HVAC chilled water coils are the backbone of many commercial and industrial HVAC operations, keeping temperature levels within optimal ranges and allowing daily business functions to continue unimpeded. For industries that require constant cooling and temperature regulation, like refineries, commercial food refrigeration and data centers, not only are HVAC chilled water coils necessary for safe and efficient business operations, but also for remaining compliant with the latest state and federal energy guidelines.
However, water coils of any kind are extremely susceptible to a number of damaging effects throughout their life span, which can decrease the effectiveness of HVAC systems and negatively impact energy budgets. The largest problem lies within the coils themselves. Water is the necessary facilitator of temperature change that allows forced air to be altered before it is filtered into an enclosed space. But because of the properties of the metals involved and the capacity for water to corrode these metals, coil performance can decline within weeks.
Preventing improper water flow
The temperature level of incoming air is much higher than its requisite outtake into the building. Particularly in warmer climates during spring and summer months, chilled water coils must drop air temperatures sometimes 50 degrees or more. However, this function is only capable if the water running through the coils is doing so at an appropriate speed and is making contact with the interior walls of the coils. And because chilled water coils are designed with more rows than their hot water counterparts, surface contact is of even greater importance because forced air has a longer route to travel before entering a building. If water isn’t properly chilling the coils, the entire process is wasting energy and money.
When water moves too slowly through the coils, known as laminar flow, there isn’t enough water splashing along the interior and cooling the copper coils. Because of this occurrence, air temperature isn’t altered quickly enough, and optimal temperature settings may never be reached. On the other hand, water that speeds through the coils too quickly creates a similar issue in that water moves in a direct line without contacting a large enough surface of the interior walls.
By monitoring the performance of the water pump, these issues can be prevented, but technicians also need to keep an eye out for any pinhole leaks or cratering that occurs within the coils. Even if water flow levels are accurate, damaged coils can impact cooling processes greatly.
Using HVAC coil coatings
HVAC units housed in harsh environments, such as those with high levels of salt and pollutants, have a much taller task in creating optimal HVAC conditions. Copper and aluminum coils can be especially affected by these elements and begin to corrode over time if necessary preventative measures are not taken.
Some of the first signs of poor coil performance are small pinhole leaks and craters along the coil walls. When water and air are allowed to leak out of the coils, the entire cooling capability of the system is at risk of degradation, and ultimately, malfunction. Additionally, small dimples that form in the coils decrease the surface contact potential of the chilled water, making the unit work harder to cool forced air. If these problems continue to worsen, chilled water coils can actually break, and must be replaced immediately.
To prevent these and other kinds of issues, coils need to be protected against rust, mold and microbial buildup. As such, HVAC coil coatings essentially turn existing coils into revamped models because they are better able to withstand corrosive elements.
When coatings are applied, the coils last significantly longer and are less likely to succumb to poor performance and eventual HVAC failure. Further, with coatings from Rahn Industries, a layer of polyurethane covers the coils in addition to removing the ability for water to collect and gather. With superhydrophobic qualities, these coatings effectively shed excess water buildup, disallowing cratering and future corrosion to occur.
Optimized chilled water coils can thus function much more effectively and improve energy savings for businesses.
Rahn has a full lineup of spray and immersion (dip)/ Bake protective coatings to meet your needs.