Currently, the most widely used residential humidification technologies are forced air furnace mounted bypass wetted media, spray mist, and steam humidifiers. They all use city water as a water source and require furnace heat or electricity to evaporate the water. Mineral deposition, white dust, and microbial growth problems are associated with these humidifiers. For commercial building humidification, de-mineralized water is typically used for humidification equipment like steam heat exchangers, fogging system, electric, and ultrasonic humidifiers. Therefore, in addition to the energy consumption for the water evaporation, energy is also needed to produce the high quality de-mineralized water.
An innovative technology called Transport Membrane Humidifier (TMH), has been developed by the authors to humidify home air without external water and energy consumption, while simultaneously recovering waste heat from the home furnace flue gas to enhance the furnace efficiency. The TMH technology is based on our previous extensive study on nanoporous membrane water vapor separation from combustion flue gas, and a design for residential home humidification application was first developed. It has been proved by both laboratory prototype testing for long term performance, and by two occupied single family home demonstrations for two heating seasons. The technology can provide whole house humidification without any external water consumption, and at the same time boost the furnace efficiency. Compared with conventional furnace mounted humidifiers, the TMH does not need additional furnace fuel for the water evaporation, no white dust in the home, no microbial growth since there is no standing water involved. Therefore, it is an innovative technology that can provide energy saving, water saving and healthy building humidification.