Archive for 'Ventilation'
Posted on 31. Jan, 2011 by Rebecca Firestone.
A few months ago, we interviewed Bronwyn Barry of Quantum Builders on the Passive House standard. When I called her again to ask about ventilation, she recommended Zehnder, a Swiss company, because their products are Passive House certified and if there’s anyone who knows about ventilation, it’s the Passive House folks. Passive Houses need state-of-the-art ventilation because they rely so heavily on an airtight building envelope, and their stringent energy budgets also mandate the most energy-efficient motors available.
I spoke with Barry Stephens of Zehnder America, the U.S. subsidiary. Zehnder has over 100 projects all over the U.S., including some larger residential complexes. Two-thirds of their projects are Passive House projects, but the company also works with other types of energy retrofits. You can see a great animation of their system here. Barry then referred me to his brother Charlie Stephens of the Northwest Energy Efficiency Alliance, who’s an energy research expert.
We asked both of them some general questions about ventilation principles, along with specific questions for Barry about the Zehnder product line. Most of the discussions here reference the Passive House standard, because it’s so far ahead on ventilation. In fact, if you’re looking for a good ventilation consultant, finding someone with Passive House certification wouldn’t be a bad place to start.
Posted on 06. Aug, 2010 by Rebecca Firestone.
Imagine a home built in the Plains region of the United States that stays warm in the winter without central heating, and cool in the summer without massive air-conditioning. It’s airtight but with an endless supply of fresh air constantly circulating through a filtered, pressure-balanced ventilation system. Every surface is comfortable to the touch, neither too warm nor too cold. Street noise is barely audible through the gasket-sealed, triple-paned windows.
It sounds futuristic, but so-called Passive Houses have been around for at least 15 years, and it’s yet another strategy for saving energy. Unlike a Net Zero Energy home that might rely on “active” power generation, albeit from renewable sources, a Passive House is just that – passively absorbing heat from its surroundings to release it slowly as it is needed. (In hot climates, Passive Houses are designed to recover and store cooler temperatures.)
Posted on 17. Nov, 2009 by Rebecca Firestone.
After January 1, 2010, all new homes in CA must include whole-house ventilation systems. Yes… we’ve made building envelopes so efficient, that now we have to in essence introduce highly controlled leakage. There are two mandatory ventilation features in the new Title 24:
- Intermittent exhaust fans for moisture control in all kitchens and bathrooms
- Whole-house continuous mechanical ventilation for indoor air quality (IAQ)
A good ventilation system will filter out indoor air pollutants (VOCs like formaldehyde from particleboard or acetone nail polish remover) as well as filtering outdoor air on the intake side; however, not all whole-house ventilation systems include outdoor air filtering. Here’s a summary of the ventilation course module from last week’s Title 24 update class.