Radiant ceiling is high-tech cool

by Robert P. Mader of CONTRACTORs staff HAMPTON, N.H. The Web site for high-tech manufacturer QA Technologies notes, The goals of our company are pursued in a manner that is socially responsible and commands respect for its integrity and for its positive contribution to our community. That philosophy applies to it headquarters building here. QAs new facility uses an ice storage system to feed chilled

by Robert P. Mader

of CONTRACTOR’s staff

HAMPTON, N.H. — The Web site for high-tech manufacturer QA Technologies notes, “The goals of our company are pursued in a manner that is socially responsible and commands respect for its integrity and for its positive contribution to our community.”

That philosophy applies to it headquarters building here. QA’s new facility uses an ice storage system to feed chilled water to a radiant ceiling panel system that QA CEO David Coe figures is saving him $4,000 a month in electric bills.

QA Technologies manufactures gold-plated probes used to test circuit boards as they come off the assembly line, Coe said.

Radiant cooling in the QA Technologies building is more than just radiant panels. The system starts with conventional components that include a Trane chiller and air handlers, Baltimore Aircoil cooling tower, Calmac ice banks and a high-efficiency stainless steel condensing boiler from Fulton Boiler, which feeds fin-tube radiation for winter heating.

A radiant ceiling system includes a greatly downsized forced-air system for dehumidification, filtration, fresh air requirements and building pressurization. The ventilation system is “de-coupled” from the cooling load, explained Kenneth Duchesne, vice president and chief estimator for Granite State Plumbing and Heating in Goffstown, N.H.

“The ventilation requirement becomes specific to occupancy and building pressurization,” he told CONTRACTOR. The result is that ductwork size and fan horsepower are greatly downsized. He estimated that fan horsepower in the QA building is 30% of what it would be in a conventional 60,000-sq.-ft., three-story building, and the ductwork is 40% of typical size.

The QA system runs at three different water temperatures. Low-temperature chilled water comes from the ice banks at 32°F and is sent through six air handlers that are dedicated to dehumidification. The 32°F water is mixed with return water to create 45°F medium-temperature water that runs through nine air handlers in a small VAV system, which is used for supplementary comfort cooling or for cooling spaces that contain so much heat-producing equipment that the radiant ceiling panels can’t handle the load. The medium-temperature water is similarly mixed with return water to increase its temperature to 54°F and the “high-temperature” chilled water runs through the radiant ceiling panels.

The price for the cooling system, the largest radiant cooling project in North America, is about double that of a conventional VAV system, said consulting engineer Al Milasauskis of AWM Engineering in Gorham, Maine. The system, however, is a reflection of its owner. QA wanted a system that uses the least amount of energy possible and precise control. Each room has its own thermostat, which would have been prohibitively expensive with a VAV system.

Employees complained about being too hot or too cold in the firm’s old building, Coe said. The new headquarters’ radiant ceiling panels, controlled with a solenoid valve in each room, make it easy to provide room-by-room control.

The building is one of the larger LonWorks controls installations in the country. Invensys provided the controls. The local Invensys field office, Control Technologies in Manchester, N.H., acted as the controls contractor.

Invensys also supplied the radiant ceiling panels, which were built by one of its European subsidiaries. Invensys has installed 700 radiant cooling systems worldwide, mostly in Europe.

The ceiling panel is part of the Redec system made by Invensys unit Siebe Comfort Systems. Building owners or architects can pick any metal ceiling panel they wish, explained John Zapalik, director of technical services/commercial properties for Invensys Energy Management Solutions in Orland Park, Ill. It just has to be a steel or aluminum panel in any color, size or shape.

Invensys makes the radiant tubing, the patented adhesive that holds the tubing to the ceiling panel and the flexible connector system that joins the panels to the cooling system. Invensys attaches the tubing to the ceiling panels.

For the QA building, the panels were fabricated in Switzerland by Invensys subsidiary Gema Metalldecken, and shipped in containers to New Hampshire. In the future, Invensys plans to fabricate panels in a North Carolina facility and hopes to be running by Labor Day, Zapalik said.

The white enameled panels in the QA building allowed the architect to use indirect lighting, Zapalik noted.

Radiant cooling panels cover about 75% of the ceiling, said Dan Wesner, Invensys’ director of operations for radiant ceiling technologies North America. The rest of the ceiling space is used for lighting, slot diffusers for the VAV system and sprinklers, although the panels can be cut to fit around sprinklers. On the QA job, the contractor cored through the panels on-site for the concealed sprinkler heads.

Engineer Milasauskis noted that the building is one of the largest installations of an Inergen fire protection system in the country. Inergen, made by Ansul Inc., is the substitute for halon, which was banned by the Montreal Protocol as an ozone-depleting substance. Inergen is a blend of nitrogen, argon and carbon dioxide that lowers oxygen in a space to 10%, too low to maintain combustion, but it’s not harmful to humans.