Prominent Real Estate Manager Solves Cooling Tower Issues with Full Flow Self-Cleaning Water FilterApr 2023
Currently managing several thousand residential apartments in Montreal, Canada and nearly 4,000,000 square feet (400,000 square meters) of offices, shops and industrial space, the real estate management company of Le Groupe Alfid is always looking for solid solutions to maintenance issues. One of their fourteen-story office buildings in downtown Montreal had an HVAC problem that had plagued management for years. Sand and debris from the cooling tower clogged the small basket strainers located on each of the 22 water condensing AC units throughout the building. A single 2-inch bag filter was installed as a side-stream system filtering only a part of the flow in an attempt to prevent this clogging of the condensing units For several years, even with the side-stream bag filtration system in place (and with bags costing $450/month), the building operations technician would spend one full day every week cleaning the debris from these 22 strainers.
Recently, two new water condensing AC units (30 tons each) were installed in a new computer room and connected to the existing cooling tower system. Only a few days after installation, the large amount of debris caught in the units” built-in bag filters cut off flow to the heat exchangers, causing the units to shut down. Once these units stopped, it took less than an hour for the air temperature in the computer room to rise enough to cause the computers of a major commercial tenant to automatically shut off. With 75 GPM of cooling water passing through each of these two new AC condensers, their strainers would get plugged every 48 hours.
When Herve de Feydeau, Eng., Director of Technical Services for Le Groupe Alfid was made aware of the problem, he quickly resounded “this makes no sense; something has to be done to correct the problem.” The company immediately released a request for proposals. Companies responded with side-stream filtration systems utilizing granular media filters. After refusing them all, Mr. de Feydeau responded, “what I need is a water filter that will filter 100% of the water going to the strainers of all the water condensing units.” After much personal research, Mr. de Feydeau chose to investigate an automatic self-cleaning screen filtration system from Orival, Inc. The regional representative for Orival equipment, Mr. Brent Baiden in Toronto, visited the site assuring Mr. de Feydeau that the 8-inch Orival Model ORG-080-LS automatic self-cleaning screen filter would clean the system of existing sand and debris and protect all the AC condensers from plugging. The filter was shipped from the Orival warehouse the day following Mr. Baiden"s visit. Within a few days the filter was installed, and Mr. Baiden returned to start up and commission the system. Because of the high concentration of solids in the cooling system, it was decided to use a 100-micron screen initially and then switch it out for a finer screen, once the initial dirt load decreased. For the first few days, due to the high concentration of dirt, a rinse cycle was triggered every 15 minutes. After three weeks, the filter was rinsing about every 2 hours, so the building operations technician replaced the 100 micron screen with a 50-micron screen (50 microns is about the diameter of a human hair), which is the filtration degree still in use today. The technician was amazed when he realized how easy and quick screen replacement was.
The Orival filter eliminated weekly maintenance with no HVAC system downtime due to water quality problems and the individual, built-in AC strainer baskets have remained clog-free. Since its installation, the filter has only needed some basic parts replaced as a result of routine use of the filter. These parts were all in-stock and supplied in a matter of days from Orival.
“The filter has saved us nearly 40 man-hours of labor per month and over $5,000 in consumable items per year”