NCI Article Library

High-Performance HVAC Resources

Mechanical Miracles (and Mistakes)

When working in the field, there are an infinite number of variables to deal with. When listing the operating ranges of equipment on all the different NCI Diagnostic Forms, 98% of equipment is covered. However, there is that last 2% that are called mechanical...

Make-Up Air Equals IAQ, Safety, Comfort & Efficiency

Most homes are already leaky and drafty so why would you want to bring in more outside air into the duct system? Because that's the best place to bring it in! Normally the air that comes into buildings, leaks through the walls, windows, doors, electrical outlets,...

Make the Decision to Make Money

NCI training seminars show you how to achieve gross margins of up to 80% on testing and system renovation work. This should result in net profits of 20% or better. Some of you make these margins regularly on this type of work, yet many still do not. As we provide...

Low-Level Carbon Monoxide Poisoning: Know the Symptoms

The most talked about symptoms of CO poisoning are those that mimic the flu, such as nausea, headache, and dizziness. Fever is another symptom we rarely hear about. These symptoms may be reactions to a short term CO exposure, but what symptoms are common in exposures...

Knockelmann Plumbing, Heating and Air Conditioning Covington, Kentucky

Kris Knockelmann of Knockelmann Plumbing, Heating and Air Conditioning, Covington, Kentucky has earned the NCI contractor of the month for August 2006 due to the company's excellence in Carbon Monoxide testing and diagnostics. One thing we search for when we write...

Keil Heating & Air Conditioning

According to most statistics, the majority of businesses fail during their first five years in existence. So a business that is thriving after 104 years is a rare phenomenon indeed. And under the guidance of owners Milton Baum and Barbara Keil, Keil Heating & Air...

Jump On the Gift Certificate Bandwagon

Gift Certificates have become a multi-billion dollar business and HVAC contractors can benefit from this boom. So many consumers are looking for effort-free ways to give gifts. Many of them are looking to the internet to purchase gift cards and certificates. Shopping...

James A. Wheat & Sons

Jeff Wheat, this months NCI member of the month is one of the family members owning and managing Wheat & Sons, Inc. a nearly $5 million per year plumbing and heating company located in Gaithersburg, Maryland. Jeff manages the technical side of the company with his...

Induced Draft & Atmospheric Common Venting Interference

When an Induced Draft Appliance (Furnace, Boiler, Water Heater) is "Common Vented" with an Atmospheric Appliance, venting interference can occur. This procedure is the proper method to evaluate this situation and take all precautions to verify safety. Necessary tools...

Adjusting a Ball Valve on Intake of 90% Appliances

Adjusting a Ball Valve on Intake of 90% Appliances by Jim Davis, NCI Senior Instructor In our combustion diagnostics class, we discuss short flues on condensing equipment as causing possible venting problems. We recommend adding a plastic ball valve to the intake of...