< Previousoversize them, and they will operate at a lower capacity. While it’s true that inverter systems can modu- late down to meet a lower load, there is a limit to how low they can go. If a system is oversized, it will need to shut down more often in low sensible load, high humidity scenarios (i.e., shoulder sea- sons, summer nights, etc.). The closer the maxi- mum capacity at design conditions matches the peak cooling load, the better the system will de- humidify. Oversizing has been a rampant problem in our industry for decades, and so has the paradigm of like-for-like equipment replacement or even go- ing up a size if the occupants aren’t comfortable with their current system. Gas-fired furnaces tend to be even more over- sized than traditional heat pumps, so replacing a furnace with a heat pump of the same capacity is likely drastically oversized. Completing heat- ing and cooling load calculations for new heat pumps is critical. In humid areas, you should take another step with load calculations. Currently, load calculation software auto- matically breaks down sen- sible and latent loads for the location you select, but only for peak cooling conditions. Peak latent loads don’t usu- ally occur under peak cooling A s inverter-based heat pumps become more common, I’m surprised to hear from some contractors and home- owners that humidity control has become more of an issue than it was with single or two-stage equipment. We all know humidity is removed in cooling mode, but only when the system runs. Inverter systems are designed to operate at a lower capacity for longer periods, theoretically improving their dehumidification performance. So, what is happening, and how can we ensure we don’t end up with unhappy customers due to high humidity after they shell out big money for a shiny new system? EQUIPMENT SIZING Equipment sizing was the first thing that came to mind as I started thinking about this issue. I sometimes hear a repeated myth that sizing doesn’t matter with inverter systems – you can 10 NOVEMBER 2024HIGH-PERFORMANCE HVAC TODAY Maximize Dehumidification with Modern Heat Pumps By Ben Lipscomb, P.E. TECHNICAL Figure 1 shows maximum and minimum inverter equipment heating and cooling capacities. The system will cycle on and off below the orange and blue lines to meet the load.calculated for peak cooling conditions, as shown in Figure 2. In this approximately 1,700-sq. ft. home in Pensacola, the sensible cool- ing load for the peak dehumidification conditions is around 26% lower than the peak sensible load, but the latent load is around 50% higher. Be sure to check the equipment’s la- tent capacities at both the cooling de- sign conditions and dehumidification design conditions, and remember that the equipment will be operating at less than full capacity at the dehumidifica- tion design conditions. In this case, the equipment will op- erate at about 75% sensible capacity (14,503 ÷ 19,565). So, we should assume we’ll get about the same percentage latent ca- pacity at the dehumidification design conditions and will likely need supple- mental dehumidification. EQUIPMENT SELECTION Since we know the home’s load, we can now focus on equipment selection. Again, dehumidification is maximized when the cooling capacity matches the peak cooling load as closely as possi- ble. However, we also have heating to consider. In Figure 3, the heating load closely matches the cooling load, so the selection is straightforward. In cooler, humid climates, heating load may greatly exceed cooling load, so we must decide whether to select equipment based on heating or cool- ing requirements. There are argu- ments for both ways on this question. If you size to the heating load, you will likely have to provide a dedicated dehumidifier to maintain acceptable humidity levels in the home. Why? Be- cause the system will cycle off too of- ten under lower load, high humidity conditions. If you size to the cooling load, then you will need to provide supplemen- tal heating, typically with inefficient electric resistance heat that can make heating bills skyrocket. I lean toward sizing for the higher load, either heating or cooling, to take full advantage of the heat pump’s ef- ficiency. Of course, that may mean I’ll need additional dehumidification through a separate dehumidifier. This conditions, so checking the loads un- der peak dehumidification conditions is necessary. Unfortunately, most programs don’t provide these conditions automatical- ly based on location, so you must man- ually enter them. LOAD CALCULATIONS SOFTWARE INPUTS To find the peak dehumidification conditions, you can visit ASHRAE Meteo and find the location. The con- ditions provided are in terms of Dew Point (DP), Humidity Ratio (HR), and Mean Coincident Dry Bulb (MCDB). Load calculation software inputs are usually Dry Bulb (DB) and Relative Humidity (RH). You’ll have to plug in MCDB and either DP or HR into a psy- chrometric calculator to find the RH. With these values in hand, you can save a copy of your completed load calculation, manually enter the peak dehumidification conditions, and re- run the calculation to find the true peak latent load. Once you do this, you will likely find that the latent load is higher than that NOVEMBER 2024 11HVACTODAY.COM Figure 2 - ASHRAE design conditions for Pensacola, FL. Peak Dehumidification conditions are given in DP, HR, and MCDB. You’ll need a psychro- metric chart or calculator to find RH to input into load calculation software. HVACTODAY.COM12 NOVEMBER 2024HIGH-PERFORMANCE HVAC TODAY TECHNICAL does not perform similarly. Different makes, models, and even sizes with- in a single model range can have dra- matically different performance char- acteristics. Check the performance for the specific makes, models, and sizes you’re considering installing. I’ve heard of inverter equipment matched with single or two-speed blowers by the manufacturer as a bud- get option. Such systems cannot mod- ulate down very far because the airflow cannot be adjusted to match compres- sor output. If these budget models do modulate down, latent performance will be poor because the airflow will be high com- pared to the compressor output. These systems are not a good choice for ar- eas with high humidity, and I would steer clear of them altogether. Review the expanded performance data of the specific make and model you select. I’ve also seen research indicat- ing that ductless heat pumps do not control humidity as well as ducted heat pumps. I’m not sure why this is, pump, but I would suggest the follow- ing considerations: zVariable capacity, oversized com- pressor and coils, vapor injection z 95% to 100% capacity down to 5°F zOperate down to negative temps (-4°F to -13°F) zBase pan heater. The chart in Figure 4 compares the heating performance of a cold-climate heat pump model to the standard in- verter example in Figure 1. Both models are nominally rated at two tons, but the cold-climate mod- el can actually provide 2.5 tons at the standard rating temperature of 47°F. It retains the complete two tons down to 5°F. This figure also plots the load of the Pensacola home we looked at in Fig- ure 3. The cold climate model will easily meet the peak heating load at the 34°F design temperature, but the standard model would require heat strips – even in Florida! When selecting equipment, re- member that all inverter equipment course of action avoids electric heat strips altogether. Even when sizing for cooling, sup- plemental dehumidification is often necessary in humid climates, especial- ly in modern high-efficiency homes. A good building envelope can signifi- cantly reduce sensible loads. Still, la- tent loads remain about the same as they would for an inefficient home because a lot of that moisture comes from indoor sources like people, cook- ing, laundry, etc. OTHER SIZING CONSIDERATIONS When sizing for the heating load, opting for a cold-climate heat pump usually makes sense. Cold-climate heat pumps provide higher capacity to lower temperatures than standard inverter units. This can minimize the gap between heating and cooling ca- pacities, providing better dehumidifi- cation performance and higher cool- ing efficiency. There are no standard criteria for what qualifies as a cold-climate heat Figure 3 – Comparison of building loads under peak cooling conditions vs. peak dehumidification conditions.NOVEMBER 2024 13HVACTODAY.COM TECHNICAL Maybe you’ll only install cold-cli- mate heat pumps. Perhaps you’ll al- ways install a standalone dehumidifi- er. Maybe you’ll avoid a brand whose performance doesn’t match well with the homes you tend to work on or your climate. Feel free to comment and share any best practices you’ve found in your area. I would love to hear how oth- ers are approaching moisture man- agement with heat pumps or even just heat pump design in general. humidity is high. I recommend lim- iting overcooling to 1°F or 2°F below setpoint, which could lead to a cold and clammy feeling in the room. IT COMES DOWN TO SIZING, SELECTION, AND SETUP As you can see, a lot goes into think- ing through sizing, selecting equip- ment, and setting it up correctly (The Three “S’s”) to provide customers with first-rate moisture management even with today’s excellent and smart in- verter heat pumps. During your next few heat pump jobs, take your time and think through the Three S’s, and you’ll begin to understand what you need to do in your area to make sys- tems work as well as they can. You’ll soon discover standard prac- tices you can apply to every job that make your heat pumps work much better than competitors simply doing like-for-like replacements. but I guess that ductless units tend to keep airflow higher relative to capacity than their ducted cousins. Why? Because they must distribute the air through the space from a single air handler head rather than through multiple supply registers. Regardless, it may be best to think twice about using ductless systems where humidity is a concern. INSTALLATION, COMMISSIONING, AND CONTROLS Proper equipment installation using adequately sized, well-insulated ducts that don’t leak is required to operate any equipment properly. Inverter sys- tems are no different. Another universal requirement is correctly setting airflow and refriger- ant charges for proper system oper- ation. When setting airflow, a lower range of 300 to 350 CFM/ton helps lower the equipment’s Sensible Heat Ratio (SHR) and is helpful in humid climates. Fine-tune the refrigerant charge af- ter setting this lower airflow. Regarding controls, most inverter systems use communicating thermo- stats that have some built-in function- ality that is helpful for moisture man- agement. There is often a “dry mode” that keeps airflow lower relative to ca- pacity throughout the operating range. Dry mode helps maximize latent ca- pacity at the expense of some total ca- pacity as the equipment modulates down. Confusingly, some manufactur- ers call this the “humid mode.” The lesson: you must know the equipment you sell! Along with dry or humid modes, some thermostats allow you to set an overcooling allowance when indoor Figure 4 - Even similar equipment offerings from the same manufacturer can perform quite differently. Get the specific data for the unit(s) you are considering! Ben Lipscomb, P.E. has more than 16 years of experience in the HVAC industry, including labo- ratory and field research, Design/Build contract- ing, and utility energy ef- ficiency program design. He is National Comfort Institute’s director of engineering and util- ity services. You can contact him at ncilink. com/ContactMe with any questions.14 NOVEMBER 2024HIGH-PERFORMANCE HVAC TODAYNOVEMBER 2024 15HVACTODAY.COM includes peer-to-peer interactions, questions, learning opportunities, and sharing with fellow like-minded contractors,” he said. “Here you will brainstorm new ideas with peers, relax in a tru- ly productive environment, and gain valuable knowledge from all of the comprehensive work- shops and general sessions.” CHANGES ARE COMING Changes in the HVAC industry are happen- ing faster than ever before. Electrification, heat pumps, inverter technology, new refrigerants, and new efficiency standards are just a few of the challenges and opportunities in front of us. The key is to be prepared, proactive, and ed- ucate your team to meet the new opportunities head-on. This ties directly into the Summit’s Outper- form theme. Among the many breakout work- shops were special sessions covering the new heat pump technology, the new refrigerants, and what changes in terms of comfort, installation, and service. It also changes how High-Performance HVAC™ contractors test, measure, and diagnose comfort issues for their customers. BREAKOUT SESSIONS FOR THE NEXT LEVEL OF SUCCESS This year’s breakouts were presented by both high-performance contractors as well NCI in- structors and included the following: zHow to Build a High-Performance Cul- ture in Your HVAC Business— Present- ed by John Boylan, General Manager, Lakeside Service, Brighton MI z Anatomy of the High-Performance Sales Process – Presented by Dawn Mroczek, Sales Manager, GV’s Heating & Air, Glenview, IL L ast month the High-Performance HVAC Industry gathered in Asheville, NC to regroup, recharge, and set the stage to Outperform in their marketplaces in 2025. What does this mean? It means contractors and other industry professionals go together from all across North America to learn how to apply technical knowledge and training to improve the safety, health, comfort, and energy efficiency of your customers’ homes. Outperform was the theme for this year’s Summit and is the mission of National Comfort In- stitute (NCI). NCI CEO and President, Dominick Guarino, told the record-breaking audience during the event’s opening general session, “Our mission is to help you implement high performance in a step-by-step, easy to follow method. “This year we have created an experience that Breaking Records and Setting the Stage to OUTPERFORM in 2025 By Mike Weil SUMMIT 2024 RECAP For the first time, industry influencers conducted live podcasts from NCI’s High-Performance HVAC Summit.16 NOVEMBER 2024HIGH-PERFORMANCE HVAC TODAY ence,” says Anthony Woo of Climati- sation ACG, Inc. of Montreal, Canada. “My main reason for being here was to learn more abut indoor air quali- ty from John Ellis, but then I started meeting all these people who think the way I do. “I was really impressed with Dawn Mroczek’s class on high-performance sales. And the networking — I abso- lutely loved meeting so many different people from both Canada and the U.S. They were all so willing to share ideas and experiences.” SUMMIT FIRSTS The 2024 Summit marked the larg- est in attendance ever. With more than 200 attendees, 30% of which were first timers, shows that the high-perfor- mance approach is moving into its sec- ond generation, according to NCI CEO and President Dominick Guarino. This is also the first Summit where HVAC Industry social media influ- encers attended AND conducted live streaming and podcasts throughout the event. One influencer, Bryan Orr, was also the keynote speaker and an instructor in the inverter breakout session. His keynote focused on how to get and keep great people on your team. He discussed recruiting the right people and keeping them engaged and fulfilled so they stay with your team. Back to the influencers, some of those who participated in the live stream and podcast events included: z John Ellis from Dynamic Air Con- sulting Services z Louise Keller of UEI zJim Bergman from measureQuick ® zBrian Orr from Kalos Services z Steve Rogers from The Energy Con- servatory and others. Contractor attendee Tom Hearn of Hearn Plumbing and Heating, Madi- son, OH, says that Summit is a place where he and his team come to learn what is new in the industry as well as to recharge their “batteries.” “The industry needs to pay attention to the concepts of high performance as NCI teaches them,” he says. “They do a phenomenal job at set- ting the standard of how HVAC equip- ment should be installed in someone’s home. Coming to Summit helps you understand what the standard should be for every homeowner and company across the country,” Hearn adds. zHigh-Performance HVAC Ren- ovations from Start to Finish– Presented by Dustin Cole, Owner, Cole Air, Inc., Lake Charles, LA z How to Take Combustion Test- ing to the Next Level – Presented by NCI Instructor Mark Hunt z The Sweet Spot: Where Build- ing Science and HVAC Inter- sect – Presented by Rob Minnick, NCI Instructor zCustomer Communication: Drop the Technospeak — Pre- sented by Chuck Worley, Worley Home Services, Yorktown, VA zClimate Resilient Heat Pump Strategies – Presented by Ben Lip- scomb, NCI Director of Engineering and Utility Programs z How To Solve the Top 10 In- verter Installation Issues – Pre- sented by Bryan Orr, President, Ka- los Services and HVAC School zHow to Properly Design with Today’s Heat Pumps – Present- ed by Adam Mufich, NCI instructor zThe Air Upgrade Cure: A Sim- ple Solution to HVAC Equip- ment Failures – Presented by Da- vid Richardson, NCI VP of Training zPerformanceTown – Take Your Testing Accuracy to the Next Level – Taught by the NCI Instruc- tor Team. “This is my first Summit experi- More than 200 attendees were welcomed to Summit by NCI CEO and Presi- dent Dominick Guarino (right).NOVEMBER 2024 17HVACTODAY.COM SUMMIT 2024 RECAP zFieldpiece zMeasureQuick z MSA Bacharach zNational Carbon Monoxide Aware- ness Association (NCOAA) zOnline Access zRE Michel z RectorSeal/DustFree zSauermann z Testo zThe Energy Conservatory zTruTech Tools z TSI zUEI Test Instruments. ANNUAL AWARDS BANQUET No NCI HVAC Summit would be complete without the Annual Awards Banquet, where NCI recognizes out- standing achievements by High-Per- formance HVAC contractors across North America. Dominick Guarino told attendees, “Tonight’s event is one of my favor- ite parts of every Summit. It’s an op- portunity for us to shine a bright light on the real heroes of this group – our amazing Award Winners. “More than just members and cus- tomers, you are the heart and soul of of two one-hour ses- sions: one dedicated to High-Performance Lead Generation and the other to Sales. Attendees present- ed their ideas on each topic and then vot- ed for those they felt were the best. The winning ideas were from: — Lead Generation: Nick Lupo of Control Point Mechanical, Shrews- bury, MA, won for his customer lunch and learn focused on the new heat pump technologies. — Sales: Creating a product demonstration kit for use at home shows and on sales calls won in this category. Will Horner of Canco Cli- mateCare, Newmarket, Ontario, Can- ada, won the cash prize. PARTNER TRADESHOW Nineteen partner exhibitors man- aged tabletop displays around the general session ballroom so con- tractors could talk with them during breaks and regularly scheduled trade- show hours. Exhibitors also participated in NCI’s Annual Preferred Partner Prize Draw- ing. Attendees received “game cards” that had to be stickered by each exhib- itor and then turned in to be eligible for the drawing. This year’s exhibitors included the following: z Arzel Zoning zBaker Distributing zConduit Tech z Daikin zDuct Saddles z Evergreen Telemetry PERFORMANCETOWN As has been the NCI tradition for many years, Summit included hands- on testing experience on several work- ing HVAC systems to help attendees learn more about delivering high per- formance through diagnostics. NCI’s John Puryear, Casey Contre- ras, and measureQuick’s Jim Berg- man guided participants through test- ing principles, instruments, mobile apps, and processes to help attendees discover the hidden defects impeding system performance. THE IDEA MEETING Contractors convened for the famous contractors-only Idea Meeting hosted by Chuck Worley of Worley’s Home Services, Yorktown, VA, and Mike Weil of NCI. This meeting consisted Dominick Guarino recognizes those technicians and contractors who won scholarships to attend the 2024 Summit. Jim Bergman demonstrates the mea- sureQuick app during one of Summit 2024’s PerformanceTown sessions. The contractor attendees were focused on learning from all the vendor partners during the 2024 NCI Summit in Asheville, TN.the industry and questioning popular trends embodied the heart and soul of this award. But this year it was time for a change. Says David Richardson, NCI’s vice president of curriculum develop- ment and the very first Debien Award recipient, “We decided to rename this award in honor of another industry pi- oneer, our very own Jim Davis, a man who has saved more lives than we’ll ever know. “Jim is the pioneer and daddy of modern day carbon monoxide and combustion safety training. In his honor, the David Debien Technical Ex- cellence Award is now the Jim Davis Technical Excellence Award.” Congratulations to all of this year’s winners. NEXT YEAR IN AUSTIN, TX Mark your calendars for the High-Performance HVAC Summit 2025. It will be held in Austin, TX, from September 9th through the 12th. We will have more information posted on GoToSummit.com. Stay tuned for more information on pricing and registration. Spirit of Excellence Award — Tom Johnson, TM Johnson Broth- ers, Grandy, MN Sales Excellence Award — Hunt- er Wallace, Progressive Heating & Air, Newnan, GA Vendor Partner of the Year Award — The Energy Conservato- ry, Oakdale, MN The NCI 2024 Chairman’s Award — Nancy McKeraghan, Canco ClimateCare, Newmarket, Ontario, Canada. More details on each of these awards can be found on our website at ncil- ink.com/2024SummitAwards. DAVID DEBIEN AWARD RENAMED For 17 years the Technical Excel- lence Award was named for David De- bien, an HVAC contractor from Hous- ton, TX who resisted popular industry trends with regard to high SEER cool- ing systems — in his climate, they sim- ply didn’t work. Instead, he designed and built his own custom systems to handle the Houston area humidity. Then his team tested and verified their oper- ation. His dedication to advancing this great NCI family,” he continued. “Your success is what keeps us go- ing. And we feel so blessed that you’ve chosen to become part of this car- ing group that continues to selfless- ly share what is working for you and mentor each other.” This year’s awards were presented to the following: Small Contractor of the Year — Southeast Clean Air Solutions, Hen- rico, VA Medium Contractor of the Year — Cole Air, Lake Charles, LA Large Contractor of the Year — Worley’s Home Services, Yorktown, VA John Garofalo Implementa- tion Excellence Award — Vin- cent’s Heating & Plumbing, Port Huron, MI Jim Davis Technical Excellence Award — Henry Sterling of DiMar- co & Associates, Chagrin Falls, OH Rob Falke Servant Leadership Award — John Boylan, Lakeside Service Co., Brighton, MI Scott Johnson Training Excel- lence Award — Davis Services, Spartanburg, SC 18 NOVEMBER 2024HIGH-PERFORMANCE HVAC TODAYNOVEMBER 2024 19HVACTODAY.COMNext >