MENU

Party Walls

About

Hi, my name is Gayathri and I'm a Principal Mechanical Engineer and proud to represent the Residential Energy Group here at SWA! Our group provides a wide range of services, from designing buildings to meet a variety of green building standards to conducting building science research that enables us to tell YOU what works and what doesn't.

Posts by Gayathri Vijayakumar

The Making of the 2021 International Energy Conservation Code (IECC)

When I first started working at Steven Winter Associates, I didn’t know that one day I’d find myself involved in the development of codes and standards that impact how our buildings get built. I certainly don’t consider myself an expert, but I have learned a few things the hard way and thought they’d be worth sharing if you might be new to it.

So, here’s my very high-level summary of the code development process with respect to the 2021 International Energy Conservation Code (IECC), aka the “model” energy code. If you are looking for more detail, the ICC webpage has plenty of resources and a more detailed infographic than the one we’re showing and discussing here.

IECC Code Development Process Chart

(more…)

Call to Action: Voting Open Until December 6th on the Changes Proposed to the 2021 IECC

ICYMI: The code change proposals for the 2021 IECC are open for voting by Governmental Member Voting Representatives (GMVR) from Monday, November 18th through Friday, December 6th, and your vote is instrumental in making buildings consume less energy! [Need a quick refresher on the code process? Check out our blog post here!]

Does your vote even matter?

Overall, there are not actually that many voters on a given proposal. In the energy proposals, last cycle, it ranged from about 200-400 voters per proposal, even though there were a total of 1,247 voters on the Group B codes, which includes the IECC.

IECC voting numbers

So a small handful of voters can entirely shape the future of the energy codes that dictate how energy efficient our buildings will be! If history repeats itself, while some online voters tend to align with the Committee, many online voters align their votes with those cast by their fellow ICC voters at the Public Comment Hearings. This happened 81% of the time in 2016. Unlike 2016, in this cycle all the electronic votes cast during the Public Comment Hearings will be rolled into the online vote tally (although those voters can still change their vote).

(more…)

Electric Cars: Are They Better for Your Pocket and the Climate Right NOW?

Last week, I read a blog post from Connecticut Fund for the Environment President Curt Johnson, and he reaffirmed what I already expected: my next car will likely be an electric vehicle (EV). I currently drive a Toyota Prius hybrid, but when I bought it in 2013, the price to purchase and to operate an EV did not work out, so I chose the Prius, which has very reliably achieved 50 mpg over the last six years.

As an engineer who admittedly knows nothing about cars, I feel like the information out there on EVs is either slightly biased (i.e., published by EV manufacturers) or not transparent enough with the math to convince me. So I set out to create a blog post that was unbiased and transparent. I liked this one from Tom Murphy, an associate professor of physics at the University of California, San Diego, so hopefully I’m making it a bit more user-friendly and applicable to your current/local situation.

I just wanted to know two simple things (and admit to ignoring a long list of other factors that influence the type of car most people will choose to drive):

Number 1: At what gas price is an EV cheaper to drive per mile?

Number 2: While EV tailpipe emissions are zero, is my local electric grid clean enough that it’s a good idea, right NOW? I know my next car will be electric, I just don’t know WHEN the grid will be clean enough that it’s better for the environment for me to switch.

When I began writing this article, I had no idea what the answers would be.

(more…)

The Second Leading Cause of Lung Cancer May Not be What You Expect

National Public Health Week is this week and Today’s theme is “Environmental Health”, which includes protecting and maintaining a healthy indoor environment.

While National Radon Action Month was in January, we wanted to share how this specific indoor air pollutant can affect your health and what compelled a group of us here at SWA to get our homes tested (and remediated).

What is radon and why does it matter?

Map of EPA Radon Zones

EPA Map of Radon Zones

Radon gas is a naturally occurring byproduct of the radioactive decay of uranium found in some rock and soil. You can’t see, smell or taste radon, but it may be found in drinking water and indoor air. This carcinogenic gas is currently the second leading cause of lung cancer after smoking, according to the National Cancer Institute.

Although radon in drinking water is a concern, radon in soil under homes is the biggest source of radon, and presents the greatest risk to occupants. This pressure-driven mechanism occurs when radon escaping the soil encounters a negative pressure in the home relative to the soil. This pressure differential is caused by exhaust fans in kitchens, bathrooms and appliances, as well as rising warm air created by furnaces, ovens and stoves.

Radon levels can vary dramatically within a region, county, or city. However, the EPA recommends that all homes be tested, regardless of geographic location. To see what the average levels are in your area, check the EPA Radon Zones map.

What radon levels are accepted? Ideal?

(more…)

ENERGY STAR New Construction Certification Programs for Multifamily to be Combined

ENERGY STAR MF LogoCurrently, to receive ENERGY STAR® certification for multifamily new construction, you would get your certification through the ENERGY STAR Certified Homes program or the ENERGY STAR Multifamily High Rise program. This may change by early 2020. According to the Environmental Protection Agency (EPA) in a recent statement, multifamily will soon have a single program, rather than splitting them across the Certified Homes program and the Multifamily High Rise program.

“To better serve the multifamily sector, EPA is in the process of creating a single ENERGY STAR multifamily program by merging the current requirements and adopting the most appropriate from each.”

(more…)

Can you do a HERS Rating on an apartment in a 30-story building? Not now, but maybe in 2019!

ANSI/RESNET/ICC 301-2014 is the Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using an Energy Rating Index. It is the basis of the most common Energy Rating Index, RESNET’s HERS Index, which is utilized by utilities and building programs like LEED© and ENERGY STAR®, which require a consistent index to evaluate performance.

ANSI RESNET ICC 301-2014 imageOn March 2, 2018, RESNET released a draft of the 2019 version of ANSI/RESNET/ICC 301, where the most significant change will be the expansion of its scope to include Dwelling Units and Sleeping Units in ANY height building, whether that building is defined by IECC as “Residential” or “Commercial”. Other changes will include those developed by the RESNET Multifamily Sub-Committee, to better address shared systems like HVAC, hot water, solar PV, and laundry, and other scenarios specific to multifamily buildings that have largely been unaddressed until now.  The 1st preliminary draft standard of the 2019 version (dubbed PDS-01) includes these important improvements, along with all addenda to Standard ANSI/RESNET/ICC 301-2014 that were approved prior to March 2.

How Does the Revision Process Work?

The ANSI/RESNET/ICC Standards 301 (and 380) are under “continuous maintenance”. What does this mean? As revisions are needed to improve the standards, they are accomplished via “addenda”. Each addenda has to go through a “public comment” period to ensure that all stakeholders get to provide their opinions or objections to the proposed change before it becomes part of the standard. Rather than re-publishing a new edition of the standard each time a revision is approved, these standards are instead updated every 3 to 5 years to integrate any approved addenda into the body of the standard (instead of as separate addenda), along with any other necessary revisions into a new edition. This is similar to other standards like IECC, ASHRAE 62.2, or ASHRAE 90.1, which typically release a new version every 3 years. (more…)