Any heated or cooled air carries energy in two forms. Sensible heat<\/strong> changes the dry-bulb temperature of the air without changing its moisture content. Latent heat<\/strong> is the energy tied up in water vapour: it moves when moisture condenses or evaporates, and it can change without any temperature change at all.<\/p>\n Air-to-air heat recovery matters because the two forms are recovered by different hardware. A \ud310\ud615 \uc5f4\uad50\ud658\uae30<\/a> only touches sensible heat; an enthalpy wheel<\/a> or membrane core recovers both. Getting this distinction right is the first step in choosing between sensible and total-energy recovery<\/a>.<\/p>\n The sensible energy in a flow is:<\/p>\n For air, specific heat is about 1.006 kJ\/kg.K and density about 1.2 kg\/m3 at 20 degC. A stream of 1 m3\/s cooled by 10 K releases roughly 1.2 x 1.006 x 10 x 1 = 12 kW of sensible heat. This is the number most recovery calculations start from, and it is what \ud6a8\uc728 \uc9c0\ud45c<\/a> report as temperature effectiveness.<\/p>\n When air is cooled below its dew point, vapour condenses and releases its latent heat of vaporisation (about 2450 kJ\/kg of water). In ventilation, exhaust air in a humid building can carry more energy as latent heat than as sensible heat. Recovering it requires a desiccant-coated wheel or a membrane that passes water vapour, not just a metal plate.<\/p>\n Can a plate exchanger recover humidity?<\/strong> No. A sensible plate transfers heat through the wall but does not pass water vapour, so indoor moisture stays in the exhaust.<\/p>\n Is latent recovery always better?<\/strong> Not in dry climates, where it adds cost and can cause over-drying. Match the recovery type to the local psychrometrics.<\/p>\nSensible heat: the temperature part<\/h2>\n
Q_sensible = mass_flow x specific_heat x temperature_difference<\/code><\/p>\nLatent heat: the moisture part<\/h2>\n
Why the split decides the equipment<\/h2>\n
\n
Frequently asked questions<\/h2>\n