< Previous20 MARCH 2018HIGH PERFORMANCE HVAC TODAYIf you proactively measure the per-formance of your Air Upgrade en-hancements by looking through the eyes of your customer, they’ll happi-ly post positive online reviews, write glowing testimonials, and refer your business to their friends, family, and acquaintances. The key is to be inten-tional about it – don’t let it “just hap-pen.” Be proactive and the results will follow. Those positive reviews, shining testimonials, and referrals are the best fuel for your sales engine.AIR UPGRADES CAN CHANGE YOUR LIFESometimes, the simplest things are the most powerful. That’s truly the case when it comes to Air Upgrades. When you can create non-emergency work all year long, add more billable installation hours, increase self-gener-ated sales opportunities, enjoy higher average sale prices, enhance custom-er delight, all while garnering more positive reviews, testimonials, and referrals, why wouldn’t you?To learn how to implement the Air Upgrade process in your business, at-tend NCI’s Airflow Testing & Diag-nostics Implementation Work-shop. ENCOURAGING MORE POSITIVE REVIEWS, TESTIMONIALS, AND REFERRALSYour growing base of delighted cus-tomers will help expand your business if you just ask them. When customers acknowledge that real value has been delivered through the Air Upgrade process (you reduced their long-stand-ing dust problem, or solved their high electric bill issues, or made the mas-ter bedroom more comfortable, or reduced the noisy fan operation...) it’s your signal to ask for their help.WHEN YOU HELP SOMEONE GET WHAT THEY WANT, THEY’LL HELP YOU GET WHAT YOU WANT.SALESDavid Holt is Director of Business Training and Coaching for National Comfort Institute, Inc. He can be reached at DavidH@national comfortinstitute.comMARCH 2018 21HVACTODAY.COMnot properly seal it to the duct. This was a missed opportunity to improve IAQ.By installing additional devices without resolv-ing the underlying duct leakage issues, the con-tractor created a source for poor IAQ instead of improving it. This is NOT how you attain system performance.WHERE DOES IAQ MEET SYSTEM PERFORMANCE? Using smoke demonstrated that the newly installed filter rack was creating more problems than it solved. Because the duct leakage was not addressed, all the contractor did was add to the energy load.Harmful pollutants are often found in the air we breathe. Indoor pollutants can affect the As weather conditions become dryer and colder, our homes and businesses become a refuge from the harsh con-ditions. Maintaining proper Indoor Air Quality (IAQ) begins with a well-performing and balanced system that controls unwanted infiltration.A well-performing system must have sealed ductwork to decrease pressure imbalances in the building. Pressure imbalances lead to uncon-trolled infiltration of air from wall cavities, crawl spaces, attics, and outdoors.So, what is the impact on IAQ when the sys-tem isn’t performing as it should? During a re-cent home inspection, we found that a contractor had installed a bolt-on air purification device (a Merv 16 filter rack) in the return plenum but did Addressing Indoor Air Quality Through System PerformanceBy John EllisMANAGEMENTPoor indoor air quality can allow airborne pollutants and viruses to proliferate in a home, causing health issues for consumers.22 MARCH 2018HIGH PERFORMANCE HVAC TODAYMANAGEMENTtems are dramatically oversized and underused. Bringing in outside air serves several beneficial IAQ func-tions. Outside air dilutes potentially harmful Volatile Organic Compounds (VOCs) given off by building materi-als and cleaning products. VOCs also include pleasant fragrances and po-tentially fatal pollutants like carbon monoxide.The second benefit for bringing in outside air through the system is to gain control of infiltration. When you bring in and condition outside air through a controlled system opening, you minimize uncontrolled leakage through the envelope of the building. If a concern arises as to the impact of excessively hot or cold air degrading system perfor-mance, you can resolve it by adding a temperature or enthalpy sensor with an automated damper.THEN THERE IS HUMIDITYHumidity leads to mold and mold leads to IAQ is-sues. Control the humid-ity and indoor air quality improves.Controlling indoor humidity levels is critical. The year-round ideal hu-ture movement into building cavities. Where there is moisture, there is po-tential for microbial growth and mold.Consider this: Air is a fluid that moves into and out of conditioned space. It is the medium on which all things travel. Liquids and gases are both fluids. A fluid is a substance that has no shape of its own; it takes the shape of the container it’s in.Both a duct system and the building are containers, albeit leaky ones. The secret is to find and seal the leaks to control the air within.THE NEXT APPROACHOnce you contain air within a prop-erly-sized and sealed duct system, turn your focus to balancing airflow. That manages the pressure balance of the building. You accomplish this by sealing the structure, replacing win-dows, increasing or replacing insula-tion, replacing recessed ceiling light-ing with ICAT-rated LED lighting, and then downsizing and upgrading the existing HVAC equipment.However, only a small percentage of residential customers can afford to take this approach.Fortunately, there are alternative methods to regain control of build-ing pressure. Most installed sys-health of every household member. In fact, nine out of 10 homes have un-healthy air quality.Studies show we spend as much as 90% of the day indoors. The quality of the indoor air we breathe has a direct effect on our health.Also, 90% of the air-borne particles in a typi-cal household are smaller than 0.3 microns in size. Many of these airborne particles and allergens are so small that if you inhale them, they enter the lungs and absorb into the bloodstream. Small children are especially affected by these ul-tra-fine particles.As you can see, air filtration is very important. We want the air the HVAC equipment conditions to stay in the house. Let’s keep inside air in, and outside air out!AIR IS A FLUIDFiltration must be based on a sealed airflow system. Air moving through openings and gaps accounts for more than 98% of all water vapor/mois-Humidity leads to mold and mold leads to IAQ issues. Control the humidity and indoor air quality improves.Using smoke showed that the newly installed filter rack created more problems than it solved. MARCH 2018 23HVACTODAY.COMmoisture to the building with devices such as a humidifier.SOLUTIONS FOR WHAT’S GOING ON IN THE HOUSEThe key to taking care of IAQ issues is identifying pressure problems that create air exchange between inside and outside. How much exhaust air do you really need? How much air-flow, for how long, and what are the properties of the air? What can you do to alleviate the pressure differenc-es between inside and outside, there-by decreasing INFILTRATION?The best filtration in the world isn’t effective if it can’t keep up with IN-FILTRATION.An HVAC system can have a com-plex zoning system, economizers, ad-vanced controls, and staging, which may or may not improve comfort and efficiency. You must have a sys-tem capable of delivering equipment- rated capacity into the space before more advanced measures can per-form properly. The same is true with IAQ. The principals of delivered sys-tem performance must be met before more advanced IAQ devices will have an impact on air quality within the building.CONCLUSIONSystem Performance is a set of measurements and tests we should all be accustomed to. This allows us to gather data, and properly evaluate any system. These measurements, wheth-er for determining static pressure, Btu delivery, air balance, combustion performance, air changes per hour, or latent and sensible Btus, are all direct-ly related to indoor air quality.Learning to collect and diagnose this data takes some practice. But once you start applying these mea-surements to your clients’ indoor air quality concerns, it allows you to make a difference in their lives. You will be equipped to assure your cli-ents have the most safe, healthy, and efficient homes or business environ-ments possible. midity range for customers is 40 to 60% Relative Humidity (RH). If RH falls below 40%, virus survivability increases, especially for those viruses associated with the common cold and influenza. An RH above 60% is ideal for fungal growth.When you set fan airflow correct-ly in the cooling mode, you can alter the Sensible Heat Ratio (SHR). That balances the sensible cooling per-formance versus the dehumidifica-tion performance. When you move into the heating season, local weath-er conditions may require you to add John Ellis is President of So Cal Air Dynamics, Northridge, CA. He has over 35 years in the HVAC industry, and is very active in several trade organizations, including NCI. John has spent the last eight years perfecting and implementing a high standard protocol for creating clean and healthy indoor environments for clients with acute respiratory issues.He got his start in performance contracting 15 years ago after attending a class with Scott Johnson. His vans say “Performance Contracting” on them. At So Cal Air Dynamics, they apply a good blend of building science and best practices from NCI in their everyday business.John Ellis: Featured Speaker at NCI Summit 2018High Performance HVAC Summit 2018 is happen-ing March 4-6 in Austin, TX. John Ellis is one of six Performance-Based Contractors™ presenting how they Blaze A Trail to High Performance. Ellis, who is president of So Cal Air Dynamics in Northridge, CA, will discuss how his team has built a reputation for solving indoor air quality issues using Performance-Based Contracting™ best practices.Be sure to seek John out and discuss his processes for getting it done. Also take the opportunity to network with your peers in Austin. Learn more about the Summit 2018 program at GoToSummit.com.The diagram shows many points for air infil-tration and exfiltration in a building.24 MARCH 2018HIGH PERFORMANCE HVAC TODAYa 1/8” coating of dust on the blower wheel vanes reduces fan capacity as much as 30%. As airflow is reduced through the equipment, so is static pressure.Remember this the next time you see static pressure readings that look great, but the fur-nace you’re testing is tripping on its high-limit switch. If you’re dealing with a condensing gas furnace, the secondary heat exchanger is prob-ably dirty too. Prevent these headaches with a quick inspection of the blower. If it’s dirty, clean it. Otherwise, your readings are suspect.MISTAKE #2 – MEASURING IN THE WRONG LOCATIONThis is the second most common mistake. There are multiple ways to measure static pres-sure incorrectly. While measuring filter and coil pressure drop is straight-forward, total external static pressure (TESP) often adds a layer of con-fusion.So to better help technicians understand where to measure TESP, Trainer Scott Johnson intro-duced the “As-Shipped” concept to NCI. To ap-ply this term, think about how air-moving equip-ment comes from the factory as-shipped in the box. When you unpackage it, what’s included? These are the components included in the TESP measurement by the manufacturer – everything else is external.Consider a gas furnace unpackaged on the jobsite. The only thing included in the box is the furnace. In other words, the indoor coil, air filter, and duct system are all external to the as-shipped furnace. This is why TESP on a gas furnace is measured after the filter (as air enters the equipment) and before the coil (as air leaves the equipment). When you remem-By David RichardsonTECHNICALAvoid Four Common Mistakes When Measuring Static PressureOne mistake made when measuring static pressure is to assume the condition of the blower wheel. A dirty blower wheel makes static pressure readings look awesome, because the fan isn’t moving the proper airflow.If you talk to anyone experienced in measur-ing static pressure, they will admit they’ve dealt with inconclusive and goofy readings that didn’t make sense. This typically results in a frustrating, but rewarding day, because they learned something they won’t forget.It’s true that most questionable readings start with forgetting and/or ignoring static pressure measurement basics. To refresh your memory, I thought it would be fun to look at four common mistakes the best in our industry make when measuring static pressure.MISTAKE #1 – OVERLOOKING BLOWER WHEEL CONDITIONIn the daily grind, it’s easy to kick into cruise control and get complacent. You install test ports, take pressure measurements, record them on the invoice, and the static pressure portion of the call is complete. If this is the rut you occasionally find yourself in, you’ve probably overlooked a dirty blower wheel.One top mistake made when measuring static pressure is to assume the condition of the blower wheel. A dirty blower wheel makes static pressure readings look awesome, because the fan isn’t moving the proper airflow. Experts esti-mate that MARCH 2018 25HVACTODAY.COMsures that look much better than they really are.You can correct this by knowing the operation sequence for the equipment you’re testing and by slowing yourself down. If unsure of the equipment’s blower delays and staging, wait about 15 minutes after it turns on to take measurements.MISTAKE #4 – INCORRECT TEST INSTRUMENT USEThe final mistake we’ll look at is in-correct use of test instruments. This follows the same pattern as improper equipment setup. Both result from an unfamiliarity with the test equipment or just not having the right accesso-ries to properly test.It is surprising how many tech-nicians don’t have a drill bit sheath when installing test ports.The first place to start is test port installation. Because of this, they’re afraid to drill into the equipment cab-inet to test pressure near the coil. They should be! One misplaced test port makes for a long day repairing a sub-sequent refrigerant leak or cracked drain. To deal with this, many tech-nicians test in the wrong location or assume coil pressure drop. Both lead ber this, it makes the TESP measure-ment much clearer.If you’re in doubt about test loca-tions, record multiple pressures. Aim to measure and record four pressures on each system. On gas furnace sys-tems, these four pressures are typi-cally before the filter, after the filter, before the coil, and after the coil. On air handlers and package units, the four pressures are typically before the filter, after the filter, after the coil, and in the supply duct.If you document pressures, you can go back and find any mistakes if there is a question or dispute. Remember, NCI has static pressure test location diagrams for common equipment types to help keep you straight. Send me an email to request your copy.MISTAKE #3 – IMPROPER EQUIPMENT SETUPAnother common mistake is failing to pay attention to equipment setup details before measuring. This issue is often tied to rushing through the call or not understanding the equipment’s operation sequence. Some common mistakes are:• Using the fan on-switch on the ther-mostat• Not letting the fan ramp up on vari-able-speed equipment• Testing in first stage on two-stage equipment• Not letting a coil get fully wet in cool-ing mode• Not paying attention to the fan speed taps being used.The fan should operate at its highest airflow and the coil should be fully wet to see how the system operates at it’s highest load. Testing static pressure as mentioned above could result in pres-It is surprising how many technicians don’t have a drill bit sheath when installing test ports.26 MARCH 2018HIGH PERFORMANCE HVAC TODAYchanged. Adjust it to inches of water column for best results.PREVENTING THESE MISTAKESNow you might think that this is common-sense stuff. It is. This is why it’s so easy to fix. You can get everyone on the same page with some attention to detail and a little bit of enthusiasm.We forget so quickly that it isn’t fun-ny. Begin with re-emphasizing the fundamentals. With all the other re-sponsibilities technicians have, re-minders of the fundamentals keep us focused on getting accurate measure-ments. Also, technicians need access to documents that promote measure-ment consistency and proper docu-mentation. You can help them by as-suring they have the right materials.If you run into trouble, don’t forget to contact NCI technical support -- it’s what we’re here for. You’re not alone in measuring static pressure. We have all faced similar challenges. The difference is how you respond to them. If you’re an HVAC contractor or technician interest-ed in learning more about adding static pressure testing to your services, contact David at davidr@ncihvac.com or call him at 800-633-7058. NCI’s website www.nationalcomfortinstitute.com is full of free technical articles and downloads to help you improve your professionalism and strengthen your company.to misdiagnosis. The best solution is to have the right accessories for doing the job correctly.Holding an analog manometer (Magnehelic™) in your hand instead of leveling and zeroing it is anoth-er common mistake leading to mea-surement errors. Holding a digital manometer in your hand is fine, but your measurement techniques must be modified as soon as you use a Magnehelic.Digital manometers also have their issues, the most common is using the wrong scale. If your pressure read-ings don’t make sense, check the ma-nometer’s pressure unit setting. It’s common to find pascals, psi, or inch-es of mercury on the manometer dis-play once the batteries have been TECHNICALDavid Richardson serves the HVAC industry as a curriculum developer and trainer at National Comfort Institute, Inc. (NCI). NCI spe-cializes in training focused on improving, measuring, and verifying HVAC and Building Performance.MARCH 2018 27HVACTODAY.COMI have something to confess when it comes to air conditioning equipment sizing: As a community, we don’t measure. We just guess. Probably 95% of us don’t use the right tools for calculating heat loads. We use rules-of-thumb instead.For example, we have a one-size-fits-all rule: 500 sq. ft. per ton. I call it “Manual J 500.” No complicated math here; divide once, multiply once, and you have your equipment sizing and job pricing done in one shot.But new energy efficient homes are messing up our game and I don’t mind telling you how.What happens when a thoroughly entrenched HVAC contractor meets a thermally enhanced building envelope? The answer is the same as when an irresistible force meets an immovable object. It’s usually not pretty. If we don’t change how we design HVAC systems, we might find our trade splat up against a wall someday. That wall will consist of regulators and even third-party en-gineers taking control and oversight of the resi-dential HVAC industry.How did Manual J design go from a best prac-tice to a code-enforced regulation? We’ll start with a look back over 40 years of our industry and where our design assumptions have gotten us.THE GOOD OLD DAYS SIZING METHODFor starters, those of us who have been ser-vicing and installing residential air conditioning systems for the last two or three decades pretty much had it figured out that if we sized systems at the ratio of one ton for every five hundred square feet, it generally worked. No difficult load calcu-lations were necessary. Bids were easy to figure. It was as easy as one, two, three. All we needed to do was (1) estimate the square footage of the house, (2) divide that by 500 and (3) multiply by our price per ton and we were done.For example: Total home size is 1500 sq. ft. × 500 = 3 tons. Next, multiply 3 tons × $1200 = $3600.We did it this way for years and everybody was happy. Well, not everybody.THE VENERABLE VENTILATION METHODIn the trades, we are responsible for properly ventilating homes. That’s why they call us Heat-ing, Ventilation and Air Conditioning Contrac-tors. For decades, builders built leaky houses that could breathe on their own. Our biggest ventila-tion issue concerned arguing with builders about who was responsible for bath fans.In reality, other trades did the grunt work in By Paul WeiboldtMANAGEMENTTime to Phase Out ‘Rules of Thumb’As an industry, we’ve been taught from the outset of our careers that sizing HVAC systems is a matter of using the “500” rule of thumb.“500”28 MARCH 2018HIGH PERFORMANCE HVAC TODAYbefore. The average duct leakage rate was estimated at 30%! Now WE were wasting precious energy resources. It’s not a good feeling to wake up and find that you are the Benedict Arnold in the War of Energy Independence.UNINTENDED CONSEQUENCES OF DUCT SEALING IN THE 1990sOut came the tape and pookey brushes, duct blasters, and legions of duct leakage commandos (Seal Teams?) to the rescue. Ten years of this and then some building science guy figured out there were some seri-ous unintended consequences related to Duct Sealing Battle.Basically, they found that ducts were undersized. As an industry, we got away with this for years, be-cause there was always enough leak-age for the blower to work under nor-mal pressure. Now fans were acting like they were blowing air through a drinking straw. Poor airflow from un-dersized SEALED ducts meant that fan motors and compressors became collateral damage.Typical fans failed when subjected to higher-than-tolerable static pres-sure. Even powerful ECM motors bit broomsticks and baseball bats. Miles of weather-stripping went up like a Maginot Line. Plumbing and electrical penetration leaks were blast-ed out of existence with carloads of canned foam. Caulk guns were fired at every crack where the enemy, “outside air,” could infiltrate.When the battle was over, experts came to assess the battlefield. Shock-ingly, they found the leaks that were left fought twice as hard as before to let outside air in. The weatherized en-ergy efficient houses of the 1970s and 1980s were just as leaky as before the Caulker Invasion.THE COLD WARThe experts mentioned above were some meddling building scien-tists with research money and noth-ing better to do. They figured out that HVAC ducts were making houses just as leaky as before! In fact, they found supply ducts leaked so badly outside the conditioned space that they caused the house air pressure to go negative relative to the outdoors. The pressure difference caused small holes to leak more air. Infiltra-tion was just as much a problem as terms of providing accidental build-ing ventilation. I am talking about the plumbers and electricians who blasted their right of way for pipes and wires through the building envelope, leaving plenty of room for outside air to move into and out of the house. There wasn’t much need for us to in-tentionally ventilate a house. If it were up to us the story would end there. They lived happily ever after. THE END.LET’S HAVE A WARBut the story didn’t end there. The way I heard it, some government bu-reaucrat asked some university pro-fessor how to save energy. The profes-sor had a theory and the government had some money, so they decided to fight a war -- the War of Energy In-dependence. As usual, this was planned as a short, inexpensive skirmish that “in theory” would fix our global energy problems so well and so fast that the oil producing countries would have to find a way to put their excess oil back in the ground. That was in 1974.For over 40 years now, we have watched the building industry go through numerous energy crises and government fixes. They come like earthquakes and hurricanes; you nev-er know when to expect them, but you know they will come.THE CAULKERS INVADE DURING THE 1970s AND 1980sFirst came the weatherization crews of the seventies. They swept in like mercenaries, caulking and sealing the daylight (no joke) out of our homes. They fiercely attacked leaky houses, the enemy of energy independence. But it was like fighting a war with First came the weatherization crews who swept in like mercenaries, caulking and sealing the daylight out of our homes.MANAGEMENTMARCH 2018 29HVACTODAY.COMtems. We do a lot of them. In fact, in the last few years, since we bought our own spray foam rig (now retired), we have designed air conditioning sys-tems for more houses with spray foam insulation than anything else.Foam is hard to beat -- if properly installed -- when it comes to making buildings tight and efficient. I must design mechanical ventilation for every home I foam insulate.What amazes me is that most con-tractors I meet don’t install whole house ventilation even though they are VENTILATION contractors. They don’t believe in it. Have you ever met a masonry contractor who didn’t believe in installing concrete? Or a plumber who only provides hot and cold-water supply piping, but no drain waste and VENT piping?WHAT HAS CHANGED?Here is what I have discovered: NManual J is building science. The building shell is a shield from weather. The effectiveness of that shield is what we are measuring NYou can insulate a house so well that it needs as little as half the air conditioning that a comparable house needed 30 or 40 years ago NHVAC contractors can lower the attic temperature in a cathedralized foam application by more than 50 F, essentially bringing air condition-ing ducts back into the same ther-mal boundary as the occupied condi-tioned space NWe can virtually eliminate the stack effect that robs so much comfort from the typical home.Here is what we can do: NProvide comfortable, efficient air conditioning systems in super-insu-telling people Clorox doesn’t kill mold on wood (Another myth. It doesn’t, according to the EPA and many other sources)!TIME TO RANT…So here we are with the big mess made for us by “those insulation” peo-ple. Now we must do load calculations for these new super-insulated homes to figure out what we need to do differ-ently with comfort system design.The average home in the U.S. is maybe 2500 sq. ft. We used to sell five-ton systems to cool that space. Now our calculations tell us we only need half that. So, are we supposed to believe that?Worse yet, the rat-ed R-value per inch for the typical ½ pound SPF product is the same as fiberglass batts. So, what gives?Nothing else in 30 years ever came close to a 1000 sq. ft. per ton. Basically, insula-tors sold their product and put a big sign on ours, “Air Condi-tioning Systems 50% Off.” Most HVAC contractors are not ready for this. They are in denial. Too many years of habit and rules of thumb are causing them to react and misinform customers.To make it worse the Manual J load calculation method is so misunder-stood and abused that most contrac-tors don’t trust the results. …AND RAVEIn my HVAC business, we design air conditioning systems for a living. We also test the performance of those sys-the dust when the amp draw went sky high as “silver bullet solution” fans tried to overcome the new restricted air flow in tight undersized ducts. The resulting lower air flow across the evaporator meant compressors suffered frequent refrigerant flood-back. Bearing wash out and compres-sor slugging created a slow compres-sor death spiral. It could take two to three seasons but sure enough one day another compressor becomes a boat anchor.500 SQ. FT. PER TON NO LONGER APPLIESContractors got along unscathed for 30 years until the foam guys came along and messed everything up. We stuck to our 500 sq. ft. per ton sizing rule, but things didn’t work the same any more. Like Detroit au-toworkers, our air condition-ers sat idle for long periods with nothing to do.We put in the same old thermostats that were too dumb to notice rising humid-ity while the air conditioners sat idle. Even when the air conditioning went to work, they quit early, leaving more humidity hanging around.Of course, everybody knew enough to blame the insulation contractors for all the problems that arose as a result. Obviously, since we haven’t done any-thing different for 30 years, how could we be blamed for causing the clammy feeling people were now experiencing. It would be crazy to change the way we do things just because somebody came up with a new insulation.Now people say the 500 sq.ft. per ton rule no longer works. That’s like Next >