When selecting inverter driven systems, the contracting community tends to ignore sizing issues because the popular belief is: The system will run only as necessary — you can’t oversize.
Nothing could be further from the truth. Proper sizing remains a fundamental in hot, humid climates. To be sure, inverter systems are here to stay and are valuable at shedding shoulder-month KWh. While the equipment may have ability to enhance humidity control during a normal run cycle with proper thermostat programming, a contractor will fight a losing battle when sizing is ignored.
If you are primarily a residential technician working on equipment under 5 tons, there is a lot of similarities between the systems you are used to and 5 – 20 ton rooftop units that
are common to the light commercial market.
Modern refrigerant systems are designed to be efficient and leak free. Refrigerant systems are pressurized and, in reality, it is widely accepted that no pressurized system is entirely leak free; it is simply a case of how much and where the system is leaking.
Service valves are so basic, and we see them with such regularity that we can miss them altogether. But, before I give the tips, I want to address the tech who tells the customer it was “probably the service valve” or “the caps were loose” as a plausible reason for a leak without actually doing a proper diagnosis. Don’t make excuses, find the leak.
Recent developments in factory-assembled cooling tower technology can increase cooling capacity per cell by up to 50 percent, expanding the applications for so called “package” towers supporting HVAC and industrial processes. Although field-erected towers have long been the preferred product for process cooling in power plants and heavy industry, new robust designs and materials coupled with cost-saving building techniques make the new generation of modular products logical alternatives for a broader range of applications.
Tim is the campus energy manager for a major northeast public university, and he has a story to tell about his major strides to reduce campus energy usage. But, he wants to be anonymous.
While CFD is used across the construction industry for analysis and design optimization of an HVAC system, some organizations and individuals have been slow to fully utilize it within their practices, citing restrictions such as cost, unreliability, and inaccessibility. In this article, we examine some of the key advantages for its use and assess how current CFD tools are addressing such concerns.
As architects and engineers draw up plans for commercial buildings, it is a common practice to design openings in walls. In many cases, these openings allow for intake and/or exhaust air that supports the building’s HVAC system and are fire-resistive rated.
Regulations, market drivers, and trends reflect that carbon dioxide (CO2) is increasingly being used as a refrigerant in a variety of applications. This includes applications such as: supermarkets/grocery stores, cold rooms, walk-in freezers, industrial cold storage, and food manufacturing/processing.
A new Center for Disease Control and Prevention (CDC) study involving 196 cooling towers nationwide found that 84 percent contained Legionella DNA, indicating that the dangerous bacteria that causes a severe, even fatal type of pneumonia were present or had been at some point. This means the real question is not “whether there will be another outbreak” but only “where and when” it will occur.