60 Hz vs. 50 Hz - Our electric fan and blower performance data represents units driven by 60 Hz motors. A motor rated for 3600 rpm at 60 Hz will run at 5/6 of that speed, or 3000 rpm, when powered by 50 Hz current. The frequency of the electric current controls the speed of the rotating field within the motor. A 2 pole (3600 rpm) motor, therefore, will make a complete rotation 60 times per second on 60 Hz current. On 50 Hz current, it will make 50 complete rotations per second.
Because of the decrease in motor speed, several properties of the fan become de-rated. Since the 50 Hz speed is reduced to about 83% of the 60 Hz speed, so is the flow through the fan. To calculate the flow through the fan at 50 Hz, multiply the airflow on our website by 0.83.
Sound Levels - Sound is an important aspect to consider for your application. In order to protect the hearing of those working around noisy equipment, OSHA has defined a set of allowable sound level exposure times:
| Sound level (dBA) | Allowable exposure per day |
|
90 |
8 hours |
| 92 | 6 hours |
| 95 | 4 hours |
| 97 | 3 hours |
| 100 | 2 hours |
| 102 | 1.5 hours |
| 105 | 1 hour |
| 110 | 30 minutes |
| 115 | 15 minutes |
Below are measurements of the sound output of each of our blowers at a distance of five feet, excluding the Mancoolers, which are measured at 10 feet. For pneumatic (air driven) blowers, the sound level varies based on the inlet pressure.
| Drive Type | Blower | Sound level (dBA) | Drive Type | Blower | Sound Level (dBA) |
| Electric | Tornado 8 | 90 | Air/Steam | Hurricane 9 | @40 psig - 88 |
| Tornado 12 | 92 | @60 psig - 92 | |||
| Water | Typhoon 12W | 97 | @80 psig - 95 | ||
| Typhoon 12A | 99 | Hurricane 10 | @40 psig - 89 | ||
| Typhoon 15W | 102 | @60 psig - 93 | |||
| Typhoon 15A | 101 | @80 psig - 96 | |||
| Air/Steam | Hurricane 3 & 3P | @40 psig - 81 | PA-12 | @40 psig - 97 | |
| @60 psig - 85 | @60 psig - 101 | ||||
| @80 psig - 88 | @80 psig - 104 | ||||
| Hurricane 6 | @40 psig - 85 | PA-20 | @40 psig - 103 | ||
| @60 psig - 89 | @60 psig - 106 | ||||
| @80 psig - 92 | @80 psig - 108 | ||||
| Hurricane 8 | @40 psig - 87 | PA-24 | @40 psig - 104 | ||
| @60 psig - 91 | @60 psig - 109 | ||||
| @80 psig - 94 | @80 psig - 111 |
| Model | Power | Sound Level (dBA) | Model | Power | Sound Level (dBA) |
| 18" Mancooler | 1/4 HP | 74 | 30" Mancooler | 3/4 HP | 80 |
| 1/3 HP | 76 | 1 HP | 80 | ||
| 1 HP | 77 | 1 1/2 HP | 92 | ||
| 24" Mancooler | 1/4 HP | 80 | 2 HP | 84 | |
| 1/3 HP | 74 | 3 HP | 94 | ||
| 1/2 HP | 75 | 36" Mancooler | 1 HP | 82 | |
| 3/4 HP | 74 | 1 1/2 HP | 88 | ||
| 1 HP | 82 | 2 HP | 82 | ||
| 1 1/2 HP | 84 | 3 HP | 90 | ||
| 3 HP | 87 | 5 HP | 94 | ||
| 30" Mancooler | 1/3 HP | 80 | 48" Mancooler | 5 HP | 92 |
| 1/2 HP | 86 | 10 HP | 105 |
Although many blowers exceed 90 dBA, most are designed to be used for short periods of time. For this reason, sound levels are not usually a problem. If an application requires the constant use of a blower, Prime-Air can supply duct that will allow a greater distance between the blower and the job site.
CFM - Cubic Feet per Minute - A value that describes the amount of air that flows through a fan.
Static Pressure - A term used to describe pressure that acts in the direction opposite the flow of the fan. It is a measure of the pressure in the environment in which the fan is used. For example, imagine a small room with only one opening. Suppose a fan were to be placed tightly in that opening such that no air could escape around the edges. When the fan is turned on, air begins to flow into the room. Since there are no other openings, no air can escape, and pressure begins to build in the room. As pressure increases, it becomes more and more difficult for the fan to push air into the room, thus the airflow decreases.
Higher static pressure values will cause the output of a fan to decrease, and some fans are not able to overcome high static pressures. Knowing the static pressure of the working environment is necessary to properly select a fan.
Free Air - Air that has no static pressure. In this environment, fans will operate at maximum flow.
In. Wg. - Inches of Water Gauge - Units used to measure static pressure. Because static pressure is extremely small compared to the pressure generated by a compressor or the pressure of the atmosphere, a unit other than psig (pounds per square inch gauge) was selected to describe it. One inch of water is equal to only 0.036 pounds per square inch.