Choosing the Right Industrial HVAC Systems for Manufacturing Plants

 

The selection of the appropriate industrial HVAC systems in a manufacturing facility does not involve the purchase of equipment but rather involves designing a stable and efficient environment surrounding your processes and employees. Any poor decision is reflected in the future as product rejections, unplanned outages, or power bills that keep on rising. The process of selection must begin with a clear idea of what the plant requires and not what a catalogue is selling.​

Know Loads and Process Requirements

Map your thermal and air quality loads prior to discussing equipment. All the production machinery, process heat, people, lighting, and envelope feed into the cooling and heating requirements. The temperature, humidity, and filtration goals of cleanrooms, food lines, coating booths, welding bays, or pharma units are very different and that is why generic comfort-cooling units can hardly be considered as the primary HVAC solutions to industries. Good designs divide the plant into zones process critical, comfort-only and storage and scale systems to each zone rather than over-scaling a single monolithic system.​

Select the Appropriate Core Cooling Technology

In the medium and larger facilities, the backbone is still central chilled-water based industrial HVAC systems. Air-cooled chillers may be reasonable with limited water supply, and with moderate loads, whereas higher, more continuous loads require water-cooled or evaporative cooling. In factories that have significant process heat (plastic molding, metal finishing, data-intensive automation) there should be a separation between the dedicated process chillers and human comfort cooling, otherwise one end will suffer at the expense of the other. It is important to match compressor type (screw, centrifugal, scroll, or magnetic-bearing) to load profile, variable-speed machines are cost-effective when load varies between shifts.​

Ventilation, Filtration and Air Handling

Air distribution without a properly engineered one renders conditioned water useless. The air handlers in industries should be able to cope with the large outside-air fractions in ventilation and ensure that pressure is balanced between dirty and clean spaces. The design of the duct is the actual error in many manufacturing plants: undersized returns, lack of balancing and duct design not to accommodate future changes of equipment. The source-capture systems and high-efficiency filters (and HEPA in the most hazardous locations) must be part of the general HVAC solutions to industries, rather than as an afterthought. This safeguards the quality of the product and the health of the workers.​

Not Extras, Humidity and IAQ as Design Inputs

Humidity is one of the mistakes that should be ignored. Tight humidity bands are required in electronics, printing, textiles, pharmaceuticals, and some food processes to stop the occurrence of static, curl, clumping or microbial growth. HVAC systems in industries can require desiccant dehumidifiers, steam or gas-fired humidifiers and appropriate control of condensate incorporated into the air-handling plan. Meanwhile, the indoor air quality (IAQ) standards of VOCs, particulates, and fumes should be corresponding to safety and regulatory standards; this frequently motivates outside air quantities and exhaust measures over comfort.​

Energy Saving and Management Strategy

The greatest lifetime cost is energy, and thus controls must be considered as fundamental design choice. Recent HVAC systems applied to industries utilize variable-frequency drives on fans, pumps, compressors; demand-based ventilation based on sensors; and building or plant-wide control systems that synchronize setpoints across zones and shifts. Makeup air or process water can be preheated by heat recovery of process exhausts or compressor waste heat. The part-load optimization strategy is most useful in plants that operate in multiple shifts or have high seasonal fluctuations, i.e. do not run the system at peak capacity on the peak day, but run it 80% of the time.​

Reliability, Maintainability and Lifecycle Thinking

Lastly, the correct industrial HVAC systems are the ones that can be maintained by your maintenance staff. That is, specifying industrial-grade parts, making sure that there are access points around the equipment to service it, standardizing on a manageable number of types of parts, and providing redundancy in the key areas. It also involves selecting the vendors that are able to offer documentation, training and long term support and not just a low bid. In situations where the total cost of ownership, capital, energy, maintenance, downtime, etc. is the determining factor, the end result is a plant with a strong, efficient system that silently contributes to production rather than consistently getting in the way.