#TXV

This is a quick tip from the “Expansion Valves – What Does and Doesn't Matter?” livestream on our YouTube channel featuring Joe Shearer, Matthew Taylor, and Corey Cruz. Thermostatic expansion valves (also known as TXVs or TEVs) don’t have little brains that tell them when to open or close to maintain a specific superheat. They […]

This is a quick tip from the “Expansion Valves – What Does and Doesn't Matter?” livestream on our YouTube channel featuring Joe Shearer, Matthew Taylor, and Corey Cruz. As metering devices, TXVs can adjust the size of their orifice to maintain a constant superheat. Some TXVs are set to maintain a specific superheat from the […]

This is a quick tip from the “Expansion Valves – What Does and Doesn't Matter?” livestream on our YouTube channel featuring Joe Shearer, Matthew Taylor, and Corey Cruz. It’s time to talk about brazing again! Even though rehashing “flow nitrogen” and “use a wet rag” gets a little old, bad TXVs and callbacks also get […]

This is a quick tip from the “Expansion Valves – What Does and Doesn't Matter?” livestream on our YouTube channel featuring Joe Shearer, Matthew Taylor, and Corey Cruz. You can watch it on our website HERE. Equalizers get their name because they provide a closing force to equalize against the bulb pressure (an opening force). […]

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 […]

As we discussed in an earlier podcast, a TXV maintains a specified and constant superheat at the evaporator coil outlet. It does this through a balance of forces between the bulb pressure (opening force), equalizer pressure (closing force), and spring pressure (closing force). We can actually adjust the spring pressure on some valves. But why […]

Photo by Ulises Palacios Refrigerant circuit restrictions can be common things like a plugged filter drier or a restricted metering device. They can also be more difficult to diagnose and stem from exotic issues like a kinked liquid line, blocked evaporator feeder tube, or a compressor connected improperly with a discharge line full of solder […]

When mounting a TXV bulb or checking bulb placement, there are a few important considerations (listed in order of importance): Mount the bulb on the suction line. Flapping in the breeze is no good. Mount it TIGHTLY with a proper metallic strap (usually copper, brass, or stainless steel)—not with zip ties or tape. Position it on […]

We’ll never run out of content to discuss as long as thermostatic expansion valves exist. Deal with it. Today, we’re going to focus on the powerheads of TXVs. This article will focus on what the powerheads do, how they work, and some basic troubleshooting procedures involving TXV powerheads.   What is a powerhead, and where […]

In this episode, Bryan talks with Jamie Kitchen from Danfoss about why and how thermostatic expansion valves (TXVs) fail and how they function in the first place. As fixed orifices become a dying breed with the development of higher-efficiency systems, TXVs take over the mantle as the primary method of expansion. Expansion valves meter the […]

In this episode of HVAC School, Bryan covers the basics of heat pumps. Heat pumps are common technologies in Florida. They reverse the sequence of the typical refrigerant circuit: the indoor coil can become the condenser, and the outdoor coil can become the evaporator. Heat pumps can achieve that transition via a reversing valve, which […]

In this episode of HVAC School, Bryan talks to Leslie about the deceptive TXV. Thermostatic expansion valves, also known as TXVs or TEVs, are metering devices that maintain superheat. They contain an external equalizer. External equalizers give the pressure reading that you would normally take with a suction gauge at the end of the evaporator […]

In this episode of HVAC School, Bryan covers the “5 pillars of refrigerant circuit diagnosis” and why they matter. They are: Superheat Subcool Suction pressure Head pressure Air temp split (delta T)   These 5 readings give you a holistic idea of the A/C system. Instead of getting hooked on checking only superheat and subcool […]

In this episode of the HVAC School Podcast, Bryan talks with Jeremy Smith about refrigeration tips, terms and processes. They also cover the similarities and differences between A/C and refrigeration. Being on-call as an A/C tech is not all that different from being on-call as a refrigeration tech. Similarly, the principles of heat transfer don't […]

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