There is no need to give most technicians details about what humidity is; however, many companies venturing into the IAQ market are seeking technology and application examples to follow that will keep techs on the cutting edge.
AxAir Nortec Inc., Ogdensburg, N.Y., and Mee Industries Inc., Grandville, Mich., are two companies bringing new humidification technology and application examples to the HVAC industry.
It features graphic representations of the humidifier and its key parameters for up to 75 functions. This program also suggests maintenance programs and is able to recognize problematic symptoms before an actual event occurs. The company calls Nortec On-Line a "24/7 humidifier watchdog."
Technology and programs aren't the only necessities for successful humidification installations. Efficiency is not only necessary, but it is also currently a great concern for end users. Mee Industries Inc. brought a new atmosphere to two locations in Ann Arbor, Mich.
The first installation example was for the National Sanitation Foundation International, The Public Health and Safety Co. (NSF).
NSF helps protect the public by certifying products and writing standards for food, water, air, and consumer goods. Its laboratories test thousands of products each year. The labs require close environmental control to maintain the integrity of the testing process, and to not introduce any variables into the results. The lab area and supporting office areas were humidified using nine gas-fired steam generators. The high energy costs and extensive maintenance required to keep the units operating were increasingly burdensome, according to the company.
Mee Industries was called in to assess the situation. The company chose the Mee Fog high-pressure humidification system.
The building has four air handlers, rated at 30,000 cfm each, with two units operating as 100 percent make-up air units for the lab exhausts and two operating on economizer cycles for the office and support areas. Each unit is served by a single high-pressure pump that provides 1,000-psi water to the nozzle headers via staging solenoids. The system is controlled by a Siemens building automation system.
Each of the make-up units has a maximum load of approximately 1,000 lb/hr, while the general-area units have loads of 300 lb/hr. The load is matched using staging solenoids that bring on nozzle headers in various combinations. Excess moisture that is not absorbed into the airstream is collected on the cooling coil and drained away. The total electrical load for this system is 2.25 kW.
According to Mee Industries and NSF, the annual energy savings for this facility, as compared to its gas-fired steam-generating humidifiers, is in excess of $75,000, with a further reduction of $18,000 in annual maintenance costs.
Chuck Carpenter, facilities manager and construction coordinator for the addition, started looking for ways to design an energy-efficient clean room that would serve the company's manufacturing needs. The present complex has multiple clean manufacturing areas. High operating costs and demanding maintenance requirements, however, have been Pall's complaints after experiencing multiple types of dehumidification systems.
Carpenter also chose the Mee Fog high-pressure humidification system. To preserve the integrity of a clean room envelope, positive pressure has to be maintained in the room at all times. To accomplish this, large amounts of outside air were required to offset the exhaust and room leakage. The large airflows must have tight temperature and humidity control, and accomplishing this in a budget-friendly way was important to Pall.
The new clean room space received a custom roof-mounted air handler rated at 45,000 cfm; 35,000 cfm recirculates air and 10,000 cfm passes through heating-cooling coils. The nozzles are located in the 35,000-cfm section and humidify the recirculation airstream.
A single high-pressure pump provides 1,000-psi water to the nozzle headers. System capacity is controlled by controlling the pump speed, which modulates the amount of water that is pumped to the nozzle headers.
"The system controls the room humidity levels perfectly. I have had to do very little maintenance on this system and it integrated into the building management system very well," said Carpenter.
Publication date: 08/14/2006