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David Holt
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Tech Tips written:

Shielded Control Cable & Communicating Controls
When I first started in the trade, we used to run into shielded control wires on the Carrier Comfort Zone 1 zoning systems and also on a Carrier VVT system I used to maintain at a bank. I knew it had something to do with electrical “noise” and that communicating systems often called for it, […]
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AHRI Ratings Are Not Design Conditions
I’ve been designing a system for a home here in Dallas and noticed a couple of interesting (and disturbing!) things about the equipment’s advertised capacity vs. the actual capacity at design conditions.  Equipment is rated at AHRI conditions (95 degrees outside and 80-degree dry bulb, 67-degree wet bulb inside). These conditions make equipment performance LOOK […]
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Valve Core Removal Tools
Valve core removal tools were originally developed to remove damaged valve cores without the need to pump the system down. This technology was a major leap forward in work efficiency, as pumping down a system can be a tedious and time-consuming task.   Eventually, technicians discovered that removing valve cores led to faster evacuation, recovery, and […]
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Podcast guest:

HVAC Training Past, Present & Future w/ David Holt
David Holt with NCI returns to the podcast to discuss the evolution of HVAC training; we cover the past, present, and the possible future of training in the industry. In the past, we had a lot of hands-on training, whether it was one-on-one or in a traditional classroom setting. These learning practices remain beneficial today, […]
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AirFlow Testing as a Customer Service Tool (Podcast)
David Holt from NCI comes on the podcast to talk about airflow testing and its importance as a customer service tool for the HVAC trade. Charging and airflow are closely linked. Even though the charge may be correct, the system can't operate correctly if the airflow is off. For example, we can only get the […]
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