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Solar Savings: 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, Pa.

MA: How do solar metal walls work and what are the advantages of utilizing them on a building?Jim Bush

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.

VictoriaHollickVictoria Hollick: 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?ATAS_Giles1

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 energy.

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 points.

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 most projects.

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.

Conversall SolarWallHollick: 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 industry.

Hollick: There is a lot of exciting innovation going on in this field. Three main areas of product innovation include:

  1. 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).
  2. 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).
  3. 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 To learn more about the SolarWall technology by Conserval, visit