Achieve increasing levels of
energy performance above the baseline to reduce environmental and economic
impacts associated with excessive energy use. Buildings are required to meet
minimum performance standards for energy efficiency. This project has been designed to achieve more than 35%
efficiency over the minimum. In
addition to the solar and geo-thermal systems, the building walls and ceilings
have insulation which exceeds code minimums. The buildings windows are thermally broken, have double
glass with low-E argon gas between panes, and reduce solar heat gain in the
summer. Finally, the roof of the building incorporates a white rubber roof,
which reflects the sun reducing the “heat island effect” on the micro-climate,
also aids in absorbing less heat than other surfaces.
Insulation:
The building consists of an R-30 insulation on the roof deck (see
sample material below), which is typical, and R-19 batt insulation in the walls
which fills the stud cavity. In addition, the project has 1” thick, R-7
rigid insulation in the cavity between the masonry veneer and the exterior wall
sheathing. This extra insulation is important to protect the metal studs
as they can conduct the heat and cold if left against an uninsulated exterior
wall sheathing. This insulation also greatly reduces the potential for
condensation occurring in the stud cavity as the dew point (where water vapor
can condense) is now outside of the wall sheathing.
Windows:
Windows are thermal holes.
An average building may lose 30% of its heat or air-conditioning energy through
its windows. This building’s windows are
thermally broken, have double glass with low-E argon gas between panes, and
reduce solar heat gain in the summer. By combining Low E Glass and Argon gas, this
building provides the ultimate in insulation performance.
Low Emissivity glass (Low
E), reflects long wave radiation. This keeps the heat inside your home during
winter and reduces heat absorption during the summer. The principal mechanism
of heat transfer in multilayer glazing is thermal radiation from a warm pane of
glass to a cooler pane. Coating a glass surface with a low-emittance material
and facing that coating into the gap between the glass layers blocks a
significant amount of this radiant heat transfer, thus lowering the total heat
flow through the window. Low-E coatings are transparent to visible light.
Different types of low-E coatings have been designed to allow for high solar
gain, moderate solar gain, or low solar gain.
Argon is a naturally occurring, harmless, inert gas that is denser than air. By
trapping Argon gas between the panes of glass, it acts as a greater barrier to
heat loss and heat absorption in this facility. Filling the space with a less
conductive, more viscous, or slow-moving, gas minimizes the convection currents
within the space, conduction through the gas is reduced, and the overall
transfer of heat between the inside and outside is reduced.
