Hilmor Scholarship Winners

Those of us who have been involved the HVACR industry sometimes wonder where the bright, energetic, new techs are going to come from. The need for more trained technicians is critical to the industry’s continued success. Recently, Hilmor showed us that the technicians can be found if we offer the right incentives and look hard enough. Hilmor, a brand new HVACR tool company offered three national scholarships in their first year of business and received over 500 applicants nationwide. Clearly there is some untapped talent out there. They chose three winners from among the 500+ entries: David Hall, Francisco Iniquez, and Kenneth Chavez. You can view their stories online at Hilmor’s web  page HERE

Watching these three young men describe why they wanted to study air conditioning it hit me: they are out there – we just have to find them. Their stories are similar to thousands of other young people who want to improve their life and are willing to work hard in order to do it. We need to show them that our trade offers that opportunity. I am proud to say that David studies at my school, and he has a bright future ahead of him. I know him personally, and I know he is exactly what this industry needs. I am sure Francisco and Kenny will do the industry proud as well. Take a look at the videos and think about the thousands of other people who could tell similar stories – then go out and find them.  They are out there.

Save the Date!

The HVACR & Mechanical Conference this year is March 2 – 5 at the Conference Center at the Maritime Institute in Baltimore Maryland.
You can see the conference sessions by clicking HERE. You can Register HERE.
If you need a way to sell your supervisors on attending, use the letter provided HERE.

The HVACR & Mechanical conference is supported by a who’s who list of industry organizations. Industry professionals are plentiful at this conference. People who are national training or service reps for companies like Danfoss, Tecumseh, or Genteque are there. There are plenty of opportunities to learn beyond the scheduled sessions. It is really pretty hard NOT to learn something while you are in the company of so many industry heavy hitters. Sharing meals with people who love what they do, have years of experience, and represent the best of our industry is awesome. The training sessions are very good as well. I will be speaking 8:30, Monday, March 3 on “Surviving the Paper Chase.” I will give you some ideas on how to manage all the “other stuff” that comes along with teaching.

The conference is free – the 16 conference sponsors underwrite the cost of putting on the conference. Of course, there are still travel and hotel costs. The Rees Foundation is offering scholarships to instructors to help pay the cost of attending. To find out more about the scholarships, go to the Rees Scholarship Foundation site

My advice to anyone fortunate enough to attend this year’s 2014 HVACR & Mechanical Workshop is to find someone who knows something and share a drink, a few laughs, and pick their brains. Go ahead and save the date now: March 2 – 5.
See you there!

Check Your Mixed Air Temperature!

Commercial and industrial air conditioning systems typically draw in air from outside to provide ventilation air for the building. This air is mixed with the return air before going across other system components, such as filters and coils. In really cold weather, it is possible for the mixture of outdoor air and return air to drop below freezing. If you have chiller coils or even hot water heating coils, allowing large quantities of sub-freezing air to pass over them for an extended time can cause them to freeze and burst. These systems typically have some type of freeze protection that closes the dampers if the mixed air temperature gets clos e to freezing. In colder climates, people know to check for this – because they pay a price if they don’t. In warmer climates, we can get lazy and forget about the fresh air dampers, freeze stats, and the controls that are supposed to prevent this. This extreme cold weather has got folks in Georgia feeling the effects of single digit temperatures, including frozen water coils from drawing in too much super cold air. If you maintain a facility that has outdoor air ventilation dampers, you might check to see what the temperature of the mixed air is after the outdoor air is mixed with the return air. If the mixed air temperature is below freezing, you probably need to check your minimum damper position or the damper controls. Many dampers leak 10% when completely shut. They typically don’t need to be open more than a crack to maintain minimum ventilation.

Why Excess Air Is Important

Combustion requires oxygen, which furnaces get from the air. Ventilation of the combustion products from a draft hood appliance, such as a water heater or an older natural draft furnace, requires even more air. For theoretically perfect combustion you need 10 cubic feet of air for every cubic foot of natural gas that is burned. However, the burners in even the most modern and well designed furnaces are not perfect. Combustion appliances all introduce excess air to insure there is enough oxygen for safe combustion. Too little excess air will have the burners operating in an oxygen starved condition, creating high levels of carbon monoxide (CO). Too much excess air can also be bad. Too much excess air will cool the flame, and also produce high levels of CO. Typical older natural draft appliances with atmospheric burners use around 50% excess air, turning the 10 CF of combustion air to 15 cubic feet. Nearly all residential furnaces manufactured today are induced draft appliances with atmospheric burners. In these furnaces, the excess air is more typically 20% - 40%. Excess air can safely go as low as 10% for commercial power burners that do a better job of mixing the air and gas.

In general, excess air decreases efficiency by cooling the combustion process. For any furnace, the ideal amount of excess air would produce the highest combustion efficiency without introducing an excessive level of CO in the flue gas. In most cases, as you reduce excess air you will see both the efficiency and CO increase. If the amount of excess air is excessive, reducing the excess air may actually decrease the CO produced in the flue gas. You want to keep the air-free CO below 400 ppm, the ANSI standard. Many techs try to keep the air-free below 100 ppm. Older gas furnaces had primary air adjustments, making it possible to adjust the amount of air being mixed with the gas. Newer furnaces do not have any air adjustments. You can only adjust the amount of fuel by adjusting the manifold pressure or orifice size. Increasing the gas being burned has the effect of reducing the excess air because now more air is needed. However, you should NOT overfire the furnace in an attempt to improve efficiency. When making any adjustments to manifold pressure or orifice size, always check orifice sizes and manifold pressure against the manufacturers specifications and the heat content of the gas supplied by the local gas utility. To read more on how combustion efficiency and CO production are affected by excess air, check out the Combustion Guide from Tru-Tech Tools (it is a free download HERE).