Keeping Los Angeles Renters Cool

Transcript

Kelly Klima

Hello, my name is Kelly Klima, and I'm a researcher at RAND. My colleagues and I have been working to identify effective and feasible ways to keep Los Angeles renters cool and safe during hot weather without risking widespread power interruptions. As climate change intensifies, we expect to have more-frequent, severe, and prolonged heat waves. Extreme heat events can be dangerous and, in some cases, deadly, especially for older adults and young children. RAND has conducted policy research in this space, all aiming to help reduce the toll on human life.

In 2024, the Los Angeles County's Board of Supervisors worked to develop an ordinance that would establish a maximum indoor temperature for rental units to help reduce heat wave deaths. Officially, this ordinance would affect only renters living in the unincorporated parts of the county, but many hope that cities around the county would join as well. We considered what might happen when a generic policy goes into effect. The simplest way for a landlord to comply may be to provide some form of air conditioning, or AC. AC units already account for 60 to 70 percent of summertime peak electricity demand within residential buildings in Los Angeles County. And they use even more energy during extremely hot days.

If you live in California, you may have already received emergency notifications during heat waves asking you to reduce your power consumption to avoid power interruptions. If more ACs are added and nothing else changes, you would likely get even more of these warnings and possibly even the power interruptions.

Hye Min Park

That's where policy research comes in to help. Here at RAND, we asked how could a temperature threshold policy be designed to protect vulnerable populations but also minimize the strain on the power grid when power is needed most, such as during periods of extreme heat? Our projects evaluate how various cooling strategies affect peak and annual energy demand, indoor temperature, and implementation costs if the proposed ordinance is adopted.

Los Angeles County is the nation's largest county in terms of population, number of residential housing units, and area. If L.A. County adopts a temperature threshold, it would directly impact over 100,000 rental homes within the county's unincorporated areas. If every city in the county adopts the ordinance, it would apply to 1.9 million homes. Multifamily buildings in Los Angeles County have already been studied, so our research focused on single-family homes. There are over 400,000 single-family rental homes in the county. About 30 percent or 120,000 of them currently lack any cooling devices, while the rest have access to air conditioning for either the entire house or a room.

We evaluated a variety of active and passive cooling strategies. Active cooling mostly means air conditioners, and we consider different types and efficiencies of AC, such as window units, central AC, ductless mini-split systems, and heat pumps. Passive cooling includes modifying or designing a building with strategies such as better insulating windows, films on windows, or a reflective or well-insulated roof. We also considered different potential cooling conditions and requirements, such as cooling just one room instead of the entire house or just using different thermostat settings for the AC.

We used the U.S. Department of Energy's EnergyPlus model to run over 1,000 building energy simulations to explore the impacts of different cooling strategies and requirements on indoor temperatures and electricity use across seven different weather conditions. Among these, we included intense heat waves to really put this strategy to the test because our goal is to find cooling solutions that can handle severe heat conditions without putting too much strain on the power grid.

Sophia Charan

Our research shows some straightforward results and some surprising ones. If all single-family rental units in unincorporated areas and cities across the county were magically, instantaneously in compliance with the indoor temperature ordinance that is being developed, there would be a significant increase in peak energy demand during the extreme heat events.

Perhaps less magically, let's assume landlords simply choose what is quick, easy, and not particularly costly: buying a cheap AC unit. Unsurprisingly, we find window air conditioners to not be sufficient on the hottest day. So might a better AC be a better choice? We find that more-efficient air conditioners, as well as central ACs, heat pumps, and mini splits can provide the same level of comfort with much less energy and much less of a risk to the electric grid. We also find that a combination of passive cooling strategies through triple-paned windows, better insulation, and cool roofs can cut the peak and annual electricity use of a home in half. The combination of efficient AC and passive cooling would be much less likely to trigger those warning notices to your cell phone.

But we also need to think beyond heat waves. Once AC is adopted, it will be used for the life of the equipment, which is typically 15 to 20 years. Using a window unit to cool the entire home may be the cheapest upfront expense, but it could result in higher electricity bills for tenants in the long term, and it could produce more heat-trapping greenhouse gas emissions, which further warm the planet. Higher efficiency offers lower peak and annual energy demand, but it comes with a higher installation cost.

To help ensure that everyone can stay cool, we may need other strategies. Raising the thermostat is one option. However, since there's a lag between when the AC turns on and when the building cools down, moving the thermostat from 75 to 82 degrees Fahrenheit will cause more unsafe conditions. Perhaps more interestingly, we determined that cooling just one room instead of the entire home will not only save energy but also maintain lower indoor temperatures in that space during the worst extreme heat conditions we tested. Similarly, if some renters choose to voluntarily leave off their air conditioners, those most vulnerable could be more assured their AC will work. There might be other possibilities beyond what we studied, such as turning on fans or inviting people to visit a splash pad, pool, or cooling center.

Kelly Klima

To effectively address the threat of climate change and to protect our communities from extreme heat, we need a holistic approach and a near-term solution to keeping renters cool that is aligned with our long-term goals. An indoor temperature threshold policy should be designed to keep everyone safe without overwhelming the electricity grid, minimize greenhouse gas emissions, and be affordable to buy and operate. This is possible with strategies such as incentivizing passive cooling, being flexible on the space required to be cooled, adjusting the temperature set points based on the vulnerability of the tenants, and phasing in requirements so that solutions that are more-robust can be implemented and can reduce the risk of power outages.

Extreme heat events are dangerous and can be deadly, but if we take the appropriate steps, we can protect our communities from the worsening threats of climate change and keep them cool too.