HVAC Systems Guide for Cold Chain & Industry
HVAC engineering for non-comfort applications: process cooling, clean rooms, mushroom houses, and food/pharma plants.
Chiller selection
Air-cooled scroll: 5–150 TR, no water, simple. Air-cooled screw: 100–500 TR, better part-load. Water-cooled centrifugal: 200+ TR, highest efficiency, requires cooling tower & water treatment. For Indian process plants, magnetic-bearing oil-free centrifugals deliver IPLV 0.35 kW/TR — 35% better than typical.
AHU sizing
Sensible heat load (kW) / 1.2 / (ΔT × 0.34) = CFM. Coil ADP (apparent dew point) and bypass factor drive dehumidification. For pharma & food clean rooms, specify HEPA H13/H14 final filters, AHU casing leak class L1, and double-skin panels with 50 mm PUF.
Clean room HVAC
ISO 14644 classes: ISO 5 (Class 100) — sterile manufacturing, 250–500 ACH. ISO 7 (Class 10,000) — sterile prep, 30–60 ACH. ISO 8 (Class 100,000) — general pharma, 20 ACH. Pressure cascade: +15 Pa step between adjacent classes, with ISO 5 most positive. Magnehelic gauges at every doorway.
Mushroom HVAC
Most complex non-pharma HVAC. Each cropping room needs: cooling (sensible + latent for crop transpiration), humidification (ultrasonic or atomising spray, NOT pan humidifier), fresh-air exchange (4–6 ACH for CO₂ control), heating (PTC) for winter, and a recirculation fan for uniform distribution. Climate setpoint stability ±0.5°C, ±2% RH.
Process cooling
Dairy: 1–2°C chilled water to plate heat exchanger for milk pasteurisation cooling. Pharma: process glycol -10°C for reactor jackets. Food: 4°C for dough proofing rooms, mixing halls. Plastics: 12°C tower water for moulding machines. Each application has different ΔT, GPM/TR ratio, and water treatment needs.
Energy strategies
Variable primary flow chillers save 8–12% vs constant flow. EC plug fans in AHUs save 25–40% vs belt-driven backward-curved fans at part load. Heat recovery from chiller condensers can pre-heat process water (CIP wash water in dairy is a perfect match). Demand-controlled ventilation cuts fresh-air load 30–50% in occupied spaces.
Frequently Asked Questions
Can my chiller also feed a cold storage?
Only for chilled rooms above 0°C via a chilled-water coil (2–4°C secondary). Below 0°C, a dedicated DX refrigeration system is required — a chilled water loop would freeze.
What is the most common HVAC mistake in Indian food plants?
Undersized fresh-air handling unit. Bringing 35°C/80% RH outdoor air into a +4°C process room without proper dehumidification creates condensation, mould, and FSSAI compliance failures.
Need an engineered cold room quote?
Get a line-item BOQ from HyperCold's engineering team — heat load, PUF, refrigeration, controls, civil, all priced separately.
Related Guides
Industrial Refrigeration Systems Guide
Selection framework for industrial refrigeration plants in dairy, fisheries, ice manufacturing, and large-scale cold chain.
Mushroom Cold Room & Growing Facility Guide
Engineering and operating guide for button-mushroom production and storage facilities in India.
Cold Chain Logistics Guide for India
How a complete cold chain works in India — from pack-house to last-mile — and the engineering decisions at each stage.