#MAD AIR

Tech Tips:

3 Things to Check When the Unit Won’t Keep Up

What is your methodology for troubleshooting an HVAC system that “can’t keep up” on the hottest days of the summer? Let me walk you through my process and hone in on one or two ideas that have been overlooked for too long in our industry. In this article, I’m assuming we have ruled out intermittent […]

The MAD Room

This tech tip features a diagnostic flowchart by Genry Garcia. Thanks, Genry! The name of this document, “The MAD Room,” was chosen as a nod to the MAD-AIR study completed by John Tooley and Neil Moyer, presented in 1989. The teachings from that document played an instrumental role in creating the following diagnostic workflow. Disclaimer […]

Angry Air

About a month ago, one of my techs went on a “no heat” call. The house is a rectory for the church next door. The call came in, and after he ran it, I assumed the problem was solved since I hadn’t heard otherwise. A few weeks later, they called back, saying the boiler was out […]

What Airflow Goes Around HAS to Come Around

Have you ever woken up early on a Saturday morning and thought to yourself, “I really wish I knew how to size transfer grilles and jumper ducts properly?” I know I have. Although come to think of it, I believe it was a Friday morning. Properly sizing transfer grilles is something I have been wanting […]

Q&A – System Won’t Dehumidify? – Short #214

In this short podcast episode, Bryan answers a listener-submitted question about an HVAC system that won't dehumidify. This question was submitted by a homeowner with a Carrier heat pump with an attic air handler that cools but won't dehumidify on the hottest days of summer. One of the past companies that serviced the system […]

Spidey Sense – Airflow – Short #205

In this short podcast, Bryan talks about how to pay close attention to airflow issues and use your “spidey sense” when you're doing a visual inspection or commissioning a system. He also covers some causes of common airflow problems and some services and upgrades you can offer to your customers. The skill of being […]

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Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

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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