A positive temperature coefficient resistor (PTCR) is a resistor that varies its resistance with its temperature. A resistor that changes its resistance characteristics as a function of its temperature is also called a thermistor. So the PTCR is technically a thermistor.
Sales Engineering, Contracting & Associates (SECA), a design-build mechanical contractor and purchasing agent, has worked with several Melia hotels over the years on various projects. Since the early 1990s, the firm has assisted 10 of the chain’s resorts, improving existing potable water systems and providing significant hot water cost reduction.
There is more to the blueberry business than pies, cobblers, and sticky fingers. There is berry picking and selection, packing, storing, and shipping. At Chambers Brothers Farms, a cooling system lends a huge helping hand. The technology is considered so innovative that blueberry farmers from throughout the U.S. travel to Homerville, GA, to see how it is done.
When a project consists of 430,000 square feet of refrigerated space, conventional wisdom would suggest a cooling system consisting of a large mechanical room with a refrigerant such as ammonia.
But the new International Produce Market in Chicago is going against convention. Instead of a mechanical room, there are more than 100 rooftop condensing units. Instead of ammonia, the refrigerant of choice is R-22.
Steve Easley, owner of S.C. Easley and Associates, a construction consulting firm, and a former professor of building construction and contracting at Purdue University, speaks and writes a lot about the subject of indoor air quality (IAQ). You want answers? Here are a few from Easley to some basic questions on this increasingly important subject.
This is the second installment of a three-part series on mold and its relationship to HVACR systems. In this installment, The News examines what some companies are recommending for the prevention and the remediation of mold.
ISH North America is rapidly becoming the “anchor” for a variety of industry-related events. ISH NA is hosted by Messe Frankfurt, Inc., in cooperation with the American Supply Association (ASA), the Canadian Institute of Plumbing and Heating (CIPH), and the Plumbing-Heating-Cooling Contractors — National Association (PHCC).
Nate and Ace are replacing a 30,000-Btu cooling system. The new system is a 10 SEER. They have removed the refrigerant by following the refrigerant handling requirements of Section 608 of the Clean Air Act. Having completed the component installation, including a new condensing unit, properly sized refrigerant lines, and a matching cooling coil with a TXV, they are preparing to charge the system.