Your complete guide to understanding home energy, improving efficiency, and reducing your environmental impact
My house is new. Do I need an energy audit? Is it only relevant to old homes?
Even new homes can have comfort issues and energy inefficiencies; however, they do provide a unique challenge since most of the ventilation systems are often brand new. Upgrading a newer home is just as important as an older one.
My house is old. Do I need a home energy audit and energy efficient upgrades?
Yes! With older homes, we find many areas and elements that can be upgraded so your home, appliances, and ventilation systems work more efficiently – resulting in big energy savings and greater comfort.
How long does the evaluation take?
The typical evaluation takes approximately 2 to 3 hours – depending on the size of your home and the systems within it.
How much will home energy efficient upgrades help me save on utility bills?
Our clients see 15%-40% reductions in their utility bills after our upgrades.
How much will the energy efficient upgrades cost?
The cost of upgrades depends on various factors such as the size of a home and issues discovered. We provide a prioritized list of recommendations, so you can choose to do some or all of them.
How long will the upgrades take?
We average one or two days for upgrade projects, although that can vary depending on the scope of work and size of the home. We will inform you of the estimated time to complete your job once we price it and schedule it with you.
What is the typical payback period for upgrades?
We pride ourselves on implementing upgrades that are projected to have less than a 5 year payback period. So, if you spend x on upgrades, we anticipate you will save at least x (sometimes more) within 5 years on your utility bills.
What do the evaluators find to be the most common issues in homes?
We often find gaps and leaks in ventilation duct work that cause conditioned air to leak into attics, garages, basements, and other unconditioned spaces. We also encounter areas that are not properly air sealed or insulated which make your heating and cooling systems work harder to maintain comfortable temperatures while allowing heated or cooled air to escape from your home.
Can I afford an evaluation and/or upgrades?
Can you really afford not to have an evaluation and upgrades? With a projected payback period of less than five years on the upgrades we do, it makes sense to spend a little bit of money up front to save much more money and energy over the years. You will either end up spending more money on higher utility bills or spending money on upgrades for future savings.
Is there financing available?
Yes! We offer several low interest loans through financial institution relationships. Alagasco customers can finance their upgrades with a low interest loan and make payments conveniently on their Alagasco bill. Check out Spire Energy’s Rebates and Offers page for more details. Financing can seem daunting, but we can help you with it to make it easy.
Which Energy Star appliances will have the most bang for my buck?
That depends on your specific usage, but Energy Star offers a wide range of products that help save energy and money in all areas of your home – heating and cooling systems, water heaters, clothes washers, refrigerators and freezers, dishwashers, computers, televisions, and more. Check out the Energy Star website for more product information.
What appliances should I replace first?
If you use your dishwasher several times per week, we would recommend upgrading to a newer model that will use less than half the energy (via heating the water).
What is a “smart” power strip?
A smart power strip is one that stops electricity from flowing when the appliances plugged into it are not being used. This prevents the “vampire” electronic effect where your appliances are still using electricity even when they are turned off.
Which light bulbs are better? Compact fluorescent lights (CFLs) or Light Emitting Diodes (LEDs)?
LEDs are more environmentally friendly, close to incandescent light, and last for many years. LEDs also do not contain mercury like CFLs. CFLs are also energy efficient, last a long time, and give off very little heat. If possible, spring for the LEDs. They cost more up front, but they will save you money and energy for years to come. And you should consider taking them with you if you move.
A
AEC
Alabama Environmental Council; the oldest environmental non-profit organization in the state of Alabama whose mission is to organize and empower Alabamians to preserve the environment in a manner that is mindful of current and future generations.
AFUE
Laboratory tested measurement of your furnace’s heating efficiency that accounts for fuel-burning losses, chimney losses, cycling losses, and heat loss through a central heater’s cabinet (does not account for distribution losses through ducts or pipes). The higher the AFUE percentage, the more efficient the furnace. The minimum percentage established by the DOE for furnaces is 78%.
Air Barrier
Materials assembled and joined together to prevent air leakage between the conditioned space and unconditioned space — or the inside and out.
Air Handler/Coil Blower
Indoor part of an air conditioner or heat pump that moves cooled or heated air throughout the ductwork of your home. An air handler is usually a furnace or a blower coil.
Air Infiltration
Air leakage in a home that is the result of air pressure differences between the inside and outside of the home.
Air-Conditioning and Refrigeration Institute (ARI)
ARI is an industry trade association that develops standards for measuring and certifying product performance.
Airflow
Distribution or movement of air.
B
Backdrafting
Continuous spillage or reversal of a chimney’s normal flow.
Bioaerosols
Microscopic living organisms suspended in the air that grow and multiply in warm, humid places.
Blower Door Test
Test that depressurizes a house which exaggerates the home’s air leaks, making the leaks easier to measure and locate; a blower door test can also tell if an airflow problem exists in a home, and if so, where it is coming from.
Blown In Insulation
See “loose-fill insulation”.
BPI
(Building Performance Institute) national standards development organization for residential energy efficiency and weatherization retrofit work; an independent, not-for-profit organization, that brings together leading building science experts from across North America to develop standards using a consensus-based methodology.
Btu
(British thermal unit) unit of heat energy. One Btu is the amount of heat required to raise one pound of water by one degree Fahrenheit. The higher the Btu rating, the greater the heating capacity of the system.
Btuh
British thermal units per hour.
Building Analyst
Person trained in the systems of buildings (usually accredited or certified by a third party such as BPI (Building Performance Institute)).
Building Envelope
(Also known as the building “shell”) the part of a house that you can draw a line around: the roof, the walls, and the floor.
Burners
Parts that ignite and supply heat to the furnace.
C
CAE
(Combined Annual Efficiency) measure of the amount of heat produced for every dollar of fuel consumed for both home and water heating.
Carbon Monoxide
Odorless, colorless, tasteless, poisonous and flammable gas that is produced when carbon burns with insufficient air.
CAZ
Combustion appliance zone: area surrounding an appliance that uses gas.
Cellulose Insulation
Insulation made from recycled paper products, primarily newsprint, and has a very high recycled material content, generally 82% to 85%. The paper is first reduced to small pieces and then fiberized, creating a product that packs tightly into building cavities, inhibits airflow, and provides an R-value of 3.6 to 3.8 per inch.
Central Air Conditioning System
System in which air is treated at a central location and distributed to and from rooms by one or more fans and a series of ducts. (also known as “central heating/cooling”).
CFM
(Cubic feet per minute) a measurement of air movement in a home – how many cubic feet of air pass by a stationary point in one minute. The higher the number, the more air is being moved through the ductwork by the system.
Chase (or Chaseway)
Open area (commonly found around chimneys) inside a home.
Chimney Draft
Force that dilutes gases and brings them up and out of a home.
Circulator
Blower or pump for moving heating fluid – air, water, or steam.
Closed Cell Spray Foam
(Also known as medium-density SPF) spray polyurethane foam expanded with non-reactive blowing agents to yield a rigid cellular structure. It is characterized by a predominance of closed-cells, a density between 1.5 and 2.5 lb. per cubic foot, and typically has an R-value of R-5 to R-6 per inch.
Compressor
Part of the outdoor air conditioner or heat pump that compresses and pumps refrigerant to meet household cooling requirements.
Condenser Coil
Outdoor portion of an air conditioner or heat pump that either releases or collects heat, depending on the time of the year.
Conduction
Transfer of heat through direct contact. (When you put your hand on a hot frying pan, you experience conduction.)
Convection
Movement of a gas or liquid in response to heat. Hot air rises, cool air sinks. (If you place a piece of tissue paper over a hot frying pan, it will float up with the hot air currents.)
Crawlspace
Space between the ground and the floor of a house in which a person cannot walk upright. An enclosed crawl space is one not accessible from the outside of the house (except by a door or window) because the walls of the space protect it from the weather.
D
Damper
Movable plate, located in the ductwork, that regulates airflow. Dampers are used to direct air to the areas that need it most. Typically used in a zoning application.
Delivered Heating Efficiency
Percentage of a fuel’s potential energy that actually heats a living space; difficult to measure because it includes distribution losses; can be as low as 35%!
Dilution Port
Part of furnace where dilution air enters to cool flue gases and reduce concentrations of hydrocarbons.
DOE
(Department of Energy) federal agency responsible for setting industry efficiency standards and monitoring the consumption of energy sources.
Draft
Force that brings combustion air into the combustion chamber and propels combustion gases out through a chimney or vent.
Dry-Charged Unit
Air-conditioner or heat pump that is shipped dry and charged with refrigerant at the place of installation. Dry-charged units are appropriate for homeowners who need a replacement unit compatible with R-22 refrigerant.
DSIRE
(Database of State Incentives for Renewables & Efficiency) comprehensive source of information on state, local, utility, and federal incentives and policies that promote renewable energy and energy efficiency.
Dual Fuel
Comfort system that pairs an electric heat pump with a gas furnace, providing an energy-efficient alternative to the conventional furnace/air conditioner combination.
Duct Work
System of trunk lines and spider lines through which air is channeled from the furnace or the blower coil throughout your home.
Ductboard
Pressed fiberglass often used in HVAC duct systems.
E
EIA
(U.S. Energy Information Administration) organization that collects, analyzes, and disseminates independent and impartial energy information to promote sound policymaking, efficient markets, and public understanding of energy and its interaction with the economy and the environment.
Electronic Air Cleaner
Electronic device that filters out large particles and bioaerosols in indoor air.
Energy Audit
See “energy evaluation”.
Energy Evaluation
Comprehensive review of a home’s energy using systems to evaluate areas of inefficiency and make prioritized recommendations for energy efficient upgrades.
ENERGY STAR®
EPA (Environmental Protection Agency) designation attached to appliances (including HVAC products) that meet or exceed EPA guidelines for high-efficiency performance above the standard government minimums.
EPA
(Environmental Protection Agency) develops and enforces federal environmental regulations. The EPA oversees the nationwide ENERGY STAR® program.
ERV
(Energy recovery ventilator) system of fans that pull fresh air into a home while simultaneously exhausting stale air from the home and also allows some of the moisture in the more humid air stream (usually the stale air in winter and the fresh air in summer) to be transferred to the air stream which is drier.
Evaporator Coil
Part of the air conditioner or heat pump that is located inside the air handler or attached to the furnace. Its primary function is to absorb the heat from the air in your house.
F
Fenestration
Openings in a building surface (usually a window or door).
Fiber Glass Insulation
Made from molten glass that is spun or blown into fibers and is commonly used in two different types of insulation: blanket (batts and rolls) and loose-fill and is also available as rigid boards to keep heated (or cooled) air within a certain area.
Flex Duct
Reinforced plastic tube with insulation and a protective jacket used to carry air throughout a duct system.
Flue
Tube or pipe that carries all combustion gas by-products to the chimney and out of the home.
Foam Board
Polystyrene, polyisocyanurate, or polyurethane material used to insulate walls, floors, ceilings, and some roofs.
Forced Air
Method of heating which distributes air heated in a furnace that is powered by electricity, propane, natural gas, or oil. System requires filtration of air and duct work to transfer air; this system can also be used to cool spaces.
G
Geo-Thermal Heating
Heat from the earth (ground loop) is channelled through a heat pump hydronic; expensive but very eco-friendly and energy efficient; may require backup systems.
Green Building
(aka sustainable building) practice of creating and using healthier and more resource-efficient models of construction, renovation, operation, maintenance and demolition.
Grid-Tied
Most common and least expensive of all residential solar (or other alternative energy source) systems. It allows you to use your own solar-generated electricity to save energy and reduce costs. At times when the solar system isn’t producing electricity, such as at night, electricity is provided by the utility company’s grid, or network of power stations.
H
Heat Exchanger
Main component of a combustion heating system that transfers heat by conduction to the surrounding air that is pumped throughout the home.
Heat Pump
HVAC unit that heats or cools by moving heat. During the winter, a heat pump draws heat from outdoor air and circulates it through your home’s air ducts. In the summer, it reverses the process and removes heat from your house and releases it outdoors.
Heater
Furnace, boiler, or space heater.
Heating Load
Quantity of heat per unit of time required to maintain a specific temperature.
Heating System
Heater and its distribution system.
HERS Index
Home Energy Rating System (HERS) Index is the industry standard by which a home’s energy efficiency is measured. It’s also the nationally recognized system for inspecting and calculating a home’s energy performance.
High Efficiency Furnace
High-efficiency furnaces can achieve from 89% to 98% fuel efficiency. This style of furnace includes a sealed combustion area, combustion draft inducer and a secondary heat exchanger.
High-Performance Home/Building
Home or building that integrates and optimizes all major high-performance building attributes, including energy efficiency, durability, life-cycle performance, and occupant productivity.
HRV
(Heat recovery ventilator) system of fans that pull fresh air into a home while simultaneously exhausting stale air from the home.
HSPF
(Heating Seasonal Performance Factor) heating efficiency rating for heat pumps. The higher the rating, the more efficient the heat pump.
Humidifier
Indoor air quality device that introduces moisture to heated air as it passes from the furnace into the ductwork for distribution throughout the home.
Humidistat
Automatic device used to maintain humidity at a fixed or adjustable set point.
HVAC
(Heating, ventilation, and air conditioning) system that heats, cools, ventilates, circulates, and removes moisture/humidity.
Hydro-Electric Power
Harnessing the power of moving water and turning it into electricity.
I
IECC
International Energy Conservation Code: model building code promulgated by the International Code Council designed to set minimum standards of energy conservation for buildings.
Indoor Coil
See “evaporator coil”.
Infiltration
See “air infiltration”.
ISO
Family of international standards for quality management and assurance.
K
Knee Wall
Walls of varying length (usually found in attic spaces) used to provide additional support to roof rafters with a wide span or to finish off an attic. An example of these are the short walls usually found in the top floor/attic of a Cape Cod style home.
L
Loose-Fill Insulation
(Also known as “blown in”) type of insulation in granular, nodular, fibrous, powdery or similar form designed to be installed by pouring, blowing or hand placement.
M
Mastic Paste
Protective coating, usually a petroleum or other base product, applied by spray or trowel to weatherproof or otherwise prevent deterioration and air leakage.
MERV Rating
(Minimum Efficiency Reporting Value) rating of a filter describes the size of the holes in the filter that allow air to pass through. The higher the MERV rating, the smaller the holes in the filter, the higher the efficiency.
Micron
Unit of measure equal to one millionth of a meter, or one thousandth of a millimeter.
N
Nest® Learning Thermostat
“The only thermostat that learns from you.” Device installed in a home that learns the temperatures you like and programs itself in about a week and automatically turns itself down when no one is present to save energy. Also controllable by phone, tablet, computer, etc. via wi-fi connection.
Net Metering
Process through which your utility meter keeps track of the “net” difference between the electricity you use from your utility provider and the electricity you produce with your own system (solar power, hydro-electric power, geothermal power, etc.).
Net Zero Building
Building that produces as much energy as it uses.
NFPA
(National Fire Prevention Association) world’s leading advocate of fire prevention and an authoritative source on public safety.
O
Odors/Chemicals
Air contaminants in the form of gases.
Off-Grid or Off-the-Grid
Off-grid electricity-generating system operates independently from the utility grid, providing all of the electricity needed in the home. Stand-alone systems are much more expensive than grid-tied systems. However, for homes located in remote areas without utility service, or where installing power lines would be extremely costly, a stand-alone system is a good option.
Open Cell Spray Foam
(Also known as low-density SPF) spray polyurethane foam expanded with reactive blowing agents to yield a semi-rigid cellular structure and a density between 8 and 22 kg.m3 (0.4 and 1.4 lb/ft3) with an R-value of approximately 3.7 per inch.
Outdoor Coil
See “condenser coil”.
Output
Term used in heating to describe the heat-production rate (usually measured in Kw or btus).
P
Particles
Any substances measuring less than 100 microns in diameter. The EPA has found that small particles (less than 2.5 microns) are responsible for the health effects of greatest concern.
Piggy Back System
See “dual fuel”.
Plenum
Section of an HVAC supply system where branch ducts start.
Plumbing Penetration
Hole or chase to provide access for pipes or other plumbing materials.
Programmable Thermostat
Thermostat with the ability to record different temperature/time settings for your heating and/or cooling equipment.
R
R Value
Measure of insulation’s ability to resist heat traveling through it. The higher the R-Value the better the thermal performance of the insulation.
R-22 Refrigerant
Old standard for residential air conditioners, R-22 refrigerant is now being phased out by the U.S. EPA.
R-410A Refrigerant
Chlorine-free refrigerant that meets the EPA’s newest, most stringent environmental guidelines.
Radiant Barrier
Material installed (usually in attics) to reduce summer heat gain and reduce cooling costs. The barriers consist of a highly reflective material that reflects radiant heat rather than absorbing it. They don’t, however, reduce heat conduction like thermal insulation materials.
Radiant Heat
Method of heating which distributes heat through hot water in embedded tubes or electric heating cables or a stove – either of which are powered by electricity (wood or coal), propane, natural gas, or oil. System cannot be used to cool, so separate duct work is required for a cooling system.
Radiation
Transfer of heat from one body to another through space. (If you hold your hand above a heated frying pan, you feel the heat from radiation.)
Refrigerant
Chemical that produces a cooling effect while expanding or vaporizing. Most residential air conditioning units contain the standard R-22 refrigerant, or Freon.
Refrigerant Lines
Set of two copper lines that connect the outdoor air conditioner or heat pump to the indoor evaporator coil.
Register Cover
Grate through which air enters a conditioned space (often slotted with an adjustable damper).
Renewable Energy
Energy obtained from sources that are essentially inexhaustible (unlike, for example, the fossil fuels, of which there is a finite supply). Renewable sources of energy include wood, waste, geothermal, wind, photovoltaic, and solar thermal energy.
RESNET
(Residential Energy Services Network) founded in 1995 as an independent, non-profit organization to help homeowners reduce the cost of their utility bills by making their homes more energy efficient.
Return Air
Path the air takes to get to an air-handling unit or furnace so it can be cooled or heated. It is the return path. The return side should be balanced with the supply side to ensure proper air flow and comfort.
Rock or Slag Wool Insulation
Man-made material made primarily from iron ore blast furnace slag and is naturally non-combustible (like fiber glass) and remains so for the life of the product without the addition of harsh or potentially dangerous chemical fire retardants.
Room Heater
See “space heater”.
S
Sealed Combustion Heater
Furnace or boiler that brings outside air directly into the burner and exhaust flue gases (combustion products) directly to the outside, without the need for a draft hood or damper.
Seasonal Efficiency
See “Delivered Heating Efficiency”.
SEER
(Seasonal Energy Efficiency Ratio) an energy efficiency rating for air conditioners. The higher the SEER, the better the energy performance, the more you save. The DOE’s established minimum SEER rating for cooling is 13.00.
Single Package
Heating and cooling system contained in one outdoor unit – sometimes referred to as a “gas pack” if it runs on gas.
Solar Power
Radiant energy of the sun, which can be converted into other forms of energy, such as heat or electricity.
Space Heater
Self-contained heating device that is usually portable and either electric or gas powered.
Spider Line
Branch tubes (or duct lines) that begin attached to a trunk line and end attached to registers in each individual room.
Spillage
Temporary flow of gas that exits a combustion furnace upon starting a combustion furnace before the chimney heats up and draws that gas up and out through the flue; it must stop within 60 seconds to avoid an unsafe scenario.
Split System
Type of HVAC system in which some components are located inside the structure of the house and some are located outside. Split systems should be matched for optimal efficiency.
Spray Foam Insulation
Spray polyurethane foam used to insulate homes and buildings.
Stack Effect
Result of large volumes of air moving through a building envelope. In the winter, the warm air in a heated building is lighter (less dense) than the cold air outside the building; that warm bubble of air wants to rise up and out.
Steam Radiant
Method of heating which uses a boiler powered by electricity (wood or coal), propane, natural gas, or oil to create hot water that is distributed through fin tubes or a radiator; systems are quiet and energy efficient.
Supply
Part of an HVAC system that takes (supplies) the conditioned air from the air-handling unit or furnace to your home. The supply side should be balanced with the return side to ensure proper air flow and comfort.
Sustainability
Meeting the needs of current generations without compromising the ability of future generations to meet their own needs.
T
Thermidistat
Device that monitors temperature and humidity and adjusts heating or cooling system to maintain desired levels.
Thermostat
Usually found on an inside wall, this device operates as a control to regulate your heating and cooling equipment, allowing you to adjust your home comfort at the touch of a switch.
Ton
Unit of measurement for determining cooling capacity. One ton equals 12,000 Btuh.
Trunk Line
Main tube (duct) that attaches to the air handler and has various spider lines branching off of it.
U
U Value
Measures the rate of heat transfer. U-factor values generally range from 0.25 to 1.25 and are measured in Btu/h·ft²·°F. The lower the U-factor, the better the insulating properties.
Unvented Gas Room Heater
Self-contained heating device that does not vent to the outside.
V
Variable Speed Motor
Motor that automatically adjusts the flow of warm or cool air for ultimate comfort.
Vented Gas Room Heater
Self-contained heating device that vents to the outside.
Ventilator
System that exchanges stale, recirculated indoor air with fresh, filtered outside air.
W
Wind-Powered
Harnessing the power of natural wind currents and turning it into electricity.
Z
Zoning
Method of partitioning a home into independently controlled comfort zones for enhanced comfort and efficiency.
Resources & References
The information provided in our FAQs and Glossary has been compiled from the following industry-leading sources:
Alabama Environmental Council
American Architectural Manufacturers Association
Building Performance Institute
Energy Star
Energy Vanguard
Environmental Protection Agency
Green Building Advisor
Lennox
National Institute of Building Sciences
Nest
North American Insulation Manufacturers Association
Spray Polyurethane Foam Alliance (SPFA)
Think Energy Management
United Nations Economic Commission For Europe
U.S. Department of Energy
U.S. Energy Information Administration
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