The building envelope has long
been overlooked and addressed uniformly throughout different
climates. We now recognize that climatic
conditions greatly effect how we should
build the “box”. The latest
research has led to newly applied perspectives in Building Science, primarily
the Thermal Envelope.
ASHRAE HANDBOOK (23.10) recognizes and
endorses this procedure in hot, humid climates.
The 1887 Florida Energy Code also
prescribes Thermal Envelopes for commercial buildings. The same techniques are being applied
to residential buildings with complete success.
The Thermal Envelope can remedy many of
the symptoms ailing “sick buildings” in Southern and Northern climates. A
necessary step in the “cure is that we must change the environment. “Fix-it” or “Band-Aid” approaches are
only a temporary solution putting the problem off to reoccur
another day. Generally
condensation, duct sweating, infiltration, humidity control
and bacteriological growths within building envelopes vanish when eliminated with
Structural Insulated Panels.
The Structural Insulated Panel System is the most comprehensive method
to address the remediation of a building envelope. The diverse application techniques and the inherent properties of Structural Insulated Panel allows it to accomplish
the most difficult and otherwise impractical sealing and insulating jobs with assured
success. The Structural Insulated Panel Thermal Envelope allows the control of humidity
levels within the 45-50% range, a level at which molds, mildew, dust mites and many
allergens perish, immediately affording the occupants maximum indoor air
quality. The system, also improves the thermal comfort within the entire envelope and
vastly improves energy efficiency. The sum
of the results is clean, comfortable, healthy, energy efficient, sustainable construction; that will extend the life of the
building envelope and the systems with in it.
Standard residential and commercial construction has traditionally
designed vented Attics without regard for regional and climatic
conditions. Also, many vented
attics are not designed and constructed in accordance with properly
proportioned eve and ridge Venting. This
can accentuate the problem of extreme attic conditions. In warm humid Climates, attic temperatures can reach well in excess of 130
degrees Fahrenheit. This,
coupled with the infiltration of moisture laden air and
attic pressurization, can cause a Myriad of problems for energy efficiency, indoor air
quality, condensation and comfort. An attic cannot be vented enough to minimize these
conditions. The ambient outdoor Conditions would be preferable to the extreme conditions
that are created.
The Thermal Envelope utilizes an un-vented, (sealed)
attic design that places the insulation at the roof plane in lieu of on the
ceiling, thereby bringing the entire building envelope within the thermal and
air barrier. Research has proven
that there are many benefits to this method. By locating the thermal and moisture barriers at the same
plane, it eliminates the
opportunity for moisture to enter the attic and condense. Moisture will not condense with in the Structural Insulated Panel (SIP’s)
making it the ideal material for this application.
The Florida Solar Energy Center attributes 65%
of the infiltration in the average Florida home to the attic. This coupled with duct leakage can
place an insurmountable burden on the mechanical systems to maintain occupant
comfort. Many times the results
are more drastic leading to failures in buildings and homes. Generally there are many contributing
factors: however, the most
significant element is the failure of the building envelope. If we first address how we build the
“closed box” then we can better engineer the mechanical systems within that