Radiant Heat Warms Up Manufacturing Plant
The new Bonide Chemical facility near Oriskany, N.Y., serves as proof that radiant heating can meet the most challenging heating requirements. This 150,000-square-foot building-with 2,900 cubic yards of concrete flooring and 40-foot-tall ceilings-will eventually house manufacturing, warehousing and office areas.
The new Bonide Chemical facility near Oriskany, N.Y., serves as proof that radiant heating can meet the most challenging heating requirements. This 150,000-square-foot building-with 2,900 cubic yards of concrete flooring and 40-foot-tall ceilings-will eventually house manufacturing, warehousing and office areas. Combined with the plant's location-upstate New York, with its harsh winters-this multifaceted environment posed some tricky heating obstacles.
Working together, the manufacturer's representative, the construction manager and the system engineer successfully designed and implemented a radiant-heating solution that incorporates 21 miles of radiant pipe and copper-finned, high-efficiency boilers. Now finished, the facility's heating arsenal includes a wealth of engineering expertise.
Heating people, not ceilings
The building's plans originally called for the installation of hanging unit heaters in the manufacturing area, with radiant floors only in the office areas. This solution proved impractical for several reasons. Hanging unit heaters must be installed near the ceiling-in this case, almost 40 feet above the floor. This would make maintenance difficult, not to mention dangerous. Also, because heat rises, the ceiling-rather than the building's occupants would be warmed, resulting in uncomfortable working conditions. Additionally, warehouse doors would be opened and shut frequently, leading to a constant cycle of hot air escaping with the heating system trying to compensate accordingly. As a result, energy costs would have been astronomical.
The project team decided that a radiant heating solution throughout the immense facility was the best solution. Because of thermal mass storage, a properly controlled radiant slab remains at the proper temperature despite changing ambient air temperatures. Installation and maintenance is safe and easy when compared with climbing 40-foot scaffolding. And while the hanging unit heaters would have required copper piping as large as six inches, the radiant solution featured tubing that did not exceed two inches, providing substantial cost savings in a facility of this size, as well as simplifying installation.
Bring on the hardware
The Bonide facility contains a total of 237 circuits of 3/4-inch-barrier PEXc tubing. Rated at 750,000 Btuh each, four gas-fired boilers are connected to the six-inch copper tube primary heating loop as individual secondary circuits. To minimize heat loss, each boiler is on line only when fired.
When engineering the radiant heating system, the building was divided into 14 zones based on function and location. Since the function and location of each zone results in different temperature conditions, one of the requirements of the heating system was that it provide separate zone control for each area. To accomplish this, a pump-injection control system was installed in each zone. Then, a mini-tube system was installed to connect each area efficiently from a cost and space perspective.
Featuring useful space-management and consistency features, minitube systems use variable-speed pumps to mix hot boiler water with cooler return water at manifold stations, rather than in the mechanical room. In addition to providing more even temperatures throughout the facility, the minitube system provides an orderly way of delivering water to each zone via small-between 1 inch and 1.25 inches-copper tubes, simplifying and reducing the cost of the tubing.
When Bonide's employees show up for work in the spring of 2001, office and plant personnel alike will experience the luxury of working in a building that was designed for comfort throughout every one of its 150,000 square feet.
For more information on PEXc piping and Thermal Solutions boilers from Burnham, circle 103 on the Reader Service Card.