In June 2023, Small Planet Supply hosted a webinar with Zehnder America’s Szabi Fekete.  In his role providing quotes and sales support to customers, Szabi has been able increase his already substantial knowledge of Zehnder systems that he had gained in his nine years as a service and commissioning agent.  Small Planet Supply’s past Zehnder webinars have been popular but often focused on the same theme.  Szabi’s presentation June was more focused on indoor air quality and air quality standards.   We sat down with him to learn more what he has planned. 

Your upcoming webinar will focus on indoor air quality and air quality standards allowed by the 2018 IRC.  Besides meeting code, why should people focus on air quality in their home or project?

Code requirements are changing in the United States and all around the world.  One of our biggest energy savings on a house is to decrease air leakage. Because we are enclosing construction more tightly, to meet the new code requirements. So, what we’re doing technically, is to build homes that are not capable of breathing by themselves anymore.  

Can you say more?

Take for an example, an old Victorian style home.  The homeowners always say it’s such a drafty home, the wind blows through.  It’s uncomfortable but that means that air can go in and out through the cracks and gaps of the construction. New homes don’t have fresh air coming through the walls and ceiling.  We know this is true because not we now have to do testing, including blower door testing, duct testing, to prove there isn’t air leakage.  So new and many remodeled homes are just not breathing anymore.

Inside these tighter homes, everybody is using oxygen and exhaling CO2.  In addition, there is a bunch of materials in the home that can produce VOC, the particles produced from cooking in the house, occupants are using aerosol sprays in the house and there is moisture that comes from showers.  In some areas there’s also radon to consider. I live in Pennsylvania, and we have extremely high radon levels. All these things are just trapped inside a home. With an airtight home, there is no option to release because the “cap on the beer bottle is on”, as they say… nothing can come out.  That’s why we need to concentrate on indoor air quality because an airtight home can’t recover fresh air by itself anymore or it takes forever.

How does the indoor air quality and air quality standards prescribed by the 2018 IRC standard impact homeowner and builder ventilation choices?

The older codes did not have mechanical requirements because our leakage allowance was much different.  The 2009 code used in Pennsylvania allowed for seven air changes and mechanical code does not require ventilation for air changes above five. Since 2015, the new requirements are three air changes (per hour).  When homes have an ACH score of less than five air change an hour, it triggers code compliance requirement to provide mechanical ventilation.  Mechanical ventilation has multiple options – the code allows it.  Three types of mechanical ventilation normally seen in residential homes:  supply only, exhaust only or balanced ventilation.  Obviously at Zehnder we concentrate on the balanced ventilation.   At Zehnder, we don’t want to just dump the air into the house, we don’t want to just suck it out, we want to move it both ways at the same time in a balanced manner.  So, the home is not getting pressurized or de-pressurized and we can filter the air as well, so the air which is coming into the home is not just tempered, it’s filtered at the same time.

Who do you think will be most interested in this presentation? 

A lot of Small Planet Supply customers are living in states (or provinces) where electrification is a big deal. In those areas, the switch from combustible to fully electric systems and increased airtightness makes focusing on indoor air quality becomes more important, so educated homeowners would be interested in this. Homeowners who are thinking about building a new home would also find this webinar compelling because they really need to understand what their ventilation choices are. There are multiple options and there are multiple variables to consider when making the decision: cost, maintenance, air quality and energy recovery.  Homeowners should consider this and make their ventilation decision based on their knowledge.

Architects are also dealing with the challenges of indoor air quality more because higher performance home normally have architects involved.  

A tract home builder who is building many homes, say four homes in four styles, they don’t usually care too much about that ventilation.  However, we do have customers who are buying these tract homes and they are asking Zehnder about using a Zehnder system for them. My recommendation is to get an architect or a mechanical engineer because involved somebody must review the plans and see how the ventilation design could be laid out for installation to be successful.  These homeowners would also be interested in the webinar.

What do you see as the biggest barrier to good home ventilation?

Lack of knowledge. Homeowners are not always thinking about air quality when they are buying a home.  Homeowners can spend hours talking with the floor guys or the kitchen designer or the bathroom designer but when it comes to HVAC and ventilation, they don’t even think about it.  They assume it is built in.   Homeowners who understand that it isn’t built in are interested in learning about it.  

Everybody tries to do the best for their home, the problem is limited knowledge.  But until homeowners know what can happen in an extremely airtight home, they just don’t even think about it.  It’s natural to look at the house and say, “it’s fine just as it is”, but when it’s explained that an airtight home is technically a submarine and the submarine needs an air supply system because there nothing comes in and out without an air supply system, then they get it.  Education is a major key element with any kind of ventilation choice.  Knowledge is power. 

You’ve worked with Zehnder systems for almost ten years, so you know what they can do.  From your perspective, what are the reasons that people choose Zehnder HRV or ERV over other systems for their home or project?

Zehnder is the only company in the United States and Canada offering the home run distribution system.  The distribution system extracts air from bathrooms, kitchens, laundry rooms, gyms, storage rooms, anywhere where the room is stinky or humid or have a higher concentration of contaminants.  The distribution system provides fresh air into rooms where we are sleeping or living during the day.    This is a unique solution.  Most of the competitors are dumping air into the central duct work which who knows where it goes.  We don’t fit 50 cfm into ductwork that was designed to 1500 cfm.  It’s like you don’t know where it goes.  It is like shooting in the dark with covered eyes.  Our system is the perfect solution to move the air across a home. That is why Zehnder is the best solution and I think it is best system on the market. 

Zehnder systems also the highest efficiency systems on market, which very significant. I always tell my customers, see your unit is running on 24 watts, or up to 60 watts for a larger system.  But this big unit runs on 60 watts, moving air every three hours throughout your house.  Even people who don’t understand energy can understand how using the same energy or less than a light bulb is amazing.

Ready to Learn More About the Webinar?

Small Planet Supply recorded this webinar and provided the presentation to attendees. You can get access to the webinar materials by clicking on the button below.    

New to Zehnder and Want to Learn More?

These Small Planet Supply resources can get you started:

• Zehnder Comfosystems: The Best Heat Recovery Ventilation

• Zehnder for Homeowners

• HRV Efficiency: No Matter the Measurement, Zehnder Tops the Scores

• California's Title 24, The Recovery Ventilator, and You

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