Humidification is important in the winter months to maintain a healthy indoor air climate. Relative humidity levels below 40% will lead to sinus irritation and increased respiratory infections. Conversely, humidity levels above 60% can lead to mold and mildew growth. Therefore, humidification needs to be well controlled to make sure it is in the proper range and in sufficient quantity. Humidity can be added with stand-alone humidifiers but is more effectively distributed if it is part of a ducted air system (as of yet, there are no humidification devices that work with mini-splits or the slim-duct units). The old-school control approach was to only run humidity when there was a call for heat; we have found that that does not permit the humidifier to operate long enough during the day to adequately humidify the space. We now let the humidifier do the control – it determines when to operate the blower and humidifier based on the humidity level required in the space.
Humidity can be generated in a multitude of ways – evaporating water through a hot element to create steam, evaporating water through a water soaked pad using air flow, ultrasonic bombardment of water to break it up into vapor, and a rotating wheel sitting in a shallow container of water. Based on our experience, we do not recommend the ultrasonic or rotating wheel type of humidifiers. The steam humidifiers and fan powered humidifiers each have pros and cons:
These are the most powerful in terms of gallons of water put into the air per day because they actively add energy to the water to turn it to steam. This in turn means that they are the most expensive to operate and require annual maintenance (or more frequently) to make sure the heating element is clean. As the heating element fouls up from minerals in the water, it uses more and more electricity to operate.
Fan Powered Humidifiers:
These units are slightly less powerful in terms of gallons per day but are much less expensive to operate and maintain. They have a built in fan inside that moves air past a pad – when there is a call for humidification, a small water valve will open to add water to the pad, and the small fan will start blowing air through the pad into the air stream of the ducted system.
Our goal is to be Martha’s Vineyard’s premier plumbing and HVAC shop – we appreciate the opportunity to service, install, and rescue your humidification system!