The heating, ventilation, and air conditioning (HVAC) system in an industrial building is like a giant version of a residential furnace and air-conditioner combination. While there are significant similarities, there are also a few differences. Size is the biggest one; industrial air-handling can take up a large portion of building space, and requires many large, high-powered fans to blow air into heating ducts. (These fans consume a large amount of the building’s total power). Typical air-handling units work in an "H". Outside air comes into the unit via one leg and stale air is vented from the other leg. The bridge of the "H" is where the new and used air is mixed to salvage some of the heat and humidity from the exhaust, which helps save money by warming and humidifying the incoming air. The mixed air is then heated or cooled, and it leaves the unit and supplies the building. Typically, 25 percent fresh air is mixed with the recirculated air. Units that use this process are sometimes called "economizers" as opposed to just regular "air-handling units."

The IL Centre has six air-handling units. The first unit houses the enthalpy wheel, which feeds air to all of the other units. Each air-handling unit serves a specific zone of the building. Each unit must provide a certain number of “air exchanges” per hour, and this number depends on the maximum number of people who will be using the space at any given time.how much does it cost to repair an ac unit The air-handling fans on the right are sending and receiving air from each of the colour-coded zones on the map. parts of a central ac unitThe white zones receive no air directly; where is air handling unit locatedair diffuses in through vents and doorways. (The sixth unit, which is not indicated on the maps, serves Goodwin Hall).

Bespoke AHU designs ensure the optimum technical and commercial solution for each individual application from basic comfort ventilation systems through to criitcal applications in hospital operating theatres, food production, and clean rooms for medical, engineering and pharmaceutical products. Imofa UK’s overall unit designs and component selection focus on achieving maximum energy efficiency within any building restrictions on unit size and configuration, and cost limitations. The latest developments in high efficiency heat recovery are employed to minimise energy costs, satisfy energy efficiency regulations part L, and contribute to building owners objectves on carbon emissions. Vertical or horizontal, double deck or side-by side design configurations are employed to suit building space restrictions and operating criteria, and are supplied as a single unit, modules, or flat-pack for site assembly. Units for standard ventilation applications are aluminium penta-post construction with double skin 25mm or 50mm, panels with galvanised mild steel inner skin and plastisol coated mild steel outer skin.

The panels enclose high density rockwool material with good acoustic and thermal insulation properties. Higher specifications include units to comply with HTM03 -01 for hospital operating theatres, and individual companies’ specific requirements for cleanrooms, swimming pools, and process systems in the food and pharmaceutical manufacturing industry . Components are selected from the most up to date energy efficient options available to best meet the unique commercial and technical requirements of each individual poject. Frequency Inverters, enabling motor/ fan speed to be infinitely varied, matching volume flow to changing demand and providing major savings in power consumption. To provide clients with a complete package solution Imofa UK, in partnership with associate specialist companies will also supply:Hospital's Aging Core Poses Maintenance, Engineering Challenges Building-Automation System Streamlines Preventive Maintenance Part 3: Energy-Efficient Chillers, Air-Handling Units Demand More Maintenance

Organization Closes Old Hospital, Opens New Facility Same Day By Chris Matt, Managing Editor - Print & E-Media The equipment lineup that has allowed Gateway Medical Center to operate at peak efficiency and optimize IAQ includes three centrifugal chillers, 22 air-handling units featuring variable-speed drives, the BAS, and high-efficiency particulate arrestance (HEPA) filters, which remove at least 99.97 percent of airborne particles 0.3 micrometers in diameter or larger. One chiller features variable-frequency drives, while the other two load and unload as needed. The old Gateway Medical Center did feature a BAS, but it was an older version of the system monitoring the new facility. Holzkamper says the newer technology does require more PM than the chillers and BAS in the old hospital. "When you get into variable-frequency drives, you have more electronics and more electrical parts involved in the controllers," he says. "You have more electrical PMs and maintenance there.

(The BAS) needs to be tuned up and looked at by the factory at least once a year to make sure it's working as it was originally designed to do when it was installed." While technicians were unfamiliar with some of the technology in the new facility, they were able to transfer their experiences with the BAS in the old hospital to the new. "It was fairly comparable to the new technology, so it wasn't a big learning curve," Skeens says. "That first year, we took a little time to find out little tweaks and nuances of the system. Maintenance-wise, it really saves a lot of time." One of the biggest equipment changes from the old hospital to the new was the air handlers. The old hospital, though it was 200,000 square feet smaller than the new building, featured 28 more air-handling units. The HVAC landscape of the old hospital, which featured under-window units on an entire floor, required more air handlers to meet the needs of various types of systems. Similar to the chillers and BAS, the new air handlers also demand more maintenance.

"On the newer units, you have more electronic sensors on the drives," Holzkamper says. "(The sensors) tell you, if you have dirty filters, to go in and clean them. They tell you basically everything that's going on with that unit. Of course, with more sensors and more electronics, you have more stuff that can go out on you." Despite being 200,000 square feet larger than the old hospital, the new Gateway Medical Center's energy bills are about the same as those of the old facility, Holzkamper says. Energy-efficient equipment, extra insulation, and improved maintenance practices all play a role in controlling energy costs. "It was a surprise for me because I figured (utility costs) would probably double," Holzkamper says. "But we had a 1954 core in the old hospital. When you have something like that and you start building additions to it, you actually have to bring all the utilities to the addition because the core was never set up for it. That's where you start losing your efficiency and losing your money."