When replacing a thermostatic expansion valve (TEV), it is usually easiest to replace the valve with the same make and model. However, there may be times when the original make and model is not readily available, so a replacement needs to be chosen.
One area in which CO2 is getting an early wave of attention is mobile A/C and transport refrigeration. Researchers from the Thermodynamic Institute in Germany looked at compressors that might work in such applications.
At a joint session of Purdue University’s Compressor and Refrigeration Conference, a high-ranking official in the Department of Energy (DOE) called on HVAC engineers to continue to improve energy efficiencies, but also offered a slap on the wrist to “tradespeople who use bad practices in the field.”
A new generation of contractors and technicians may not know how the industry moved from CFCs to HFCs. To a great measure it was the result of government regulations, but officials merely called on our industry to come up with alternatives to CFCs. The industry responded. DuPont, for example, has taken part in the search for alternatives from the beginning, and the search for acceptable alternatives is not over, says the company.
Residents of Hawaii know that with high year-round humidity, the climate is very conducive to mold growth. However, when potentially dangerous mold closes all 453 guestrooms of a Hilton hotel building, sending guests elsewhere at the height of tourist season, that’s big news.
Careful consideration must be given to the refrigerant receiver in the design of new systems or when upgrading existing systems. Who hasn’t, at one time or another, experienced problems with this essential component? With its many connections, it is important to select the receiver that meets the system’s needs, as well as all applicable building codes.
Perhaps it is time to think of HFCs as only being conditional “long-term replacement” refrigerants for the air conditioning and refrigeration (ACR) industry. At the recent Purdue University Compressor and Refrigeration Conference, a number of papers looked at alternatives to HFCs, with CO2 being the most talked about.
Jerry Elam left a full-time contracting business to bake cookies. But his experience from his former occupation has been helpful in his new one. His baked goods business has grown so big that refrigeration is vital. And his company’s refrigeration systems have benefited from his expertise and that of his refrigeration equipment suppliers.
Potential or “voltage” relays are used with single-phase capacitor-start/capacitor-run motors, which need relatively high starting torque. Their main function is to assist in starting the motor. Knowing the sequence of operation for this type of starting relay can help you diagnose, confirm, or rule out certain service problems.
There are many conflicting reports regarding the future availability of HCFCs in general and of R-22 in particular. This article will summarize the current situation, to attempt to reduce the confusion that contractors and wholesalers may be feeling.