EPA Indoor airPLUS and Radon Resistant Construction

0Today’s guest blogger is Tony Lisanti, PHIUS+ QA/QC manager. 

One of the prerequisite programs required for PHIUS+ Certification is the EPA’s Indoor airPLUS Program.  Born out of a need to minimize indoor air pollutants, the EPA dove-tailed this program with the ENERGY STAR Labeled Homes Program, which is also a prerequisite for the home or dwelling unit to earn both Indoor airPLUS and PHIUS+.  This serves to ensure that the dwelling unit is relatively tight, insulation is properly installed, the HVAC systems are properly sized, and bulk moisture throughout the building assembly is properly controlled.

Indoor airPLUS then takes indoor air quality to the next level. Integrating the Construction Specifications and Checklist requirements into the design, homes/dwelling units can then be verified to ensure greater precautions are taken for moisture control and dehumidification, air intakes are protected from birds and rodents, HVAC systems are kept clean, better filter media is used, and potential sources of moisture and contaminants are vented to the outdoors. Additionally, HVAC systems and ducts are prohibited in garages, pollutants from combustion equipment are minimized, and low VOC products are used.

One of the unique and important aspects of Indoor airPLUS is the requirement for radon-resistant construction measures in EPA Radon Zone 1. If you are not familiar with the Radon Zone map, it can be found here:  https://www.epa.gov/radon/epa-map-radon-zones.

Radon is a naturally occurring radioactive gas that can cause lung cancer. In fact, the EPA estimates that 21,000 deaths each year in the U.S. are attributable to radon exposure. The EPA has very good resources to read up on the health risks of radon. Their site can be found here: https://www.epa.gov/radon/health-risk-radon#head.

So why should PHIUS stakeholders be concerned with this? As mentioned above, PHIUS relies heavily on prerequisite programs such as ENERGY STAR and Indoor airPLUS. Since the airtightness standards for PHIUS Certified projects are up to 10 times more stringent than a typical code-built home, dilution of the indoor air cannot occur as readily. PHIUS ventilation requirements go well beyond those of systems found in typical Code built or even Energy Star Labeled homes. Good ventilation design, whether for code or for PHIUS starts with source control, i.e. minimizing the source of contaminants along with proper ventilation.

An example of a passive radon system.

An example of a passive radon system.

In high risk areas such as Radon Zone 1, EPA Indoor airPLUS requires installation of a passive radon system, at minimum. EPA also recommends utilizing active radon systems to further reduce radon concentrations in the home, although this is not yet an Indoor airPLUS requirement. The most modern radon standards are developed through an ANSI-accredited consensus process by the AARST Consortium (American Association of Radon Scientists and Technologists). EPA recommends following the ANSI/AARST CCAH Standard for 1-2 family dwellings and townhouses (max. total foundation area of 2500 sq. ft.) or the ANSI/AARST CC-1000 Standard for larger foundations, which often apply in multifamily buildings. However, the key components of a passive radon system for the purposes of Indoor airPLUS verification are succinctly outlined in Item 2.1 of their Construction Specifications.

ANSI/AARST will soon publish updated standards to provide guidance for the design and installation of two radon system options in new low-rise residential buildings. These systems, passive and powered, are designed to reduce elevated indoor radon levels by inducing a negative pressure in the soil below the building. The practice provides design and installation methods through soil depressurization systems that can be installed in in any geographic area.

Each of the two options consists of soil gas collection and a pipe distribution system to exhaust these gases. The first standard is for the design of passive radon reduction systems, sometimes referred to as a “radon rough-in” (ANSI/AARST RRNC). The second newly updated standard (anticipated in early 2020) includes details for a fan-powered radon reduction system, as well as radon testing (ANSI/AARST CCAH). Passive systems can result in reduced radon levels of up to 50%. These standards suggest that when radon test results for a building with a passive system are not acceptable, the system be converted to fan-powered operation. Typically, the action level is 4 pCi/L (Picocuries per liter). If the tested radon level exceeds 4pCI/L, then a fan is added to further depressurize the soil and positively vent the gas to the outside.

Recently, the EPA Indoor airPLUS team sent out this Technical Bulletin. The Technical Bulletin provides simple guidance on the installation of passive and active radon systems. Please pay particular attention to the drawings in the Bulletin, and note that the active system depicted has the fan located in a vented attic. This is outside the pressure/thermal boundary of the home. This has special significance with homes/buildings constructed to PHIUS Standards, because often, the attic space is WITHIN the pressure/thermal boundary of the home. Therefore, the fan cannot be located in the attic and must be outside the pressure/thermal boundary. The reason for this is, should there be a failure on the discharge or pressurized side of the fan, the building can actually be filled with radon gas.

Some other precautions that include a tight seal at the slab and vapor barrier to the vertical riser. Additionally, ensuring the riser is clearly labeled as “RADON” to minimize the chance that a plumbing waste line will be accidentally connected to it in the future is also important.

Tony Lisanti CEM, CPHC
PHIUS+ QA/QC Manager

With thanks to Nicholas Hurst from the EPA Indoor airPLUS Team

Exhaust fans and make-up air

SONY DSC

PHIUS Certification Manager Lisa White weighs in on a common challenge for passive house designers.

When it comes to exhaust for the kitchen range/cook-top, either a re-circulation hood or direct exhaust hood is allowed in PHIUS certification, and among projects in certification, there has been no dominant approach — we see it both ways about equally. 

When projects use kitchen hoods that exhaust directly to the outside, it’s common practice to provide makeup air relief when the hood is in operation. This is because that additional exhaust airflow is separate from balanced ventilation system, the building is very air-tight, and without pressure relief, the exhaust airflow causes slight depressurization in the building.

PHIUS has been asked to clarify if makeup-air is required for projects when direct exhaust is utilized in the kitchen. The short answer is, it depends. The longer answer is below.

The ventilation balance  requirements for certification are outlined in the PHIUS+ Certification Guidebook v2.1 Section 3.5.3.3, and copied below:

Regardless of type, the ventilation system must meet one of the following requirements for balance:image-2

  1. Total measured supply and exhaust airflows are within 10% of each other. (Use the higher number as the basis of the percentage difference.)
  2. The total net pressurization or depressurization from the un-balanced ventilation system does not exceed 5 Pa. The net pressurization/ depressurization that the ventilation system imbalance causes on the building is determined using the multi-point air-tightness test results graph.

Intermittent exhaust airflow rates for kitchen exhaust hoods are generally much higher than a continuous exhaust airflow rates in the kitchen.  For example, a whole house may have a total of 150cfm continuous, balanced ventilation, and may have a 125cfm kitchen intermittent exhaust hood. With this combination, option 1 above would likely never pass.

PHIUS has established a method for determining compliance with option 2 during design. A stress test must be used to see if this intermittent ventilation system would cause more than 5 Pa of depressurization in the building. For a single unit building, the stress test is simply measuring the effect of turning on the range hood. If that airflow rate causes more than 5 Pa of depressurization in the building, there must be a provision for makeup air. For multi-unit buildings, an appropriate ‘stress test’ has now been defined that is both conservative and realistic.

Read the full Tech Corner Article here: https://www.phius.org/Tools-Resources/TechCorner/Makeup%20Air%20Requirements%20for%20Direct%20Kitchen%20Hood%20Exhaust%20.pdf

And try out the Intermittent Exhaust Allowance Calculator here: https://www.phius.org/PHIUS+2018/Kitchen%20Exhaust%20Calc%20v1.13/Kitchen%20Exhaust%20Calc%20v1.13.htm

 

This Holiday Season, Get PHIUS the Gift that Keeps on Giving

James Ortega, PHIUS Certification Staff

 

thatdbegreatThis year marked a major milestone in PHIUS’ history as PHIUS+ Certified and Pre-Certified projects reached over 1.2 million square feet across 1,200 units nationwide. As of the end of 2016, there are 377 total certified and submitted projects in our database.

We could not have achieved this outstanding milestone without the hard work and efforts of all the project team consultants, architects, builders, and raters that helped to get these projects off the ground. In celebration of these accomplishments, we put together a virtual map of all of the PHIUS projects that have been submitted to date.

We understand that every project has its own unique hurdles, and we want to make sure we can help you get off on the right foot each time. That’s why it’s so important that a project is submitted to PHIUS as early in the design process as possible so that our team can help guide the “make or break” decisions that affect the project’s likelihood of getting certified.When a project is submitted during, or too close to, the beginning of construction, the feedback and recommendations provided by our knowledgeable PHIUS certification staff may unfortunately already be too difficult or costly to implement.

Save yourself the time, money, and headache by submitting your project early. The PHIUS certification team is here to help you on your path to certification!

On this note, we have prepared a short list of holiday gift ideas – things that PHIUS would love to see you do before submitting a project for certification. (Hint: Pouring the slab is not one of them.)

  1. Read the PHIUS+ 2015 Certification Guidebook.
  2. Explain the difference between passive solar and passive building to a curious client.
  3. Refer a friend or colleague to the PHIUS website or to the new PHIUS Multifamily Resource Center to learn more about the work we do.
  4. Tell Certification Manager Lisa White how much you appreciate her.
  5. Breathe. (Since this is a fairly simple task, we would ask that you multi-task and submit your project simultaneously.)

The holidays are just around the corner, so in the spirit of giving PHIUS is asking you for the greatest gift of all: SUBMIT YOUR PROJECTS EARLY!

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