Humidification

[NorPwr]

I have a 20,000 cfm air handling unit with 214lb/hr humidifier, the injectors are located in the outlet duct of the AHU. Every time the unit shuts down, the humidifier fills the duct work and unit with steam. The humidifier shuts down immediatly when the unit does but holds enough heat to fill the ducts. This is an unpressurized system so I was thinking of simply installing an electric cutoff valve in the steam line to the injector that would direct the steam outside. However this is located in an extremly cold climate, and like they say where there is water there is ice so blockages are an issue. Any thoughts..

 

[ChrisConley]

Hi NorPwr,

Is there any way to get the unit to run for an extra minute or so after the signal to shut down? On a DDC system this could be fairly simple, if not you could look into timers.

Or, if you do install a cutoff valve, why pipe the excess to atmosphere? If you stop the steam, then allow it to condense in the piping and humidifier and run to drain you should be ok. What kind of humidifier is it: Natural Gas, Direct, etc?

You could also talk to the humidifier suppliers, or to other manufacturers for ideas:

http://www.dristeem.com,

http://www.humidity.com

 

[NorPwr]

Thanks for the quick reply Chris

No there is no way for the unit to continue running, usually I run into problems with this on power fail. I like the idea of not using an atmosphere vent that simplifies things alot. I wonder is there a simplier way of solving the problem without having to use such a valve?

It is an electric boiler

Regards,