NCI Article Library

High-Performance HVAC Resources

Hydronic Balancing: A New Frontier for NCI Contractors

As we are in the process of developing a commercial air and water balancing training and certification program for larger systems, we have been creating hydronic balancing forms and procedures. Water systems have been an integral part of commercial air conditioning...

HSER™ Season is Upon Us

HSER™ Season is Upon Us by Rob "Doc" Falke In May of 2004 we released the CSER ™ and HSER ™ procedures to NCI Members. With the success many members have enjoyed with CSER this summer, several members requested that we address HSER again this fall with additional...

How to Use Static Pressure Budgets

How to Use Static Pressure Budgets by Rob "Doc" Falke, NCI President Static pressure budgets were originally developed to help new air diagnostic technicians interpret static pressure readings. These budgets provide a set of rules to compare pressure readings so they...

How to Use Air Density Correction Factors

Air density correction factors have been a part of our air balancing curriculum since the early 1990's. NCI published a small table years ago and encouraged you to make corrections for air density when measuring airflow at higher altitudes. But the accuracy you are...

How to Size a New Fan Belt

When you spin an adjustable pulley and increase its diameter to squeeze a little more air out of a belt-drive fan, there are times you'll find the old belt no longer fits. The first fix is to loosen the bolts on the motor mount and slide the motor as close to the fan...

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 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 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...