Frequently Asked Questions
Updated: Sep 4, 2019
How to choose fans for livestock ventilation? Fans are driving force behind exchange of air, and good quality fans are essential for proper performance of mechanically ventilated livestock facilities. Fan selection should be based on the following criteria:
The quantity of air delivered at different static pressures.
Quality of dealer service and support
Reliability and life
Suitability for application
Cost - Purchase
Cost - Operating & maintenance
The quantity of air delivery and energy efficiency are particularly important criteria in selecting fans
How to compare fans? Never assume that two fans of equal size will perform the same. Fans from different manufacturers may act differently. Fans should be rated to show performance as a function of static pressure. This information should be presented by using either a graph or table from the supplier’s product literature.
Testing data should be from a third party laboratory to assure authenticity and reliability. Two laboratories, the Air Movement and Control Association (AMCA) and the Bioenvironmental and Structural Systems (BESS) lab, are known to test fans impartially.
Why fan efficiency matters? For the same performance, choosing an efficient fan can cut electricity costs in half. The annual electricity cost of operating one of the most energy-efficient 48-inch fans is about $300 compared to $600 for an inefficient fan (at 10-cents per kWh). This is based on 120 days of fan use for hot weather ventilation. Also, in most case, higher efficiency fans are of better quality, which means they usually run longer and have fewer problems in their lifetime.
Why are some fans better than others even though they look the same? To human eyes, they may look the same, but during the manufacturing process, every step is essential. Those that outperform their peers are designed carefully and build with the high-quality components. As a result, they will have higher efficiency and longer operation life with fewer maintenance cost.
What kind of accessories will an Exhaust fan need? Accessories are necessary for proper functioning of the fan as part of a ventilation system, even though they often reduce airflow and efficiency. Shutters should be used to prevent backdrafting when fans are not running. Guards are necessary for the safety of people and animals around the fan and to prevent objects from damaging the fan. Discharge cone can improve fan efficiency and also provide some protection from the weather.
What is the advantage of a fiberglass fan? fiberglass VS stainless steel VS PVC VS coated steel
Fiberglass Reinforced Polymer (FRP) combines glass fiber and thermosetting polymer resin to produce physical properties not present in each component.
FRP provides a better solution than other materials for the following reasons:
FRP can be made into complex shapes while it is often difficult to create complex forms out of metals at a reasonable cost.
Livestock housing ventilation utilizes FRP fans due to the high humidity and corrosive gas.FRP is much more economical than stainless steel or other corrosion-resistant alloys.FRP fans often provide better performance than some alloys in handling air streams that are particularly corrosive to metals.
Fans made of (PVC) have all-around corrosion resistance and generally cost less than FRP fans. However, PVC fans have two significant shortcomings. First, PVC will become brittle at temperatures below freezing; Second, PVC loses its’ strength very rapidly when the temperature increases.
Coated steel can be good, but they usually vary significantly in the degree of protection provided; cost is proportional to the surface preparation required and type of coating applied. Price for coated fans ranges from 30% less than FRP fans to about 50% more expensive depending on the layer used. Regardless of the level of corrosion resistance of the coating, coated steel has an inherent failure. This failure is due to the coating having the high possibility of a pin-hole fault occurring during application or damage associated with handling, or use, which allows the environment to attack the base material.
FRP fans built with UV inhibitors have a life expectancy of anywhere from 25 years to 50 years in any environment when adequately applied, installed and maintained.
With a thermal conductivity of only 4 BTU in./ (hrft²°F) compared to that of steel 323 BTU in./ (hrft²°F), heat loss or the concern for condensation forming on the material is almost eliminated, thus making FRP a favourable material in climates that vary significantly between summer and winter temperatures.