from the SE and south?

Can east, south and west windows be better screened or shaded in summer?

Are exhaust vents from and least airtight assemblies around conditioned spaces sheltered from winter winds?

Do living spaces have openable window layouts for good natural ventilation

Are high-moisture room windows and exhaust vents directed downwind?

Do you have south-facing roofs or another sunny place for solar panels?

Are exterior drains, grades and pavements around your foundation sloped down and away for best natural drainage?

Could rainwater be collected, stored and used onsite?

How is recycling and composting accomplished?

Can energy efficiency be improved for transportation to/from most-traveled locations (especially work, stores, schools)?

Is firewood from local deadwood or waste?

III. Maximize Insulation and Airtightness

Opaque Assemblies (good targets)

.....Ceilings (R-38 to 60) with ceiling airtight

.....Attic-access doors (R-38 to 60) and weather-stripped

.....Walls & floor edges (R-15 to 30) and airtight

.....Near-grade slab edges (R-10-20) and airtight

.....Basement walls (R-10 to 20) and airtight at top

.....Basement slab edges (R-5 to 10)

.....Below slabs (R-5 to 10)

Windows

.....Total unit R-3 or higher

.....Air leakage no higher than 0.10 cfm/sf @ 25mph

.....Less solar-transmittant glass if no shading from summer sun

.....No all-metal or aluminum frames

.....Full screens for double-hungs for top-down operation

.....Able to be ‘latched’ tight

.....Weather-stripping in good shape

Doors

.....If glazed, at least double pane w/ low-E

.....If opaque, either solid wood or foam-core

.....Air leakage no higher than 0.10 cfm/sf @ 25mph

.....Weather-stripping in good shape

.....Storm Door?

IV. Review the HVAC:

Are the systems sized and installed correctly?

.....is heating sized to hold 70F when it's lowest normal temperature outside?

.....how many heating system output BTUs/hr per conditioned floor area (sf)?

.....is all combustion supplied with adequate outside air?

.....are all combustion chambers sealed from living space?

.....is ductwork airtight?

.....are ducts inside conditioned space or well sealed and insulated if outside it?

.....is the AC system properly sized?

.....Are exposed hot water pipes insulated?

Is heating equipment efficient and least polluting?

.....efficient furnace combustion (90% min. AFUE)?

.....heatpump with HSPF 8.8 or higher? (aka HSPF2 7.5 or higher)

.....pellet stoves & fireplaces with firebox airtight to living space?

.....most efficient (70% min) wood fires with lowest emissions (< 3 grams/hr)?

Are cooling systems most efficient and least environmental impact?

.....SEER 14.5 to 15 or higher? (aka SEER2 13.8 to 14.3 or higher)

.....outside units not in full afternoon sun?

.....reasonably short refrigerant lines?

.....refrigerant line insulation in good shape?

.....outdoor unit access to plenty of free airflow?

.....non-CFC refrigerant?

.....in-room fans to increase air movement so t-stat setting can be higher?

Are heating & cooling systems operated efficiently and appropriately?

.....turned down or off when not needed for long times?

.....controlled by a programmable thermostat?

.....electric water heater timer?

.....more manual and automatic switches?

V. Take Advantage of Solar

Passive Solar:

Can a south-facing sunspace or greenhouse be attached to the house with south-facing glass? Or can more south-facing glass be added to the house (upto 8-12% over the conditioned floor area)? Could there be more openings in walls to and from passive solar-heated areas of the house and other spaces outside the passive solar area? Can south-facing glass be added without adding more cooling load? Do few windows face east, west, north or up? Do interior design and window treatments allow good daylighting but avoid glare? Are summer sunbeams adequately blocked or shaded from entering windows and doors, as by roof overhangs, sunscreens, lower SHGC glass?

Active Solar Heating:

.....Solar panels to heat water?

.....Solar panels to heat air during winter?

.....Solar cooking or food drying?

PV:

.....Solar electricity, grid-connected or offgrid, or just to charge small batteries

VI. Improve Indoor Air Quality

Prefer low pollution materials in construction and operation

.....no or few exposed particle boards?

.....no or few carpeted floors?

.....no and low VOC paints and finishes?

.....no exposed loose insulation?

.....measures to control and minimize dust & pet dander?

Apply paints and finishes when windows can be open for maximum ventilation

.....can living spaces be "baked" after new finishes to accelerate offgassing?

Make envelope interior surfaces warm enough to prevent condensation when indoor air is humid and outdoors is cold

.....no indoor concrete directly on the ground?

.....foam exterior wall sheaths over wood or metal framing?

.....high-R windows without metal framing?

Ensure ample exhaust ventilation, fresh air supplies, air filtration and dehumidification

.....exhaust fans?

.....air-to-air heat exchanger?

.....air filters?

.....efficient vacuum cleaning?

.....dehumidifiers?

Educate occupants to shut windows when outdoor dewpoint exceeds 65F.

Prohibit smoking inside the living space.

Avoid the use of toxics inside the conditioned space except when maximum ventilation is possible, especially open windows.

VII. Use Most-Efficient Appliances, Equipment & Devices

Hot water

.....install lower-flow showerheads and faucets

.....insulate exposed hot water pipes

.....aim for shortest runs from tank to points of most use

.....consider solar water heating especially for electric or LP water heaters

.....consider replacing an electric water heater with a heatpump water heater

Refrigerators & Freezers

.....smallest acceptable size with least energy-using special features

.....top-bottom refrigerator door style, chest-type freezers

....."most efficient" according to USDOE EnergyGuide

.....not exposed to direct sun or next to ovens

.....lids and doors close tightly

Laundry

.....front-loading washers (horizontal axis) or other low-water-using type

.....cold or coolest wash & rinse

.....outdoor hang-drying when above 50F and not too humid, or indoor hang-drying with adequate ventilation

.....electric dryer used only when no other way

Dishwashing

.....machine used to wash only full loads, cold rinse, air dry without heat

.....hand-wash small loads, cold rinse, air dry

Lights

.....only fluorescent and LED electric lamps

.....dimmer general lighting, brighter task lights close to light-demanding tasks

.....outdoor lamps lowest-watt, aimed down, shielded from direct view and kept off during daylight

Computers & Small Electronics

.....notebooks and tablets instead of stationary desktop models

.....flat screens instead of tube monitors

.....computers, TVs, entertainment centers, etc., switched "off" when not in active use for one or more hours

.....solar electric as possible for landscape lights, pumps, small battery chargers, calculators, wrist watches

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John F Robbins, CEM / CSDP
859.363.0376
john@johnfrobbins.com
www.johnfrobbins.com
3519 Moffett Rd
Morning View, KY USA
41063-8748

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