Custom misting pump and the use of variable frequency drives

Fogco Systems has been designing innovative products for the outdoor cooling and humidification markets for over two decades.  Sometimes it involves a completely novel idea; other times it is simply an improvement to what already exists.  Either way, it is a commitment to excellence that has resulted in Fogco being a perennial leader in the misting industry.

Over the last couple of years, Fogco has been focused on humidifcation applications for many different industries.  These industries include textiles, paper processing, woodworking, wine storage, and greenhouse humidity control.  In all of these applicatuions, increased humidification is required for maximum results from the product and/or the equipment that is used.

In many cases, to effectively control the humidity system, multiple zones are required.  this allows for a ‘staging’ of the mist system so that just the right amount of increased humidity can be introduced into the air at the precise time and in the proper area needed.  This multi-zone mist system design does provide for improved performance but it also presents a few challenges.

When a high pressure pump is built for a specific flow, it must create that flow when it is operating.  If the mist system has multiple zones and only one of the particular zones is required at a given time, the standard misting pump will still create its rated flow but it must internally bypass all the unused water.  This process creates heat within the misting pump and can cause premature failure of the pump seals or other critical components. In addition, the large pump is using electricity that would otherwise be unnecessary and this is seen as a waste of company resources.

One solution is to provide multiple pumps for a system that requires multiple zones.  Although this ‘solution’  does allow for a series of pumps to pressurize the exact amount of moisture that may be needed at any given time and it does ensure that only the amount of electricity that is needed is actually consumed, it is costly and cumbersome and dramatically increases the amount of maintenance time required for a system.

The preferred option is to design the mist system to include a variable frequency drive or VFD.  These unique controllers have the ability to change the operating speed of a motor so that one properly sized and designed pump can be used to operate a multi-zone system with flows that vary from 5% to 100% of the pumps total designed flow rate.

The advantages of these VFD designed systems are significant.  In addition to the elimination of the need for multiple pumps, the VFD has many different built in capabilities that can be used to enhance the operation and performance of the misting system.

Once of the most significant advantage, however, is the cost savings that the VFD provides.  Because of the way that the VFD operates (it essentially synthesizes the required alternating current by using a direct current),  it can deliver the required power to the motor much more efficiently using as little as 10% of the required wattage when compared to a system that incorporates a 1-pump option.  Obviously, the initial cost of a VFD system is higher than a comparable single pump option, but over time the cost savings can be significant and usually pay for themselves within a year.

If your system requires multiple zones and you think it might be worth considering a VFD design, talk to our Customer Service Department and let us help you determine if it is right for you.  It may be much less expensive over time than you expected.