Humidifirst’s patented Mist-Pac series of ultrasonic humidifiers are designed for space-saving humidification and replacement of steam canister humidifiers. Each unit is designed and built for simplicity of installation and maintenance. Simply plug the electrical cord into a standard outlet, and turn the humidifier on.


It’s as easy as “Plug ‘n Go!”

models and configuration of









  • 5

  • 15

  • 20

  • 30

  • 40


  • 9x14x12.5

  • 21x14x12.5

  • 21.5x16x13

  • 29x16x13

  • 37.5×18.5×15


  • 120/140

  • 120/420

  • 120/490

  • 120/700

  • 120/1050

WEIGHT (lbs)

  • 10

  • 16

  • 28

  • 42

  • 60

features and benefits of





  • Plug ‘n Go. The MP5, 15, 20 & 30 are the only humidifiers that do not require hard power and control wiring.

  • Require hard power and control-wiring.

  • Reduces price of installation.

  • Quick connect/disconnect fittings for both power and water.

  • Hand piped and hard wired.

  • Easier and faster to service.

  • Easy access to all parts.

  • Difficult, tight access to parts.

  • Easy to service. Reduced maintenance costs.

  • No flush cycle.

  • Steam canisters require hard pipe drains for boiling water flush cycles.

  • Reduced installation cost.

  • Uses energy-efficient ultrasonic transducers to produce a pure mist.

  • Many use steam boilers or electric calrods that are high electricity consumers.

  • Can save the user thousands of dollars per year in operating costs.

stainless steel cart

This stainless steel cart holds a Mist Pac 20 or Mist Pac 30 Ultrasonic Humidifier. It has a factory mounted blower, pre-built stainless steel piping for supply water and safety drain mounted humidistat, stainless steel control panel and 120v powercord. The supply water connection can be ordered with either a standard garden-hose fitting for regular building water or with a stainless steel fitting for de-ionized treated water. This high-capacity, mobile HumidiCart is designed for large open rooms, winery barrel rooms, grow rooms and for the “immediate-need” rental market. The HumidiCart is completely turn-key—attach a garden hose for water and a 120v extension cord for power-and the HumidiCart can be rolled anywhere in the building for high-output spot humidification.

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Ultrasonic humidifier Specifications


The humidifier shall be a packaged, self-contained ultrasonic humidifier using the principle of ultrasonic nebulization.  Each humidifier shall use a multiple of ultrasonic transducers that vibrate at approximately 1.65 megahertz, producing a droplet size of approximately 1 micron.  Each transducer circuit shall use the “thickness vibration method” of humidification via a piezoelectric converter.  The ultrasonic transducers shall convert the electric energy into mechanical energy, causing the water to cavitate, resulting in the production on one micron sized water particles. The design of the humidifier housing shall prevent larger droplets from leaving the humidifier assembly.


The humidifier shall consume no more than 33 watts per pound of humidification generated. The ultrasonic humidifier shall not produce any unacceptable noise.  The sound level shall not exceed 50 db at 5 feet from the humidifier module. The ultrasonic humidifier shall not require a flush cycle and shall have instant on and off operation in order to maintain precise room relative humidity. The humidifier housing and discharge baffles shall be made of high grade stainless steel or plastic, depending upon the Mist Pac model.


The Master Panel will be provided with:

  1. Pre-wired humidistat with 10’cord
  2. 6’ power cord with 120 volt plug
  3. MP-5,15,20,30: 10′ harness to quick-connect the control panel and humidifier
  4. MP-40 only: 18″ harness to quick-connect the humidifier water pan to the upper housing
  5. Fan cooled electronics

Each humidifier shall have the following components:

  1. 24vac Solenoid valve to control water flow into the humidifier.
  2. One (1) Float switch that controls water level, transducer operation and provides low water shutdown.
  3. Piezoelectric transducers with printed circuit boards.
  4. A water tube connection kit to include a set of quick-disconnect service valves to easily isolate the humidifier when servicing.
  5. On/Off digital humidistat.
  6. Supply water debris strainer.
  7. Optional relay for field adjustable mist output control (“Ultra-Pulse”).



Humidifirst is an American company that has been manufacturing ultrasonic humidifiers since 1993 and holds two patents; U.S. patent numbers 5,653,919 and 5,702,648. Humidifirst manufactures only ultrasonic humidifiers and, compared to all other companies, has the most experience with this humidifier technology. Humidifirst invented the ducted/AHU model ultrasonic humidifier design currently used by other major humidifier companies. Humidifirst also invented the only mist-less humidifier.


Humidifirst’s competitors are either foreign companies or USA subsidiaries of foreign companies, and they sell a variety of products other than ultrasonic humidifiers.


Humidifirst is committed to being the innovative leader in ultrasonic humidifier technology. As a result, we continually test our products to find ways to improve them. We use a large wind tunnel to simulate high and low velocity air patterns commonly found in field ventilation systems. This wind tunnel led to the development of Humidifirst’s unique DT Series discharge baffle, which can be field adjusted, allowing our ducted humidifiers to work exceptionally well in slow air speeds of 300 fpm or in fast air speeds up to 2000 fpm.

sizing and calculations


When calculating the humidification loads of a space we will generalize and assume that the majority of the humidification load will come from two areas:

1. Ventilation, Exhaust, or Infiltration of air: Most buildings have air exchanges with the outside because of one or more of these three items.

A. Ventilation is a result of air conditioning systems bringing outside air in to provide fresh air to the inhabitants.
B. Exhaust is the mechanical removal of air from a space when processes inside of the building require the removal of dirty, hot or unwanted air.
C. Infiltration occurs when air comes into a space from outside. Air may come in through small openings around doors, windows, ceilings, etc. Also, infiltration often occurs from frequent opening of doors.

For each Cubic Foot per Minute (CFM) of outside air that is brought into the space, moisture must be added to achieve your relative humidity requirements.

2. Air conditioning: When an air conditioner runs, it removes moisture from the air. This is known as Latent cooling. If the air conditioner will be running during your humidification season, you must take this dehumidification process into account.

The cooling ability of an air conditioner is normally rated by the manufacturer and is stated in Sensible and Total cooling capacity in btu’s per hour. Subtract the Sensible cooling capacity from the Total cooling capacity to get the Latent cooling capacity. For every 1000 btu’s/hour of Latent cooling capacity you will need to add one pound of moisture.

Please note that there are other factors that can add to your humidification requirements, such as moisture absorption of items in your space. We generally ignore them because most often they play only a minor part of your humidification requirements. Contact us if you think you have unique requirements.

    Indoor design conditions:
    °F Temperature
    %RH Relative Humidity

    Let HUMIDIFIRST assist you with your humidifier sizing. Use the form above that will be automatically emailed to us or fax us the information to 801-760-2777.