#power factor

Tech Tips:

Blower Fan Watt Draw Considerations for ECMs

I'd like to give special thanks to Steve Rogers from TEC for helping write this tech tip and sharing some helpful visuals. Thanks, Steve! ACCA Standard 310 introduced a grading protocol for HVAC systems. While HVAC practitioners won’t be the ones carrying out the tasks laid out in Standard 310, energy raters will conduct them […]

Tool Selection: Electrical Meters

I'd like to give a special thanks to Tony Gonzalez from Fieldpiece for providing technical guidance about the SC680's power measurement capabilities, as well as VAC and AAC measurements on ECMs. We’ve talked through specifications, applications, and features for a few tools, but none of them have been quite as hardcore as electrical meters. Like […]

HVAC Moneyball: Could It Work?

This tech tip was submitted by Tim De Stasio. He originally published it on his website, which you can visit HERE. Thanks, Tim! Winning takes strategy and the right information. The HVAC business is no different. But what information should we collect, even pay for, to get better and win? What if these widely accepted […]

Using Power Factor to Check Capacitors Under Load

Capacitors are traditionally tested with a capacitance meter (commonly found as a function within a multimeter), with the component taken entirely out of the circuit. “Bench testing,” as this method is referred to, is hands-down the safest method of checking capacitance in microfarads. All other methods require the capacitor to be wired into the circuit […]

An even EASIER way to check capacitors

In a previous article, we covered the standard way to check capacitors under load. I am now going to give you an even easier test. A properly functioning PSC (permanent split capacitor) or CSCR (capacitor start capacitor run) motor should have a power factor of very close to 1 if they have a properly sized […]

What Is Up With Blower Amps & Watts w/ Steve Rogers

Bryan Orr and Steve Rogers dive deep into measuring power consumption in HVAC blower motors, particularly focusing on the differences between PSC (Permanent Split Capacitor) and ECM (Electronically Commutated Motor) technologies. The discussion stems from a question raised at an educators' conference about the accuracy of clamp-on meters in measuring blower motor watt draw, […]

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Chris Hughes and Steve Rogers from The Energy Conservatory discuss TEC’s TrueFlow technology and its crucial role in predicting airflow issues in the sales process, particularly for heat pump retrofits. They explain how the TrueFlow app helps contractors accurately measure both static pressure and airflow in existing systems, enabling them to predict whether proposed equipment changes will work effectively. This is especially vital when considering the growing trend of replacing gas furnaces with heat pumps, as the airflow requirements can differ significantly.

The conversation delves into a detailed example of replacing an 80% efficient 48,000 BTU furnace with a heat pump. They demonstrate how the airflow requirement would nearly double from 652 CFM to 1,200 CFM, potentially causing the static pressure to quadruple due to Fan Law 2 principles. This dramatic increase could lead to significant performance issues if not properly addressed during the system design phase. The experts emphasize that using TrueFlow during the sales process allows contractors to identify potential problems and necessary modifications before installation rather than discovering issues during callbacks.

The discussion also covers the ideal workflow for system assessment and sales, starting with customer comfort evaluation and proper load calculations. It’s important to reduce loads through envelope improvements when possible, particularly in cold climates where heat pump retrofits are becoming more common. Proper system sizing often means going smaller rather than larger, contrary to common industry practices, and the worst HVAC systems are often found in expensive custom homes rather than tract housing.

Key Topics Covered:

TrueFlow technology and its role in system forecasting
Fan Law 2 and its impact on static pressure when changing airflow
Heat pump retrofit challenges and considerations
The importance of accurate load calculations
Dual fuel systems as a solution for cold climates
The relationship between airflow and static pressure
Sales process integration of technical measurements
Common issues with oversized equipment
The importance of envelope assessment
Methods for reducing system loads
Proper duct sizing and modification strategies
The role of proper filter sizing and selection
The benefits of flat-rate pricing for duct modifications
Training resources and support available for TrueFlow users

Check out TEC’s YouTube channel at https://www.youtube.com/@energyconservatory, and you can visit TEC’s website at https://energyconservatory.com/.

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