Despite normally high energy costs in the Pacific Northwest, three counties in Washington State enjoy one of the lowest power rates in the U.S. due to the local utilities' operation of hydropower dams. "To the uninformed customer, electricity is the way to go for this region," notes Tom Rissman of Space-Ray Northwest, Space-Ray's representative for Washington State and Western Idaho. "Even so, Space-Ray's gas infrared heaters easily compete because of the technology's high comfort level and other unique benefits it has over electricity."
Take, for example, N.C. Machinery, the local Caterpillar dealer in Wentachee, WA. When a larger facility was needed to service its expanding array of heavy-duty earthmoving and excavation equipment, tractors and backhoes, a site was selected in East Wenatchee to construct a new 15,000 sq ft metal building, including a 6,000 sq ft service area with large roll-up bay doors that open to admit equipment needing servicing. The ceiling in the service area is 26 ft high at the eave and 31 ft at the peak. The 16 x 16 ft metal roll-up doors do not have windows.
Infrared Heaters Selected
At a pre-construction meeting, design/build contractor Hansen, Hansen and Johnson of Sumner, WA was advised by local contractors and others that the most economical way to heat the service area and adjacent wash bay was electric heat. But 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," MacKenzie noted. "I was concerned with the high ceiling heights and large metal roll-up doors, which would open frequently to service the equipment."
MacKenzie also felt that equipment outside waiting for service, often in sub-zero weather, would affect the efficiency of electric heating once it was brought in. Winter stand temperatures normally range from 15ºF to 20ºF.
"Equipment could be covered in snow or ice, which would make it difficult to work on without many hours of warm-up time," MacKenzie noted.
Hansen, Hansen and Johnson contacted Space-Ray Northwest's Rissman, who determined the heating requirements of the building using Space-Ray's exclusive COMPUHEAT™ computerized heat loss analysis system. Four Space-Ray LTU130 U-Tube unitized low intensity infrared gas heaters, each with a 130,000 Btu/hr heating capacity, were selected for heating the main service area, and a fifth for the wash bay, to melt snow and ice off equipment without negatively affecting the indoor temperature.
To heat the building, a Space-Ray perimeter heating system was selected. The four heaters were mounted horizontally 25 ft above the concrete floor and suspended from the metal roof near the roll-up doors, where the highest heat loss would occur. The system was vented to the outside.
Space-Ray LTU tube heaters were specified because their unitized pre-assembled design allowed for lower installation costs, simpler arrangement within the facility, and less maintenance. The calorized emitter tube of the LTU heater provided higher emissivity, unsurpassed corrosion resistance and made it extremely efficient. Operating independently, Space-Ray's infrared heaters can be individually thermostatically controlled for greater operating control of the heaters.
"Radiant heating is just more effective and efficient than electric heat, " Rissman says. He says that the LTU heater has one of the longest life expectancies of infrared heaters which, he noted, average over 22 years. That compares to about five years for electric heating, which normally also requires a great deal of repeat maintenance.
The heaters were installed at N.C. Machinery in December 2001, with startup two months later. Bob Remington, service supervisor for N.C. Machinery, said that Space-Ray heaters have exceeded their expectations and created a very comfortable work environment.
"Our employees like them," he noted. "Productivity has been enhanced and employees seem more comfortable as compared with other heating systems I have evaluated."
Rissman said that both companies were quick to experience the benefits of radiant heat technology, which works from the bottom up, warming people, floors, and machines first for optimum comfort.
"Since hot air rises, with the electric heating system, air is overheated above most people's heads, which is wasteful, " Rissman said. "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 mounted five feet above the floor. Heaters are usually cycled off before they can provide heat below this level. Thus, the concrete floor never becomes heated. Body heat is drawn out of the feet and legs of the employees, normally causing fatigue, low productivity and absenteeism. Air is not heated to the point where it would provide an even temperature at the floor level for optimum employee comfort."
Product Features
Space-Ray LTU130 U-Tube low intensity heaters have a unique self-contained draft inducer, which pulls the products of combustion through the combustion chamber for increased radiant efficiency and safety. Other features include a factory-assembled tube and reflector body with quick three-bolt control box assembly for easier on-site installation, unique monitoring lights for online diagnosis and simple, easy maintenance, and a calorized steel emitter tube for higher radiant efficiency.
CSA design certified for horizontal and vertical venting, the draft inducer rotates 90 degrees by simply moving the assembly. A state-of-the-art step opening combination gas valve also provides for quieter ignition. Safety is enhanced by the closed combustion chamber design and direct spark ignition with 100% safety shut off control. The rugged one-piece cast iron burner comes with a 10-year limited warranty. Units are adaptable for either vented or indirect vented applications.
