The site A 12,000 m2 district with a hospital wing, pool, and offices had a steady year-round heat demand and paid high grid electricity prices. A 500 kWe natural-gas CHP engine was installed to supply base-load power and capture jacket plus exhaust heat for space heating and domestic hot water. What it recovered Electrical output: […]
Food Processing Heat Recovery: Capturing Process and Exhaust Heat
A heat-rich sector Food plants bake, cook, pasteurize, and chill around the clock. Both the process air and the building exhaust carry large amounts of recoverable energy – often with moisture, grease, or particulates that demand a cleanable, robust exchanger. Technology fit Enthalpic plate or rotary wheels recover both heat and moisture from humid exhaust […]
AHU Heat Recovery Selection Calculation: A Step-by-Step Method
Step 1 – Known airflow Start with the supply/exhaust airflow Q (m3/h). For balanced AHUs, Q_supply approx Q_exhaust. Step 2 – Temperature difference Find the outdoor design temperature T_out and the exhaust (room return) temperature T_exp. The available temperature lift is DeltaT = T_exp – T_out. Step 3 – Effectiveness Choose an effectiveness epsilon (typical […]
Waste-Heat Recovery Case Study: Stack & Exhaust
The opportunity A metal-finishing plant exhausted 18,000 m3/h of 160C air from curing ovens to atmosphere – pure lost energy. The brief was to recover it for winter make-up air heating and preheat a process water loop. The solution A high-temperature plate air-to-air exchanger (stainless, rated to 200C+) transferred exhaust heat to incoming fresh air. […]
Heat Recovery Standards and Certifications
When you specify or buy a heat recovery unit, third-party standards tell you the numbers are comparable and real. Knowing the key marks helps avoid inflated claims. Testing Standards AHRI 1060: North American rating method for air-to-air heat exchangers. EN 308: European test method for heat transfer in recovery components. ISO 16494: International method for […]
Heat Recovery Payback Calculation
Before buying a recovery unit, a quick payback calculation shows whether it makes sense. You only need a few field numbers and the local energy price. The Core Formula Annual energy saved (kWh) = 1.2 x airflow (m3/h) x eta x dT (C) x hours/year / 1000 Where 1.2 is the approximate volumetric heat capacity […]
Geothermal and Ground-Source Air Pre-Heating
The earth a few meters below the surface stays near constant temperature all year. That stable thermal mass can be used to pre-condition ventilation air before it reaches a building, cutting heating and cooling loads. How Ground Coupling Works Outdoor air is passed through a buried pipe loop (ground heat exchanger) or across a ground-coupled […]
Pharmaceutical and Cleanroom Exhaust Heat Recovery
Pharmaceutical plants and cleanrooms move huge volumes of HEPA-filtered air. Codes generally forbid recirculating exhaust that may carry contaminants, but the energy in that air can still be recovered using physically separated exchangers. Why Separation Is Mandatory GMP and HVAC codes require exhaust from containment areas to be discharged, not reused. Cross-contamination could compromise product […]
Commercial Kitchen Heat Recovery
Commercial kitchens run powerful hoods that throw away large amounts of hot, greasy air. Replacing it with conditioned make-up air is a major cost. Kitchen heat recovery captures the sensible heat while keeping grease and smoke out of the supply. Why Separation Matters in Kitchens Exhaust carries grease aerosol and odors, so any recovery device […]
Heat Exchanger Cleaning and Maintenance Guide
Heat recovery equipment only delivers its rated savings if it stays clean. Dust, grease, and moisture film raise pressure drop and lower effectiveness. A simple maintenance plan protects the investment. General Inspection Schedule Environment Inspect Clean Clean office air Every 6 months Annually Dusty / industrial Quarterly When dP +15-20 % Greasy (kitchen, booth) Monthly […]