ASHRAE 55 and Thermal Comfort ASHRAE 55 defines acceptable thermal environments through the PMV or PPD model, balancing air temperature, mean radiant temperature, humidity, air speed and clothing. Heat recovery changes supply-air conditions, so it must be designed without degrading comfort. Humidity and IEQ Enthalpy recovery transfers moisture as well as heat, helping hold indoor […]
Heat Recovery in Greenhouses and Horticulture
The Energy Challenge Greenhouses and indoor farms maintain warm, humid conditions around the clock. Heating can be 30 to 50 percent of operating cost, while transpiration loads create enormous latent heat in the exhaust air. Recovering Heat from Exhaust and Condensation Air-to-air plate exchangers recover sensible heat from ventilation exhaust; condensing heat-recovery units capture latent […]
Brazed Plate vs Gasketed Plate Heat Exchangers
Construction Brazed plate exchangers fuse stainless plates with copper or nickel under vacuum, with no gaskets and no frame bolts. Gasketed plate exchangers clamp plates between a fixed and moving frame using elastomer gaskets, allowing plates to be added or removed. Comparison Factor Brazed Gasketed Max temperature or pressure Higher Moderate Maintenance Sealed, service-free Plates […]
Variable Refrigerant Flow (VRF) Heat Recovery Systems
What Is VRF Heat Recovery Variable Refrigerant Flow (VRF) heat recovery systems use a single refrigerant loop with branch selector boxes to deliver simultaneous heating and cooling to different zones. Recovered heat from cooling zones is redirected to zones calling for heat, reducing the building net energy use. Heat Recovery vs Heat Pump VRF Two-pipe […]
Heat Recovery Ventilation in Schools and Classrooms
Why Schools Need Heat Recovery Ventilation Classrooms are among the most densely occupied spaces in any building. With 20 to 30 students per room and high metabolic CO2 loads, ventilation rates under ASHRAE 62.1 approach 10 to 15 litres per second per person. Without recovery, exhausting that air year-round means discarding both heating energy in […]
Heat Recovery for Sports & Recreation Facilities: Pools, Gyms, Arenas
Swimming pools Pool halls exhaust warm, moisture-laden air constantly. Without recovery, that latent heat is lost. An enthalpic rotary wheel or membrane plate unit recovers both temperature and humidity, slashing pool heating and dehumidification bills 40-60%. Gyms and fitness centers High occupancy means high fresh-air demand and high moisture. Sensible plate recovery handles the heating-season […]
Desiccant Wheel vs Energy Recovery Wheel: When to Use Which
Energy recovery wheel Transfers both sensible and (if enthalpic) latent heat between supply and exhaust air. Goal: cut HVAC heating/cooling load. Made of aluminum or polymer matrix, sometimes with a moisture-absorbing coating. Desiccant wheel Impregnated or coated with a desiccant (silica gel, molecular sieve, or zeolite). Its job is dehumidification - it pulls moisture from […]
Laboratory Heat Recovery: Capturing Fume Hood Exhaust Energy
The separation rule Laboratories are energy hogs - fume hoods run at high face velocities and dump conditioned air outdoors continuously. A lab can use 5-10x the energy per square meter of a typical office. Recovering that exhaust energy is one of the fastest paybacks available. Fume hood exhaust may carry chemical vapors, so supply […]
Combined Heat and Power (CHP): Cogeneration Meets Heat Recovery
What CHP does Combined Heat and Power (CHP), or cogeneration, produces electricity and useful heat from a single fuel source. Instead of venting engine or turbine exhaust and jacket heat, a CHP plant captures it for space heating, process steam, or domestic hot water - lifting total fuel efficiency from ~40% (grid power alone) to […]
Energy Recovery Wheel Troubleshooting: Common Faults and Fixes
Low effectiveness Cause: wheel not rotating (motor or belt failure), or condensate/fouling blocking the matrix.Fix: verify rotation and speed; wash the wheel with low-pressure water and a mild detergent; confirm belt tension. Frost or ice buildup (cold climates) Cause: exhaust-side temperature dropping below freezing.Fix: enable purge sector, reduce speed, or add preheat. See frost protection […]