Dennis Holloway, An Architect in Northern New Mexico

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Bicentennial Solar Pavion for the Arts (Project),
Minnesota State Fair,Saint Paul, Minnesota, 1976

Collaborating Mechanical Engineer: Prof. Perry Blackshear, University of Minnesota, Institute of Technology

Exterior of Model from Southwest.

Unbuilt Minnesota
A Glimpse of What Might Have Been

By Robert Gerloff
(Excerpted from an original article in Architecture Minnesota, March/April 1990)


In 1973, during the Arab-Israeli Yom Kippur War, the Arab members of OPEC embargoed oil shipments to the United States, and overnight energy awareness exploded from the back pages of ecological newsletters to the covers of Time and Newsweek. Americans, trapped in long lines at filling stations, were suddenly "energy conscious".

Washington made it a national priority to develop alternative energy sources free from political meddling. Solar energy seemed the most promising, and universities began churning out research.

In 1975 Dennis R. Holloway, a professor at the U of Minnesota School of Architecture and Landscape Architecture, designed a solar-demonstration building for the Minnesota State Fair. His Pavilion for the Arts, powered entirely by a solar system designed by mechanical-engineering professor Perry Blackshear, would have been built at the top of Machinery Hill.

[The photographs of the model (see next two pages)] show how the massive bank of solar collectors stood proudly on the roof, a bright, shiny technological vision of the future as a time when people would depend only on the sun for energy. Larger ecological concerns are expressed through symbolism: The square plan symbolizes masculine earth and the circular roof plan represents feminine heaven. By coming together, the opposites create harmony.

In 1976, with funding for the building secure and construction documents almost complete, the State Fair was shaken by scandal. A legislative sub-committee investigated accusations of price-fixing among concession booths at the State Fair, and Holloway--not wishing to be associated with unethical behavior--quit. The building was never built.

From the Architect's Brief to the Client

January 19, 1976:

The Plan

The plan consistes of the exhibition hall, entrance lobby and restrooms, kitchen and workroom, and a mechanical room under the entrance lobby containing a public 'system viewing' chamber. Earth (glacial till) removed during construction of the underfloor solar storage system is employed in the final construction as a perimeter insulating berm that covers the ten foot high perimeter wall of the Pavilion, and is also used to construct a performance arena to the south.

In essence the concept of the building is the ancient symbol of the co-inciding circle and square. The circle represents the feminine heaven and the square represents the masculine earth. Together they represent harmony.

The plan of the exhibition hall is a square 140 feet on a side. Superimposed over this is the circular roof tensegrity truss system supporting the solar collectors above. The circular edge beam of the roof is in turn supported be twelve columns resulting in a clearspan exhibitions/performance hall 136 feet in diameter. The perimeter of the hall consists of a series of exhibit niches illuminated by a continuous skylight above.

Although the Solar Pavilion for the Arts (was to have been) built on one of the open parks of the State Fair Grounds, most of the site in the final plan was useable in ways similar to the present. A significant portion of the site to the north of the Pavilion reatains its park-like character. The berms on the east and west sides of the building are covered with native ground cover and contain "art-in-the-park" alcoves under temporary shading awnings; thus, both Cosgrove and Cooper Streets take on a new pedestrian shopping character. The Arena / Amphitheater to the south also serves as open park with generous planting, and as an exhibition space.

Together, the Pavilion and its perimeter site are conceived and designed to accommodate a wide range of artistic exhibition and performance activities, ranging from fine art exhibitions, visual art exhibits, musical performances, dance recitals, conferences, lectures,films and events. Exhibition and seating systems can be designed to optimize moveabiltity and flexibility.

Audiences ranging from 200 to 1500 can easily be contained in the Pavilion.

The Cross Section

On the roof of the Pavilion, a 13,500 square foot array of Sheldahl solar collectors, SLATS, cover the circular roof. To optimize the summer collection of solar energy the roof is tilted at a 20 degree
slope, with the highest side on the north. The Exhibition Hall below thereby is provided with a flexible ceiling height ranging from 12 feet to 55 feet.

The roof of the entrance lobby is a public observation gallery accessible via stairs and ramps to the east and west. From the gallery the public will get a close up view of the solar collector system in operation.

Below the floor of the Exhibition Hall is the Blackshear Annual Cycle Energy Storage System.

The Annual Cycle Energy System

Because the proposed Solar Pavilion for the Arts is planned for twelve month operation, a mechanical back-up system is required. Recent developments in the solar energy research and development field have resulted in widely accepted views about the real potential of wide-spread inplementation as alternative energy source.

After investigating a number of alternative solar energy systems, the Sheldahl SLATS system was carefully studied. The system now in its second year of successful testing in Northfield, Minnesota, may prove to be one of the most important collecting systems.

Simultaneously, Dr. Perry L. Blackshear, Professor of Mechanical Engineering at the University of Minnesota has developed a revolutionary and unique system for storing high temperature solar energy, which is what the SLATS system provides.

In combination these two systems have the capacity to collect and store summer solar energy for summer and winter utilization. Effectively they will provide100% of the space heating plus electricity and air conditioning.

Major design and system integrations study will occur in the next phase of the work.

During clear weather solar energy is collected, reflected and focused on the collector pipes and heats the circulating water in the pipe to 350 degrees F. The water gives it heat to forced air in a heat exchanger. The air heated to 350 degrees F is sucked through 10 feet of gravel in the Blackshear Annual Cycle Thermal Energy Storage System (ACTES). Summer energy is thus stored for winter and summer use.

50 degree F air is drawn off the bottom of the system and then through 3 feet of 'active insulation' gravel. Three feet of gravel treated in this manner has insulative value equal to 60 feet of gravel without forced air, and prevents the high temperatures in the storage bin from rising into the floor of the Exhibition Hall.

250 degree F water returnign to the collector drives a turbine and 12 Kw generator for the building's electrical load.

Three air-conditioning systems are presently being studied for cost effectivenss, and the optimum system will be selected during the next phase of the work.

1. Absorption Cycle System: this system uses heat from solar storage to provide cooling. An additional 2000 square feet of collector is required.

2. Ice Bank Annual Cycle Energy System: A tank of water is frozen during winter to provide summer cooling.

3. Electric Air Conditioning from Solar Income: Electric generators driven by steam from solar storage operates air conditioners at night to cool a water tank; during the day the air conditioners use the cool water to provide cooling to the building.

During overcast weather the air flow in the storage system is reversed; energy stored in the hot gravel is drawn upwards to heat exchangers for production of electricity and heating of the building's air. 50 degree F air tempered by fresh make-up continues to actively insulate the floor from the high temperatures of the ACTES system.

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