A site was selected in East Wenatchee, across the Columbia River from Wenatchee, to construct a new 15,000-square-foot metal building for the CAT dealer. The building also included a 6,000-square-foot service area with roll-up bay doors, which open for equipment needing service. The building was all-metal except for some decorative brick in the office area. The design/build contractor chosen for the job was Hansen, Hansen, and Johnson of Sumner, Wash.

The design/build team was advised by local contractors that the most economical heat for the service area would be electric heat. John MacKenzie, project manager, was not convinced.

“I didn’t feel that unit heaters or other electrical systems would provide an efficient heating system for N.C. Machinery or their employees,” he said. “I was concerned with the high ceiling heights and large metal roll-up doors, which would open frequently to service the equipment.”

The design/build team decided to contact Rissman who determined the heating requirements of the building by using Space-Ray’s Compuheat™ loss analysis system. Four Space-Ray LTU130 U-Tube unitized low-intensity infrared gas heaters, each with a 130,000 Btuh heating capacity, were selected for heating the main service area and a fifth LTU 130 tube heater for the wash bay to melt snow and ice off the equipment, without negatively affecting the indoor temperature.

To heat the building, a Space-Ray perimeter heating system was selected. With this system, the four heaters were mounted horizontally at heights of 25 feet above the concrete floor and suspended from the metal roof near the roll-up doors, which is where the highest heat loss would occur. The system was vented to the outside.

Bob Remington, service supervisor for N.C. Machinery, said that the Space-Ray heaters have exceeded expectations.

“Our employees like them,” he said. “Productivity has been enhanced and employees seem more comfortable as compared with other heating systems I have evaluated.”

Rissman said that both companies have experienced the benefits of radiant technology.

“Since hot air rises with the electric heating system, air is over-heated above most people’s head’s, which is wasteful,” he explained. “Only after extensive heating of the air in the ceiling cavity is it forced down to a level where it can be sensed by a thermostat, typically five feet above the floor.”

Rissman also explained that heaters are usually cycled off before they can provide heat below that level. This means that the concrete floor is never heated. Body heat is drawn out of the feet and legs of employees and causes fatigue and low productivity.

“Air is not heated to the point where it would provide an even temperature at the floor level for optimum employee comfort,” said Rissman.

Publication date: 06/02/2003