Passive Heating & Cooling System Relies on Sunshine and FGS PermaShine Polished Concrete Floors To Achieve Net-Zero Energy for LEED Platinum School Classroom

 

There is a little sun worshiping going on at the Da Vinci School in Portland, Oregon.

The project team of this LEED Platinum registered school hopes to achieve both LEED Platinum certification and Net Zero Certification, which would be a first for both certifications for a free-standing school classroom in the United States.

Much of their success so far has relied on sun power, diffusing sunlight and storing its heat within the classroom's interior concrete walls and foundational slab, which was treated with the FGS/PermaShine Polished Concrete Floor System.

"The most sustainable material you can use is no material at all," said Project Architect Tim Grinstead, with SRG Partnership of Portland, explaining the ways the project team eliminated an HVAC unit and floor coverings from the building.

The Da Vinci Arts Middle School in Portland, Oregon, opened the building for students and teachers in the fall of 2009. The classroom is 1,490 square feet in size and is reserved for the teaching and practicing of musical instruments on the campus. The Evans-Harvard Music Conservancy and High Performance Classroom is expected to gain LEED for New Construction v. 2.2 Platinum Certification in 2010. The building contains a main classroom and office alcove with two rooms for recording and practicing.

The project received more than $500,000 in design, construction and consulting services from local business, non-profits and government agencies with student fundraising and school district funding making up the rest of the project's $775,000 price tag. While the classroom is designated for music, already teachers in the math and science departments have toured the experimental classroom to teach about sustainability.

The building's very low electricity needs were met with photovoltaic roof tiles that generate 5.2 kilowatts of power, an R-60 insulated roofing system, a state of the art daylighting strategy, and a passive heating and cooling design that incorporates the thermal mass of an FGS/PermaShine Polished Concrete Floor System.

"It's a critical heat sink," explained Randy Bachelor of the Bonneville Environmental Foundation. With a polished concrete foundation slab, "that's an amazing amount of energy you can capture."

The passive heating and cooling system eliminates the need for an HVAC unit. The FGS/PermaShine Polished Concrete Floor System with an exposed aggregate finish absorbs heat from the sun during winter. A damper below the skylight can be opened overnight for passive cooling of the concrete slab and walls during warmer months with a turbine ventilator that helps draw out hot air. This eliminates any need for mechanical cooling equipment. Wall mounted heating units provide comfortable temperatures during winter.

The energy performance is projected to be 70% above the existing Oregon Energy Code. The passive heating and cooling system was designed by SRG Partnership. The daylighting strategy was executed by G.Z. "Charlie" Brown, an architect and director of the University of Oregon's Energy Studies in Buildings Lab.

The experimental natural lighting system was designed to provide enough light that it eliminates the need for artificial light during the school day. The system channels the sun's rays through a skylight and into a diffuser on the classroom ceiling at the right angles to spread the natural light evenly throughout the room. At night or on cloudy days, the lights go on but their light is diffused and amplified, using only 0.4 W/sq. ft.

The Da Vinci school building is a prototype for the Portland School District, and the project team's strategy of incorporating passive systems have many benefits, including the elimination of periodic replacement of floor coverings with the FGS/PermaShine Polished Concrete Floors.

"There was no waste at all, only the energy needed to install a polished concrete floor," Grinstead added.

L&M Construction Chemicals and the manufacturer of the FGS/PermaShine family of products has a certified installer program. Installer Jenci Bergen of Specialty Coatings in Portland installed the floor system for the Da Vinci project.

In addition to energy conservation, the FGS/PermaShine Polished Concrete Floor System contributes to regional and recycled content, and provides a laboratory-tested Low-VOC flooring solution for assisting LEED and CHPS project teams. Polished concrete floors also provide more than a 60% reduction in ongoing maintenance costs compared to floor coverings and vinyl tile products.

The project team might have designed and constructed it, but the students and staff want to get to net-zero, too, according to Randy Bachelor of the Bonneville Foundation, which donated the photovoltaic roof tiles through the non-profit organization's Solar 4R Schools program and provided an energy monitoring kiosk needed to verify Net Zero Energy compliance. The students are always checking the monitoring equipment, which tracks consumption and energy generation.

"I think that integrated student knowledge will help the project stay on track," Bachelor explained. There are Net Zero occupant behaviors that have to be learned in order for the building to use less energy than it makes from the photovoltaic panels over the course of a year.

The Da Vinci addition is the second building to test the diffuser designed by Charlie Brown's lab one of five Pacific Northwest labs in the Betterbricks Integrated Design Lab Network, which is researching how to improve energy efficiency in schools, hospitals and office buildings. The Mt. Angel Abbey was the first collaboration between Charlie Brown and SRG Partnership.

By Paul Nutcher, CSI CDT