ACCA’s QA Program: A 360° View

Posted on:

May 1, 2012

ACCA recently spoke with a Quality Assured (QA) recognized contractor, a home builder, and a RESNET rater to learn about their experiences implementing the new HVAC requirements as part of ENERGY STAR for Qualified New Homes (version 3.0). Greg Cobb is the president and CEO of Sonoran Air, Inc. in Phoenix, AZ, Mike Mancini is the National Director of Project Integration for Meritage Homes in Phoenix, AZ, and Daran Wastchak is the president of D.R. Wastchak, L.L.C. in Tempe, AZ, a RESNET rating provider.

To give us an overview, walk the readers through the role that you each of you play in qualifying a v3 home, how do the three of you collaborate to get a particular home qualified?

MICHAEL: As the Builder, it is most important to produce a predictable and reliable “built environment.” This is no easy task. It takes great diligence and focus to ensure, in every climate zone, that we apply sound building science principles to our construction specifications. Many times, this involves multiple trades and requires group training to implement changes to building practices that have existed for decades.

Once the commitment has been made that the builder will make the necessary changes to produce a super-efficient home, the coordination with the Energy Rater and HVAC contractor is now imperative. As a group, we review all design assumptions for ACCA and RESNET modeling, and ensure that the building specifications are in alignment. Once we have consensus on all assumptions, there is clear direction for all 3 parties to move forward with their work.

At this point, the rest is execution…..HVAC designer designs according to the science based procedures, the Builder builds in accordance with the predetermined specifications, HVAC contractor installs per the design, Rater documents and certifies the home. The message is simple….do the prep work up front….don’t attempt to force it in the field after construction starts.

GREG: For an HVAC company, it begins with the planning and design phase. There needs to be extensive collaboration between the builder, energy rater and HVAC engineer/contractor. The builder must provide a clear definition of the building materials to be used, expected envelope leakage, etc. so the energy rater can calculate the HERS Index and the HVAC engineer can calculate the Manual J heat load with consistent design data. Ventilation strategy must also be defined at this stage. Exhaust fan specifications may need to change to meet both minimum airflow and maximum sone levels. Return air cans and filter grills often must to be resized to reduce the risk of excess static pressure caused by MERV 6+ filters, which cause more airflow restriction than basic fiberglass filters. After completing proper Manual J, Manual D and Manual S calculations, updated mechanical plans must often be filed with local building/plan review officials. Again, close coordination between the HVAC engineer/contractor, builder and architect is required to ensure both local building code and Energy Star v3.0 requirements are met with updated mechanical plans. Beginning January 1, 2013, load calculations, equipment sizing and duct design must be performed for the plan, options, elevation and solar orientation of each lot. A single “worst-case” design for each plan will no longer be allowed. Coordination and communication will need to increase even further to implement the upcoming Energy Star v3.0 requirements that HVAC designs be lot specific. Planning should begin now to manage the complexity of these changes. HVAC engineers/contractors must make builders, architects, energy raters, other contractors (electrical, plumbing & framing) and municipal plan review officials aware of the coming changes and added HVAC design complexity so they can each prepare for it.

Ensuring everyone understands the goals and the plan are important, is there anything else?

GREG: Attention to detail during installation is critical to ensuring compliance with Energy Star v3.0 specifications. The ACCA QA program and Standard 5 provide guidance on how to accomplish this requirement. Coordination between the builder, the HVAC contractor and other trades (framing, plumbing, electrical, etc.) is important at this phase to ensure a quality installation. Proper spacing between framing components to allow ductwork to be installed without restrictions is important, as is avoiding conflicts with plumbing pipes and electrical light fixtures. HVAC contractors must train their installers to properly install and seal duct systems to ensure efficient airflow without leaks. This will ensure room-by-room design airflows are achieved and duct leakage is minimized. Equally important is the proper installation of pressure relief components such as dedicated returns, jump ducts, transfer grills, high-low grills, etc. to ensure the +/- 3 pascal requirement is achieved for all bedrooms, dens, etc. If a door undercut has been built into your assumptions on pressure relief component sizing, coordinating with the builder and trim carpentry contractor to ensure this is in place (especially if thick carpeting is planned) will be important to avoid a testing failure. Planning for extra framing components so exhaust fans can be installed without looped ducts is also a good idea. If plan design, solar panels or other components will cause a long exhaust duct run, plan to size the fan and duct appropriately to meet the 50 cfm minimum airflow requirement.

So, after the design and installation phases…what’s of value to the HVAC Contractor?

GREG: After a proper design and quality installation, a detailed start-up/commissioning of the HVAC system is critical to its long-term efficient performance and homeowner comfort. Again ACCA documents provide the proper general guidelines to follow with manufacturers’ providing specific instructions for their equipment. The HVAC documentation process starts with an Energy Star v3.0 installation contractor checklist for each system with design data filled out by the HVAC engineer, an air balance report with design airflows for each register, a ventilation system description with design airflows and control settings, an AHRI certificate for each system and Manual J load calculations for each system. The start-up technician must complete the checklist, confirming electrical, refrigerant and airflow measurements meet manufacturer and design specifications for each system. The ventilation system must be commissioned with controls settings and measurements recorded. The air balance report must also be completed to ensure target airflows are within design parameters. It is also wise to perform pressure relief tests in bedrooms and airflow tests on exhaust fans so any corrections can be made before energy rater inspections are performed (to avoid a return trip on a testing failure). The final step is to deliver the completed Energy Star v3.0 checklists and other documentation to the energy rater and/or builder. For high volume construction on tight build schedules, electronic capture of this data in the field with wireless communication should be considered. If all of these tasks have been completed properly, you can now relax as the HVAC rater inspections are performed and enjoy the silence of the phone calls that are never made to your warranty service department! If a warranty service call does come in, you now have a documented baseline at start-up that will allow you to quickly get to the root of the comfort problem (equipment failure, change in refrigerant charge, change in airflow, building envelope not performing as designed, etc.).

Daran, how about the Rater, where do they fit in?

DARAN: The home energy rater typically facilitates the specific requirements of the ENERGY STAR for Homes program because they ultimately have to provide the third-party verification that all the parts and pieces are done and, in most cases, done right. Without question, the HVAC piece of the new ENERGY STAR version 3 program represents the greatest new innovations, and therefore the highest hurdles, for successfully delivering ENERGY STAR compliant homes. When it comes specifically to these HVAC requirements, it is absolutely critical that the rater work closely with the HVAC contractor to coordinate assumptions between the energy modeling and Manual J load calculations, testing and inspection techniques deployed in the field, and documentation flow at the time of final certification for each home. This level of coordination requires as strong a working relationship as possible between the rater and HVAC contractor so that communication is clear and open, there is flexibility on both sides as details and unique circumstances are worked out, and ultimately trust between the parties that is gained by a mutual understanding and respect for what each party must do to be successful. This may sound a bit Pollyanna, but the closer the two parties can get to this type of a working relationship, the more successful the delivery of ENERGY STAR version 3 homes is going to be for the builder and, ultimately, the homeowner. As a rule, we as the rater do not burden the builder with implementation issues unless there is a breakdown somewhere trying to get the details right working directly with the trade contractors. Builders can prevent these breakdowns by selecting the right contractors to begin with. It is obvious that this is doubly true of the HVAC contractor.

What’s the most important lesson learned since you’ve started implementing this process?

MICHAEL: You can’t communicate enough……to our Trades, Field Staff, Sales Agents, Realtors, Appraisers, Homebuyers…….Educate, Train, Inform, Lead.

GREG: Two key lessons: over communicate and pick your partners well. Communication during the design phase and planning the document exchange phase cannot be over-emphasized. Without this, a lot of delay and cost will be incurred by correcting items in the field. We have learned that if a builder does not wish to invest the time to properly plan a v3.0 implementation, it is best to walk away. Close collaboration between the builder, energy rater and HVAC engineer/contractor is required to execute v3.0 well. If a builder wishes to use traditional bidding practices of swapping out the engineer/contractor if someone presents a bid a few nickels lower, the necessary investment in collaboration is lost. Trust and closer relationships between builder and engineer/contractor are required to improve quality and drive down costs over the long term. The manufacturing industry realized this over 30 years ago, but the construction industry is just now beginning to adopt these concepts.

DARAN: The importance of staying on top of the changes that are part of the ENERGY STAR version 3 program as well as knowing the program as thoroughly as possible. This intimate understanding has given my business a competitive edge over the competition because builders and trade contractors know they can rely on me to give them answers to specific questions and effectively assist them with implementation of the program. In fact, it’s my observation that any individual or company that has made a point to operate at this level of understanding, be that a rater, builder, HVAC contractor, etc., has found the greatest success with the ENERGY STAR version 3 program. Those who have tried to skate by without “sweating the details” have struggled mightily and are more likely to fail rather than realize the many benefits that come from building ENERGY STAR labeled homes.

It is obvious that ENERGY STAR has raised the bar in the new homes market. Homebuilders are learning the value of HVAC contractors than can provide comfortable homes with healthy indoor air quality. The QA Program identifies for homebuilders and homeowners the HVAC contractors that are able to deliver on that responsibility.