The piston (fixed orifice) and TXV (thermostatic expansion valve) are the two most common metering devices in use today, though some modern systems utilize an electronically-controlled metering device called an EEV (electronic expansion valve). It should be noted that there are other types of fixed-orifice metering devices, like capillary tubes; however, their use is not […]

If you don't do a lot of commercial work, you may see a system like the one above and wonder what the heck it is. It is a 100% fresh air unit or a makeup air unit. You will see them more and more as codes start to reflect that balanced ventilation and conditioned outdoor […]

Our technician, Sam, sauntered into my office this afternoon like techs often do on a slow spring afternoon before the summer hits. It's been a long day for me, lots of training prep, a bunch of little fires, and errands to stomp out, and I still didn't get my article for the day written. I […]