Help Wanted: Identifying conditions that can complicate retrofits

32tev__gPhius Senior Scientist Graham Wright weighs in here with a guest post about some on-the-ground research he did regarding retrofits. Graham conducted a brief street-view survey of residential housing in Portland, Oregon (Glenfair, Glendoveer, Rockwood neighborhoods), and documented conditions that would complicate panelized retrofit solutions. He invites you to do the same in your neighborhood, and to submit what you find to advance research on panelized retrofit solutions.

It looks like I will be pivoting to concentrate my work on retrofit for a while. This is in connection with the Advanced Building Construction Initiative (ABC) of the U.S. Department of Energy. Under the program, RMI was funded to set up a collaborative and phius is a member. The vision shared at the recent summit is to figure out how to decarbonize ALL BUILDINGS by 2050. A study of the building typologies is underway, led by NREL.

It is already clear that single-family detached houses are the vast majority of buildings by number, they probably also dominate the aggregated “thermal loads” of heating, cooling, and hot water that comprise most of the energy/emissions savings opportunity.

The NREL data set does not have all the building properties that one would need to identify the technical barriers to deep energy retrofits. There is general awareness on the ABC team that the U.S. housing stock is very diverse and that this is a challenge to the concept of industrialized retrofit. So to get a better sense of this I spent a couple of hours looking at houses within walking distance of where I live in east Portland, Oregon. I looked for conditions that would complicate an exterior panelized envelope insulation retrofit, or that would complicate air-sealing. I looked at 33 houses and noted 30 separate conditions. These are assigned four-letter codes as shown in the table below. Some were much more common than others, such as attached garages, and some were so universal I did not even list them, such as gutters/downspouts.

My takeaway from this excursion was that the number of conditions that one would need to have a plan for is large but not endless. There are obviously some missing, such as balconies and widow’s walks. It’s not a large sample and I could only see one or two sides of the houses from the sidewalk. Many of the houses pictured are on crawl space foundations as indicated by vents, and that could also be considered an air-sealing complication, though I did not call it out here.

Here’s a slide show with problem conditions annotated:

 

Please send photos of houses near you! If possible, annotate conditions as I have in the gallery, using  the codes in the table below, or adding other conditions not listed, that also seem troublesome from the point of view of exterior retrofit and air-sealing.

Here are the problem conditions I classified, along with the number of cases I identified on my walking tour:

ACOD – air conditioner outdoor unit (3)
AGAR – attached garage (10)
CATV – cable tv line (1)
DISH – satellite dish (5)
DRYV – dryer vent (2)
E@RF – electrical mast through the roof (8)
EMTR – electrical meter (3)
EOUT – electrical outlet (1)
FENC – adjacent fence (13)
FCHM – fireplace chimney (17)
GCHM – gas appliance chimney (5)
GMTR – gas meter (3)
HOSE – hose bib / reel (3)
MLCA – mature landscaping close aboard (9)
MSXT – masonry extension from wall (5)
OV@R – overhang attached at roof (5)
OV@W – overhang attached at wall (5)
PBVT – roof plumbing vent (3)
PBCO – plumbing clean out (1)
RFVT – roof vent (4)
SKLT – skylight / sun tunnel (3)
SOFF – overhang with soffit (3)
STOV – wood/pellet stove chimney (1)
TCOM – telecom or mystery wall box (7)
THIC – change in cladding thickness (5)
TITE – can’t add wall thickness (20)
WART – wall art (1)
WBOX – window box (2)
WING – wing or fin wall (1)
XTLT – exterior light fixture (12)

Mechanical Summit Re-cap: A Good Time Was Had by All

Al Mitchell

Al Mitchell

Phius technical staff member Al Mitchell is our guest blogger, providing a thorough re-cap ofthe Phius Mechanical Summit. Remember that the entire proceedings were recorded, and you can still register to view all four or any of the days a la carte. You can earn up to 16.5 CPHC CEUs.

In the week leading up to Earth Day, Phius hosted the  Mechanical Summit online, a virtual gathering to advance the conversation around mechanical systems in passive buildings. Some came for direct solutions to their problems, some came for involved discussion between designers and manufacturers, some came for CEUs, but everyone had a rousing good time.

The summit was organized into four days, each with a defining theme. Pre-recorded presentations from expert panelists were available on-demand and led up to a two-hour live webinar; each featured a lead panelist presentation and short distillations of the pre-recorded presentations, after which the panelists fielded questions from the live audience.

Attendees asked their questions via the Zoom webinar format, but the chat remained open for the audience to debate and respond to different ideas.mech summit sig

The first of four days detailed building mechanical design principles and best practices. Lead panelists Dan Whitmore and Sloan Ritchie discussed their past experiences and used previous projects as case studies to demonstrate how they developed mechanical solutions for their Pacific Northwest climate. Other presentations included topics such as properly-sized domestic hot water distribution systems, ventilation integrated space conditioning, proper duct sizing, and rater-focused commissioning and testing of systems for passive house certification.

On the second day, presentations focused on solutions for closing the gap and tools and strategies to respond to the design principles. Lead panelist Tim McDonald detailed mechanical designs from multifamily projects located in the Philadelphia, Pennsylvania area. He explained his incremental development of mixing an ERV and ducted heat pump system by dumping the fresh air supply from the ERV into the return of the heat pump, and eventually trying a ventilation and space conditioning integrated unit. Other presentations explained proper space conditioning load sizing for single family homes, building monitoring and comparing results to predicted outputs, design of space conditioning integrated ventilation units, and mechanical systems controls.

Day three dealt with products and systems designs. Lead panelist Chris Benedict presented on a retrofit project in Brooklyn, New York, where the mechanical systems and building enclosure were rebuilt with minimal tenant disturbance. This raised questions on system choices and detailing the complicated world of building retrofits. Other presentations included manufacturers explaining improvements to their products and how they are responding to the needs of passive building designers, and some design methodologies and installations that are aimed at efficient, low carbon mechanical systems.

The closing dayffeatured Doug Farr, determined architect and new urbanist from Chicago. He celebrated Earth Day and discussed how to build a ground-up movement to build more efficient and sustainable communities, a more optimistic and engaging approach to the problem compared to many top-down approaches. To carry off at the neighborhood level, the additional presentations detailed building electrification, smart DC low voltage power systems, and passive buildings’ interaction with the grid. PHIUS Executive Director Kat Klingenberg made another nod to Earth Day and unveiled the new Phius branding and re-alignment to the institute’s mission.

There were a few themes that seemed to interweave through the days. One is the ever-popular question of kitchen range hoods and managing make-up air for direct exhaust devices. Without fail, it was discussed on all three mechanically focused days of the summit. While the panelists and attendees presented multiple solutions, no “silver bullet” solution emerged. This represents the reality of many passive buildings, that a one-size-fits-all solution is not available, and each project requires a thoughtful and inquisitive design professional to determine the correct path.

Many panelists mentioned that they felt that the building enclosure is the easy step for them, and the mechanical systems require more thought. A lot of these issues have been known from the beginning: the need for balanced ventilation, tight enclosures, and the massive reduction in sensible and increased need for dehumidification. Some designers called on manufacturers to address the need for microload equipment, and the manufacturers’ representatives showed some products in the works, and made the case for increased demand to bring the types of mechanical products to the North American Market. Seeing the large uptick in Phius Certified buildings, there is good reason to be optimistic.

While mechanical systems are frequently seen as the weak link in passive building design, the Phius 2021 Mechanical Summit left many feeling sanguine. Phius will continue to work and keep the conversation going on mechanical systems moving forward. Help Phius continue the conversation and submit an abstract for PhiusCon 2021 in New York.

PHIUS Mechanical Summit – Why?

mech summit sig_v1

About a year ago I met with Gabriela Martin for coffee (outdoors, socially distanced and masked up). Gabriela is the Zero-Energy program mastermind and manager at the Illinois Clean Energy Communities Foundation. Several school buildings used PHIUS standards to meet the ICECF zero-energy goal. The projects that receive ICECF funding only receive the full grant when the project actually meets the zero-energy goal, which requires detailed monitoring of actual performance. Gabriela tells me about her findings, sighs… says the envelope is next to perfect, doing its job but the systems…a whole other story. Almost all the awarded buildings have missed the target so far. The culprit: the performance of the mechanical systems.

Mechanical…what do we mean by that and why does this topic warrant an entire summit in and of itself? I think of mechanical as encompassing balanced ventilation, space conditioning, hot water and electrical…in short all active systems and their components needed in a building. In terms of achieving, mechanical systems are the weakest link.

This is due for two main reasons.

1. Claimed systems efficiencies often are optimistic.
2. Installation is often wanting, including distribution, significantly reducing whole systems efficiencies.

Neither of these are necessarily anybody’s fault. But it points out that existing mechanical systems design for inefficient buildings: Designers and installers over-compensate for inaccuracies and potentially bad installs by designing and installing oversized systems allowing for redundancy.

Belts and suspenders.

Passive building requirements are different. The tolerances for inaccurate assumptions are much smaller. Passive buildings fundamentally act differently and need differently calibrated components to account for comfort.

In absence of systems and equipment designed for low-load buildings, most design teams are left to improvise. They assemble components that might not typically be used in conjunction in conventional construction…they have to make do with what they can find on the market, improvising solutions that are not ideal for passive buildings.

We need and deserve better!

• We practioners need to keep pushing to build the market to help manufacturers justify new products that meet our needs. We need to be clear about what we need.

• We need manufacturers to hear us, to offer help creating solutions from existing products, and to eventually respond with new products for low-load buildings.

We want the PHIUS Mechanical Summit to accelerate our efforts; to advance the conversation between the designers, manufacturers and installers.

Policy makers are taking notice, and that’s great. But to fulfill the net Zero promise, it is clear, we need the larger HVAC and other manufacturers to enter the scene, and in short order!

Passive building, low load systems design can be the economic key to mainstreaming zero energy buidlings. Its mechanical systems can be minimized and designed in an integrated way, offering “plug-and-play,” it would yield a significant reduction in terms of first cost, operational cost and maintenance. This could dramatically change the economic feasibility of zero energy buildings and facilitate it going mainstream.

During the first CPHC classes in 2008, I used to describe how we conventionally build our houses. We build the same envelope in all climates (usually with scant attention to insulation and air sealing), and then we put a giant furnace into it to keep us comfortable. The size of that furnace is variable, depending on the climate, it comes in big or huge. Energy was not a prime concern.

In a passive building we turn that idea on its head. What if we made the shell of a building do most of the work instead of the furnace? We’d make its shell match the climate when insulating it and air-seal it. We then make sure it is right-sized so that the small “micro-load” system has no trouble keeping the space comfortable no matter where we build. The micro-load system of a predetermined size would also assure that we meet our carbon reduction goals and reduce our carbon footprint. It would act like cruise control to stay under the emissions speed limit.

What if the envelope is designed to do the heavy lifting, to fit the micro-load system instead of the other way around? That was the initial ground-breaking idea brought forward by the passive house pioneers in the 1970s in response to the oil embargo in an effort to reduce total energy consumption by about 70%, reducing the micro-load mechanicals to only about 15% capacity of a regular system! This idea is a BIG DEAL! 85% in reduction of systems size!

We on the building and design side have been hampered by the lack of low load systems on the market specifically designed for the changed dynamics in low load buildings. Mechanical engineers often are unfamiliar with passive building design. Manufacturers have not yet responded to the emerging passive building market’s unique demands—to now, the market wasn’t there. But that is changing.

Growth has been driven by creative design teams that often make do with components designed for conventional buildings. But in terms of maintenance and scaling, the status quo won’t do.

We need solutions that account for balanced ventilation, loads, load relationships and distribution requirements in passive buildings. Such packaged solutions are emerging, driven by small companies, that can make progress only very slowly but it is a positive sign. What about joint ventures?

That’s the kind of question we’d like to address at the summit, in addition to sharing lessons learned about how existing equipment has been used to solve the passive mechanical puzzle.

We’ve come a long, long way since I built my own passive home back in 2003. But to get where we want to go: mainstream passive building to achieve Zero, we need to tackle the mechanical issue.

Let’s do it like we always have, together.

Please join us during Earth Week for the PHIUS Mechanical Summit.

Each day of the Summit will cover one of four main topics in an effort to bring further awareness to what components and practices can help create a solid mechanical system across different climates:

Day 1, 4/19: Design Principles / Best Practices
Day 2, 4/20: Gap Solutions / Tools
Day 3, 4/21: Products / Systems Designs
Day 4, 4/22: Earth day: Zero Energy and Carbon / Electrification

PHIUS will offer both pre-recorded, on-demand content and a live panel Q&A discussion for each day of the Summit. The experts featured in both mediums will cover a large segment of passive building practice areas. Attendees will hear from those involved in product development, systems design, energy modeling, HVAC installation, and quality assurance.

See you there!

Kat

When Sam-I-Am Met Kat in the Hat

Sam is sorely missed.

Sam is sorely missed.

PHIUS co-founder and Executive Director Katrin Klingenberg reflects on the one-and-only Sam Hagerman. 

It was 2008 when PHIUS launched the CPHC® training in Urbana, Illinois—it was so successful that we took it on the road in 2009. First stop was Boston in the East, then a West Coast swing through San Francisco, Portland and Seattle.

Back then, we delivered all training in-person. All students attended three segments with a few weeks in between each—it required a serious commitment. Though the passive movement was nascent, a cadre of forward-thinkers filled all our dates and locations. One of them was Sam Hagerman.

I was fortunate to meet Sam during the second segment of our West Coast swing.
The Integrated Design Lab in Seattle had graciously agreed to host the training. The class room was full except a seat in row two in the middle. Sam was fashionably late and made an entrance, stopped the class in its tracks, scootched past people on the right, charmingly smiling and cracking a joke, all eyes on him, including mine.

Sam could command a room.

He wore a casual plaid jacket, casual to a point of laissez faire, he had pizzazz, a combination of vitality and elan that stuck with me. I wasn’t sure he had staying power to last through serious calculations and building science but he did. This, in spite of having to step out frequently to make calls; he clearly had a bustling business.

I learned later at a class social event that Sam was a builder from Portland, owner and founder of Hammer and Hand. Eventually Sam offered me a ride, and we stopped at the grocery store getting a bottle of wine and a giant bag of cherries.

These are my most valuable memories of Sam, first impressions count and I remember every second of it. It was a good one.

Soon thereafter we held the Third Annual North American Passive House Conference in Urbana, when we founded and launched the Passive House Alliance. I asked Sam if he was interested in chairing it. He clearly had construction, business and political acumen, people skills and plenty valuable connections up the food chain. He graciously accepted the invitation and the rest is history.

Sam Hagerman became the driving force and the bedrock, took us all patiently by the hand, mentored us and me in countless phone calls, advice on industry politics, and strategy. Sam was determined to make passive building mainstream, and to save the planet. We were on a mission together.

Sam had an endearing frontier kind of charisma, combined with big-city business acumen. Most of all, he loved people and his friends and they loved him. He was wont to generously throw parties for them at a nearby restaurant. He brought everyone together and was just a hell of a lot of fun to be around.

He also saw talent and attracted talent. At the training in Seattle he met Skylar Swinford and took him under his wing at Hammer and Hand. What Skylar and countless others learned was that working together with Sam always also meant being friends, having fun and exploring.

I was lucky enough to experience him and Zack Semke, two peas in a pod at the time, on our trip to Innsbruck for the international Passive House Conference in 2011. We ran into them coincidentally on a mountain hike, sat in the sunshine at a small restaurant up there with Graham Irwin and Mike Kernagis…good times! (I hope you’ll view Zack’s tribute to Sam.)

He weathered some early storms within the passive house community as the chair of a rambunctious bunch, including some personal attacks, but nothing seemed to faze him. He kept his eyes on the prize nonchalantly and brushed off slights and difficulties like they were nothing. And in the big picture they weren’t; another valuable lesson learned for all of us.

Under his leadership his firm went on to build one of the very first PHIUS certified passive houses: a ground-breaking positive energy project in the Northwest called Karuna House. The project was way ahead of its time, in a stunningly beautiful setting and the name deeply meaningful. Karuna in Sanskrit means compassion and self-compassion, it is part of the spiritual path of Buddhism. This is how I will remember Sam…the Karuna House spirit.

Life is fragile. He had demons as well, as all artists and deeply thinking and feeling people do, those who are not afraid of living and taking risks. And he was not. And he met his limits eventually, just way too early.

He was a celebrity in his own right, out there, building bridges where he could, creating, playing music (the sax), bringing joy. He was having it his own way. Always.

Sam, you will be so missed, the community is no longer the same without you.

A star has fallen.

Make a wish.

PHIUS+ 2021 Source Energy Factor for Grid Electricity

PHIUS+ 2021 will include a change to the source energy calculation for grid electricity to more accurately reflect future grid conditions and better weigh the impact of electricity versus natural gas use on site.

In past versions of PHIUS+, the source energy factor for grid electricity was defined by the Energy Star Portfolio Manager and was determined based on past generation and consumption data from the EIA. The calculation methodology accounts for the total primary fuel needed to deliver heat and electricity to the site, including conversion losses at the plant as well as transmission and distribution losses incurred to deliver electricity to the building. Under PHIUS+ 2018, the source energy factor for grid electricity for the U.S. was 2.80, which was an average of the EIA reported data from 2012-2016.

With the release of  PHIUS+ 2021 the calculated factor for the United States grid electricity is 1.73 which reflects a 2050 outlook. 

Figure 1: U.S. power sector evolution over time for the NREL Mid-case scenario

Figure 1: U.S. power sector evolution over time for the NREL Mid-case scenario

Calculating a future source energy factor for the United States electric grid electricity required the combination of three data sets: 

(1) The projected future electricity generation mix, which was taken from NREL’s Mid-Case Scenario for 2050.

(2) Fuel conversion energy factors per generation type from the EIA.

(3) Total system losses from transmission, distribution and storage, taken from eGRID2018 and NREL’s future grid mix scenario.

A detailed description of the calculation methodology and corresponding data sources can be found in the PHIUS Tech Corner article. Read the full article here.