This topic came up because I was testing out the new MR45 digital recovery machine. That machine goes off by itself when it hits a 20″ Hg vacuum. It's a cool feature, but it is good to know when that level of vacuum is overkill and when it's not enough according to EPA requirements. You […]

We've seen it before. A tech diagnoses a failed blower relay or board. They leave the blower jumped out by putting a terminal multiplier on the common terminal of the relay/board and connecting the fan speed tap right to power. There can be an issue with that. Some electric heat fan coils have a heat/blower […]

Simply stated, a compressor’s volumetric efficiency (VE) is its ability to pump the most pounds of refrigerant over time. The compressor’s function is right in the name: it compresses vapor refrigerant. After compression, the gas moves to the condenser via the discharge line. From there, the refrigeration cycle continues. However, some of the refrigerant vapor […]