NCI Article Library

High-Performance HVAC Resources

Current Article Library Category: Air Conditioning

Member of the Month – T.M. Johnson Bros

Member of the Month - T.M. Johnson Bros Statistics tell us that the majority of new businesses fail in their first five years of operation, and only about 1 in 4 make it past the 15 year mark. So, for a company to beat the odds and not only survive, but thrive, for 50...

Mechanical Venting vs. Mechanical Combustion Air

Mechanical combustion air is the only proven way to provide adequate combustion air to appliances under most field conditions. There are, however, certain cases where because of the size of a mechanical room, the amount of internal forces in a building or mechanical...

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...

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...

Know Your Flue Temperatures

Whenever you're servicing or starting up heating equipment, it's important to know what discharge temperatures should be in the outlet or flue. Our industry often teaches that the lower the flue temperature, the more efficient the equipment will be. Most combustion...

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...