It may be hard to believe, but very few office locations provide humidification for human comfort during the heating season. It seems that if humidity is not required to facilitate the manufacture of a product it doesn’t get installed, yet we would not think of going without a humidifier in our homes. Why we won’t tolerate nose bleeds and static electric shocks in our homes yet accept poor air quality in our place of business has always confused me. Many businesses could not operate without the addition of humidity such as textiles, printing and agriculture to name a few. May-be it is the cost of the equipment or the cost of energy or possibly the maintenance costs. Did you know that if the air is too dry that your nasal mucous glands kick into high gear and will make your nose run like a faucet. Air that is too dry will provide the ladies with a “Bad Hair Day” and make your hair stand on end. Dry air will generate static electricity that can give you a very uncomfortable electric jolt when touching a door handle or make your clothing cling just the same way as it does in a clothes dryer if you don’t toss in a Bounce or Fleecy sheet. You need more heat (higher temperature) to feel the same level of comfort than if the humidity was correct. More heat means higher energy costs and expense. Germs, bacteria and viruses breed in conditions outside of the normal comfort zone and generate lost time due to illness. With this understanding there is no business owner that would not want to make the office environment comfortable.
Humidification systems in commercial, retail and industrial applications are quite different from the residential models of yesteryear where a simple tray of water on a radiator or a boiling pot of water on the stove or hot shower would add lots of moisture to the air. Residential humidifiers started with porous water plates that wicked water up into the air stream and developed into rotating sponge pads that air flow caused evaporation of the water into the air. The modern residential humidifier uses a water panel and flow through design to prevent the stagnation of water and bacteria buildup in the systems.
Commercial / Retail and Industrial systems require a tremendous amount of humidity by comparison to residential systems as there are more air changes per hour, more traffic, looser building construction and most likely some form of exhaust running constantly. Systems for these applications can take on many forms from steam to atomizing sprays to fogs and can use electricity or gas or simply water pressure to generate the humidity. Whether steam, spray or fog is introduced through a ducted air system or directly into the air there is a concern for condensation that can be very damaging. This condensation occurs at a combination of temperature and humidity called the “Dew Point”. There is actually a chart that was developed to illustrate where the Dew Point would occur and also how much moisture could be added to air at specific temperatures. The chart is “Phychrometrics” and is the key tool for engineers and designers for sizing equipment. Excess humidity can be just as damaging as too little humidity and is important to regulate in areas such as indoor pools. A company called Dectron who manufactures the Dry-O-Tron unit for efficient climate control of indoor pools effectively wrote the book on this subject.
Any of the above humidity systems that use ductwork for the delivery system will generate condensation in the ductwork that if not properly contained will rust out ductwork in short order, but also leak from the duct connections and destroy ceilings plus anything below. Special care must be taken with the control system to ensure a high enough air temperature upstream of the humidity distributor to lessen or prevent condensation. It is typical design of those that know what to do, to seal the ductwork with a joint compound and slope the duct so any condensation can be collected and drained as needed. Additional controls will ensure the fan of the HVAC unit is moving air before allowing the humidifier to cycle on and also cycle the humidifier off if the percentage of moisture in the air exceeds limitations. The slope of the steam probe and condensate return lines are essential to proper operation of the unit. The most common of the steam type of humidifiers uses high voltage electricity to boil waterin a disposable cylinder and pipe the steam through a rated hose assembly to a nozzle or probe that fits into a duct. The replacement cylinders are not cheap and will last for “may-be” one season depending upon the hardness of the water and the demand for steam. These units use a considerable amount of hydro whether 208/230 single or three phase or 600 volt, three phase power.
I have seen an innovative way of humidifying a classy office space with the addition of a waterfall fountain in the reception area. If there was a problem with this method it is in preventing over humidity and maintenance of the unit.
The “Father of Modern Air Conditioning”, Mr. Willis Carrier developed all his ideas from humble starts in the control of humidity in textile mills while employed by the Buffalo Forge Company.