A Case Study in Coordination: Energy Star Partners and HVAC Contractors
Over the past 17 years, more than 1.4 million new homes have been certified to earn EPA’s Energy Star label. The Energy Star Certified Homes program, together with its thousands of partners, has transformed the construction of new homes by incorporating key efficiency components: more insulation, higher-efficiency HVAC equipment, tighter ducts, reduced infiltration, better windows, and Energy Star-certified lighting and appliances (see “Energy Star Certified Homes Program at a Glance”).
In 2012, Version 3 of the program was launched in part to tackle the challenging goal of delivering three critical systems in every certified home—a complete thermal enclosure system, a complete HVAC system, and a complete water management system (see “Three Key Systems Required in Every Energy Star-Certified Home”). Not only does this contribute to meaningful savings above the 2009 International Energy Conservation Code, these systems also help to ensure that Energy Star-certified homes deliver not only energy efficiency, but also comfort, durability, and quality.
This new frontier requires unprecedented coordination and teamwork. In this article we will discuss with one team why such coordination is necessary, how to accomplish it, and what benefits it brings. The team is comprised of builders C.R. Herro and Mike Mancini of Meritage Homes; home energy rater Daran Wastchak of D.R. Wastchak, LLC; and HVAC contractor Greg Cobb of Sonoran Air, Incorporated.
Like Three Ships Passing in the Night
The customer is not happy. It’s the summer of 2013 in Phoenix, Arizona; outdoor temperatures are topping out at 112°F, and the owner of a new high-efficiency home is uncomfortable. While the indoor temperature might be expected to float up a few degrees during these peaks, it is instead reaching the mid- to upper 80s. Something has gone wrong.
This is every HVAC contractor’s worst nightmare. And yet it was happening to Cobb. In the past, Cobb would have been told to fix the problem, no matter what the cause or the cost. But something was different this time. Not only was Cobb on-site—but so were the builder, the insulator, and the home energy rater.
After double-checking the load calculations and the equipment installation, the group narrowed the root cause of the problem to the thermal enclosure system. This home was built with an unvented attic using R-38 fiberglass batts, which should have held the attic temperature to about 5°F higher than the thermostat set point (see “An Emerging Trend: Unvented Attics”). Yet the attic in this home was about 15°F hotter, 3 times the expected temperature split. Instead of the low 80s, it was in the mid-90s. With only drywall separating the attic from the living space below, the ceiling was radiating heat like one of those luxury towel warmers on a cold winter day. But this was no cold winter day. Armed with this information, the insulator was able to correct the problem at its source, with no change to the HVAC system.
“That was a scary event out of the gate,” Cobb says. But Cobb largely credits the Energy Star program with bringing the parties together to work toward a resolution. “There were various paths the conversation went down: Well, can’t the home energy rater model it at R-38 and Sonoran Air model it at R-13 [for the load calculation] and we’ll just kind of make this work? No, the program requires that the home energy rater and HVAC contractor model it the same. So through that process, that allowed us to force the issue of—look—we need to actually make these homes perform the way they’re modeled and score them the way they actually perform. That way we’re not cutting corners to get the result we’re seeking, but actually make the home perform properly.”
While this sounds like a process that should be followed for every home, let alone Energy Star-certified homes, too often that’s not the case. For many new homes, the HVAC contractor and home energy rater don’t even know each other. This is true despite the fact that home energy raters model and verify many of the same inputs that the HVAC contractor needs to design the HVAC system.
Even for HVAC contractors of Cobb’s caliber, this collaborative approach is a relatively new paradigm. “Several years ago we were very much a typical contractor. We manipulated the Manual J to give it the outcome we wanted instead of using it as a real tool for design, and used the rule of thumb to guide us on sizing equipment and ductwork. It was very much driven by what we thought would work. That approach gets you in the ballpark but often will be wrong.”
That’s not to say that HVAC contractors bear the only responsibility for a broken process. Wastchak chimes in: “You have a lot of builders that are trying to cut corners to get to an end result, and they just don’t realize that what they’re doing is wrong. And that’s where training comes in, about what insulation done right is supposed to be, and you can start to get them to think differently and do differently. Builders just trying to do the program because they feel they have to do it for competitive reasons but not because they really get it or want to—those are the ones that are a real struggle.”
Like Wastchak, Cobb now triages builders into three categories. He says that builders in the first group “really get it. They are leaders and wish to deliver a great energy-efficient home that performs well over a long life cycle.” Builders in the second group “are those that wish to do it, but don’t have the experience or skills yet to do a great job. But they are on the right path and need a lot more work and education and patience trying to help them get from where they are to where they want to be.” Cobb will work with these first two groups, but shies away from engaging the third: “There are those that don’t really care. They want to get a rebate check and build the house as cheaply and quickly as possible. They generally take the easy route, which is to say, ‘As the contractor, you’re required to keep this house comfortable. I don’t care if this house isn’t performing. Step up and do whatever you need to and make it work.’ And frankly, that conversation is the one that’s happened countless times for every HVAC contractor and is the underlying cause of oversizing for years and years.”
This suggests that some partners are particularly well suited for enhanced coordination, while others are not. Beyond identifying the right people, though, what is it that these people actually do differently?
Turning Home Building from an Art into a Science
As the story above suggests, coordination can set those three ships sailing in the same direction. But that’s not all it takes.
Energy Star Certified Homes Program at a Glance
- 1,460,311: Number of certified homes built since the program’s inception in 1995.
- 101,006: Number of certified homes built in 2012.
- 3,364: Number of current partners in the program.
Certified Homes Built in 2012 Saved as Much Energy as
- eliminating emissions from 45,453 vehicles;
- not burning 187,972,166 lb of coal;
- planting and growing 5,555,330 coniferous trees every year for ten years;
- eliminating emissions from all sources of 481,394,596 lb of CO2.
Some builders have locked on to the importance of delivering a complete thermal enclosure system with every home. Meritage Homes is one of them. “In years past, it was very componentized,” says Mancini. “We were taking an approach of Let’s put some better windows in the house to make it more efficient, or Let’s bump up the insulation to make it more efficient, or Let’s change the lighting. In contrast, with this approach, it’s more holistic. What we need to consider is the way we put the house together that delivers a consistent building envelope and a more predictable built environment for the HVAC contractor and energy consultant to do their job properly.”
Herro further explains that delivering a complete thermal enclosure system goes beyond just the design: “The predictability and the consistency are a big part of innovation. It’s not just Can you think of a good idea, but what is the implication of conventional trades applying that idea? Can it be consistent and can it be predictable?” And a lot of that consistency and predictability comes down to selecting and training trades that can deliver.
“It takes a lot of hands-on, in-market, in-person training, education, and explanation,” Mancini says. Herro agrees: “You’ve got to help with change by explaining why, instead of just what. If they don’t have context behind the change, they’re not a partner in the change; they’re being subject to the change. That subtle difference is really important.”
It’s not enough just to explain the rationale for doing things differently, though. It’s equally important to demonstrate how the change will benefit everyone. “One of the things I think Mike does really well in his role is demonstrating the value to the entire chain,” Herro says. “The customers get a better home. Meritage builds a better home, and therefore is more successful in the marketplace. And our trades, then, help make us more successful, and therefore get more work.” This process is logical, Mancini suggests, but not effortless when you’re engaging “a contractor who says, ‘I’ve been doing it this way for 40 years and you’re not going to tell me what to do.’ These are guys that cut their teeth on tin and mastic, and you’ve got to be sensitive to their world but help them understand why we’re doing what we’re doing.”
The home energy rater also plays a pivotal role in seeing this intent through. “The way I see it,” Wastchak says, “builders are spending their time just trying to get houses built. Builders have got so much to deal with. The area that I live and breathe every day is Energy Star certification, worrying about making sure that these things are done. And to the extent that we can take that concern and worry and those coordination issues off the builders, we’re doing what we’re supposed to do.”
This coordination role extends to HVAC contractors as well. “I think that’s actually one of the more important things that Energy Star Version 3 has done,” Wastchak continues. “It’s brought these two areas that are making assumptions separately and tried very hard to bring them together so they are being compared and synced up.” In this way, not only do the home energy rater and the HVAC contractor know each other, but they begin to cross-check each other’s work.
Leveraging this coordination, the HVAC contractor must step up to deliver a complete HVAC system, just as the builder delivers a complete thermal enclosure system. “We all know you can drive a truck through code in terms of how the house is going to perform,” Cobb says. “We saw improvements with the Environments for Living and early Energy Star programs, but Energy Star Version 3 really set the bar at a level where we had the ability to have a very predictable envelope. It was kind of ‘code’ for performance. It’s no longer Can you fake it? It’s no longer Can you push someone to do something that may be cost-effective in the short term but in the long term creates a whole different set of issues? So what we found was that by having the Energy Star checklists and by having the other elements there of the known envelope, it really allowed us to use math to zero in on how this should perform.”
Three Key Systems Required in Every Energy Star-Certified Home
Thermal enclosure system. A well-insulated and air-sealed home, with good windows and doors, needs less energy to keep it comfortable.
Heating, cooling, and ventilation system. Heating and cooling equipment that is high efficiency; is properly designed and installed; and is combined with a duct system that’s insulated, sealed, and balanced maintains comfort with less expenditure of energy. Ventilation systems remove low-quality air, provide outdoor air, and filter contaminants to improve indoor air quality (IAQ).
Water management system. A water management system that directs water off the roof, down the walls, and away from the foundation and site, as well as keeping building materials from getting wet, improves durability and IAQ.
With a predictable thermal enclosure system, Cobb has been able to redouble his efforts to deliver a complete HVAC system. He utilizes not just math, but a scientific approach, to incrementally identify and eliminate whole categories of HVAC problems. While this goes beyond the minimum requirements of the Energy Star program, Cobb emphasizes that “ACCA Manuals J, S, and D are the fundamental starting point. If you’re not doing that as your starting point, then you’re really grasping at straws. So if you have a problem—well, what’s your mechanism for trying to solve it?”
Rather than relying on intuition first to guide their decision making, this builder, HVAC contractor, and home energy rater have taken a more systematic approach to delivering a complete thermal enclosure system and HVAC system with every new home.
Silence Is Golden
Nothing soothes the ears of HVAC contractors like a quiet customer service center on a hot summer day. For them, silence is the sound of a happy customer.
Changing old habits to remake the home-building process from an art into a science is not easy. If it were, everyone would already be doing it. So with that investment must come results greater than just Energy Star certification or the satisfaction of doing the right thing. After all the added effort, what practical benefits have these partners seen?
Cobb begins: “It took a bit of a leap of faith from the old-school guys saying, ‘There’s no way that’s going to work.’ But wow, we found that by doing the math, the opposite was actually true, particularly for several builders we’re working with who have done a custom per-lot HVAC design, where we’ve been removing all the buffer, and every single lot is designed with the correct equipment. That scared the hell out of people, because it’s not like one or two homes may be at worst case; now every single house has no buffer.” And the opposite of this old-school intuition turned out to be true, Cobb says. “We had many fewer comfort calls instead of many more comfort calls. And that unexpected result was a very pleasant one, and that is really what spurred us to take that capability to the next level. And now we’re not doing any designs through the traditional approach. We’re using a custom per-lot design approach for all new sites that we control. I’m a more effective contractor today, so I can do better, faster, cheaper by doing this extra work instead of rule-of-thumbing it and just seeing how it turns out.”
This has fundamentally reshaped Cobb’s business. “During the heyday of construction in the early 2000s,” he says, “we had a customer service call center that had about 40 reps that handled calls for warranty, and we had two guys in what we called our CAD department—not really even engineering. Now we have 14 members in our engineering department and we have four people in our customer service call center. And they’re primarily scheduling start-ups, as well as the warranty calls that come in. So it’s been a pretty significant change of putting the effort into designing it right instead of fixing it after the fact.”
And his builder clients have been noticing a change, too. “We’ve been working with one production builder for a little over three years doing custom HVAC designs for them. We tracked all the customer service calls during the warranty period for those homes done before the custom HVAC designs, and for the year after the transition to custom HVAC designs, leaving out the year of the transition.”
And what did he find? “We had an 88% reduction in the number of comfort calls related to airflow in the homes from the year before to the year after. And we’re seeing that trend continue—those types of calls have basically dropped off a cliff. So we’ve seen significant savings for those homes that have been designed right from the beginning.”
“The good thing about the Energy Star program,” Cobb concludes, “is that you get to the root cause of why a house is not performing. If you screwed up the load, or the equipment isn’t performing, or some other thing, it’s still on you the HVAC contractor to make that work. But if the envelope is not performing as it should, then it’s a different kind of conversation. You can help be a source for identifying and solving the problem, but you’re not in the line of basically throwing dollars at the problem to make it go away. Okay, you may make the homeowner comfortable, but they’re going to have utility bills 40% above what they should be for the life of that home.”
Like Cobb, Herro found that belief in the process was required at first. “It was a leap of faith for us. We’ve now demonstrated for years with thousands and thousands of homes built that it is doable, it is trackable, it is performance based, we have performance data and utility bills and customer logs and warranty logs. We can show beyond a doubt that this is a better, more fiscally responsible thing to do.”
An Emerging Trend: Unvented Attics
While not a mandatory requirement in the Energy Star Certified Homes program, an increasing number of homes are being built with unvented attics. Unlike a standard vented attic, where the thermal and air-sealing boundaries are at the ceiling, unvented attics move these boundaries to the roof deck. This provides the following benefits:
It improves efficiency and comfort, because the ceiling temperature is closer to the thermostat set point; the ducts and HVAC equipment in the attic are brought within the thermal enclosure; and having fewer penetrations through the roof deck than through the ceiling often reduces infiltration.
It simplifies the work scope, because it requires less-stringent duct sealing and reduces the number of air-sealing details, such as gaps between the top plates and the drywall; and because it eliminates the need for attic hatch insulation.
It makes the home a better investment. Not only do unvented attics improve performance, but the added costs may be partially offset by the need for lower-capacity HVAC equipment, and the need for fewer efficiency measures to hit the efficiency target.
And not just for Meritage Homes, but also for the HVAC contractors that he works with across the country. “The good news is that it is absolutely better for the HVAC contractors. They have fewer warranty calls if they’re properly sizing and they’re attaching HVAC equipment to a much more consistent, predictable envelope. So by partnering with a home builder like Meritage that has third-party verification, like with Daran, what the HVAC contractors get is a sense of confidence that they can be accurate. That they don’t have to add 50% because they’re not really sure what’s going to show up in the field or how much variation there is.”
Wastchak has noticed similar benefits among other builders, too. “The Energy Star Version 3 homes that are being built today are by far the most energy-efficient homes that have been made widely available to home buyers. Without Energy Star, I have great faith that Meritage would be doing great things with their homes. However, for all home builders, Energy Star Version 3 has now brought together in one package all the necessary components that are key to building truly high-performance, energy-efficient homes. In short, what the Energy Star Version 3 program has done so well is create a platform for delivering some of the best homes that the standard home buyers, Mr. and Mrs. Smith, have ever had an opportunity to purchase in the marketplace.”
Herro echoes this sentiment, although for his customers, it’s not silence but unsolicited praise that signals success. “There continue to be great opportunities to further advance home performance. But with the advancement available in the market today, I get testimonials from customers that say, ‘I don’t understand everything you did, I don’t understand all this building science, but I would never live in a home that doesn’t live like this anymore. It’s quiet, it’s comfortable, my utility bills are low, I’m very, very happy.’”
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