Pressure Made Simple
Recent articles have generated many questions and comments related to HVAC system and building pressures. Heres a look at some basic principles of pressure...
Sell a Well-Performing System, and Stop Swapping Boxes
There are two camps forming in our industry. There are contractors that continue to swap boxes, and there are contractors that take responsibility for...
Be the Best at One Thing
One of the best things about about the work I do is that I am in constant contact with others throughout our industry. I believe some of the best people...
When to Use Extreme Weather Duct Diagnostics
This summer has been so hot that Ive even entertained the idea that refrigerants might be contributing to a hole in the ozone layer. Not really, I was...
What's the Value of Various System Renovations?
More than 40% of the Btus that your customers are paying for don't make it from the laboratory, where the equipment is rated, into their homes. However,...
How Much Fresh Air is Enough?
Everyone knows its important to introduce fresh air into buildings. However, there are two questions to be answered: How much air does a building need,...
Why and How to Sell Heat Recovery Ventilators
Heat Recovery Ventilators (HRVs) have become mandatory, according to energy codes in several U.S. states, and many other counties and states have the...
The Many Benefits of Adding Fresh Air
Adding fresh air to a heating or cooling system accomplishes two primary indoor air quality goals: It pressurizes a building, and increases indoor air...
How to Measure Building Pressures
The heat is on. Summer is bearing down on us, and its bound to stick around for a while. As youre in and out of buildings day-to-day, could a five minute...
Practical Standards to Measure HVAC System Performance
Practical industry standards are rock-solid principles that you can depend on to evaluate how well your HVAC system is performing. You can measure any...
How to Measure Economizer Airflow
Fresh air is essential to good indoor air quality in some homes and nearly all commercial buildings. Its primary use is to freshen the indoor air and...
How (and Why) to Measure Return Air Grille Pressure Drop
You know the sound when the fan comes on and the filter in the return grille smacks the back of the filter grille housing? Is that good or bad for your...
A Peace Plan to End Thermostat Wars
The next time your customers are trying to explain their comfort issues relating to their thermostat, help them out by mentioning the term Thermostat...
A Simple Way to Test: Balance by Temperature
When a building has been properly air balanced, the primary evidence to the occupants is that the rooms are all the same temperature. If youre in the...
How We Made a Heating System Really Work
Readers of Contracting Business Hotmail, our e-mail newsletter, know that just before Christmas the National Comfort Institute (NCI) crew teamed up with Henry Sterling of Pompeii's Heating to renovate the heating system of an 80-year-old Cleveland resident named Betty. She had been living with her thermostat set just high enough to keep her pipes from freezing, and wearing up to five layers of clothes to keep warm. All the time, material, and effort was donated, and the group effort improved the operating efficiency of Betty's system to 99% — from the 31% she had been suffering with....
What's the Value of Various System Renovations?
More than 40% of the Btus that your customers are paying for dont make it from the laboratory, where the equipment is rated, into their homes. However,...
Rating The HVAC Pressure Diagnostic Methods
Recently we have experienced an increasing number of tech support calls about different pressure diagnostic methods here at National Comfort Institute...
How Much Heat Is That Heat Pump Really Delivering?
Have you ever found yourself standing outside on a cold day, looking at a heat pump and wondering how much heat the unit is really delivering? If so,...
How to Size a New Fan Belt
Have you ever spun an adjustable pulley and increased its diameter to squeeze a little more air out of a belt-driven fan? If so, there have probably been...
How to Correct for Air Density
Four hundred CFM per ton has been the gold standard for cooling airflow since Willis Carrier proclaimed it so nearly a century ago. While the basic principal...
HOW TO MEASURE BLOWER MOTOR AMP DRAW
Amp draw is a measurement of the power being consumed by a blower motor to move the air through your HVAC system. Its one of the lesser-used diagnostic...
13 SEER Equipment: Buyer Beware
There has been a lot of talk about the coming 13 SEER (seasonal energy efficiency ratio) minimum equipment standard, and the expected impact it will have...
CAN YOUR FAN REALLY AFFORD THAT FILTER?
The air filters we use in our heating and cooling systems are becoming more and more efficient every year. Filter marketing brochures compete to raise...
AIR BALANCING HOODS: THE GO-TO TOOLS FOR MEASURING AIRFLOW
Many technicians attend our air balancing seminars expecting to learn how to use an air balancing hood and turn a damper. Sixteen training hours later,...
AIR BALANCING HOODS: THE GO-TO TOOL FOR MEASURING AIRFLOW, PART 2
In our last installment, we talked about the value of air balancing hoods in measuring HVAC system performance. However, air balancing hoods alone cannot...
