Natural Ventilation vs Mechanical Ventilation


Proper ventilation is a critical consideration for homes and buildings. Poor ventilation can cause a buildup in indoor air pollutants like dust, pollen, mold, and household chemicals. An efficient and reliable ventilation system works to remove polluted air while continuously introducing fresh, clean air. While natural ventilation may be a viable option, there are a number of variables and reliability issues that should be considered. Instead, many energy-efficient builders and homeowners opt for the efficacy and reliability of a mechanical ventilation system

Read More

Ventilation Considerations for Home Remodeling


In today’s energy-efficient homes and buildings, more airtight construction plays an important role in preventing energy loss. While an airtight building envelope is a key foundation for saving energy, health and comfort problems may arise when proper ventilation is not also addressed. An airtight building strategy works to prevent air flow into and out of the building. When a mechanical ventilation strategy is excluded, the indoor air quality of the building may suffer. When remodeling your home for energy efficiency, consider

Read More

HVI Testing and Certification


Before purchasing a home ventilation system such as an energy recovery ventilator (HRV) or heat recovery ventilator (HRV), we recommend builders, architects, contractors, and homeowners do their research on the best available options.  The Home Ventilating Institute (HVI) or  is a good resource. In order to receive HVI certification, products must undergo uniformly-applied testing. Here is a full list of HVI- certified HRV and ERV systems.  Zehnder most recently tested its ComfoAir 200 HRV.  With Apparent Sensible Effectiveness between 92%-94% and

Read More


Zehnder Interview Series: Kevin Rapp, Technical Sales Representative


Interviewer:  Could you introduce yourself, Kevin? Kevin Rapp:  My name is Kevin Rapp. I’m the Midwest Technical Sales Representative for Zehnder America, which includes most of the central United States. Interviewer: What kind of green building trends are you seeing in the HVAC industry? Kevin Rapp: I’m seeing an increased adoption of centralized ventilating systems instead of either an exhaust-only system or a partnered ventilation system with the central heating and air system. Interviewer: How does an HRV or ERV help with the home’s indoor air quality? Kevin Rapp: With

Read More


Cost Savings of Living in a Passive House


Some of the most energy-efficient homes on US soil, Belfast Ecovillage homes use 90 percent less energy to heat and cool. While typical homes of a comparable size require families to spend several thousand dollars each year on heat alone, my family of four in Midcoast Maine spent less than $120 a month last winter on all our utilities, including heat and hot water. On cold, windy days, our home has no drafts. During sunny winter days, our home is heated exclusively

Read More

The Benefits of Heat and Energy Recovery Ventilation in Southern Climates


With a product name of “Heat Recovery Ventilator” or “Energy Recovery Ventilator,” it’s a common initial assumption that the primary benefit of the heat exchanger is to reduce heating loads and heating costs. However, in hot Southern climates (or any hot summer climate) the opposite benefits are true as well.  The heat exchanger greatly reduces the cooling loads and cooling costs of an air conditioning system. Why use an HRV/ERV as part of a strategy for a comfortable indoor temperature during the hot

Read More

Common Home Energy Myths


There are a number of ways to save a home’s energy and use energy more efficiently on a daily basis. While many common energy tips are helpful in achieving these goals, some tips are more useful than others. Before implementing a home energy-efficiency strategy, homeowners should do their research to make sure their efforts count. Myth #1 “Off” Means No Energy Use Many believe that electronics and appliances only use power when they’re turned on. While these items certainly use less energy

Read More


Understanding Home Energy Score


The U.S. Department of Energy (DOE) developed a national rating system for home energy efficiency called the Home Energy Score. Similar in function to a vehicle’s mile-per-gallon rating, a Home Energy Score provides an objective scale to measure a home’s energy efficiency as it compares to other homes. Additionally, the Home Energy Score system provides homeowners with tips and suggestions for improving their home’s energy efficiency. Homeowners are urged to evaluate the energy efficiency of their homes and consider implementing the

Read More


Summer in a High-Performance House


Summertime in coastal Maine involves warm days, gentle ocean breezes, and lots of blueberries. My family and I are enjoying our first summer in a high-performance house in Belfast Cohousing & Ecovillage, a 36-unit multigenerational community with ultra-energy-efficient homes on 42 acres. The house performed well on windy winter days and during an extended five-day power outage, but now we are seeing how it fares during hot July afternoons without air conditioning. Despite lots of south-facing windows, our home stays comfortable

Read More


Zehnder Interview Series: Micky Dunegan, Technical Sales Representative


Zehnder Interview Series:  Micky Dunegan, Technical Sales Representative Interviewer: Could you introduce yourself, Micky? Micky Dunegan:  My name is Micky Dunegan. I am the Technical Sales Representative for the Southwest region, which includes California, Arizona, Utah, and Nevada. Interviewer:  Micky, what do you like best about working with this type of HRV/ERV system? Micky Dunegan:  It’s great representing products that provide such a high level of health benefits while dramatically reducing energy consumption as well. Interviewer:  How does a Heat Recovery Ventilator (HRV) contribute to the

Read More