There are various reasons why a client desires to have an energy audit. First and foremost is usually to reduce energy bills.Other reasons are to improve comfort, lower your carbon footprint and to reduce or eliminate ice dams and moisture problems. A professional well trained auditor can also address issues such as moisture and ventilation problems within the structure.With the appropriate diagnostic tools a professional auditor will look at your structure as a "System" to include not only the building shell but also heating / cooling and ventilation systems along with appliances and other electrical loads.One of the best results of an energy audit is that you will receive an unbiased, cost effective and long lasting plan based upon established building science principles to address the issues with your structure.
If you are mainly concerned about the cost to heat your residential home during the winter season a good place to start is to calculate your Home Heating Index (HHI).This is a rough guide as to where your home stands on energy consumption compared to an established scale.The total consumption of energy is a combination of the performance of your residence as a "system" and occupant behavior and habits which can influence youur heating index. Examples would be the temperature you keep you home in the winter, setting back the temperature at night or when away from home, sleeping with a window open, etc.If you are very energy conscious and already attempt to conserve heating costs as much as possible your HHI will calculate slightly lower.
To calculate your Home Heating Index you can open the auto HHI calculator to the far left and plug in your seasonal fuel use and square feet of the heated space of your home. The calculator will automatically calculate your HHI. You can also calculate the index yourself using the table to the left and the equation below. Use the table to convert your units of fuel into BTUs. If you use more than one fuel type to heat, calculate the associated BTUs consumed for each type then add to obtain total BTUs consumed. To obtain your HHI divide total BTUs consumed by the heated square feet of your home, then divide by the local Heating Degree Days. Heating Degree Days for New Hampshire's Lakes Region is 7383. Once you know your Home Heating Index you can use the HHI Scale below to see where your home stands. Note for electrical heat: If you use electricity to heat you must subtract your monthly "base load" from your total use to determine the amount of electricity consumed for heat. The base load is the electricity to operate lighting, appliances and any other device not used for heating. To do this pick the one or two months with lowest electrical use and where heat or air conditioning was not used. Average the usage for these months and add 10%. This is your "baseload" and the electrical use over this amount during the heating months is a good approximation of the energy required to heat your home.
Type of Heating Fuel
BTUs per Unit
Home Heating Oil
139,000 / Gallon
Propane
92,000/ Gallon
Natural Gas
100,000 / Therm
Kerosene
134,000 / Gallon
Tons of Wood Pellets
16,000,000 / Ton
Cords of Hardwood
20,000,000 / Cord
Cords of Softwood
15,000,000 / Cord
Kilowatts of Electricity
3412 / Kilowatt
HHI = Total BTUs Consumed per Heating Season ÷ Sq-Ft of Heated Space ÷ Heating Degree Days for Geographic Area (7383)
Home Heating Index Scale
HHI
Airtight, super insulated, 90+ heating efficiency, heat recovery ventilator, small window area and high window R-value.
0 - 2
Well insulated, low air leakage, efficient heating systems, Homes labeled Super Good Cents in U.S. or R-2000 in Canada
2 - 4
Better than average homes with good insulation, relatively low air leakage, and better than average heating efficiency.
4 - 8
Average homes with average insulation, average air leakage, and average heating efficiency
8 - 13
Worse than average homes with little insulation, high air leakage, and worse than average heating efficiency.
13 - 18
Older homes with poor insulation, abundant air leakage, and very inefficient heating systems
18 – 22+
Obviously the higher your HHI the more potential savings exists. Cost effective saving opportunities usually can be found if your HHI is 6 or higher. However, this only addresses energy consumption where moisture and ventilation problems may also require the attention of a professional auditor regardless of the HHI calculation.
