Before spending capital on an air-to-air heat recovery system, any serious buyer asks the same question: how long until it pays for itself? The answer is not a mystery and it does not need specialist software, a spreadsheet and a clear method give a defensible simple-payback number that survives scrutiny from finance and from the […]
Enthalpy vs Sensible Wheel: Moisture Transfer
A rotary energy wheel is one of the most effective air-to-air recovery devices available, routinely reaching 70 to 85 percent total effectiveness, but not every application wants what the wheel is selling. The deciding factor is the matrix coating: a plain aluminium wheel moves only sensible temperature energy, while a desiccant-coated enthalpy wheel also transfers […]
Run-Around Coil Systems: Design Rules for Separate Airstreams
When the supply and exhaust ducts are in different parts of a building, or when you need absolute stream separation with no rotating parts, the run-around or coupled coil loop is often the only sensible recovery option. It uses two hydronic coils, one in the exhaust and one in the supply, joined by a pumped […]
Frost and Defrost Strategies for Rotary Energy Wheels in Cold Climates
A rotary energy wheel is exceptionally effective at recovery, but in cold climates that same effectiveness becomes its weak point: the wheel constantly rotates the cold supply side through the warm, moisture-laden exhaust, and below freezing the exhaust condensate freezes onto the matrix and can block the duct. Understanding why wheels frost and how to […]
Pool Dehumidification & Heat Recovery
A natatorium is one of the toughest HVAC environments in any building: warm water evaporates continuously, loading the air with vapour that condenses on every cold surface and rots the structure if ignored. Ventilation must remove moisture, not just heat, and the make-up air it pulls in is expensive to condition. The right air-to-air recovery […]
Classroom ERV: Cutting HVAC Energy in Schools Without Sacrificing IAQ
Cramped classrooms with 30 students can blow past 1,000 ppm CO2 within an hour of occupancy if ventilation is weak, and ASHRAE 62.1 sets a minimum outdoor-air rate that, met with simple make-up air, dumps expensive conditioned energy straight out the window in winter. An energy recovery ventilator (ERV) or heat recovery ventilator (HRV) breaks […]
Heat Recovery for Hospital Operating Theatres and Isolation Wards
Hospitals ventilate harder than almost any other building type, and operating theatres and isolation wards sit at the extreme end: 20+ air changes per hour of conditioned air, strict directional pressure relationships, and zero tolerance for contaminated air reaching patients or staff. That intensity makes recovery valuable but also constrains it. This article covers where […]
Cleanroom Make-Up Air Recovery: GEP & ASHRAE 90.1
Pharmaceutical cleanrooms condition enormous volumes of 100% outdoor air to hold tight temperature, humidity and particulate limits, and that make-up air is the single largest controllable energy drain in a GMP facility. A properly specified air-to-air heat recovery core can hand back 60–75% of the sensible energy in the exhaust before it is thrown away, […]
Sensible vs Total Energy Recovery: How to Pick the Right Exchanger
A practical guide to choosing between sensible-only and total-energy recovery for commercial AHUs, with capital cost ranges and break-even analysis.
Plate vs Heat Pipe vs Rotary Heat Exchanger: Which One to Specify
A practical selection framework comparing plate, heat pipe, and rotary enthalpy exchangers across efficiency, cross-contamination, pressure drop, and lifecycle cost for industrial ventilation projects.