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It’s Time to Focus on Our Schools

If you are a parent like me, I am sure you cherish your kids and seek to offer them the best opportunities in life. I even moved to a different school district. And, while the education is top-notch in my town, I have come to realize that it really doesn’t matter what school district you are in…all our schools need help. I am not talking about smaller class sizes, better pay for teachers, after-school programs, and more school supplies, although those are important. School buildings need attention. With budgetary pressures, a lot of maintenance and repairs are being deferred and schools are not aging well. Whether it is repairing existing systems, replacing systems at the end of their useful life, renovating, or building a brand-new school to service your community for future generations, advocate for your Board of Education (BoE) to think holistically about improving the conditions for our children.

Why My Call to Action?

This year I was asked to join our elementary school’s Tools for Schools committee, which is tasked with implementing an indoor air quality (IAQ) management plan. This experience gave me an opportunity to get involved and provided me insight into the school’s systems and the operations and maintenance (O&M) processes that were in place.

Unfortunately, at the start of the 2018 school year, mold issues were identified in our local middle school and the building was closed. In fairness, I quickly realized that buildings were outside the BoE members’ knowledge base. Afterall, they are educators, not facility managers or building scientists. They sought outside consultants but didn’t know the right questions to ask. After some time, the BoE decided to get input from local experts in the community. Fortunately, we have several experts (including me) who were willing to volunteer their time. As part of a task force, we laid out a strategy to remediate the mold issues in the school and to implement short- and long-term repairs to minimize/eliminate water incursion and elevated moisture issues within the building.

I am not saying you must get involved at this level, but I do encourage you to attend a BoE meeting and start asking questions related to IAQ. Ask if the school has deferred maintenance needs and if/when these are being addressed in the annual budget. Ask when (if) comprehensive physical needs assessments and energy audits were performed on all school buildings. Educate yourselves; then help educate your BoE and your community on IAQ guidelines for schools. Here are some great resources:

How Can SWA Help?

In working with schools, I have learned that one of the greatest challenges school decision-makers face is not knowing where to turn for support and guidance. Steven Winter Associates, Inc. (SWA) has been working to improve educational facilities for decades. Whether you have questions related to mold, moisture, comfort, absenteeism, accessibility, high utility bills…on up to zero energy design and progressive learning environments, SWA can support you. Here is just a sample of past school projects that SWA has worked on:

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The First Certified Passive House in Southeast Asia – Star Garments Innovation Center

Following up on our blog post in August 2018 – Just Your Typical Blower Door Test… in Sri Lanka – Star Garment Innovation Center – we have exciting news coming out of Sri Lanka. The Star Garments Innovation Center is now officially certified as a Pilot EnerPHit building, the building retrofit standard under the Passive House Institute (PHI).

EnerPHit logo with project details

EnerPHit certification for this project is a milestone achievement on many levels. The Innovation Center is now the first certified Passive House in Southeast Asia and one of only a handful of certified PH projects in tropical climates. PHI deemed the project “a milestone in industrial energy efficient retrofitting in a tropical monsoon climate.” Many of the passive measures employed at the Innovation Center, including continuous exterior insulation, highly efficienct windows, variable refrigerant flow heat pumps for cooling with wrap around heat pipe for enhanced dehumidification capacity, and balanced ventilation with heat recovery can be utilized across all future construction projects in tropical climates. The Passive House team here at SWA is excited to see the potential growth in tropical-climate Passive House construction as a result of the Innovation Center’s success.

But what good is certification if the building doesn’t perform as well as the energy model predicts? Well, we have exciting news on this front too!

At the very start of SWA’s involvement in the project back in the summer of 2016, SWA conducted a utility analysis of the base building prior to any renovations to predict and later verify the energy savings of the Innovation Center by designing to the PH standard. Once the energy model was developed, SWA predicted approximately 50% in energy savings when compared to the previous building’s energy bills.

Fast forward to Fall of 2018 and the building has now been occupied for a full year. The two inevitable questions are:

  1. How much energy is the Innovation Center saving as compared to the previous building?
  2. How does the modeled energy use for the Innovation Center compare to what it is actually using after a full year of occupancy?

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Establishing Moisture Control in Multifamily Buildings

Most of us are familiar with the feeling of a humid apartment after taking a hot shower. Some of us kick on an exhaust fan, perhaps un-fog the bathroom mirror, or even open a window to get the moisture out. Domestic moisture generation—moisture from human activity—is a major factor driving the humidity levels in our residential buildings, especially in super air-tight, Passive House construction. Before diving into just how much of an impact domestic moisture has in our buildings, let’s first look at average daily moisture generation rates of a typical family of three[1]:

  • breathing and transpiration—6 to 9 pounds of water vapor/day;
  • 10-minute shower in the morning for each individual—3.6 pounds of water vapor;
  • cooking fried eggs and bacon for breakfast—0.5 pounds of water vapor;
  • cooking steamed vegetables with pasta for dinner—0.5 to 1.0 pounds of water vapor; and
  • one small dog and a few plants around the house—0.5 pounds of water vapor/day

This brings the daily total to 11.1 to 14.6 pounds of moisture generation per day, or about 1.5 gallons of liquid water.

Where does all of this moisture go? In a typical code-level apartment building with moderate to high-levels of air leakage, water vapor has two year-round exit pathways: exfiltration through the façade and dedicated kitchen or bathroom mechanical exhaust. Additionally, in the summer, moisture is removed via condensate from the cooling system.

Let’s now put this in the context of a highly energy-efficient apartment with very low levels of air leakage (about 5 to 10 times less than the code-compliant unit), and balanced ventilation with energy recovery. The first means of moisture removal, façade exfiltration, is virtually non-existent given the building’s superior air-tight design. Next is mechanical exhaust ventilation in the kitchens and bathrooms. Because the unit has balanced ventilation and energy recovery, the exhaust air stream in a Passive House project typically passes through the energy recovery core. Depending on the core selection, a large percentage of the interior moisture may be retained in the apartment air despite the constant mechanical air exchange.

There are two basic types of cores:

  • Heat recovery ventilator (HRV) in which a certain percentage of sensible heat is recovered (transferred from the exhaust air stream to the supply air stream) while no moisture is recovered.
  • Energy recovery ventilator (ERV) in which a certain percentage of sensible heat and a certain percentage of moisture in the air is recovered.

To fully understand this issue, Figure 1 breaks break down the moisture-related pros and cons of ERVs and HRVs in the context of a high-density, Passive House building.

  ERV HRV
Pros Summer – prevents high exterior air moisture load from being supplied to interior air; cooling loads are minimized Winter – flushes high internal moisture load out of building; humidity levels reduced
Cons Winter – if internal moisture generation is high, interior moisture load is not flushed out of apartment; humidity levels increase Summer – allows exterior air moisture load to be supplied to interior air: cooling loads increase

Figure 1. Moisture related pros and cons with ERVs and HRVs in high efficiency, airtight construction

 

Traditionally, the key factor in deciding between an ERV or HRV for a high-efficiency building has been the project’s climate. However, as internal moisture loads begin to exceed exterior moisture loads in high-density projects, the decision between ERV or HRV must be looked at more closely for each project regardless of climate.

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The Top 10 Party Walls Posts of 2018!

2018 has been a year to remember for SWA’s Party Walls blog. Our consultants have shared their passion for high performance buildings by recounting stories from the field and providing information, new findings, and best practices to improve the built environment.

Whether discussing topics based in New York City or Southeast Asia, here are our fan favorites from 2018…

Collage of blog images

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Multifamily Green Building Certification Program Comparison

If you’re designing and constructing multifamily buildings, chances are you’ve run into one of the many green building certification programs. Whether mandated by code, tax credits, your loan, or because you want to improve building performance, the differences between programs can be difficult to understand. One of the most frequent questions we help design teams answer is “which multifamily green building program should we choose?”

To help shed some light on the major green building standards, we’ve outlined some of the most important requirements for multifamily building performance that tend to differentiate the programs the most.

ENERGY STAR

Administered by the U.S. Environmental Protection Agency, ENERGY STAR is a free program that includes envelope, mechanical, and moisture management requirements. There are two pathways to certification – ENERGY STAR Certified Homes and ENERGY STAR Multifamily High-rise – based on the height of the building. In the near future these programs will merge into one Multifamily New Construction standard.

Although it isn’t considered a full green building program (it doesn’t address materials, site or water), ENERGY STAR is included in this comparison because several programs and standards reference it as a base requirement.

Energy Star comparison chart Read more