At www.achrnews.com, The NEWS’ Extra Edition page is home to hundreds of online-exclusive service and maintenance, technical, and business management articles. Here are some of the best.
AVOIDING TXV TRAUMA
The thermostatic expansion valve (TXV) is a metering device designed to regulate the flow of liquid refrigerant into the evaporator at a rate equal to the evaporation of the liquid in the evaporator. The TXV responds to both the temperature and the pressure of the refrigerant exiting the evaporator to maintain a constant superheat at the evaporator outlet. Positive superheat at the evaporator outlet in the suction line will help ensure that only refrigerant vapor returns to the compressor. Here are some tips to ensure maximum TXV performance..
BTU BUDDY 26: CHECKING A HEAT PUMP WITH DIRTY INDOOR COIL
The first call of the day was from the owner of a strip mall. There’s a post office in the mall that is serviced by a 10-ton heat pump. The owner told the dispatcher that the post office had called and complained about the electric utility bill for the last two months. It seemed that it is much higher than usual. The day was cold for early spring, 40°F, so Bob would get to operate the heat pump under heating conditions without overheating the conditioned space. The indoor coil was in an equipment room with plenty of space around it and the outdoor unit was on the roof.
Publication date: 2/8/2016