Chicagoland’s First Certified Passive House: Part 2
Following the last blog post on Chicago’s First Certified Passive House, built by WBD, read on to hear common Q&A surrounding this type of home (See April 2013 Archive For or scroll down forPart 1):
Shouldn’t My House Breathe?
Your house should definitely breathe, but that breathing should be controlled. A code built home as well as traditional construction methods of letting a home breathe through gaps, cracks, and drafts have proven to be outdated. Since the widespread use of insulation, uncontrolled “breathing (really leaking)” is undesirable. It is an excuse for builders to be lazy, cut costs, or build homes as fast as possible without attention to details. Not to mention that way of thinking also leads to a lot of moisture problems in the wall cavities which can lead to mold. Do you really want to be breathing in air that contains dirt, insulation fibers, and passes over mouse droppings or do you want clean fresh filtered air?
A home should have a controlled path of breathing. In Chicagoland’s first Passive House project, we used an energy recovery ventilator (ERV) to manage controlled air exchanges. This system exhausts air out the rooms that tend to contain moisture and smells, such as the bathrooms, laundry room, and kitchen. That air passes through the ERV box where the incoming fresh air (lets assume winter – it will pre-cool and dehumidify in summer) is pre-heated and humidified before entering the home. The heat recovery is rated at 85% so it recovers most of the energy from the outgoing air. It is also filtered before it enters the ERV as well as filtered again before it leaves the ERV to supply all of your living areas and bedrooms with constant fresh air. Both filters are rated at MERV 13, which is the rating used for surgery rooms. The system runs 24/7/365 at a very low cfm to provide constant clean fresh air, but at the low cost of $3 a month with the super efficient ECM motor. It changes the complete volume of the air every 3 hours! Sound expensive? It’s not, like I said before, we spent much less money on our mechanical systems than a code built home.
No Traditional Furnace In Chicago?
It is true that WBD’s first Passive House does not contain a forced air furnace or air conditioning system. Most of the heating comes from sunlight through the windows, internal gains by appliances and cooking, body heat given off by the inhabitants, and lighting. There is an extremely low heating load on the house of 13,500 BTU’s. This house runs on 2 wall mount minisplit heat pumps. There is one on the first floor and one on the second floor. They are point source so they distribute the heat to the two rooms they are in, but the ERV unit mixes the air in the home like a “Vitamix for air” so that heating or cooling is distributed through the home. The benefit is having no duct system for heating and cooling which also equates to much less dust than a traditional home.
Anything Else On Health?
I’m glad you asked. Even though we have a mechanical ventilation system to filter air and do fresh air exchanges, I really wanted to focus on indoor air quality with regards to the materials that went into the home. Every product that was used in construction and was researched with regards to indoor air quality. We used third party certified products for indoor air quality such as GreenGuard Children & Schools. Many products on the market make green claims and make up their own in house green certification to stamp on it. Most homeowners and builders do not realize this but with air quality being the priority of construction methods at Weiss Building & Development, we are onto their “games”. Third party certification tests for sVOCs, tVOCs, formaldehyde, and all aldehydes. This ensures we can track various products and continually make improvements to the air quality in our homes. These tests show that our homes are up to 70% better air quality than other new construction homes.
Chicago’s first Passive House is at the cutting edge in terms of energy efficiency and health and also became a pilot project for a Healthy Home Initiative, a partner of the Healthy Child Healthy World non-profit organization.
For more information on the health of WBD’s first Passive House, please see the blog “ Building Health Into Homes” at weissbd.com/green_building/?p=54
STAY TUNED IN JUNE FOR PART 3 (Final Chapter) OF THIS BLOG