Window comfort and condensation

 

Graham Wright

Graham Wright

At the 10th Annual North American Passive House conference in Chicago, Steven Bluestone and PHIUS’ Lisa White made a presentation about the design of the Beach Green North (BGN) project in New York City, a seven-story multifamily residential building of some 94,000 square feet and 100+ dwelling units. The design featured double-pane windows with R-5 glass and R-4 frames.

A number of people were surprised that R-7 triple pane windows were not in the design. Low performance windows can indeed lead to comfort and condensation problems, and we did look into that. Here, PHIUS Senior Scientist Graham Wright posts about window comfort and condensation, both for the BGN project itself and how that may inform the PHIUS certification protocol going forward.

Background

Performance of building components such as windows has not been in the category of “hard-and-fast” requirements for certification. The hard requirements have been on overall building performance – the “three pillars” of space conditioning loads, primary energy, and air-tightness.

Though we have been adding more requirements over time, window performance has remained in the category of recommendation, not requirement. Since 2013 we have been recommending window performance by climate according to this table. You can see that for zone 4A, we are indeed recommending an R-7 window.

To be a bit more granular about it, New York (LaGuardia climate) has 12-h mean minimum temperature of 6.44 F, which would require a window U-value < 0.16 Btu/h.ft2.F or R-6.3, to maintain interior window surface temperature of 60.8 F (within 4 C of a 68 F air temperature, assuming an interior surface film resistance of 0.74 h.ft2.F/Btu.)

In terms of comfort, the first line of defense is the limit on peak heating load. Window U-value has a strong effect on peak heating load and, as explained in the report on the standard-setting process for PHIUS+ 2015 , we now require that projects meet limits on both annual heating demand and peak heating load (same for cooling). Moreover, the model building used in the standard-setting studies had its window U-values constrained so as to maintain 60 F interior surface temperature under winter design conditions (12-hour mean minimum outside temperature).

Thus the peak heat load criterion for the building overall is predicated upon windows that good, and it serves as an indirect curb on bad windows, while allowing the designer some flexibility to meet the overall peak load in different ways.

That is working well for buildings that are not tremendously larger than the study building. But BGN is fifty times larger, in terms of floor area. In the standard-setting report, we anticipated that there would be consequences of applying the same energy-per-floor-area criteria to all sizes of buildings; that is, larger buildings with lower surface-to-volume ratio (or surface-area-to-floor-area ratio) would more easily meet the criteria. We opted for giving this allowance to larger residential buildings, because such forms of housing are more efficient in terms of their materials usage or embodied energy.

Because of that large-building break, the BGN design could meet the peak heat load criterion with windows as low as R-2.5. The best double-pane windows available are in the R-4 to 5 range and the team asked if those would be acceptable. So we did some additional calculations on comfort and condensation.

Comfort analysis

The comfort analysis was done largely using the ASHRAE Comfort Tool, a standalone software that allows you to put an occupant in a room, then compute the radiant and operative temperatures and the human comfort metrics Predicted Mean Vote and Predicted Percent Dissatisfied (PMV and PPD).

The comfort standards ISO 7730 and ASHRAE 55 are in agreement on fundamentals. Their development was coordinated and they share the same models for the PMV and PPD metrics for overall bodily comfort, as well as “local” discomfort on different parts of the body. ISO 7730 is focused on analysis and assessment methods. ASHRAE 55 draws pass/fail lines whereas ISO 7730 just makes recommendations; it sets up categories A, B, C of design criteria for consideration.  The ASHRAE 55 pass/fail lines correspond to ISO 7730 category B. In terms of overall body comfort, the criterion is less than 10% dissatisfied. (Even at a predicted mean vote of zero, that is, on average feeling neither warm nor cool, there are still 5% of people dissatisfied.)

Worth noting is that our protocol of modeling buildings with a heating setpoint of 68 F already pushes the winter comfort to the cool end of the acceptable range of Category B or ASHRAE 55, even if there are no windows in the room at all. The clothing and activity level of the occupants are factors in the PMV, but even with Clo=1 (long sleeves and sweater) and a little activity of Met=1.1 (seated, typing), in order to get a PMV near zero you need an operative temperature of around 22 C (71-72 F). The Building America default heating setpoint happens to be 71 F.

At 45% relative humidity (RH) and an operative temperature of 68 F, the PMV is minus 0.6 and the PPD is 12%. Because the operative temperature is approximately the average of the air temperature and the mean radiant temperature, it will be lower than the air temperature in the winter when the window surfaces are colder than the walls. Thus, under the scenario shown in the first column of Table 1, the lower setpoint for air temperature has used up the design margin for comfort, leaving none for windows. If the activity level is a little higher but the RH is a little lower, as in the third column, then there is some comfort latitude remaining to accommodate windows.

Table 1. Winter comfort at two heating setpoints.

Air temp F

68

71

68

71

Radiant temp F

68

71

68

71

RH %

45

45

30

30

Air vel ft/min

20

20

20

20

Met

1.1

1.1

1.2

1.2

Clo

1.01

1.01

1.01

1.01

PMV

-0.6

-0.2

-0.43

-0.08

PPD %

12

6

9

5

There are two ways to look at this

One is that, under our current recommended way of modeling things, the improved comfort that high performance windows would bring is taken back with the lower heating set point, traded to save energy.

Another way to look at it is that as a general point, really good windows really are required for comfort at a 68 F heating setpoint.

However, to use this type of analysis to derive an absolute minimum window surface temperature criterion from the comfort standards, it would have to be carefully contrived to allow any windows at all. One would have to be specific about the activity and clothing and activity level of the occupants at least in an average sense, and small differences could make the difference between say, an 8 F margin between the window surface and the air, to no margin at all.

For the BGN window comfort analysis we instead performed a relative comparison, first constructing a baseline scenario wherein the occupant comfort was close to neutral with no windows, and then adding windows and checking the difference in comfort.

Typical main-room dimensions for the Beach Green North project are 10 x 22 feet. There are corner rooms with one window on each of the two exterior walls. Windows are 3’ 3” wide and 5’ 2” tall. Geometrically, an occupant in the corner with the windows also near the corner would feel the greatest comfort impact.

Results:

Baseline scenario (See Figure 1):

Occupant is seated, quiet (1.0 met), typical winter clothing ensemble (0.9 clo). Air temperature and radiant temperature both 74 F, humidity ratio 0.010.

Comfort is almost exactly neutral: PMV -0.10, PPD 5%

Figure 1. Baseline comfort scenario

Figure1

 

Windows scenario (See Figure 2 and 3):

Room 22 x 10 x 8 feet. Occupant seated in corner 3.3 feet from each wall, facing the short wall. Window jambs are 2 feet from the corner on each side. Window inside surface temperature is 50 F, corresponding to window U=0.4 at 6.44 F outside.

Mean radiant temperature drops to 71.2 F. PMV drops to -0.30 and PPD increases to 7%. This is still within the ASHRAE 55 or Category B criteria range of PMV +/- 0.5 and PPD < 10%.

Figure 2. Mean Radiant temperature with windows in the corner at 50 F.

Figure2

Figure 3. Overall comfort in window scenario, shifts PMV 0.2 cooler.Figure3

Conclusions:

Going from no windows to U=0.4 windows caused the PMV to shift cooler by 0.2, and the PPD to increase from 5% to 7%.

There is also local discomfort to consider. Even if the whole wall was at 50 F, this would still be just within the acceptable range for cool-wall radiant asymmetry.

We communicated to the BGN team that windows up to U=0.29 would be acceptable, splitting the difference between U=0.18 and U=0.4 (figuring that the shift in PMV would be even less going from U=0.14 to U=0.29 than it would be going from no windows to U=0.4.)

One of the other benefits of keeping the window surface temperature up within 3 or 4C of the air temperature is that there is less pooling of cold air under the window, and no need for heat under the window to prevent discomfort due to head-to-foot temperature difference. Some loss of amenity is occurring in this respect, but we did not attempt to quantify it.

One interesting point is that head-to-foot is indeed one of the local discomfort criteria in both ISO 7730 and ASHRAE 55 (per clause 5.3.4.4.) but, in ASHRAE 55, none of the local discomfort criteria apply unless the occupants are at Clo<0.7 AND Met<1.3. With that low of a clothing level, they would not be overall comfortable at 20 C (68 F) air temperature anyway, so likely they are bundled up to 1.0 Clo and the local discomfort isn’t as important.

Anecdotal feedback has been mixed. Our Canadian friends tell us “no one is complaining about comfort here with R-6 windows” even where we would recommend R-8. Our Lithuanian colleagues say “double-panes are uncomfortable; no one uses double-panes in Lithuania.” Lithuania is 10 F colder than NYC though, with a 12-hr mean minimum temperature of 3.8 F below zero versus LaGuardia at +6.4 F.

As to the certification program going forward, the matter was brought before the full PHIUS Technical Committee at our October meeting,

For the time being, the Committee decided to refrain from imposing a “hard requirement” on inside surface temperature for winter comfort, or directly on window U-value, and to continue in the category of recommendation.

We have already collected the data to set recommended winter-comfort-based U-value maximums for all the climate locations on our criteria map, and could make those show up.

A possible approach for certification could be to require that those recommendations are followed but give an option to do a more detailed comfort assessment like the one shown above.  This very kind of material-cost versus analysis-cost tradeoff is done elsewhere in the program, for example with thermal bridges. One can do a conservative design following simple rules , or make an edgier design and do more engineering work to verify whether it meets criteria.   Such an approach would require the development of some additional calculation protocol.

Condensation analysis: Background

One of the “hard requirements” PHIUS has added pertains to avoiding mold growth on interior surfaces caused by thermal bridges. Even if a thermal bridge is tolerable in terms its impact on the space conditioning loads and demands, it is not tolerable if it can lead to mold growth on the inside. Our protocol follows ISO 13788, and one of our calculator tools follows its methods. Just as in calculating the energy impact of a thermal bridge, we make a THERM model of the detail. But instead of calculating the extra energy loss, the critical result is the point of lowest temperature on the inside surface, and the criterion is that at that point, the interior air, when chilled down to that temperature, should be at less than 80% relative humidity.

ISO 13788 addresses how to determine the appropriate boundary conditions – the outside temperature and the indoor relative humidity. This is based on consideration of the monthly average outside temperature and humidity for the climate. The outdoor humidity is added to an indoor source that depends on one of five building humidity classes from low to high.

For each month, a psychometric calculation is then done to determine a minimum inside surface temperature needed to keep the RH at the surface below 80%.

The critical month is the one in which that minimum surface temperature is farthest from the outside temperature and closest to the inside temperature, because that requires the detail to be the most “insulating.” This “surface temperature factor” (fRsi) of the building element is defined mathematically as

fRsi = (inside surface temp – outside temp)/(inside temp – outside temp),

with a surface resistance at the inside surface of Rsi.

(Usually the critical month is also the coldest month but not always – depending on the climate it might be in October, for example)

ISO 13788 also addresses assessment of condensation on “low thermal inertia” elements such as windows and doors, using a similar procedure, but with some differences: instead of keeping the RH below 80%, the goal is to avoid outright condensation (RH=100%), because windows and doors have impermeable surfaces that aren’t as subject to mold, but vulnerable to rot and corrosion if outright wet. But the outside design temperature is more severe – instead of a monthly average, it calls for the lowest daily mean temperature of the whole year.

For our BGN analysis, we:

1. Used the 13788 procedure for “low thermal inertia” elements to determine the required minimum surface temperature and fRsi to avoid condensation.

With an interior RH of 48% in the coldest month, the dew point of the interior air was 47.7 F, so the inside surface must be warmer than that.

2. We then did a one-dimensional calculation with the frame U-value at 0.28 to determine if that was the case. Instead of the lowest daily mean temperature, we used (for convenience) the ASHRAE 99.6% design temperature, as AAMA does for their Condensation Resistance Factor. This was 13.8 F.

With an interior temperature of 68 F, and an inside film resistance of 0.74 h.ft2.F/Btu, the inside surface temperature then is 68-(0.29*0.74)*(68-13.8) = 56.7 F, that is, 9 degrees above the dew point.

Of course, this does ignore the fact that the surface temperature could be lower right in the corner where the frame meets the glass, because of the conductivity of the spacer, but 9 F provides a comfortable margin. ISO 13788 does caution that one-dimensional calculations aren’t generally good enough, but it is a place to start. We will refine the “low thermal inertia” version of our 13788 calculator and publish that soon.

We’ve also been asked whether we can specify an NFRC Condensation Resistance rating (CR). The AAMA recently published a good summary paper [AAMA CRS-15] that explains the differences between NFRC’s Condensation Resistance (CR), AAMA’s Condensation Resistance Factor (CRF), and the Canadian temperature Index or I-value, per CSA A440.2.  All of these are 0-100% higher-is-better ratings, but they are not directly comparable to each other.

From that paper it is clear that the CRF and the I-value are the same kind of thing as what ISO 13788 calls fRsi – ratios that indicate how far some critical inside surface temperature is towards the inside air temperature. Therefore, if that data is available for a window of interest, those ratings could be compared directly to the required fRsi from a 13788 calculation for “low thermal inertia elements” for an indication as to whether a window is good enough in the climate location of interest.

The AAMA white paper indicates that the I-value is generally more conservative/stringent than the CRF due to differences in the temperature sensor placements. Both of these are physical tests.

AAMA provides an online calculator that takes a given outdoor temperature, indoor temperature, and relative humidity, and computes the dew point and the required CRF, so it is making the same kind of calculation as called for in ISO 13788. (The disclaimer for it makes many good points.)

http://www.aamanet.org/crfcalculator/2/334/crf-tool

The NFRC Condensation Resistance rating is more complicated and harder to interpret, except as a relative ranking. It is basically the percentage of the window frame, glass, or edge-of-glass area (whichever is worst) that is below dew point under the standard test condition temperatures, averaged over interior RH levels of 30, 50, and 70%. It is based on modeling rather than a physical test.

At the October Technical Committee meeting there was consensus on the general matter of setting a definite requirement to avoid condensation on windows.

The next issues then are: under what circumstances a window condensation check should be required in project certification, and what the passing criterion should be.

PHIUS’ Certification staff are working out those details and plan to phase in the requirement.

In the meantime, a determination about “when to check” should key on risk factors such as:

  • Window U-value significantly above the comfort requirement.
  • Frame U-value significantly above the glass U-value.
  • Presence of aluminum spacers.
  • Lo-e coating on the inside surface of the glass.

Our recommended passing criterion is that 1-D calculations on the surface temperatures or fRsi of the frame and the glass, or an AAMA CRF rating, should meet the ISO 13788 minimums at the ASHRAE 99.6 design temperature for the climate, with some safety margin, or that a CSA I-value meets it without a safety margin.

We will also consider adding to our window rating data the fRsi calculated at the worst-case location, the inside corner where the glass meets the frame.

 

10th Annual NAPHC – best party of the year, maybe ever…

Wow – was that a successful conference! It has been a week and I am still processing it all. Chicago was unlike any other conference — things did not slow down in the office after it was all over, they rather accelerated. It indeed appears we have reached a tipping point.

From more than one person I heard that it seemed that the quality of work, detailing expertise and technical knowledge, size of projects and complexity of building types had reached a new high. And, compared to the early years, we were not just talking theory and intentions—but what people had done! Really impressive.

LEFT: Dr. Hartwig Künzel giving the Day 2 Keynote -- RIGHT: Sebastian Moreno-Vacca participating in the Architects' Hootenanny (L-R: T.McDonlad, T.Smith, J.Moskovitz, Sebastian, ?)

LEFT: Dr. Hartwig Künzel giving the Day 2 Keynote — RIGHT: Sebastian Moreno-Vacca participating in the Architects’ Hootenanny including (l-r): T.McDonald, T.Smith, J.Moskovitz, Sebastian, C.Hawbecker)

New modeling tools such as WUFI Passive (Technical keynote Hartwig Künzel, day two) are making building science interrelationships more visible and intuitively understandable. WUFI Passive is enabling CPHCs to optimize designs using “hygrothermal mass” (ever heard of that?) to optimize humidity loads and even to inform design decisions overall (as Sebastian Moreno-Vacca illustrated in his session) to create a unique architectural language! How cool is that! Science, heat fluxes and thermal dynamics begin to shape architectural form.

Dirk Lohan, Principal, Lohan Anderson -- Welcomes conference attendees to Chicago

Dirk Lohan, Principal, Lohan Anderson — Welcomes conference attendees to Chicago

Dirk Lohan—Mies Vander Rohe’s grandson, and an extremely accomplished architect in his own right—hinted at this development during his welcoming remarks.

“I believe that we will begin to see as beautiful what also is energy-conscious,” said Lohan.

Supported by the John D. and Catherine T. MacArthur Foundation

But maybe the most significant news is the explosive development in the multifamily affordable housing sector. It is seeing significant growth, interest and pilot developments going up in many places of the country. Thanks to the support from the John D. and Catherine T. MacArthur Foundation, we were able to make this our core topic for the conference and will be able to actively provide support to the affordable development community.

The pre-conference sessions included a daylong affordable housing Hootenanny that brought together successful affordable, multifamily housing project teams together who generously shared lessons learned and experience. Four different project teams presented during an intense full day. The morning and afternoon presentations drew full rooms of affordable housing developers who soaked up the information and had terrific, incisive questions

The same teams presented again during the core conference breakouts in a more condensed form for those who were unable to attend the hootenanny. In addition, there were more presentations on even bigger size affordable projects in progress:

  • A 101 unit affordable development in New York now under construction in the Rockaways (Steve Bluestone, Bluestone Org.)
  • A planned affordable retrofit of a 24 story historical brick building in Chicago (Doug Farr, Tony Holub from Farr and Assoc.), the Lawson House.
  • 24 story residence hall under construction in NYC (Matt Herman, BuroHappold)
L-R: Steve Bluestone presenting with Lisa White, Doug Farr, Matthew Herman

L-R: Steve Bluestone presenting with Lisa White, Doug Farr, Matthew Herman

Really amazing stuff.

Katherine Swenson

Katherine Swenson, Vice President, National Design Initiatives for Enterprise Community Partners — Day 1 Opening Keynote

Of course this growth has been fueled by forward-looking programs that recognize that energy efficient homes make so much sense for affordable housing developers/owners and dwellers. Katie Swenson from the Enterprise Foundation was a breath of fresh air–dynamic, positive, and motivating opening keynote. She explained that in her and her organization’s eyes energy is a critical part in assuring not just housing for people—but healthy housing! “Health is the new green,” she said, and of course passive housing delivers here with excellent comfort, indoor air quality and the added bonus of resiliency when the power goes out. Katie announced that the Green Communities criteria had just included PHIUS+ 2015 certification as one of the highest energy point options.

Other affordable housing agencies also have made a move: the Pennsylvania Housing Finance Agency (PHFA) awarded bonus points in its last round of selecting projects for Low Income Housing Tax Credits. More recently the New York State Homes & Community Renewal (HCR) effort was mentioned in a release regarding energy efficiency measures from the White House. Those agencies now directly encourage passive building standards in their RFPs. Remarkable!

Sam Rashkin, U.S. D.O.E. -- Closing Plenary Keynote

Sam Rashkin, U.S. D.O.E. — Closing Plenary Keynote

On the other coast. Seattle just amended their multifamily building code to allow additional floor area ration (FAR) for projects that meet the PHIUS+ 2015 criteria. That’s a significant incentive for developers.

Things are cookin’!

The core conference, as usual, was chock full of goodness. There were examples of how the new PHIUS+ 2015 climate specific passive building standards helped to optimize costs both here in North America (presentations by Chicago’s Tom Bassett-Dilley, Dan Whitmore, and) and internationally (Günther Gantolier from Italy). There were nuts-and-bolts presentations on wall assembly solutions (Tom Bassett-Dilley again), air and water barrier best practices (Marcus and Keith). And, the Builders Hootenanny—led by Hammer & Hand’s Sam Hagerman, focused on component challenges such as sourcing airtight FDA approved doors for commercial construction.

The U.S. DOE’s Sam Rashkin closed the conference with an unexpected message: he suggested that we needed to rename a few things to facilitate behavioral change. He posited that ZERH, LEED, PHIUS and other green building programs are essentially fossil fuel use rehab centers trying to rehabilitate an addicted nation and to show how it can be done differently. He received a standing ovation.

A few more comments on pre-conference workshops – three WUFI Passive classes drew almost 80 people and they all were super happy throughout the two days! Who would have thought! Happy people energy modeling!

LEFT: Marc Rosenbaum's lecture on Renewables -- RIGHT: Joe Lstiburek on Multifamily Building Science & HVAC

LEFT: Marc Rosenbaum’s lecture on Renewables — RIGHT: Joe Lstiburek on Multifamily Building Science & HVAC

Marc Rosenbaum single-handedly won first place in registering the most people for his class to connect passive principles with renewables to get to positive energy buildings (the logical next step).

Joe Lstiburek placed a close second (sorry Joe) and did a phenomenal job in covering ventilation concerns in large multifamily buildings. Rachel Wagner showed the most awesome cold climate details that I have ever seen. Galen Staengl took folks on a spin to design multifamily and commercial mechanical systems.

And Gary Klein topped it all off by reminding us that without efficient hot water systems design in multifamily, no cigar!

Thanks to all presenters and keynotes! You made this an excellent and memorable event.

I have not even mentioned the first North American Passive Building Project Awards—the entries were just beautiful projects—check out the winners here. I must mention the overall Best Project winner of 2015, as I believe this is pivotal: Orchards at Orenco. What a beautiful project, the largest fully certified PHIUS+ project in the country to date, a game-changer, underlining affordable multifamily projects on the rise.

I’m extremely happy that the Best Projects winners for young CPHC/architects was a tie, and both winners are women! Congrats to Barbara Gehrung and Tessa Smith! Go girls, you are the next generation of leaders!

L-R: Best Overall Project: Orchards at Orenco; Best Project by CPHC under 35 (tie): Island Passive House, Tessa Smith; Best Project by CPHC under 35 (tie): ECOMod South, Barbara Gehrung

L-R: Best Overall Project: Orchards at Orenco; Best Project by CPHC under 35 (tie): Island Passive House, Tessa Smith; Best Project by CPHC under 35 (tie): ECOMod South, Barbara Gehrung

One last note on a thing: Passive building people know how to party while devouring the most challenging, inspiring energy science, details, philosophies (Jevons paradox – Zack Semke’s fascinating lunch keynote) from the field.

And the architectural boat tour on Saturday to top it all off was almost surreal. When we were all out on Lake Michigan and the fireworks went off over the magnificent skyline, I thought, “that’s how we roll :).” Plus, the docent from the Chicago Architecture Foundation was a font of information, and even long-time Chicagoans learned a lot along the way. If you weren’t there, you missed the best passive building party of the year, maybe ever. (But we’ll try to top it, promise.)

Finally, for the crew that just can’t get enough, the Passive Projects Tour on Sunday was, as always, an enormous hit. Tom Bassett-Dilley and Brandon Weiss put together an array of completed and in-progress projects that generated a buzz at every stop. Thanks to Tom and Brandon and to PHA-Chicago for all your help!

Cheers!

Kat

 

Step it up from Earth Day to Energy Independence Week

Here’s a great idea from Graham Wright, PHIUS Senior Scientist and Chair of the PHIUS Technical Committee. We hope you’ll take up the challenge.

So, Earth Day was great, and everything. And the Earth Hour there.

Energy Independence Week. It's fun, it's patriotic, and we're virtually certain Stephen Colbert would approve.

Energy Independence Week. It’s fun, it’s patriotic, and we’re virtually certain Stephen Colbert would approve.

But let’s be real, Earth Day doesn’t challenge you to actually do anything in particular, and while Earth Hour does, that is vanishingly little  — one hour out of 8760 is addressing like 0.01% of the problem. After how many years now of Earth Day, what do you say we step the game up?

I call it Energy Independence Week. The idea is that, you extend the 4th of July holiday to a full week, during which you observe these three rules:

1. Use no grid electricity.
2. Burn no fossil fuels.
3. Make no trips to the grocery store.

It’s patriotic and fun. Like a staycation. You’ve got the charcoal grill out anyway. Notice that it’s twice as good even as “1% for the planet” in a couple of ways.

A) it’s 1 out of 52 instead of 1 out of 100, and
B) it’s not just a sacrifice concentrated on you for a diffuse benefit to the planet – it increases your own resilience.

I did this in 2008, a few months before I ever heard of passive house. But I like how it ties in – because of the time of year, it focuses attention on avoiding overheating, not a bad thing. (You will be fine if your passive house is not designed too hot. 😉 And it’s forgiving to the many of us who do not yet live in passive houses; this would be a much harder challenge yet in the winter, in most places.

At the time, I was living in rural Minnesota in a straw bale cottage, so heating and cooling wasn’t a problem. I got by with one solar panel and one battery for electricity. That was enough to run the well pump and my laptop. You don’t need much lighting in Minnesota that time of year. Instead of hot showers I swam in the river, which was a short bike ride away. It’s like camping but, you’ve got all your books or shoes with you.

Your challenges may vary. On rule 3 there, stocking up ahead of time is ok, preparations are part of the idea here. One of the other preparations I made was for irrigation — at the time I was trying to keep a bunch of discount hazelnut seedlings alive in the baking sun. I figured my little panel could not generate enough electricity to run the well pump for that, so I set up a big water barrel so I could gravity feed the orchard. Yeah, I faked it by filling it from the well ahead of time; ideally it would have been a real rain barrel all along.

Again, learning stuff like this is part of the fun. So, I hope you’ll take up the challenge and start planning now. And please, share your strategies, tactics, and experiences in the comments section here at the Klingenblog.

From passive house to passive buildings–what’s new and how manufacturers are stepping it up

BE15banner-LARGE

Exciting times indeed for passive building in the United States: Passive design principles that originated here and in Canada are all grown up and making a furious comeback. Policy makers, researchers and scientists, builders and designers are all embracing passive building in their everyday practice.

And as always, the growth is evident here at NESEA’s annual high-performance tour de force: NESEA BE15. A quick recap: Passive Building Place–a concentration of passive building component exhibitors, and the tour of their offerings, is in its fourth consecutive year. For those who remember, we started my first blog on the NESEA trade show focusing on passive house products in 2012. Passive building was still tiny then compared to what it has grown into now.

PHIUS and its membership organization the Passive House Alliance US (PHAUS) – the leading passive building research institute and alliance in the US – is the anchor of Passive Building Place for the fourth straight year.

NESEA never stands still. In its topic selection for conference workshops and presentations it continues to ask the tough questions and pushes the boundaries. I am talking about the passive building standard adaptation work we have been doing on Tuesday in a half day workshop. On Wednesday afternoon as part of the core conference I’ll be presenting about very exciting multifamily developments specifically. The Passive Building Place has become a mainstay and is expanding every year with new manufacturers who have recognized that passive building will be a significant driver for high performing materials and components.

Larger projects like Orenco Orchards in Eugene, Ore.,  by CPHC® Dylan Lamar and GreenHammer are coming on strong–they need more manufacturers to step up to the multifamily and commercial passive building market.

But, as multifamily and commercial projects come on strong, we see hesitation amongst manufacturers regarding new components and material needed for larger building developments. This follows the past trend with single family passive homes: the architects and CPHC®s (Certified Passive House Consultants) have taken on the design of the first larger buildings find themselves ahead of the curve.

While this might sound glamorous to some, in practice it is quite a challenge for the teams. Architects are out to make ambitious reductions in energy and carbon with large buildings, and they need appropriate high performance components. In principle, much of what’s been learned and accomplished in single family applications is transferable. Ideally, however, manufacturers will develop turnkey and warranted solution packages for multifamily and other large buildings. What about superinsulated thermal bridge free airtight curtain wall systems? Is this too much to ask for?

Here’s a good place to start: At last year’s 9th Annual North American Passive House Conference in San Francisco, five leading multifamily passive building teams came together for a presentation.  The one component they all wanted was a fire-rated door, that complies with ADA requirements of a low threshold, is airtight and has exceptional thermal performance comparable to the passive house windows that have taken the BE Passive Building Place by storm over the past few years.

To see what’s cooking this year, we are back for another tour of the trade show with you! I will have the pleasure of guiding a tour on Wednesday, March 4 beginning at 5.30 pm just before the boat tour. We’ll be visiting exhibitors who offer products and components germane to the passive building community. We will stop at selected passive building place exhibitors and Passive House Alliance sponsors inside and outside Passive Building Place. Because there are so many it’s impossible to visit all–instead we’ll focus on innovations and a more in depth conversation of 5-10 minutes discussing the manufacturers’ products.

Also different this year:  We will take the investigative role and instead of highlighting the passive building products we’ve seen in past years, we will challenge vendors with a different question: What are you doing to support larger passive building developments? Are you seeing the effects from it in your practice and what are you doing to respond, to prepare for it? Are there new offerings in the pipeline? What are designers asking for, what is missing?

Our goal is to identify the gap so that we can fill it. We like to inspire manufacturers to take the growth in passive building seriously. Please join us on this tour to hear from manufacturers what they are hearing and to ask the right and tough questions to inspire more high performing systems development for larger U.S. passive buildings.

Twenty-four exhibitors are joining us this year in the Passive Building Place or elsewhere on the floor–they include sponsors of PHAUS, firms with PHIUS certified professionals on staff, firms offering PHIUS verified windows or doors, or that are collaborating with PHIUS/PHAUS otherwise. Those partners are listed here:

475 High Performance Building Supply (Booth # 759)

Auburndale Builders (Booth # 913)

Bright Build Home (Booth # 549)

Conservation Services Group (Booth # 709)

Fraunhofer CSE (Booth # 660)

H Window/Energate (Booth # 642)

Huber Engineered Woods (Booth # 743)

Klearwall Industries LLC (Booth # 862)

Intus Windows (Booth # 624) PHAUS Green Sponsor

Marvin & Integrity Windows (Booth # 939) PHAUS Silver Sponsor

Mitsubishi Electric (Booth # 707) PHAUS Silver Sponsor

New England Homes by Preferred Building Systems (Booth # 919)

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

Pinnacle Windows Solutions (Booth # 763)

PowerWise Systems (Booth # 814)

PROSOCO Inc. (Booth # 949) PHAUS Green Sponsor

Roxul (Booth # 860)

Schock (#636)

SIGA Cover, Inc. (Booth # 620)

Steven Winter Associates (#844)

Stiebel-Eltron Inc. (Booth # 749)

Yestermorrow Design/Build School (Booth # 1036)

Zehnder America, Inc. (Booth # 864) PHAUS Friend Sponsor

Zola Windows (Booth # 755) PHAUS Friend Sponsor

 

We won’t have time to stop at all passive building component vendors, but we urge you to stop check them all out as you find time. Make sure to stop by:

Dryvit (Booth # 430)

Enovative (Booth # 945)

European Architectural Supply (Booth # 727)

Fantech (Booth # 828)

Foard Panel (Booth # 830)

Green Fiber (Booth # 717)

Led Waves (Booth # 628)

Main Green Building Supply (Booth # 622)

Retrotec (Booth # 541)

Sanden International (# 563)

Schock USA (Booth # 636)

Tremco Barrier Solutions (Booth # 719)

Viessmann Manufacturing (Booth # 565)

Yaro DSI (Booth # 638)

Thank you all for participating in this and putting your weight behind this exciting emerging construction market. Again, you are true leaders in this market transformation towards high performance building products that is so needed to achieve zero/positive energy buildings through passive design. Thanks again for joining!

And have a great BE15!

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!