An inside look at solar metal walls
Metal Architecture talks solar metal walls with Victoria
Hollick, principal with Conserval Systems, Buffalo, N.Y., and Jim
Bush, vice president of sales for ATAS International, Allentown,
MA: How do solar metal walls work and what are
the advantages of utilizing them on a
Jim Bush: The InSpire system is a transpire
solar collector. It consists of perforated wall panels installed on
framing attached to an exterior (southern facing) building wall.
Sunlight heats the collector surface, and warm air is drawn via
fans through the perforations and into the air space created
between the walls. This pre-heated air is then used to provide
replenishment air to buildings having a fresh air requirement. The
pre-heated fresh air produced by InSpire can be more than 75
degrees warmer than the outside air temperature. This pre-heated
air can also be customized as a direct heating system for buildings
that have no air handling system.
The SolarWall technology by Conserval is a solar air heating system
that heats incoming ventilation air for commercial, industrial and
institutional facilities. It offers large-scale energy reductions,
typically reducing 20 to 50 percent of the building's heating load.
SolarWall systems also generate up to 10 LEED points. Conventional
systems are usually all-metal with a perforated exterior surface
that is affixed to the exterior wall of a building. The SolarWall
collector heats incoming air by 30-70 F on a sunny day, producing
1.5-4 therms per square foot per year. The SolarWall technology has
been used extensively around the world and represents one of the
lowest-cost approaches to implementing a meaningful "Green
Strategy" that yields substantial dividends in terms of
cost-reduction and CO2 displacement.
MA: What type of applications are a good fit
for solar metal walls?
Bush: InSpire has great energy savings
potential for schools, hospitals, military facilities, theaters and
industrial/manufacturing buildings. Virtually any building type
that has a fresh air replenishment mandate and a southern,
southeast or southwest exposure are excellent candidates for this
system. Spaces such as warehousing and manufacturing are ideal for
using InSpire as a direct heating system.
Hollick: Any type of commercial, industrial or
institutional facility with a heating requirement is a potentially
good SolarWall candidate, and in the past 20 years in the business
we have "solarized" virtually all types of buildings. Facilities
that have a high ventilation requirement-like manufacturing plants,
vehicle maintenance garages or hospitals, for example-represent an
exceptionally good opportunity to offset a very large usage of
MA: How do solar applications work well with
metal walls as opposed to other materials?
Bush: Metal wall and roof systems are ideal for
use with renewable energy technologies because of the durability of
metal and the superior paint systems that can be applied to the
material. In addition, metal is the only roof material that has as
long or longer life expectancy than that of the solar cells. Both
the ATAS InSpire wall system and ATA-Solar building integrated
photovoltaic roofing system contribute to LEED certification
Hollick: SolarWall systems are made of metal,
and resemble a conventional metal wall from a distance. They can be
applied in either new construction or in retrofit applications.
MA: How costly are solar metal walls and how
long might it take to see a return on an
investment in them?
Bush: The InSpire system is a custom built,
designed and engineered sustainable building product with a minimum
life of 30 years. Cost will vary based on the specifics of the
project, but it should be noted that InSpire is eligible for the
Federal Tax 30 percent Grant Program and accelerated depreciation
(MACRS). A typical ROI would be in the five to seven year range for
Hollick: The SolarWall technology is a
custom-engineered energy solution so there is a small premium for
upgrading a conventional wall to a solar air heating system. In new
construction it may be less expensive than a conventional metal
wall as a result of financial incentives for solar technologies
(for example the 30 percent solar tax credit).
MA: Compare solar metal walls to solar
roofs. Do they serve different purposes?
Bush: The InSpire system is designed to provide
pre-heated air for introduction into a facility for air
replenishment and heat. InSpire can significantly reduce the
heating costs of a building. The ATA-Solar system is a solar BIPV
system that produces electrical power for the building on which it
is installed. When the system produces more electricity than the
building is using, the balance is sent back onto the grid and a
credit is issued to the system owner.
Hollick: The SolarWall
technology can also be used in roof applications as well-typically
known as "SolarDuct" in these cases. Roof-mounted solar air heating
systems are specified when there is no available south (or SE or
SW) façade or if there are some architectural considerations.
SolarDuct systems are also being used now in conjunction with solar
electric PV systems (known as SolarDuct PV/T) where they act as the
thermal racking system for the PV; improving the PV efficiency by
removing the heat energy which is then ducted to a rooftop HVAC
system to offset the heating load. These types of hybrid systems
(producing heat + electricity) are considered by many to be the
next frontier in the solar industry.
MA: How attuned is the market to solar metal wall
applications? Is it something not a lot of people know about yet?
Is it still catching on? How do you see it growing over the next
five years or so?
Bush: The market is still in its infancy when
it comes to its knowledge of this renewable technology. It requires
education and information dissemination to all the design parties,
including architects, engineers and project managers. InSpire is a
sustainable building technology that will continue to grow
exponentially as renewable energy solutions are incorporated into
an ever expanding array of building designs.
Hollick: Demand for the SolarWall technology
continues to grow. We continuously see that the market places a
high premium on established products with an extensive track record
in this field, so that bodes very well for us. There does continue
to be a learning curve for the building industry in terms of
educating them that solar energy is more than just PV (electric)
systems. We have recently launched a certified SolarWall training
program with the International Ironworker's Union to create a
trained installation workforce across the country.
MA: What are some of the unique product
innovations in solar metal walls right now?
Bush: ATAS has expanded its wall designs to
meet and exceed the expectations of our customers. Our engineering
and design expertise allows our organization to maintain our
leadership position in the sustainable building products
Hollick: There is a lot of exciting innovation
going on in this field. Three main areas of product innovation
- Hybrid SolarWall /PV systems-the hybrid solar
systems combine two types of energy generation (heat + electric)
into one integrated system. There are also many technological
synergies associated with incorporating a heating component into
conventional PV systems that will result in improved system output
and a more compelling payback (for the PV component).
- SolarWall High Performance System for Space
Heating-the SolarWall technology was originally introduced
to heat large volumes of ventilation air in large industrial
buildings. It has been widely received in the broader commercial
and institutional sector as well, and to better serve those markets
we are introducing a high-performance system that will provide more
space heating (higher temperature rise).
- NightSolar-Our NightSolar invention is a
roof-mounted system that will provide nighttime cooling in warmer
desert climates from sunset to sunrise. This will expand our
technology offering into the areas of solar cooling and we see
tremendous potential for this product.
For more information on ATAS' InSpire wall system, visit www.atas.com. To
learn more about the SolarWall technology by Conserval, visit www.solarwall.com.