Field Notes
Plain-language notes on components, circuits and how to read a schematic, written for people at the bench, not for a classroom.
Field Notes
5 Methods to Determine if The Indoor Air Conditioning Coil is Clogged with Dust!
When servicing an air conditioner or heat pump, we often notice a low airflow problem which needs to be fixed. If there is no indoor air filter or there is air skirtin...
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Measuring the Static Pressure Drop Across an Evaporator Coil to See if it is Clogged!
If you suspect that an evaporator coil is clogged with dust but cannot visually see it, such as when you can't directly inspect on a furnace and evaporator coil, stati...
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Measuring Airflow in CFM Using the TrueFlow Grid
Measuring airflow is one of the most commonly missed or ignored topics in HVAC when commissioning or diagnosing problems in systems. I don't believe this topic is purp...
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Carbon Monoxide Alarm vs Low Level CO Monitor
Today most people are aware of the invisible, odorless, poisonous gas of Carbon Monoxide or CO for short. Now we know that even low levels of CO can have long term hea...
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Top 10 Gas Furnace Package Unit Problems!
Problem #1 : No Power to the Package Unit On all HVAC systems, power is critical to operation, and a package unit is no different. There several reasons a package unit...
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UNCONFORMED Review (Quick Tip)
I just finished reading the book Unconformed, by Bryan Orr, from HVAC School. I invested about 5 hours spread over three days and let me tell you, the payoff was worth...
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