NCI Article Library

High-Performance HVAC Resources

How to Redesign an HVAC System – Part I

We've looked, but can't find it. There are mountains of information about how to design a new HVAC system, but nothing much that addresses how to redesign an HVAC system. It would take hundreds of pages to completely detail the process, but let's take a stab at the...

How to Red Tag a Defective System

How to Red Tag a Defective System When following National Comfort Institute Carbon Monoxide and Combustion Efficiency Protocols and procedures there is a chance a dangerous or potentially dangerous condition will be uncovered. If this happens, there are times when...

How to Plot Fan Airflow

How to Plot Fan Airflow by Rob Falke To be well prepared for this new level of diagnostics, begin collecting copies of the fan data found in most installation instructions for the equipment your company installs and services. The most important diagnostic truth about...

How to Measure Economizer AirFlow and BTUs

Measuring airflow and BTU's through an economizer can be a challenging task. Many have walked away from economizers shaking their heads without the confidence they have taken good readings. The goal of this article, and the related report and procedure, is to give you...

How to Measure Commercial System Efficiency

How to Measure Commercial System Efficiency by Rob "Doc" Falke, President, National Comfort Institute It’s just not fair. Some contractors have a distinct advantage in the marketplace over their competitors; they ruthlessly and knowingly measure the live operating...

How to Maintain Your Combustion Analyzer

The primary goal of combustion testing is to take readings you can trust so you can evaluate the operating condition of the combustion appliance. In order to take readings you can trust you have to be sure your combustion analyzer remains in tip-top shape. The...

How to Hire and Train Duct Renovators

Duct renovators can be entry-level employees that don't have any previous HVAC experience. What's needed are a fair driving record, a clean drug test, physical ability, good people skills and the ability to learn and follow instructions. As you consider making this...

How to Get Diagnostic Work

Nearly all systems are in need of air-side and combustion diagnostic, but getting permission to test the systems, and getting the customer to agree to pay for repairs requires more than technical genius. We asked a number of successful NCI Performance-Based...

How to Determine Combustion Air Performance

Combustion air testing is performed using a draft gauge and a CO analyzer. When the draft in the flue of an appliance is low or below -.01" to -.02" W.C. and when CO reading are rising, combustion air problems are present. Carbon Monoxide diagnostics consistently...

How to Adjust Barometric Dampers on Gas-Fired Appliances

The procedure and purpose for adjusting barometric dampers for gas appliances is completely different from the reason you adjust barometric dampers on oil equipment. Let's take a look at each method to get a clearer picture of what we're trying to accomplish. OIL...