humidifiers

dana_3

what are the advantages to using hot water on by-pass type humidifiers ( eg. skuttle, aprilaire )

Brad White_119

Slightly higher

evaporation but the difference is minor. The only margin you are saving is the sensible heat of taking cold water from the 50-65F temperature starting range to the point of evaporation (which depends on the RH if incoming air more than anything).

The heat required to evaporate, as in steam, is far greater than the initial rising of water temperature.

You probably would not notice any difference at any given time. If you monitored your RH with a data logger I suppose you might see a difference in rate of rise. If I had to guess I would say 10% would be a generous dividend.

Firstly, if a rotary reservoir (yuck) the incoming water is immediately diluted to practically room temperature.

Secondly, if a wetted pad type, when the solenoid valve opens, the water sitting in the pipe is also practically at room temperature, unless you are right off a running recirculation line. (Similarly, the cold water sitting in that line would as well be close to room temperature at first anyway.)

Thirdly, supposing you were coming off a fresh hot water recirculating line- by the time the water hits the pad it almost immediately cools (by evaporation granted, so that works), but the incoming bypass air would also be about as warm. It is the entering low RH of the incoming bypass air that evaporates and carries off the moisture.

Brad