Most of the homes are older and many lack central air conditioning. Families sometimes cluster in one room with a window AC unit.
Rodriguez, 63, and his wife, Laura, lived in those conditions for more than 40 years in their home, which is near Lanier High School.
They are currently taking part in a study led by University of Texas at San Antonio researchers to collect data from homes in parts of San Antonio that are designated as heat islands.
The pilot project, which has been going on for more than three years, is being conducted by UTSA's urban heat island research team in partnership with the Historic West Side Neighborhood Association.
The research team is using digital twin technology — essentially, creating a digital replica of physical homes — along with artificial intelligence models to study potential renovation options that could lessen heat's effects on residents in the homes. The researchers also provide the residents taking part in the study with data captured by sensors and tailored to help them cool their home during extreme heat days.
The UTSA team is led by Esteban López Ochoa, associate professor of urban and regional planning. The project, which is being funded by a $700 grant from the National Science Foundation, is focused on creating digital twins for 10 homes, López Ochoa said. The team leader said the fast-paced project has an one-year turnaround and reports and videos of the work will be available by the end of October 2026.
"The goal is to understand the space and have a safe virtual reality type of situation for us to assess the house conditions and devise the best path of action to retrofit and improve the home quality, so we can improve urban thermal comfort for the residents there" López Ochoa said. "We have a big problem brewing here. We have homes in this neighborhood that are spending $400 in utility bills."
Rodriguez's home is one of 10 residents outfitted with air quality sensors that track dew readings, air quality and temperature. A UTSA student team member installed sensors that resemble a car's oil filter on his front porch and in his living room. López Ochoa said they educate residents about what each color means and how to see the room temperature on the sensor's app that replaces a thermostat.
Rodriguez learned the sensors change colors when the temperature rose in the home. The inside sensor glowed red when his wife turned the stove on, indicating heat and volatile organic compounds in the air. Rodriguez checked the outdoor sensor for a green glow first, a sign that it was OK to open windows and the door to let in cool air. Not long after, the inside detector flashed green for good air quality.
Rodriguez said he and his wife have seen a big difference in the temperatures in their one-story home since joining the program. Rodriguez learned about the city's cooling initiative when a volunteer left a flyer at his gate. After he was approved for the city-run program for lower income residents, workers made a series of improvements: planting trees for shade, replacing a metal roof with shingles, and installing an air conditioning/heating unit and ceiling fans.
"I recommend this (program)," Rodriguez said. "Because here in the neighborhood, there's a lot of people that need help, especially older ones like me."
URBAN HEAT ISLANDS
The area on San Antonio's West Side is considered an urban heat island, defined by the U.S. Environmental Protection Agency as an urbanized area that experiences higher temperatures than rural areas due to a high concentration of buildings and other infrastructure that absorbs and re-emits the sun's heat and the lack of green space.
According to Climate Central, 88 percent of the city's population live in urban heat islands. Two years ago, the city worked with UTSA's Sustainable Pervasive Urban Resilience Center led by Kristen Brown, assistant professor in civil and environmental engineering and construction management. The data collected was used to assess which areas are most affected by extreme heat.
In 2023, the hottest summer on record, the city of San Antonio reported 835 heat-related illnesses. The next year the number decreased to 571. As of Sept. 20, the city has reported 432 heat-related illnesses this year. Incorporating technology into heat research gives the cooling program another resource, said Leslie Antunez, senior municipal sustainability manager with the city's office of sustainability.
Antunez said city officials know heat affects different parts of town in different ways, but it was important to take that base level information and confirm the data. A heat equity map was the first step in giving every neighborhood a score: The higher on the scale, the more vulnerable an area could be to heat. After the top 10 communities were identified, the team narrowed the scope and broke down what could be done within budgetary constraints. The list was comprised of two neighborhoods in City Council District 5, one in council District 2 and one in council District 3, west of the missions.
The findings resulted in a coordinated approach from the city that included the Cool Neighborhood Program, where the city partnered with the neighborhood housing department, the cool pavement projects with public works and the parks and recreation department that serves as tree stewards to plant trees at homes in need of shade.
She said collaborating with the "highly knowledgeable and experienced" team offers new and different strategies.
"That's one of the exciting parts of our partnership with UTSA," Antunez said. "This is what things could look like if we made these changes. We want to continue to collaborate. This is something we know will take time. Every day is progress."
A PROBLEM ALL ACROSS TEXAS
Farzad Hashemi, a UTSA assistant professor of architecture who is on the heat research team, said each house being studied is unique and will need a specific strategy to be paired with available resources. He said residents talked about being used to having heat related illnesses during the summer.
"We cannot normalize people having heat strokes because they cannot have access to better housing conditions," Hashemi said. "If we fix this problem of housing conditions, these dimensions are going to get fixed too."
Extreme heat is a problem throughout Texas, López Ochoa said. The issue stretches to the South, in the Rio Grande Valley and colonias, low-income communities in unincorporated areas on the Mexican border.
"This goes beyond San Antonio," López Ochoa said. "There's collaboration being done across the UT system. We've submitted a National Institute of Health grant proposal to look at extreme heat impacts on youth and housing conditions in the Valley. It is such a prevalent issue."
He said the neighborhood association was instrumental in connecting the team with residents to understand their housing deficiencies. López Ochoa said the team has assessed almost 600 homes in need of improvements. The team and the association developed a housing conditions inventory survey that provided data to the city about homes in need of updates.
"We're one of the cities that have implemented this approach very successfully," López Ochoa said.
Leticia Sanchez, co-chair of the Historic Westside Residents Association, said the hope is that the city and partners will use the analyzed data to help people be healthy in their homes and reduce utility costs. She said UTSA's technology will allow residents to see the best approach to making renovations.
"It's not just going to be somebody does something to their homes," Sanchez said. "They're definitely going to be involved in all of the learning and decision-making."
© 2025 the San Antonio Express-News. Distributed by Tribune Content Agency, LLC.
