From Twin Countries to Twin Cities: China is Making Strides in Bringing Passive Building Mainstream

Katrin Klingenberg, PHIUS Executive Director

 

Passive House Alliance China’s 3rd China Passive Building Summit in Shanghai was followed up by a one-day expert meeting and workshop. The group rode out together to old town Shanghai, a nice area of the city consisting of mostly low-rise buildings. The fall weather had now finally turned a little nippy and drizzlier than the days before, and I was happy to have worn my jacket that day. Shanghai is unique: for two months out of the year (one each in the spring and fall), the temperatures are on the cool side, requiring no cooling and almost no heating, but the humidity is still too high to be comfortable.

The workshop was organized by Passive House Alliance China and took place onsite at a high-performance multifamily retrofit project located in a high-end gated community. Upon our arrival we were welcomed into a beautifully designed lobby where refreshments were being served to the invited stakeholders representing the construction industry and building science field from different cities in China. Following lunch, we had the opportunity to tour several of the completed high-performance apartments and begin to delve deeper into high-performance construction methods in mixed/humid climates with a focus on the cities in the Yangtze Delta. The main focus was on large-scale multifamily buildings, a rather typical and ubiquitous building typology throughout China.

If China and the US are country climate twins, then Shanghai is a close twin to Houston’s southeast Texas climate with the exception that Shanghai gets a little bit more rainfall. The most important challenges for passive design space conditioning solutions in these cities are not the thermal loads – it’s the humidity! Thermal loads are easily reduced to very low peaks by using passive design strategies such as moderate amounts of insulation (4 inches of mineral wool for a larger scale buildings will suffice), balanced ventilation with very good energy recovery efficiencies, excellent windows (double pane with thermally-broken frames), and passive level airtightness. But the high humidity load from ventilation during summer and the shoulder seasons can only be reduced so far. A significant dehumidification load remains, often during seasons when little or no cooling is required, as was the case while we were in China.

Improvements to the building envelope to minimize heating and cooling peaks also effects the ratio of sensible to latent cooling loads – resulting in the latent load becoming equal to or larger than the sensible load. While in less efficient buildings the sensible load far exceeds the latent load and can be taken care of by traditional cooling equipment, in highly efficient passive buildings it is the latent load that is now equal to or even dominant (see examples from Beijing and Hong Kong in the graphs below). This poses a new challenge for low-load comfort systems.

sensible-heat-ratio

The graphs illustrate how the sensible heat ratio decreases if the building envelope is improved for the climates of Beijing and Hong Kong. (slide credit: Hartwig Kuenzel, Fraunhofer IBP, NAPHC2015 keynote)

Climate specific targets also matter a great deal in this climate. In mixed climates, the right balance between heating and cooling targets becomes critical to avoid over-insulation and overheating risks. Window performance in mixed/humid climates needs to strike the right balance as well in order to not inadvertently increase cooling loads. Windows need to be optimized for both cases, heating and cooling, to perform at their best. In the climate of Shanghai as mentioned previously, good double pane windows with a lower solar heat gain coefficient and thermally broken frames are typically the right choice to meet comfort targets and to avoid contributing to overheating. Accurate assessment of internal gains must take into account culture, lifestyle, occupancy, and other factors as they have a significant impact on the overall energy balance of high-performance passive buildings.

In the case of China for example, cooking plays a major role in the vibrant Chinese lifestyle and culture, as we were lucky enough to experience first hand as our gracious hosts showed us the best and most interesting dining spots around Shanghai. Food is central to the culture and if folks are cooking a lot of flavorful and spiced foods in their homes in a climate with significant cooling loads, they will want directly vented kitchen exhaust hoods! Grease, odors, and heat need to get captured and thrown out right at the source. I was impressed to see a novel solution to this problem as we toured the retrofitted apartments. Each unit had two kitchens: one being the “real kitchen” with the big stove, prep area, and fridges which were separated from the main living space by sliding doors to minimize the negative indoor air impacts on the rest of the apartment, and the other one adjacent was an open kitchen concept with a bar for entertaining! What a brilliant idea (if you can afford it)!

Now, what about energy modeling? We have often said that more complex climates really should be modeled using dynamic whole building energy balancing tools such as WUFI Plus. What makes the climate more “complex”? Cooling and dehumidification is needed when the exterior temperature gets closer to the interior comfort zone and begins to fluctuate around it. The warm season is dominated by diurnally reversing heat and moisture flows – in during the cooler nighttime, and out during warmer daytime temperatures. Add moisture into this back and forth and it becomes really complex. To be able to accurately predict how components and the whole building will perform from an energy and hygrothermal perspective, the designer really needs to perform a dynamic whole-building energy model based on hourly data to make the right choices. In contrast, in a heating dominated climate, exterior temperatures are swinging far enough away from the interior thermal comfort zone so that heat and moisture flows are mostly flowing out. Static models are accurate enough for simpler climates such as this.

The graphs illustrate conditions for both heating and cooling/mixed climates. The static monthly balance method as employed by WUFI Passive is sufficiently accurate to predict energy use in a heating dominated climate. In cooling/mixed climates such as Shanghai and Houston, dynamic whole-building energy simulation (WUFI Plus) is recommended. (slide credit: Hartwig Kuenzel, Fraunhofer IBP, NAPHC2015 keynote)

The graphs illustrate conditions for both heating and cooling/mixed climates. The static monthly balance method as employed by WUFI Passive is sufficiently accurate to predict energy use in a heating dominated climate. In cooling/mixed climates such as Shanghai and Houston, dynamic whole-building energy simulation (WUFI Plus) is recommended. (slide credit: Hartwig Kuenzel, Fraunhofer IBP, NAPHC2015 keynote)

Hygrothermal wall performance checks should be best practice for passive designs in mixed/humid climates to avoid any kind of condensation risk. As China ramps up their energy efficiency efforts in varying climates to near passive building levels and experiments with materials it will be critical that these models are created as project teams might not be familiar with just yet or have no long term experience with this risk management in mixed/humid climates, which can lead to critical and significant failures.

Now, what about the high-performance apartment tour, where are the Chinese at with their high-performance solutions today?

I was thoroughly impressed with what they had already in place in terms of execution, performance, details, mechanical solutions, and – to top it all off – a standardized monitoring interface centrally located in the home providing constant feedback on thermal comfort and indoor air quality to the home owner including fine particulate matter (PM 2.5) and inside to outside air quality comparisons. In Shanghai it is often the case that outdoor conditions are worse than indoors due to high pollution levels.

The project we toured was a retrofitted five-story brick building that had been upgraded by adding a 4-inch layer of mineral wool exterior insulation, airtight layer, and a new clay tile façade. The reported tested air-tightness result was 1.5 ACH, which is very respectable for a retrofit! Space conditioning was solved in a very elegant and most comfortable way: a separate energy recovery balanced ventilation system with appropriate filtration and dedicated integrated dehumidification took care of controlling ventilation humidity loads and outdoor pollutants (as evidenced on the screen of the monitoring interface in the living room, see opening photo). Space conditioning was handled by a separate point source solution consisting of hydronic heating and cooling integrated into the room’s ceiling. Radiant heating and cooling is a more costly, yet very comfortable high-end solution. Controlled infiltration and humidity loads are key to this solution to avoid condensation. So is awareness by the homeowner. They need to be put on notice that they can’t cool the home and leave the beautiful lift and slide high-performance balcony door open at the same time!

The developer reported that the passive house approach works financially for them for the high-end market. As you might expect, two bedroom apartments were selling in the millions, as would be the case for similar real estate in any other cosmopolitan global city.

Can passive go mainstream in China?

If I may offer my personal prediction: the Chinese have taken a surprising global lead in fighting climate change and have identified aggressive conservation goals for buildings as a valid strategy. The government has passed mandates to local jurisdictions to find appropriate cost effective solutions. If China addresses the cost optimization of passive building measures based on varying climates, construction paradigms, and energy costs in China similarly to what PHIUS did in the US, then they should certainly be able to generate design guidelines aimed at presenting the most economical path to zero. At the rate that they are going, I believe China will bring passive building to the mainstream before he US does because they have the political will, effective materials and components, knowledge of building science and energy modeling, and cost effectiveness strategies to get there.

What about the state of typical mainstream construction in China?

From what we saw, most apartments in Shanghai already have their own air-to-air heating and cooling heat pump unit sitting on their balcony. Pair that common solution with good airtightness, balanced energy recovery with dedicated dehumidification, moderate amounts of insulation and appropriate hygrothermal wall design, good windows, and you are there.

It would be great to see China taking the lead!

 

– Katrin

The North American Passive House Conference in San Francisco – a hard act to follow for NAPHC2015 (in Chicago)

Every year we say “This was the best passive house conference ever, we better stop now, we can’t possibly top this experience, the quality of the presenters, the “meat on the building science bones” presentations, technical details and specific construction solutions, cutting edge projects of all building types showcased throughout all climate zones, policy and government role discussions and incentives… and this year in addition to the Builders’ Hootenanny the Architects’ Hootenanny which, you might have guessed, was a hoot.

Let me take this opportunity to thank our community of longstanding CPHCs, PHIUS Certified Builders and PHIUS+ Raters who have shared this passive building path with us now for almost 10 years. It has been a pleasure knowing so many great folks with their hearts in the right place and a common characteristic: a determined pioneering spirit to make the energy transition in the way we build and live happen. Thanks to all passive building practitioners and to newcomers to the conference especially the international speakers from the UK and Japan.

Together you submitted nearly 100 abstracts and we had a hell of a time to choosing the best ones. We ended up with an unprecedented total of 72 sessions in 4 tracks this year, more than ever before (we cut the plenary short upon your request to get to the meaty sessions quicker and to have more of them).

Special thanks go to Sam Rashkin from the DOE, for his invaluable contributions to the tracks on government perspective and for the great partnership he and the DOE have provided to the PHIUS+ certification program over the past couple of years. Sam took time to be with us on the Sunday tour of passive buildings in the bay area, which was a lot of fun.

I would especially like to thank all of our outstanding pre-conference workshop presenters who covered topics in great depth, most popular were the Multifamily Palooza (kicked off by Chris Benedict who currently leads the field with the most passive projects in this sector realized), Passive Building Science with Joe Lstiburek (our unofficial lounge sponsor), packed the house closely followed by Mechanical Systems and commercial applications. Many thanks to the outstanding instructors who tackled more specific technical issues and new frontiers, such as efficient water systems design by Gary Klein, and Matthias Patzold from the Fraunhofer IBP and PHIUS staff presenting on dynamic energy modeling in WUFI Passive, THERM/windows modeling and PHIUS+ certification QAQC during the rater training. To all our presenters, pre-conference and main session: Thank you all so much! It would have not been possible without you!!!!

We owe many thanks to Michael Hindle, our charismatic Master of Ceremonies, and President of the Board of Managers of Passive House Alliance US (PHAUS). His opening speech was inspiring, artful and philosophical, The Passive House Alliance is now 16 chapters strong with 7 more in formation all over the country. It is starting to develop an impressive momentum regarding advocacy for passive buildings across the nation. Michael pledged to the membership that he would keep increasing member benefits and participation opportunities and closed with a call for action to join the many committees that have been formed to get the work done.

Michael also made a very well received announcement: the PHAUS  board has moved to remove any reference to a specific passive house standard from chapter founding documents. This decision rightly recognizes that since the inception of the passive house concept in the 70s in North America, it has undergone more than just one transformation and that evolution and learning will continue. It must continue to evolve for us to be successful. PHAUS leadership supports the new climate specific Passive Building standards brought forward by PHIUS as part of such evolution.

Bill Rose followed with the most thoughtful, most provocative keynote given at the North American Passive House Conference yet. Many of you came to me afterwards expressing that sentiment. He showed a short video recording from the early 70s of the researchers credited with formalizing the superinsulation/passive concepts. They worked at the Small Homes Council, University of Illinois at Urbana-Champaign in Illinois. The video reinforced the notion that the passive house community has a longstanding history here in the United States. He then showed a document written by the Nixon administration predicting peak oil and climate change to happen in 2010. It was a stunning piece of evidence that the issues had been known then, as well as the possible remedies outlined in the document. The document, then issued a clear call for action, recognizing the emerging passive community as having the best approach for reducing the demand side of buildings.

Rose made clear that facing the climate crisis means we also need to step up to transform the supply side of the system, coming up with strategies of how to keep the fossil fuel reserves in the ground and how to challenge the current economies that are all built around such assets. He ended provocatively saying, that we need to get to a point where we will be saying: “Energy (fossil fuels), what’s that?”

After the keynote and during all breaks, the exhibit hall was buzzing. A big thank you to all exhibitors of high performance materials and technologies! Every year the cast has been expanding significantly and new useful materials and systems manufacturers join the core group of providers. Thank you, without your products and services it would be impossible to realize passive buildings as well as we now do. Of course, also thank Exhibit Hall sponsor Bayer MaterialScience and our lanyard sponsor Hayward Lumber. Bill Hayward joined us on the tour and provides some great local background. Be sure to check the Hayward Health Home, a very cool initiative.

Achilles Karagiozis delivered the closing keynote. He spoke on the view forward, the implementation of passive buildings worldwide in all different climate zones and the challenges and responsibilities that come with it. He stressed the importance of dynamic modeling for accurate energy prediction results as passive building is applied in different climate zones. He cited an astounding example: WUFI Passive is now able to predict insulation material dependence on temperature on an hourly basis. And of course, this is important to assess hygrothermal performance of enclosures as well as to get the energy balances calculated with more accurate granularity. A great new age has arrived for us designers to manage our risks in designing passive buildings, thanks to the emergence of more powerful computing capabilities that make dynamic models feasible.

At closing, maybe best of all, the incredible sense of community of people who trust each other and know each other well:  We have been coming together now for almost a decade, reuniting at this amazing annual event working together to devise solutions for the North American market, its climate zones and building sector.

And this year, for the first time, the event was held in one of the largest and most exciting metropolitan areas: the San Francisco Bay area. This meant a significant step up from the previous conferences and importance in visibility of our community to city and government leaders, in California and beyond.  Passive building has turned the corner. And so has PHIUS as we were more than once told during the event by you.

PHIUS’ Senior Scientist Graham Wright’s presentation on new North American Passive Building Standards that are currently being completed under a DOE Building America grant was very well received: “This sounds like a really good program” was consistent feedback. The interest was so large that the session had to be moved from the break out room to the ball room. Most everybody was in support, not one negative comment! Kudos to excellent work by Graham Wright and a clearly laid out and scientifically founded argument by the tech committee.

And last but not least thanks to the PHAUS San Francisco chapter and John Sarter and Lizzie Adams from PHCA for helping to organize a fantastic tour of project on a beautiful Sunday in paradise: From multiuse building to state of the art office building to residential retrofit projects, it was great!

Thank you all for coming, for your contributions, participation and feedback on what to do better next year. Keep it coming so that the next act will be better yet again… see you in Chicago, details to come!

 

 

 

 

Join me at NESEA BE14 Passive Building Zone

March 4-6, 2014 at Boston’s Seaport World Trade Center

“A friend and co-instructor sneaks up on me and whispers into my ear – everybody should have the opportunity to live in a passive house – then he gives me this giant smile and I know he is dying to tell me something he is so excited about.”

For those who remember, that’s how I started my first blog on the NESEA trade show passive house products in 2012. “I have a dream of my very own passive house…”, was the title.

A year later this trend took off. The Passive House Institute US (PHIUS) and its membership organization the Passive House Alliance US (PHAUS) – the leading passive building research institute and alliance in the US – helped assemble a dedicated area for passive building vendors and organizations. In all, twelve highly impressive manufacturers of passive-appropriate components participated.

For 2014 NESEA took action and built on the success story and overwhelmingly positive responses of last year’s Passive Building place. The organizers blocked out an even greater area this year for this fast growing group of manufacturers.

So we are back! Bigger and better than ever! This time the Passive Building Place includes 21 exhibitors! I will again have the pleasure of guiding a tour on Wednesday, March 5th at 5.30 pm, visiting exhibitors with products and services indispensable to the passive building community. We will also visit some passive exhibitors who are located outside the zone. We’ll get a 3 minute elevator speech on each of the manufacturers’ products, a quick concise overview directly from those who know best. This year the professional film crew of Fine Homebuilding and Taunton Press will capture the tour to post on NESEA’s, the Passive House Alliance’s and Fine Home Building’s websites.

Passive building has traction—as the growth of certified projects above attests. And our roster of exhibitors at PHAUS’ Passive Place is also expanding. Thank you all for participating and putting your weight behind this exciting emerging construction market. Again, you are true leaders in this market transformation to achieve zero/positive energy buildings through passive design. Thanks again for joining:

475 High Performance Building Supply (Booth # 759)

Air Pohoda USA (Booth # 945)

H Window/Energate (Booth # 959)

Huber Engineered Woods (Booth # 953)

Klearwall Industries LLC (Booth # 751)

Intus Windows (Booth # 624)

Mitsubishi Electric (Booth # 707)

New England Fenestration (Booth # 955)

Passive House Institute US/Passive House Alliance (Booth # 753)

Passivhaus Maine/NA Passive House Network (Booth # 862)

Pinnacle Windows Solutions (Booth # 763)

PowerWise Systems (Booth # 856/854)

PROSOCO Inc. (Booth # 949)

Roxul (Booth # 860)

Solar Hot (Booth # 943)

Stiebel-Eltron Inc. (Booth # 749) 

The Energy Conservatory (Booth # 828) 

Transformations (Booth # 844) 

Yestermorrow Design/Build School (Booth # 1036) 

Zehnder America, Inc. (Booth # 864) 

Zola Windows (Booth # 755) 

There are other terrific vendors at BE14 – but time doesn’t permit us to visit all. Please, I encourage you to visit these vendors’ booths during your time on the show floor:

Affordable Comfort Inc. (Booth # 1024)

Bensonwood (Booth # 662)

Dryvit (Booth # 430)

Enovative (Booth # 939)

European Architectural Supply (Booth # 727)

Led Waves (Booth # 612)

Main Green Building Supply/ Northeast Performance Windows (Booth # 622)

National Fiber (Booth # 717)

Nectar Energy – Syracuse Tech Garden (Booth # 521)

New England Homes by Preferred Building Systems (Booth # 917)

Schock USA (Booth # 636)

ShowerStart (Booth # 723)

SIGA Cover, Inc. (Booth # 620)

Stebbins Duffy/Daikin (Booth # 418)

Steven Winter Associates (Booth # 450)

Tremco Barrier Solutions (Booth # 719)

Tremco Commercial Sealants and Waterproofing (Booth #907)

Vantem Panels (Booth # 652)

Viessmann Manufacturing (Booth # 666/565)

Yaro DSI (Booth # 660)

Let’s get to it…once again, organized by passive building design principles:

PRINCIPLE NO.1: CONTINUOUS INSULATION

Roxul is the coming superinsulation material, period. Not yet readily available in the US market, its benefits are attracting building professionals and Roxul is responding. Thank you Roxul!

So, why is this material such a great fit for highly insulated building envelopes? It is versatile. It can be used for roofing, cavity and curtain wall applications, it can be used for sound proofing in interior walls. Stone wool (or mineral wool as it is also called), maintains its R-value very well in extreme temperatures. That’s important for a designer, because the actual R-value of an insulation material varies with temperature. Foam insulation, for example, varies more and loses some of its R-value at very cold temperatures. Instead of the rated R6 it might only perform at an R4.

Also, in making stone wool, no blowing agents are required. The material maintains its physical properties over its lifetime and is dimensionally stable. Its advantages go on. It is non-combustible, “hydrophobic” (another word for water repellent), it can be used as a drain board and in contact with the ground. It provides no food for mold. It absorbs sound very well. And it is a very sustainable material. It comes as batts, higher density boards with higher R-values (depending on density R goes up) and I believe it can also be blown into cavities to make sure all little nooks and crannies are filled. What more do we want? The picture shows a mineral wool application in a superinsulated passive approved curtainwall application, thermally broken.

PRINCIPLES NO. 2+3: BUILD AIRTIGHT & PREVENT MOISTURE MIGRATION INTO WALL

PROSOCO, Inc. is a star among the air barrier systems manufacturers. It uses a liquid applied installation process that can easily be scaled from a small residential building to a 60 story apartment building. You can apply it to frame as well as to massive construction. Fluid exterior application assures evenness and continuity of the air barrier. Builders can dial in openness/permeability by specifying appropriate consistency of the material to meet climate specific hygrothermal requirements on wall assemblies. Prosoco made the news for meeting the Living Building Challenge: the company’s leading chemist figured out how to configure their product without Phthalates, which are considered highly carcinogenic. This achievement will likely result in an industry shift for the better. Kudos to the Prosoco team. The flagship project “the Bullitt Center” in Seattle used their product with amazing results: the blower door test showed a passive building level of air-tightness, under 0.6 ACH50.

Huber Engineered Woods, LLC offers the ZIP-system that many passive house teams have used as their air-tightness approach. In ZIP, the structural sheathing is used as the air-tight layer, and it’s perfect for single family framed homes. All seams are sealed with a special tape that adheres to the sheathing permanently. This is a great approach to “tunnel through the cost barrier”: A material that is already necessary – the structural OSB – can be cross purposed as the air-tight layer and vapor control layer! But careful: this approach is highly climate specific. The passive house consultant needs to pay very close attention to properly locate this air-tight/vapor control/zip system layer within the wall assembly. OSB has only a 0.7-1.0 perm rating.

475 High Performance Building Supply is a Brooklyn, NY based outfit focusing on a variety of European passive house air barrier product imports. They include smart airtightness membranes and tape solutions by INTELLO and Pro Clima and a wood fiber sheathing/insulation product from Gutex, that can also be used as an air tight layer. The company also distributes other European high performance products: triple pane skylights from Fakro, thermally broken fasteners from Schoeck and a through-wall decentralized apartment venting solution with a ceramic heat recovery core from Lunos. The system has a relatively low capacity to really provide sufficient balanced ventilation for new construction, but seems to be a great option for retrofit solutions. Point ventilation sources can be strategically placed after the fact in a living space without requiring space for mechanical installation or running ducts.

PRINCIPLE NO. 4: HIGH PERFORMANCE WINDOWS AND DOORS

The competition has increased and the prices have come down a bit: European windows are still stealing the show in regards to window performance and quality.

H Windows/Energate, Klearwall Industries, New England Fenestration and Zola European Windows are represented in the Passive Building Place for one stop shopping. Intus Windows is a Passive House Alliance US sponsor that is located across the aisle this year.All these windows are great options for the passive building envelope in a cold climate. The installation is quite different from the install of a typical North American window, so buyer and builder: inform yourself upfront to learn about these differences. The Passive Building Place will have installation examples where you can see how it’s done right and discuss the critical differences with the knowledgeable window experts.All European windows have tilt and turn hardware, typically open inward, are durable and very high quality, and use a thicker triple pane package that is in part responsible for the better thermal performance and a relatively high solar heat gain coefficient of around 0.5. The windows come in wood frame (thermally broken and insulated of course) as well as in clad or vinyl. I hear a few window companies will unveil new, even more improved high performance window models at NESEA. Come and see!

 

Pinnacle Window Solutions This company’s star is Alpen High Performance Products’ fiberglass window, the only North American made window on NESEA’s show floor that meets passive house requirements. This window has several advantages over its stellar European competitors. It is light compared to the European windows. The triple and quadruple pane is lighter because it uses a mylar film as its interior “pane(s)”. The frame itself is much skinnier which allows for more glass area and hence more solar gain if so desired. The fiberglass frame is also insulated and dimensionally more stable than vinyl, which at that slender level of frame is an important characteristic. And lastly, it comes with the customary mounting flange, no need to learn different installation protocols — high performance and business as usual.

 

Passive House Institute US | PHIUS is the leading passive building research organization in the United. It has made significant progress over the past year and a half establishing a window data certification program. The new program provides concise performance data verification for manufacturers who want to provide clients precise data for energy modeling, and an easier way to pick and chose windows for their respective climate zone. The right design decisions for various climates are not always obvious. The comprehensive window certificate provides guidance on what window combination of U-value and Solar Heat Gain Coefficient is the best for a particular climate. The comprehensive window certificate will be on display by the window manufacturers that have gone through the program. The data will also be made available on PHIUS’ website.

 

PRINCIPLE NO. 5: BALANCED VENTILATION WITH HEAT RECOVERY AND MINIMIZED SPACE CONDITIONING, EFFICIENT HOT WATER

 

Zehnder America, Inchas made an impressive run for the US market in terms of high performance balanced ventilation. Zehnder ventilators are all rated for efficiency on the European rating protocol, as well as by the Home Ventilation Institute. This is critical to the accuracy of energy modeling for passive buildings. Its two most popular models are Comfoair 350 and Novus 300. The efficiency ratings for heat recovery and efficiency of the input power required to move air are truly exceptional. Zehnder has all climate zones covered: it offers HRV and ERV counterflow heat exchange cores, an insulated box, options for defrost and pre-cooling / -heating / dehumidification through passive closed ground loop heat exchangers and summer bypasses. Zehnder offers a time saving polyethylene 3” ducting system that has become very popular for its ease of installation. More, the Comfo tubes are installed as home runs from the unit to the room, which provides built in sound proofing and makes telephone effects a non issue. (The finished installation does sometimes remind me of spaghetti). The ducts are double-walled, ribbed on the outside, smooth on the inside and provide some level of insulation as well.

 

Air Pohoda is a relative new kid on the block and comes in with a bang: not only does it offer a highly efficient balanced ventilation system with heat recovery; it also offers some new interesting features not seen in ERVs so far. Their model Ultima240E i-ERV is what they call the first smart ERV, able to control the level of humidity in a home. In the hot and/or humid climates of the United States, this could be a market changer. In such climates, it is not the sensible cooling load that drives the design of the mechanical system but the latent load! A good example of that condition is the first PHIUS+ certified home in Austin, Tex. Air Pohoda of course also has regular HRVs with respectable European style performances of heat exchange and fan energy consumption and is currently working on a smaller unit for smaller homes as well. Check ‘em out!

 

The Mitsubishi Electric mini-split heat pump is the perfect space conditioning point source companion solution to the ventilator. Mitsubishi has led the industry in efficiency ratings. Their mini-split systems are quickly becoming the most popular heating/cooling and dehumidification systems for Passive Homes in all of North America including the very cold climates. The units can be obtained in small sizes for single zone and multi zone systems. They have excellent SEER ratings. They are available in three capacities, 9k, 12k and 15k BTU/h, the Hyper-Heat model that works down to temperatures as low as -15 F is available in 9k, 12k and 18k. An excellent, efficient, cost effective way to heat and cool a passive house by point source! This year, Mitsubishi’s larger multi-zone heat pumps are also taking multifamily passive buildings by storm.

 

Stiebel-Eltron Inc. again provides an anchor point for the Passive Building Place. Solid engineering and world class energy efficiency characterize this company. Passive buildings allow designers to account for solar thermal energy in the energy balance. And PHIUS is looking at standard adaptation for the primary/source energy to more accurately reflect the US grid in the certification requirements (sorry, it will get harder to meet this requirement because the US grid is much dirtier than we have assumed in the previous editions of certification targets!!!). Consequently, solar thermal systems will become a very important component to meet the standard as well as super energy efficient and superior superinsulated hot water storage tanks to minimize heat losses of the overall system. And the same is true for Stiebel’s heat pump hot water heater, a true heat pump and not just a hybrid water heater, with an E.S. energy factor of 2.73. Impressive! The superior efficiency of the mechanical system is critical to meet the standards and to assure the lowest carbon emissions and source energy results that passive buildings are excelling in. In PHIUS+ certifications over the past year we have seen increased installations of heat pump hot water heaters inside of the thermal envelope. This confirms what we reported on last year: in super low load homes the heat pump hot water heater contributes to cooling and dehumidification, even in heating dominated climates and the location inside of the thermal envelope makes sense as long one does not only use direct electric heating. Last year the Stiebel team, seeing all the uptake in the passive building sector, was considering to bring some of their ventilation or even compact energy systems for very low load and passive homes that they produce for the European market to the US market. I am very curious to hear how that thought has progressed.

 

Solar Hot is providing efficient solar thermal systems and hot water tanks. As mentioned above, solar thermal technology is a good way to reduce the source energy in a passive home and it might become more important as we switch to the actual US primary energy conversion factor. We are glad that Solar Hot is joining the Passive Building Place this year, offering a choice to potential passive home clients.

 

 

PRINCIPLE NO. 6: ASSURE QUALITY AND MEASURE YOUR SUCCESS

 

Passive House Institute US | PHIUS  The PHIUS+ passive house and building certification program really excelled in 2013 and continued to grow exponentially (see fig. 1 above). We collaborated with the industry’s best quality assurance systems and requirements such as RESNET and adopted them to passive house and building practices. From the pre-certification process and design review/feedback through detailed quality assurance on site to the final issuance of the certificate and plaque – the process is comprehensive, complete, and diligent leaving little room for anything to go wrong. The result is a superior product we are proud of. A suite of certifications for professionals that hold up to accepted training practices and conventions (including industry appropriate passing rates for exams, continued education requirements, testing through the online testing platform Prometric etc.) assures that the design, construction and quality assurance team has been well educated on climate specific passive building design principles. There have been almost 1500 people who have gone through the trainings since 2008 in the US and Canada. CPHC© Passive House Consultants, certified PHIUS+ Raters and PHIUS Certified Builders work together seamlessly to meet the industry’s highest performance and quality standards. (Upcoming PHIUS trainings calendar.) Well done, PHIUS certification team! The certification has been recognized by the DOE encouraging Challenge Home builders to take the next step referring to the PHIUS+ certification on its website.

 

PowerWise Systems  PHIUS strongly recommends installing a monitoring system to confirm and maintain passive building performance. We’re partial to the inView Passive monitoring package from PowerWise as it is the only one that is customized to passive building principles and systems. PowerWise offers monitoring solutions for all building types, but the system especially developed for passive houses — a circuit-by-circuit energy management and monitoring system, sold us. It is the perfect partner system for the PHIUS+ passive house/building certification to assure quality.

 

Why would one want to add such a system? Despite a very rigorous commissioning and testing protocol during the construction process things can go wrong at a later time. Monitoring systems not only check if the predicted energy performance is being met (and help optimize the systems if there is a discrepancy), they can also be an important warning mechanism in the rare case that there is some malfunction. In very tight houses the indoor air quality can decline quickly if there is a failure in the ventilation system. The monitoring system provides feedback in such cases. Without such feedback the issue might go unnoticed for a long time (you can’t smell or see radon for example!).

 

Specially designed monitoring dashboards for all passive house typical systems components and indoor air aspects are part of the base package. Even a closed ground loop defrost system dashboard is included, which is a very passive-house-specific system. The passive house monitoring package is available as a baseline package as well as a custom package for monitoring needs above and beyond. Information on ordering the system and prices can be found on PHIUS’s website or on the PowerWise website.

 

The Energy Conservatory is a Passive House Alliance sponsor and long time high performance building trailblazer. This team is a terrific knowledge resource as well as equipment resource for all PHIUS+ Raters who are in the business of assuring quality. The Conservatory has never rested on its laurels and has forged ahead as the market for high performance homes kept changing. To their credit, they saw the passive building increase coming a mile away and developed testing equipment that is calibrated to measure the very low ventilation air flows that are characteristic for passive homes. The Mini-Fan Blower Door system development is another such example of market awareness: the duct blaster was repurposed and inserted into a red door, all one needs for a truly high performing very large home to conduct the blower door test!! Infrared cameras, flow blaster accessories, you can find it all at the Conservatory.

 

Transformations is one of the leading zero energy home consultants and builders in the Northeast. This firm is “zeroing in” so to speak on the sweet spot between passive and zero, which makes it a uniquely positioned company. Transformations just recently partnered with Bluestone RRSI, Building Science Corporation and PHIUS on a successful grant application to NYSERDA to rebuild Staten Island to Passive House Standards. We are all thrilled about this project and can’t wait to get started on it. As for Transformations: we will see more stunning and groundbreaking work from this company in the near future, I can almost guarantee it!

 

 

PRINCIPLE NO.7: SPREAD THE WORD, SHARE THE TALE AND TEACH ALL YOU HAVE LEARNED

 

The leading national advocacy, education and membership organization for passive building professionals in the US is the Passive House Alliance, a program of the Passive House Institute US. Passive House Alliance US | PHAUS co-organizes the annual North American Passive House Conference, now in its 9th year. It is the biggest educational event in North America in regards to technical information sharing by the community of passive building practitioners. The 2014 conference is scheduled for September 10-14 in San Francisco – San Mateo.

 

The Alliance also conducts ongoing webinars and offers opportunity for its members to share experiences, knowledge and information on new passive products, design challenges in different climates, and business and marketing issues. Membership also offers discounts for all training and conference events as well as for PHIUS+ certification. The alliance has grown significantly. There are today 14 chapters across the nation in all critical climate zones with three more in the works. PHAUS lists all educational events offered by PHIUS. All educational opportunities including the professional PHIUS Certificate trainings are listed in the Passive Building University. The schedule is complete through the end of June. More trainings will be announced for the second half of 2014 soon.

 

Passive House Institute US | PHIUS engaged in 2012 to developing a new modeling tool based on all our learning from projects across varied climate zones.The renowned Fraunhofer Institute for Building Physics, PHIUS and Owens Corning collaborated on a next generation passive building modeling tool – WUFI© Passive – which is now being taught by PHIUS as backbone tool of the CPHC training. The tool combines the monthly static energy balance with dynamic and hygrothermal capabilities. An eye opener for anyone who has tried to design a passive project in a North American climate zone using a simple energy balance calculator (and did not entirely believe the results). WUFI Passive will revolutionize our industry, once the word gets out. An introductory training for WUFI Passive is scheduled for Boston for April 24-25 at the Fraunhofer CSE in Boston.

 

Yestermorrow Design/Build School Yestermorrow has grown into the most successful educational partner of PHIUS. For the third year in a row, I arrived in Warren, Vt., this past December to find a full CPHC class. The demand for passive building classes prompted Yestermorrow to host the PHIUS Certified Builders class in April. (The class is sold out, but we’ve just scheduled another Builders program for Baltimore, May 10-13). Yestermorrow classes are unique. The CPHC class for example  is the only offering that provides all in person instruction (no online portion). It is absolutely intense: eight consecutive days conclude with the exam on the afternoon of the last day. People are on site 24/7, form study and discussion groups beyond the class time and prep for exam together. Yestermorrow provides an unforgettable learning experience with a retreat flavor.

 

Passivhaus Maine/NA Passive House Network is advocating for passive homes in the Upper North East. This non-profit organization conducts local seminars and educational events to spread the word about the benefits of passive homes and construction. It is a place where professionals who are already immersed in the field or those who are interested in getting involved can go to share or to get more information. This group is sharing the booth with the NA Passive House Network located in California, which is another advocacy and information sharing platform in the West.

 

I owe much gratitude to NESEA and NESEA staff who all have been terrific friends over the past few years. I like to say thank you for your support and trust. I admire that you constantly have your eye on the prize, pushing ahead, identifying the most important issues, and zeroing in on where we need to be in the future. It has made NESEA the leader in energy efficient construction and this team will maintain that leadership, shaping its conferences and educational offerings. My utmost respect. Thank you for allowing me to contribute to your event!

 

Notes from the Frankfurt Conference

The impetus for my journey to Frankfurt, Germany in April was the 17th International Passive House Conference. As I walked toward the venue it occurred to me that this is my 10th anniversary at that event…

…and that we’ve come a long way on this side of the pond. It looks like we might be able to match participation this year at our upcoming 8th Annual North American Passive House conference in Pittsburgh. Overall participation in Frankfurt, according to the distributed participants list, was 650 people.

CompacFoam

Ninety exhibitors were on the exhibit floor. Among those were quite a few very large companies such as Saint-Gobain and Sto, who have embraced passive building solutions. One company struck me as especially interesting for the U.S. market: Compacfoam. They offer very simple thermally broken solutions using their compressed and structurally stable foam product. Those work for window installation, thermally broken point connections of curtain wall facades, point connections for balconies or porches attached back to the house structure as well as for the insulation of window frames. Those solutions could easily be implemented in the United States. All we need is the material.

Overall on the trade show floor, the innovations seemed to have leveled off some. In many cases the innovations presented were refinements of an already existing product. This is rather good news as it signals that passive in Europe has truly become mainstream. The smaller numbers of participants and exhibitors at the conference can be explained that way as well: other larger more general building conferences have absorbed the topic and are offering equally qualified information. Passive building is everywhere!

Some significant updates from the passive building modeling front:  This year, only one year after the last 2012 PHPP update came out, a new 2013 PHPP version has been published. Word is that the PHI significantly improved the cooling demand and latent load algorithms to be more appropriate for hot and humid climates. A new latent demand annual budget had already been included in the overall cooling demand certification criterion for 2012.

Newly unveiled to the European market (it was released earlier here in the States) at the conference: WUFI Passive developed by Fraunhofer IBP. The new passive modeling tool — that in addition to just a static calculation method also includes hourly dynamic simulation capability and hygrothermal assessment — was presented to the worldwide passive building community. Overall it was good to see that everybody in the field is working diligently on passive modeling tools that are accurate for all climates including the more challenging hot and humid ones.

Back to the PHPP update: be aware that if you still use the older versions of PHPP (2007 through 2012) for your passive designs, it is very likely that your results may not be as accurate as they could be. You should consider upgrading. If you are working in more complex and challenging climates (very cold climate zones starting at 8 as well as mixed humid, hot humid, hot and dry climate zones, plus  all zones with very high solar radiation) PHIUS very strongly recommends to use a dynamic model in addition to PHPP (or to use WUFI Passive which does both calculations — passive static verification and dynamic modeling).

Some caveats: The stated improvements/changes in the algorithms in PHPP 2013 are a great step – it marks an acknowledgement that cooling latent issues were indeed not properly addressed until now. But, these changes for cooling and latent have not yet been verified in the various North American climates. Moreover, with more built examples and data now available, the larger question is: How accurate can a limited static representation relying only on monthly climate data really be? It is very likely that it does not afford enough granularity to accurately predict very complex interactions of buildings with a multitude of climate factors.

For those more complex climates with heating, cooling, latent and solar climate factor combinations dynamic modeling appears to be quite a bit more accurate, allowing designers and consultants to limit the inherent risks in modeling: under or over-predicting performance as well as verifying that comfort conditions are assured throughout all rooms and spaces.

PHIUS is not alone with this recommendation of combining a dynamic model with a simplified static one for the best results. Belgium, the country that recently made the news with its decision to make Passive Standards code by 2015 for all new and retrofit construction projects, also requires all designers to back up the static passive house model with an additional dynamic model! Hence, the Belgian representatives of the Plate-forme Maison Passive I met with in Frankfurt were very interested and excited to learn about the advent of WUFI Passive.

Progress!

Kat

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Part 3: NESEA BE13–the passive building journey continues…

 

OK, the finale! In part one we looked at the growth of passive building and how it’s reflected in Passive Place at BE13.

In part two we embarked on the passive building tour of the BE13 trade show floor–mapped to the fundamental principles of passive building.

Today, we introduce some unofficial passive building principles and visit some terrific partners.

Onward!

Unofficial passive building principle No. 6:

ASSURE QUALITY AND MEASURE YOUR SUCCESS!

Only PHIUS+ projects earn the plaque!

PHIUS (www.passivehouse.us) offers certification programs for projects and products. PHIUS+ Certification for new and retrofit applications is the only voluntary certification program in North America that requires a thorough design as well as an onsite third party review process. PHIUS+ certification is the most rigorous on the market–and the best value. That’s because PHIUS has partnered with the Department of Energy and RESNET. That means industry-standard certification protocols for design and onsite verification. And it means one-stop certification shopping. Earning PHIUS+ Certification also nets a HERS rating, DOE Challenge Home Status, and EnergyStar status.

PHIUS+ has jumpstarted certifications. We expect to have fully certified approximately 100 passive building projects by the end of 2013 in North America (if apartments are counted, then the number is closer to 200) and yes, the growth is exponential!

At the 7th Annual North American Passive House Conference in Denver last September, PHIUS launched its Window Data Verification Program. In cooperation with NFRC PHIUS is identifying a North American window data verification protocol and climate appropriate guidelines and recommendations. Several leading window manufacturers have signed on and submitted various window frame and glazing combinations for calculation and verification, and listing in the coming PHIUS window data base.

PHIUS recently partnered with PowerWise Systems–Booth 961 (http://www.powerwisesystems.com/passive) to promote their newest product – the inView Passive™ monitoring package. PowerWise offers all kinds of monitoring solutions for all building types—but we’re really excited about the value that the inView Passive monitoring package brings to our community. For passive builders, the proof is in the pudding–monitored performance is where it’s at. inView Passive includes monitoring dashboards optimized for typical passive house components and systems. We think it’s a great tool for anyone certifying a project through the PHIUS+ Certification and Quality Assurance Program.

Besides verifying predicted performance, monitoring systems like inView Passive can serve as early alerts for routine maintenance. For example, energy consumption might rise because a filter in the ventilator has not been cleaned on schedule. Monitoring also provides safety. Say one of the two ventilator fans fail; this could depressurize the house. Without monitoring, it might take some time to notice that indoor air quality declined, back drafting on vented appliances or fireplaces might have occurred or radon levels might have climbed.

inView Passive includes dashboards for typical passive house systems and components and indoor air aspects. Even a closed ground loop defrost system dashboard is included. Information on ordering the system and prices can be found on PHIUS’s website or on the PowerWise website. PHIUS has negotiated a 5% discount for all PHIUS+ certification enrolled projects and the Promo Code is available through PHIUS when registering.

The Energy Conservatory–Booth 828 (http://www.energyconservatory.com/) is the PHIUS+ Certified Rater’s best friend. Commissioning equipment for low load and airtight superinsulated homes has become more sophisticated and is now affordable.  What exactly has to be commissioned and tested? The most obvious—the air-tightness of the envelope needs to get tested during construction and then again upon project completion. For very tight homes the rater can now use the Mini-Fan Blower Door System, a duct blaster in a newly developed red door insert to test the entire building, A small fan is all it takes if the home is that tight! The mechanical ventilation system also has to be commissioned and flows have to be verified. Very small ventilation air flows need to be measured. The Energy Conservatory Flow Blaster Accessory measures air flows at diffusers down to very low levels such as 10 CFMs. And lastly FLIR infrared cameras are used to check insulation quality, thermal bridging and also interior surface temperatures. Indispensable tools throughout QAQC process to verify a building has been built as designed and performs.

 

Unofficial passive building principle No. 7:

SPREAD THE WORD, SHARE THE TALE AND TEACH ALL YOU HAVE LEARNED

The leading national passive building research, education and alliance organizations are the Passive House Institute US (PHIUS) (www.passivehouse.us) and the Passive House Alliance US (PHAUS) (www.phaus.org).

PHIUS was founded by myself and Mike Kernagis in 2003, initially as Ecological Construction Laboratory, a non-profit, promoting and building passive houses for low income home buyers. It changed its name later to Passive House Institute US when it went national. Since 2008 PHIUS has been offering the hugely successful CPHC®Passive House Consultant training nationwide (NEW in 2013: Virtual segment online saving cost and travel time), we have added Certified PHIUS+ Rater trainings and PHIUS Certified Builder trainings over the last few years. We have trained more than 800 architects, engineers, energy consultants and builders and have certified more 500 of them as CPHCs, PHIUS Certified Builders and PHIUS+ Raters in the US and Canada. These are the folks you want on your passive building team!

In 2013 the renowned Fraunhofer Institute for Building Physics, PHIUS and Owens Corning collaborated on a new next-generation passive building modeling tool – WUFI© Passive. WUFI Passive now replaces PHPP as the backbone tool of the CPHC training. Like PHPP, the tool includes a static passive house energy balancing capability. But it also offers dynamic whole building energy modeling and individual component hygrothermal analysis. And it covers another critical modeling variable: thermal mass, which is necessary for the cooling energy balance. In WUFI Passive all of these assessments use the same project data; no double entry of project data in multiple modeling tools is necessary. Risk and performance management all in one. This tool is seriously cool!

In 2009 PHIUS launched a membership/chapter program, the Passive House Alliance US (PHAUS). The mission: to support the community of professionals who had been trained, to educate the public, and drive the market by involving manufacturers and advocating for making passive building standards the norm in North America. Since Mark Miller took on the Executive Director role of this ambitious program in 2011, PHAUS has a thriving and growing membership program, now up to 350 members. PHAUS’ manufacturer sponsors program (amongst them founding sponsor CertainTeed and Rocky Mountain Institute) is growing, as is the chapter organization—now up to 13 nationwide Chapters with two pending.

PHIUS and PHAUS have significantly shaped the landscape of passive buildings in America over the past 10 years and will continue on our mission: the transformation of the marketplace to make passive buildings commonplace. We are a non-profit and if you like what we have done so far and would like to help, you can donate to PHIUS, become a PHAUS member, or certify and train with us.

Building Science Corporation (http://www.buildingscience.com/)  has been a leader in high performance building consulting and education for decades. BSC Principal Joe Lstiburek was a pioneer way back in the 1970s; that’s why at his keynote address at last year’s 7th Annual North American Passive House Conference, he closed his presentation with: “You guys are family.” I was totally moved—and I wasn’t alone. It was inspiring. Joe started building superinsulated buildings in the late 70s when he was just 23 years old!!! The details matched what we consider to be good passive building practice today. He has been on the forefront all along – vapor retarders, thermally broken fasteners, insulated foundation systems, energy heel trusses and even earth tubes (which he is not a great fan of )(link to his article). He knows what the trenches look like.

Building on that energy from the conference, BSC and PHIUS resolved to work together in promoting passive buildings. A first step: We decided to cooperate on the Passive Building University which lives on the PHAUS website (link): BSC bookends PHIUS executive certification classes with a Building Science Fundamentals program, the ultimate preparation for the CPHC Passive House Consultant class. BSC also offers Advanced Hygrothermal Analysis, truly building a science master class. I encourage you to visit BSCs table as they have the best selection of  cutting edge literature that applies to passive buildings. Be prepared to spend some money and schlep books home!

The most recent Yestermorrow CPHC class.

Yestermorrow Design/Build School (http://www.yestermorrow.org/) This past December I arrived in Warren, Vt.,for the second CPHC class offered through the Yestermorrow Design/Build school. Yet another full class, intense and dynamic.

How is Yestermorrow different? It teaches all modules in person on 8 consecutive days with the exam on the 9th. People are on site 24/7, they form study and discussion groups beyond the class time and prep for exam together. You talk bonding…the food is exceptional and the people who show up for this are some of the smartest and unique. Yestermorrow truly attracts exceptional individuals. The classes took the passive discussion to new heights and aside from that, Vermont is just stunningly beautiful – an unforgettable learning experience with a retreat flavor.

Passive House New England (http://www.passivehousenewengland.org/) is one of the first independent passive house groups in the country. Many of its members are some of the most experienced CPHCs in the country with one or more certified passive houses under their belts. This group is a great resource for anyone who is interested in building a passive house or building in the North East region. The group has a very active meet up group schedule and hosts a passive house symposium annually in the fall highlighting most recent projects of special interest. Great group: Get involved!

Passivhaus Maine (http://www.passivhausmaine.org/) is carrying flag in Maine in regards to passive house (don’t you love the lobster in the logo?). This is also an area that has very many experienced passive house consultants and builders solidly on their way. This group also is making strides by providing great information and by putting on symposia. Join the meet up group and help getting the word out!

Well, that’s about it–and that’s plenty!

Thanks to NESEA and all the friends out East that have given me the opportunity to do this review and I hope to see a few of you on the BE13 NESEA trade show floor!!!!!!