Tests to Ensure Your Home is Energy Efficient
A home energy audit, also known as a home energy assessment, is the first step to assess how much energy your home consumes and to evaluate what measures you can take to make your home more energy efficient. An assessment will show you problems that may, when corrected, save you significant amounts of money over time.
The Department of Energy has a few tips before you have an energy auditor visits your home. “Make a list of any existing problems such as condensation and uncomfortable or drafty rooms. Have copies or a summary of the home’s yearly energy bills. (Your utility can get these for you.) Auditors use this information to establish what to look for during the audit. The auditor first examines the outside of the home to determine the size of the house and its features (i.e., wall area, number and size of windows). The auditor then will analyze the residents’ behavior.”
They also warn you that, before contracting with an energy auditing company, you should take the following steps:
- Get several references, and contact them all. Ask if they were satisfied with the work.
- Call the Better Business Bureau and ask about any complaints against the company.
- Make sure the energy auditor uses a calibrated blower door.
- Make sure they do thermographic inspections or contract another company to conduct one.
An alternative is to do the test yourself. You can do a rudimentary assessment just by walking around the house on a cold, windy day looking for drafty windows and identify places in rooms that tend to be cold.
When an energy assessment is performed, the following tests are done.
Air Leakage Assessment
Air leakage can be assessed with a blower door test. This test measures air flow through the house and is accomplished by either pressurizing or depressurizing the structure with a large fan that fits into a doorway.
Typically, air is pulled out of the house with a large fan to recreate the conditions the house experiences during 20 mph wind gusts. This test is the only way to know exactly how tight or leaky your house is and at what point mechanical ventilation (e.g. – a bathroom exhaust fan) is required to maintain good indoor air quality.
While the blower door test is underway, the Energy Advisor will look through the home with a thermal camera and use a smoke pencil to identify the most significant sources of air leakage in the structure. Identifying and sealing leaks in the building envelope can save hundreds of dollars in energy costs per year.
Combustion Safety Testing
Energy Advisors also conduct combustion safety testing on heating equipment to ensure that it is operating efficiently and removing exhaust from the house. Combustion air is needed by heating systems that create heat by burning fuel including oil, gas and wood. This air is provided by ducts connected to the outdoors or by indoor air and unintentional air leaks. Because of the reliance on air leakage for combustion air in many homes, combustion safety tests are done before and after air sealing projects.
Infrared or thermal cameras allow trained users to see the temperature of any surface and identify weak points in the thermal envelope of your home such as missing insulation in wall cavities.
Indoor Health and Safety
Your Energy Advisor might also recommend projects to reduce moisture or improve indoor air quality as part of your energy savings plan. Health and safety projects will not necessarily save you money, but they often are needed to eliminate potential hazards, as well as improve the comfort and longevity of the home.
Air source heat pumps can help ensure that your home is truly energy efficient. According to the Department of Energy, an air-source heat pump can provide efficient heating and cooling for your home. When properly installed, an air source heat pump can deliver one-and-a-half to three times more heat energy to a home than the electrical energy it consumes. This is possible because a heat pump moves heat rather than converting it from a fuel like combustion heating systems.
In addition to the energy assessment, companies will often provide a print-out sharing the results of the audit. This will allow you to make some improvements immediately while planning for future upgrades.
There are different types of air source heat pumps as described below:
Ductless vs. Ducted vs. Short-Run Ducted
Ductless applications require minimal construction as only a three-inch hole through the wall is required to connect the outdoor condenser and the indoor heads. Ductless systems are often installed in additions. Ducted systems simply use ductwork. If your home already has a ventilation system or the home will be a new construction, you might consider this system. Short-run ducted is traditional large ductwork that only runs through a small section of the house. Short-run ducted is often complemented by other ductless units for the remainder of the house.
Split vs. Packaged
Most heat pumps are split-systems—that is, they have one coil inside and one outside. Supply and return ducts connect to the indoor central fan. Packaged systems usually have both coils and the fan outdoors. Heated or cooled air is delivered to the interior from ductwork that passes through a wall or roof.
Multi-Zone vs. Single-Zone
Single-zone systems are designed for a single room with one outdoor condenser matched to one indoor head. Multi-zone installations can have two or more indoor heads connected to one outdoor condenser. Multi-zone indoor heads vary by size and style and each creates its own “zone” of comfort, allowing you to heat or cool individual rooms, hallways, and open spaces. This distinction may also be referred to as “multi-head vs. single-head” and “multi-port vs. single-port.”
To ensure you working with home energy efficiency experts and securing the most competitive prices, ask about relevant certifications. The best companies are certified by both the National Comfort Institute, as well as BPI.
It’s important to take all of the steps necessary to ensure that your home is energy efficient, and air source heat pumps could be the right way to go for you and your family. You just need to take the time to find out which kind is right for you.