The Hotline Newsletter
Fall 2001
Is Inducing Rotating Air the same as Air Rotation®
The answer is both yes and no! Both space heating concepts are used to circulate and heat the air in open areas over 10,000 square feet as typically found in manufacturing plants, warehouses and distribution centers. However, the Cambridge Induced Rotating Air approach is more effective and more energy efficient than conventional Air Rotating and Air Turnover Heating systems (called Air Rotation® by Johnson-Marcraft). The Cambridge Induced Rotating Air concept is different because the heated air mass is directed towards the floor where you want the heat. All other Air Turnover and Air Rotating systems are floor mounted and direct their heated air toward the ceiling, resulting in heated ceilings and cold floors.Cambridge Induced Rotating Air System Designed for Maximum Operating Efficiency
INDUCED ROTATING AIR is possible because the Cambridge Direct Gas-Fired Space Heater has the industry's highest discharge air temperature (160°F) and a high discharge air velocity that induces more than 10 times the blower CFM (10:1 induction ratio). The high velocity air (primary air) emerging from the Cambridge S-Series heater induces air movement within the building (secondary air). This effective process of entrainment, or drawing of secondary air into the warmer primary air, is an essential part of the dilution of the high discharge air temperature and good air distribution. This creates total air movement within the building, thereby eliminating stagnant air areas and reducing temperature differences in the building. This resulting air mass consisting of induced air also overcomes stratification caused by the natural effects of heat rising to the ceiling.
The Proven Difference Between Induced Rotating Air & Air Turnover
A Consolidated Stores distribution center in Ohio provides an excellent real world comparison of the true differences between the Cambridge Induced Rotating Air System and conventional air turnover equipment. They built a new 40 ft. tall, 340,000 square foot facility which was originally heated with four floor mounted air turnover heaters. The system had lots of btu's (17,500 MBH input) and horsepower (100 HP continuous usage), but it wasn't providing heat in the right places. Employees complained during the winter that the upper mezzanines were overheated and the dock floor areas were freezing. The four large indirect-fired heating units occupied valuable floor space and were quite noisy. Management was unhappy with the high gas and electric operating costs because the large heating system was running continuously.
Finally, four years later, Consolidated Stores replaced all four of their air turnover heaters with five direct gas-fired Cambridge Space Heaters using the Induced Rotating Air concept. The Cambridge heating system required only 10,325 MBH input (41% less) and only 37.5 HP (62% less) on an intermittent basis. The results were dramatic. Additional valuable warehouse floor space was made available. The employees enjoyed a quieter and improved work environment with warmer dock floor areas and a cooler, more comfortable upper mezzanine. Lower gas and electric utility bills, reduced maintenance costs and improved employee productivity enabled the owner to pay for the Cambridge replacement system in less than two years.
After only four years they replaced air turnover heaters with more energy efficient Cambridge space heaters.
Before - Air Turnover System
After - Cambridge Solution
