Frequently Asked Questions

Energy Diagnostics Frequently Asked Questions

What is a blower door test?

A blower door test measures how airtight a home is. It is designed to check for air leaks in walls, attics, and mechanical penetrations. While a blower door test does not evaluate how well a structure is insulated, it can reveal drafty walls and air-bypass situations that could undermine otherwise well-insulated wall assemblies.

What are the two building code paths?

Performance and Prescriptive.

What is the difference between performance and prescriptive path?

The Prescriptive Path presents a specific list of features and items that have to be met for compliance, with no deviations allowed. If you choose to go this route, you must follow all the guidelines outlined in the IECC book (International Energy Conservation Code). The Performance Path offers the designer or builder the most flexibility in meeting the energy code requirements.  A HERS Rater is involved in the project from the early design stage to model the energy performance of the home and to determine compliance.

What is a HERS rating?

The 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.

What is the 45L tax credit?

Under the provisions of the 45L Energy Efficient Home Tax Credit, builders and developers can claim thousands of dollars in federal tax credit for each new home or dwelling unit that meets 45L energy efficiency requirements. In many states, most new residential projects qualify for this credit.

What does an energy rater do?

A Certified Home Energy Rater or Rater is a person trained and certified by an accredited Home Energy Rating Provider to inspect and evaluate a home’s energy features, prepare a home energy rating and make recommendations for improvements that will save the homeowner energy and money.

What is air sealing?

Air sealing is the process of discovering and sealing all areas of air leakage in a home in order to make it more energy-efficient.

Why is a blower door test required on new construction homes?

A blower door test is used to measure how airtight a home is and is commonly required for state-mandated energy code compliance inspections. They are also a component of whole home green building certifications such as LEED, HERS, and Energy Star.

Why does my bath fan run all the time?

It is likely a dual-speed continuously operating exhaust fan that forms part of your house’s mechanical ventilation system. It runs continuously to provide a continuous stream of fresh air.

What is mechanical ventilation?

Mechanical ventilation improves indoor air quality by providing fresh air and diluting pollutants, controls moisture, prevents inadequate airflow, and doesn’t rely on occupants to open windows.

What is a manual J?

The Manual J calculation is a formula that identifies the HVAC capacity of a building. It is also called an HVAC load calculation because it describes the size of equipment needed to heat and cool a building.

What is the building envelope?

A building envelope is commonly defined as the separation of the interior and exterior of a building.  It helps facilitate climate control and protect the indoor environment. It includes doors, windows, roof, foundation, floor, siding, and all the components such as structural masonry and insulation.

What are the benefits of an energy-efficient house?

There are numerous benefits of a home that is designed and constructed with energy efficiency in mind, including lower heating and cooling bills, lower carbon emissions, better indoor air quality, better resale value, more comfortable/consistent temperatures throughout the house, fewer drafts, more efficient use of HVAC systems, and lower cost of ownership.

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