Comparing ASHRAE 90.1 Appendix G / PHIUS+ / Passivhaus methods and standards

– James Ortega, PHIUS Certification Staff

The New York State Energy Research and Development Authority (NYSERDA) promotes energy efficiency and the use of renewable energy resources. NYSERDA has been at the forefront of promoting adoption of passive building in NY State. For example, over the past several years, NYSERDA has partnered with PHIUS and other organizations to offer qualified students substantial fee reductions for passive house professional training.

For the past year, PHIUS has collaborated with NYSERDA on a vital study of multifamily buildings in New York. The results of that study were released this past October, and we’re excited to share some of the summarized highlights that show we are on the right track with PHIUS+.

NYSERDA conducted the study to compare standards and methodologies to inform its development of the Multifamily New Construction Program (MF NCP). This program follows the goal of 40% reduction in greenhouse gas emissions that New York State set as part of the Clean Energy Fund (CEF), one of the pillars of the Reforming the Energy Vision (REV) program launched in 2014.

The study is part of NYSERDA’s exploration of alternative approaches and standards to promote high-performance buildings to supplement the ENERGY STAR® Multifamily High-Rise (MFHR) program, which NYSERDA has supported in the past.

The goal of the study is to create equivalent building performance targets for each certification program with the intent that the submitted projects achieve similar energy performance to qualify for incentives offered through NYSERDA’s new MF NCP, regardless of which energy modeling tool and protocol are followed.

Comparing ASHRAE 90.1 Appendix G_PHIUS+_Passivhaus methods and standardsStudy Description

This case study emulated a typical high-rise multifamily building designed and constructed in New York State based on the DOE/PNNL Prototype Models. The five design cases created and modeled using the three tools and protocols described above are listed below[i]. You can also review a fully detailed description and full PDF version of the NYSERDA report here.

Energy Modeling Tools

The study looks at and compares three different approaches and energy modeling tools and protocols.

  • The MFHR program uses the Quick Energy Simulation Tool (eQuest) in combination with ASHARE 90.1 Appendix G Performance Rating Method as the modeling tool and protocol
  • WUFI® Passive is used by the Passive House Institute US (PHIUS) to model performance
  • The Passive House Planning Package (PHPP) is used by the Passivhaus Institute (PHI)

Note: There neither was nor is an expectation that the three different methods would yield equal energy usage estimates because each protocol has different assumptions for operating conditions.

Conclusions

The Base Case and Packages A-C have prescriptive envelope and mechanical systems, but some assumptions such as occupancy, residential plug loads and residential lighting patterns vary based on the different modeling protocols from each organization. As shown in Figure 1 below, the difference in results between protocols is substantial.

For example, the PHI protocol estimate for source energy usage is nearly half of the Appendix G cases. This discrepancy stems directly from the PHI assumptions for residential plug loads and lighting.

Figure 1: Annual Source Energy by end use and Protocol (Using EPA Portfolio Manager Site-to-Source Conversions)

Figure 1: Annual Source Energy by end use and Protocol (Using EPA Portfolio Manager Site-to-Source Conversions)

The NYSERDA report explicitly calls out the plug loads category. First, while acknowledging that some difference in plug load assumptions were to be expected, the report finds the size of the difference troublesome, suggesting that the PHI assumptions are overly optimistic and warrant review.

From the report:

            Variations in this category [plug loads] are expected due to differences in the protocols’ assumptions, but the magnitude of the difference appears excessive, and warrants further investigation. Aside from affecting the total electricity consumption, plug loads interact with heating and cooling and significantly impact the total energy use of high-performance buildings.

The report summarizes that:

            PHI defaults for in-unit lighting and appliances energy use are significantly more optimistic than presented in references such as Building America and COMNET, which contributes to a much lower EUI projected by the protocol for equivalent design. It is recommended that PHI review those default assumptions made regarding multifamily buildings in the U.S.

Packages D-F designs include changes to envelope and mechanical systems by PHIUS and PHI to comply with their respective standards. The proposed design changes by PHIUS and the PHI for these cases are translated into eQuest to investigate the associated energy savings/difference that eQuest registers. There are some exclusions to these proposed changes that are left out of the eQuest model. For example: Both the PHIUS and PHI models incorporate interior blinds to incorporate passive cooling, but Appendix G protocol does not allow manual controls to contribute towards savings.

The difference in Source Energy by End Use between PHIUS and PHI improvements as modeled in eQuest are minimal as shown in Figure 2 below. However, the difference in envelope assumptions are not (particularly windows and airtightness) as shown in Figure 3.

The PHIUS Package (D) uses windows with overall U-value of ~0.28 Btu/hr.sf.F and an airtightness limit following the PHIUS protocol of 0.05 cfm/sf @50Pa. The equivalent infiltration at natural wind pressure is 0.017 ACH. The PHI Package (F) uses windows with overall U-value of 0.15 Btu/hr.sf.F and an airtightness limit following the PHI protocol of 0.6 ACH @50Pa. The equivalent infiltration at wind pressure is 0.05 ACH. The difference in required window U-value between these two models has significant cost implications in that the PHIUS modeled window performance could be met with high performing double-pane windows, while the PHI modeled window performance could only be met with triple-pane windows.

When it comes to airtightness, Appendix G protocol assumes an infiltration at natural wind pressure of 0.186 ACH. PHIUS protocol mandates an airtightness 10x tighter than the Appendix G Baseline for this building (0.017ACH). The airtightness is specified for this particular building because the PHIUS limit is per square foot of envelope area, which equates to varying ACH values with different building sizes. While the PHI target of 0.6ACH @50Pa may be comparable to the 0.05cfm/sf @50Pa target of PHIUS for small buildings, for large scale buildings such as used in this study, the PHIUS target is 3x tighter than the PHI requirement. (0.017ACH PHIUS vs 0.05ACH PHI). This difference in requirements has important ramifications for building durability as well as energy loss.

Figure 2: Energy by Protocol and End Use (Using EPA Portfolio Manager Site-to-Source Conversions)

Figure 2: Energy by Protocol and End Use (Using EPA Portfolio Manager Site-to-Source Conversions)

Figure 3: Modeled Configurations - Packages D-F window U-values and airtightness

Figure 3: Modeled Configurations – Packages D-F window U-values and airtightness

This comparison study is an important step for financing bodies and agencies to meaningfully evaluate performance and incentivize passive buildings. It also serves as a solid case study to build upon for other building types and sizes across the country. As larger passive projects continue to develop, monitored data will become an important assessment tool to verify the modeled results of comparison studies such as this one.

 



[i] Base Case: ASHRAE 90.1-2010 Appendix G Baseline Design

Package A: Base Case modified to include building components found in better performing MF NCP projects.

Package B: Package A with exhaust air heat recovery in corridors

Package C: Package B with Variable Refrigerant Flow (VRF) heat pumps in apartments

Package D: PHIUS design to meet PHIUS+ 2015

Package E: PHI Team 1 design to meet PHI Standard

Package F: PHI Team 2 design to meet PHI Standard

PHIUS Monitored Data Collection: Initial Results Are Encouraging!

– Jordan Frazin, PHIUS Certification Staff

INTRODUCTION

Passive building strategies have become increasingly common throughout the green building community and there is an ever-expanding network of Passive House Institute US (PHIUS) certified builders, CPHC®s, raters, and verifiers throughout the country. Thanks to these professionals, PHIUS has a catalog of over 250 certified and pre-certified projects and hundreds more that have been submitted.

Many of these certified projects have been fully occupied for months or even years, and we now have the opportunity to dive into monitored data collection and analysis.

By gathering actual performance data – in the form of utility bills – we can improve our modeling protocols, and refine the practices used by all parties involved in the certified project, including component manufacturers. We also hope to gain insight into the intricacies of climate specific design and its financial implications for the passive building owner.

With the support and guidance of the Industry Advisory Council, this past summer, we began this data collection and analysis process in earnest. (Thanks to the project teams who’ve already volunteered to participate!) We are always seeking additional utility data—if you are willing to share your project’s utility data with us, please send a message to certification@passivehouse.us to state your interest. We will reply with your next steps.

We’re excited to report that we’ve already processed some utility data and begun to analyze project performance with regard to predicted versus actual site energy use. Here’s a summary of the process, and preliminary findings:

PROCESS

The data analysis process began by gleaning the appropriate data from the project’s energy model and then by organizing it in spreadsheet format to account for all categories. This was broken into space conditioning, hot water, auxiliary energy, lighting, appliances, and miscellaneous loads. (see Figure 1 below).

Fig. 1: A portion of our monitored versus modeled site energy calculations.

Fig. 1: A portion of our monitored versus modeled site energy calculations.

Once we determined the estimated monthly energy use for the building from the certified energy model, we then compared these predictions with the actual utility data provided by the CPHC or project owner (see Figure 2 below).

Fig. 2: An example of some especially thorough, recently received utility data.

Fig. 2: An example of some especially thorough, recently received utility data.

Due to the nature of the utility data billing period (often not beginning on January 1st), it sometimes became necessary to cobble a year’s worth of data together using months from adjacent years. In the cases where this occurs below, it will be noted in the chart title.

RESULTS

Project 1 – Single family home

This project, a single-family home located in ASHRAE climate zone 4A, was certified under the PHIUS+ standard prior to the release of the PHIUS+ 2015 standard. It houses four occupants. The ‘modeled’ monthly estimates shown below follow PHIUS+ 2015 modeling protocols.

Fig. 3: Monthly site energy use for project 1, using 12-months of data from the end of 2015 and start of 2017. PHIUS modeling protocol estimated annual site energy use with 92.59% accuracy.

Fig. 3: Monthly site energy use for project 1, using 12-months of data from the end of 2015 and start of 2017. PHIUS modeling protocol estimated annual site energy use with 92.59% accuracy.

Fig. 4: Monthly site energy use for project 1, using 12-months of data from 2016. PHIUS modeling protocol estimated annual site energy use with 87.91% accuracy.

Fig. 4: Monthly site energy use for project 1, using 12-months of data from 2016. PHIUS modeling protocol estimated annual site energy use with 87.91% accuracy.

As seen above in figures 3 and 4, PHIUS modeling protocol slightly underestimated the actual site energy performance of this project. Specifically, it appears as though we have overestimated July loads in both cases, and slightly underestimated most other months. However, overall, the estimates still track the actual usage quite well month by month and are only off by ~10% on average. 

Project 2 – Single family home

This project, a single-family home located in ASHRAE climate zone 5, was certified under the PHIUS+ standard prior to the release of the PHIUS+ 2015 standard. It houses two occupants. The ‘modeled’ monthly estimates shown below follow PHIUS+ 2015 modeling protocols.

Fig. 5: Monthly site energy use for project 2, using the same 12-months of data from years 2015 and 2017 as above. PHIUS modeling protocol estimated annual site energy use with 96.28% accuracy.

Fig. 5: Monthly site energy use for project 2, using the same 12-months of data from years 2015 and 2017 as above. PHIUS modeling protocol estimated annual site energy use with 96.28% accuracy.

 

Fig. 6: Monthly site energy use for project 2, using 12-months of data from December of 2015 and January through November of 2016. PHIUS modeling protocol estimated annual site energy use with 98.30% accuracy.

Fig. 6: Monthly site energy use for project 2, using 12-months of data from December of 2015 and January through November of 2016. PHIUS modeling protocol estimated annual site energy use with 98.30% accuracy.

We were very pleased with the results of this case, as it was by far our most accurate. However, we were soon informed of the occupants’ varied heating set-point preference of 65°F as opposed to the 68°F set-point embedded within our protocol. So, out of curiosity, we analyzed another energy model with the heating set-point at 65°F. The results of this exploration are shown below.

 

Fig. 7: Monthly site energy use for project 2, with interior temperature set to 65°F. This figure shows 12-months of data from years 2015 and 2017. PHIUS modeling protocol estimated annual site energy use with 87.28% accuracy.

Fig. 7: Monthly site energy use for project 2, with interior temperature set to 65°F. This figure shows 12-months of data from years 2015 and 2017. PHIUS modeling protocol estimated annual site energy use with 87.28% accuracy.

Fig. 8: Monthly site energy use for project 2, with interior temperature set to 65°F. This figure shows 12-months of data from December of 2015 and January through November of 2016. PHIUS modeling protocol estimated annual site energy use with 89.31% accuracy.

Fig. 8: Monthly site energy use for project 2, with interior temperature set to 65°F. This figure shows 12-months of data from December of 2015 and January through November of 2016. PHIUS modeling protocol estimated annual site energy use with 89.31% accuracy.

Despite the project operating at a lower heating set-point, our models still predicted site energy use with ~ 88% accuracy, with especially close predictions during the non-heating months of the year. As expected, these results shifted due to a predicted lower space heating energy use during the winter.

Project 3 – Single family home

This project, a single-family home located in ASHRAE climate zone 4C, was certified under the PHIUS+ standard prior to the release of the PHIUS+ 2015 standard. It houses four occupants. The ‘modeled’ monthly estimates shown below follow PHIUS+ 2015 modeling protocols.

Fig. 9: Monthly site energy use for project 3, using 19 months of data from January 2016 through July 2017. PHIUS modeling protocol estimated annual site energy use with 131.68% accuracy.

Fig. 9: Monthly site energy use for project 3, using 19 months of data from January 2016 through July 2017. PHIUS modeling protocol estimated annual site energy use with 131.68% accuracy.

In the case of project three, PHIUS modeling protocol significantly overestimated site energy use during the non-heating period . Heating months, however, were estimated with greater accuracy. Of the three projects analyzed, this was the only project with energy consumption far lower than we predicted.

We were initially stumped by this comparison, until our suspicion of unique occupant behavior was verified during this past October’s North American Passive House Conference in Seattle, Washington. Upon seeing these results during a presentation, an audience member (and friend of the home’s occupants) confirmed the occupants have extremely energy-conscious living habits.

CONCLUSIONS

Based upon these comparisons, the PHIUS modeling protocol appears to predict annual site energy within roughly 10% – a promising statistic moving forward. In some cases though, unique occupant behavior impacts actual performance of passive house projects in ways we cannot predict.

By continuing to analyze monitored data, we hope to increase our total sample size to the point of discovering climate-specific trends. Additionally, we believe that increased availability of monitored performance data will become a useful technical and marketing resource for passive building professionals, and lead to improved practices in the coming months and years. And lastly, this data can validate the level of savings you can achieve through PHIUS+ certification and provide a foundation of assurance that incentive programs can rely on.

PHIUS+ 2018

— Lisa White, Graham Wright, PHIUS 

During NAPHC2017 in Seattle, PHIUS Senior Scientist Graham Wright provided a glance at PHIUS+ 2018 during a lunch input session. Wright highlighted updates to the standard and also touched on what will stay the same. Much of the content discussed is also summarized in this blog post: Getting to Zero Part II: PHIUS+ 2018. PHIUS Certification Staff fielded questions and encouraged audience input – overall feedback was supportive. The updated standard is currently under development by the PHIUS Technical Committee. There will be a public comment period, more details on that will be released soon.

We also announced that PHPP models will not be accepted for PHIUS+ 2018 projects. Following rationale in this blog post (Transitioning from PHIUS+ to PHIUS+ 2015 Passive Building Standard), WUFI Passive continues to see notable updates. The next update will include an improved shading algorithm for PHIUS+ 2018, among other improvements. The two modeling platforms have diverged and PHPP is no longer suitable for PHIUS+ Certifications. PHPP is still accepted for PHIUS+ 2015 projects. Accepted PHPP versions are: 06-02-10 IP-overlay of v2007 through PHPP v8.5.

The new program is scheduled to begin taking pilot projects in January 2018, and will be fully released mid-March 2018. There will be a 6-month transition period, from March through September 2018, where projects will be accepted for certification under PHIUS+ 2015 or PHIUS+ 2018. After September 15, 2018, no new projects can register under PHIUS+ 2015. In order to ‘lock-in’ a project under PHIUS+ 2015, both a contract and project payment must be in place before September 15, 2018.

PROJECTED TIMELINE *

January 2018: Accept pilot projects under PHIUS+ 2018
Mid-March 2018: Full release of PHIUS+ 2018
September 15, 2018: Projects no longer accepted under PHIUS+ 2015

*Please subscribe to the PHIUS Newsletter for updated release information as it becomes available

An Update from the New Gravity Housing Conference

Lisa White, PHIUS+ Certification Manager

This past week I had the opportunity to visit Philadelphia and attend the first annual New Gravity Housing conference, hosted by the Delaware Valley Green Building Council (DVGBC) in partnership with the Greater Philadelphia Passive House Association (GPPHA) and Philadelphia Collaborative.

The Pennsylvania Housing Finance Authority (PHFA) wrote passive building into their 36345506521_044a0a22a9_z application for tax credits in 2014. That spark ignited significant growth in the passive building market of Pennsylvania and opened the eyes of other finance authorities to jump on board this effort, which has brought a momentous shift in the affordable housing market. The energy surrounding that was evident at this conference; it was quite inspirational.

The discussion didn’t focus only on dollars and BTUs, but also around providing affordable, comfortable, resilient, efficient and healthy housing to low-income residents. As a lunch keynote, Jonathan F. P. Rose, author of The Well-Tempered City, inspired the audience to connect affordable housing with cultural, health and educational centers.

We also heard from many great project teams — some who have worked on multiple passive projects, and others who were tackling it for the first time. Regardless of the level of experience project teams had, there was a noticeable sense of excitement and passion for what they were doing. That was great to see.

Alongside the optimistic dynamic, there seemed to be a few consistent questions from the audience, mainly: 1) How much does it cost, and 2) Will these buildings really perform? — show me the data.

I’m happy to relay many PHIUS+ project teams reported a very low additional cost to get to passive relative to how they’d typically build. Specifically reported on was Elm Place, a recently PHIUS+ 2015 certified 30-unit multifamily project in Vermont, achieved with only a ~1-2% increase in cost.

Hank Keating and Lauren Baumann provided monitored data from their “passive-inspired” (not certified) 160 unit development, showing significantly lower EUIs for these buildings relative to the LEED Gold townhomes they also monitored.

CaptureKatrin Klingenberg and I reported on monitored data from four of the first affordable multifamily passive building projects and, overall, we’re happy with the results. While our findings confirm the notion that all occupant behavior can’t be predicted, however, when it comes to the average occupant or residence, these projects are quite close to hitting their expected energy use targets. The data from Orchards at Orenco Phase I shows in terms of overall annual energy use, the WUFI Passive energy model prediction came within 2% of the total energy use than was actually measured. However, other projects showed a larger gap. As we continue to collect data, we’re using it to continue developing our energy modeling protocol and calculation methodology. Our goal is to predict energy use as accurately as possible in WUFI Passive so we can be realistic about expected performance and potential savings in PHIUS+ projects.

Galen Staengl presented various innovative mechanical system designs for multifamily passive buildings across the country. Scott Pusey provided great insight from the field from the role of a PHIUS+ Verifier, and the best practice processes his firm has developed over time from their experience. In her keynote, Lois Arena presented that finance agencies in 11 states now have written passive building into their incentives in one form or another.

Zach Semke provided an inspirational closing on the impact renewable energy will play in the future. He exposed the unpredicted and unprecedented investment and deployment in worldwide solar energy capacity this past year, and spoke about how, like solar energy, passive building is a technology and therefore poses the opportunity to follow the exponential growth curve that technology follows.

I imagine there will be many more conferences like this around the nation soon. The sharing of knowledge, positive and negative experiences, as well as the ability to disclose what might be done better the next time around, is critical to the advancement of passive building.

Getting to Zero Part II: PHIUS+ 2018

Graham S. Wright, Senior Scientist & Product Program Manager

PHIUS took a leap a couple of years ago with the launch of the PHIUS+ 2015 Passive Building Standard: North America. It’s been great to see how well the standard was received, and the number of projects seeking certification is way up.

Pembina
Pembina Institute: Accelerating Market Transformation for High-Performance Building Enclosures

Back in 2015, we committed to updating our standard periodically. Earlier this year, the Technical Committee began to discuss a PHIUS+ 2018 update, and we are now gearing up for some number crunching. In this post I’ll give an overview of what’s likely to change and what’s not.

 

PHIUS+ is a “performance based” energy standard mainly concerned with the operating energy of buildings, meaning compliance is largely determined by energy modeling and thus emphasizes designing for low energy use. As such, it’s a great compliment to other green building rating systems and standards such as LEED, NGBS, Living Building etc. In addition to the performance modeling requirements there also a number of “prescriptive” requirements having to do with quality assurance that have to be met as well. Compliance-wise, it’s a pass/fail standard rather than a “rating system.”

 

What makes PHIUS+ a passive building standard is that it sets limits not just on overall predicted energy use, but also specifically on the heating and cooling loads. Those targets guide the designer to use passive measures first, upgrading the envelope and limiting ventilation losses to reduce the annual heating and cooling bills and the size of the required heating and cooling systems— passive measures are a formal/structural priority for the standard.

 

Thus the standard has three pillars:

  • Limits on heating and cooling loads (peak/design and annual)
  • Limit on overall operating energy (source not site)
  • Air-tightness and other prescriptive quality requirements

 

As mentioned in the PHIUS+ 2015 development report published by the DoE, the limits on heating and cooling loads and the overall source energy limit are based on different underlying principles. The annual heating and cooling limits are based on economic optimization, minimizing the total energy-related costs (utility bills plus the annualized cost of the energy-saving upgrades). The annual criteria are a reasonable indication of where to stop investing in passive measures, denoting the economic sweet spot between conservation and generation. The peak heating and cooling loads assure thermal comfort and limit the size of active systems needed to maintain comfort. The resulting targets for both annual and peak loads are climate-dependent. The limits are absolute numbers in terms of energy/power use intensity per square foot of floor area. The targets are not relative to a baseline, and do not follow a “percent better than code” approach .

 

The overall source energy use, however, represents the building’s impact on society, the national environment and the global climate. Therefore, source energy use is allocated on a fair-share principle: a certain amount per person for residential and per square foot for nonresidential, plus allowance for industrial/process loads. This does not vary by climate, and is not subject to economic analysis. When it comes to the environment, we are under a global emissions cap and must do what is necessary to meet the reduction goals.

 

Most of the meta-structure for PHIUS+ described above will stay the same for 2018, but there will be changes that will touch all three pillars. Here are the possible/probable changes, pending input from members and final Tech Committee voting:

 

On the heating and cooling front, the criteria will become more nuanced and will vary by building size and occupant density. The adjustments for size might be categorical, i.e. mid-rise versus high-rise, and/or key on a continuous variable such as envelope to floor area ratio. Because the heating and cooling criteria are lifecycle cost-optimization based, they need to be updated periodically as the cost and performance of energy-saving technologies changes. A lot of the development effort will go into the heating/cooling criteria because many cases need to be set up and run in different climates. In terms of comfort constraints, the criteria will again be predicated on strict limits on window U-value, and the assumed humidity ratio setpoint might be lowered from its current value of 0.012. The analysis period may be increased from its previous value of 30 years, but a discount rate will still apply.

 

We also aim to implement new calculation methods in WUFI Passive for solar shading and non-residential peak cooling load. This will likely mean only WUFI Passive energy models can be used for certification under PHIUS+ 2018.

 

On the source energy front, the limits will begin tapering to zero over the coming decades. In PHIUS+ 2015, only onsite renewables with storage or coincident production-and-use count as offsets to the energy usage; therefore, tightening the criterion to zero would effectively force all buildings to go off-grid. This is not a practical route to Zero Emissions or 100% renewable for the building sector, particularly in cities where larger buildings with limited onsite potential prevail. Therefore, for PHIUS+ 2018, off-site renewables will also be allowed to offset source energy use.  

 

Architecture 2030’s Zero Net Carbon (ZNC) building definition allows for procurement of off-site renewable energy, though it doesn’t go into any hard-and-fast rules. The US Dept. of Energy has a definition for both a Zero Energy Building (ZEB), which is source net zero with only onsite renewables, and a Renewable Energy Certificate Zero Energy Building (REC-ZEB), which also allows renewable energy obtained via traded certificates. Both of these definitions recognize that, at some point, the building designers have done all they can to reduce energy use with conservation and on-site renewables and the responsibility to get to zero emission or 100% renewable energy shifts to the building’s energy providers. This now involves building occupants who can choose their energy providers.

 

Renewable energy certificates are currently quite cheap. For PHIUS+ 2018, the idea is to impose a limitation on their use so on-site efficiency measures do not go by the wayside. This will probably take the form of an REC allowance with several terms: a fixed amount available to any residential project to get from 6200 to 4200 kWh/person, an amount proportional to the number of stories (that is, the ratio of floor area to roof area), plus RECs could be used for any process loads.

 

Also, with respect to the use of local source energy factors for grid electricity and other fuels, national averaging will likely remain the rule but will align with Energy Star Portfolio Manager, which has different values for the US and Canada.

 

On the prescriptive requirements and quality assurance front, we aim to publish a new protocol to cover non-residential buildings in addition to the current single-family and multi-family inspection workbooks. There are a number of existing non-residential building commissioning standards and guidelines that already cover  many items. These are being reviewed to create more focused synthesis that will cover items that bear on the energy performance.

 

Also, spray foam with low-global-warming-potential HFO blowing agent has become more available, and the use of high-GWP foam may be restricted.

 

As we did last time, the intent is to have PHIUS+ 2018 ready for pilot projects starting in the 4th quarter of this year, with a formal launch in March 2018.

 

Looking forward to your comments!

 

Regards,

Graham