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It’s been a good mission so far
In 1996 Higher Elevations evolved from a techno-gadget chance enterprise, to a mission of treating customers as friends. Looking out for them and providing both support and the effective information they need.
I was told in 1988 that customers don’t remember favors. In 1996, I was told that I was not ‘the company’.
In 1997… I was.
My name is James S. Hall, ‘Steve’ to those familiar, but even though Higher Elevations is for the most part, a one horse company, I am not alone. I am blessed to have my former spouse, and best friend Deborah Hall, as the web master of www.higherelevations.com .
We’ve had our differences over the years, but cross either one of us and you’ll meet the other.
We both feel the same way about the friends we serve… our customers.
In that regard, HVAC automation and control systems support comes secondary to our number one responsibility, which is taking care of those who support us as we effort to support them.
If it all stopped tomorrow, there would be no way to deny that our course has been blessed by God. Customers may not remember favors, but people and friends do.
Our secret is simple: take care of people; save them more than you cost them; say what you know; understand that looking out for their best interest, is in your best interest.
HVAC automation is an evolution of many paths that serve a common and finite result. Starting from the pneumatics (air control) of 1988, through the computer control of today, the functions and governing dynamics remain the same.
We approach new control systems from the standpoint of the task they must do. We determine effectiveness by how well they complete those functions. You can’t write that process into extinction by changing the DDC.
Competitors are people too. We can, have and will continue to assist them to gain proficiency in applying their systems to the process. We are most inclined to do so when knowledge and respect is reciprocated. The inverse is also true.
At the end of the day, it’s about helping people, and helping people help people. That is our mission. If you are a competitor with a grudge to bear, ‘that’s what you have to beat’. ‘Good luck with that.’ James S. Hall – Higher Elevations Company |
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Higher Elevations Co. Steve Hall - Consultant Cell (509) 710-9129 P.O. Box 263 Springdale, WA 99173 Contact Email
HE Work Calendar 2012
PCT Chart Download
Calendars Year Index 1 01 Sunday 02 Monday 03 Tuesday 04 Wednesday 05 Thursday 06 Friday 07 Saturday 08 Sunday Leap 09 Monday Leap 10 Tuesday Leap 13 Friday Leap
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IAQ Theory 101
‘In theory, theory works, but in practice it is too theoretical…’
We shall start off by covering ‘that which should not be left behind, when doggie goes’. I’m speaking of Indoor Air Quality, or IAQ. Before its arrival, we all just died to get to work! According to some experts, we also died while we were there. Throw in a few lawyers and we have ample reason to take up finger painting, pottery and gardening professionally.
It’s the ‘new math’, but before we get to that… what ever happened to the old math and why was it in place before? Enter the air diffuser delivering air at 300 CFM (cubic feet per minute), times four into a classroom, which will be our model. A fan sized to deliver 1200 CFM was placed thoughtfully upstream at the mouth of the ductwork. Heating and much later, cooling was sized adequately to serve the predicted needs of air delivery.
Initially, 10 percent outside air was picked as an ideal minimum, because at 63 degrees (Fahrenheit) the flow would be perceived as introducing fresh air without significant cooling. This would be theoretically, the resulting temperature of a 70 degree room, introducing 10 percent outside air at 0 degrees F.
0.9 * 70 = 63 degrees
Often times we have seen mixed air reset, set points, range from 65 to 55 degrees, based upon room cooling demand. Therefore, we would quite often introduce much more fresh air at warmer temperatures. For example, at 65 degrees outside air we would need 100 percent outside air to achieve our 65 degree set point. Once it got warmer than the room outside, (which should be the litmus test), we closed the dampers back to minimum (10%).
Then one day, someone left their home, which had 0% air exchange by the way and found themselves feeling sick, obviously due to the minimal air exchange at school, where they spent 25 to 30 percent of their time, not considering lunch and recess.
Experts, politicians, and expert politicians were called upon to arrive at an ultimate conclusion, which would later be backed up, by reasoning and thought process. And so it was thought, that again, ‘man could fix it’!
Fifteen CFM per student would do the trick, which equaled out to seven students and a teacher, per classroom, for our legacy design air handling unit, delivering 120 CFM at 10 percent. Maybe the economists won’t notice the change and the teachers will love the class size.
But they did and weren’t impressed saying, “no, that will never do”. So it was decided to introduce 15 CFM per student, times 30 students, that is to say 450 CFM of ‘fresh outside air’.
Of course, that didn’t work so hot in practice, because 450 is 37.5 percent of 1200 CFM. Applied to the same physics that originally dictated 10%, our mixed air temperature would drop to about 44 degrees, when it was 0 degrees outside. This could be interpreted as ‘cold’ by some folks. Our heating apparatus, originally designed for 10% may have a hard time keeping up with the change and the state’s energy budget was way north of the charts.
Enter the ‘grandfather clause’… that would be the father of the father, of Santa Clause. You don’t have to meet the requirement, if you can’t meet the requirement. But, oh yeah… they kind of forgot to include that clause, which put the entire balance of compliance and function, on the shoulders of operations.
Another development further complicated matters. It was deemed that on/off style heating and cooling offered advantages over the central hydronic heating and cooling systems. In some cases, a single stage of heat was designed to overcome this deficit of calories at the mixed air. Additionally, the ratio was sometimes modified by increasing the fan size, to say 2000 CFM, for example.
Now this mind wave was of epidemic proportion! Going back to our chart, now with an encouraging 22.5 percent of outside air, we achieved 54 degrees, an increase of 10, at the mixed air. And let’s not forget our original mixed air reset… one degree below effective cooling, at 54 degrees.
Our new supercharged heat, could easily raise that to a more than adequate temperature, say 110-120 degrees? Now this was appreciated by the class and the teacher with the megaphone, trying to teach over the inrush of 500 CFM per diffuser. For three minutes, or often less, they were blasted with heat and during the off cycle they were crystallized, by 54 degrees of cooling at force four wind velocity.
The story gets worse during the cooling season, which I will not bore you with.
So for the past fifteen years, engineers have had to re-think the wheel, some quicker than others. Terms like IAQ monitoring and heat recovery have found their place on calculators that replaced slide rules.
Heat recovery retrofit is big and ugly… and necessary. Multiple stages of temperament will replace single stage heating and cooling, at a greater cost. Class sizes and schedules may be included. IAQ control cost money, which a public will have to provide. Already, priority conflicts exist in specifications, such as “introduce fresh air to control the air quality, but do not let the mixed air temperature drop below 50 degrees”.
Some controls have fixed programs, which can’t cut the new mustard.
I offer this solution to the industry, for legacy systems, (those designed for 10% minimum outside air).
It is not practical, or possible to introduce the 37.5% outside air, during ventilation cycles (when the heating and cooling are off). But, take a look at what can be done during the heating and cooling cycles. Often, you will be able to introduce more than 37.5% during these cycles and drop back to lesser minimums during the ventilation cycle.
The overall effect will meet, or exceed the required number of air exchanges per hour. You will heat with cooler air and cool with warmer air, which will increase the duration of the heating and cooling cycles and the introduction of fresh air along with them. Your occupants will notice a more even level and duration of comfort. Your equipment will cycle less often.
And finally… your energy budget will still increase, perhaps not quite as much, but then… no plan is perfect. Lock the Architect in the closet and tell the accountant you want the big ugly heat recovery system added imposingly down the side of your, once beautiful, building. Just make sure the make-up air unit, working in conjunction with the heat recovery, has multiple stages of tempering control, or is analog in nature, (analog = varying gradually between temperatures, as opposed to “on/off” control).
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Higher Elevations Company “Our business is founded upon helping people help themselves |
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Higher Elevations Company Springdale, Washington Copyright © 1993 ~ 2012 All rights reserved. |
