Nearly a quarter of the nitrogen oxide pollution in the state stems from fossil fuel-burning furnaces and water heaters — eight times more than the state’s power plants, according to a report released Wednesday by Connecticut environmental groups who are advocating for zero-pollution air quality standards for heating, ventilation and air conditioning.

The report, authored by Save the Sound, Conservation Law Foundation, Sierra Club Connecticut and the Rocky Mountain Institute, encourages homeowners to swap their fossil fuel-burning systems for electric heat pumps and calls on policymakers to mandate that all furnaces and water heaters sold in the state after 2030 must be pollution-free.

“Buying a new fossil fuel HVAC or water heater instead of buying a heat pump would be like choosing dial-up internet when you could be using wifi,” Leah Louis-Prescott of the RMI Carbon-Free Buildings team, said. “It’s time to upgrade.”

While environmentalists lead the push for electric heat pumps, leaders in the state’s HVAC industry caution that a statewide ban on fossil fuel heating options may not be in the best interest of consumers.

The report, titled “Connecticut’s Hidden Air Pollution Problem: Fossil Fuels in Buildings,” found that homes and businesses emit approximately 30% of the state’s greenhouse gasses and 23% of the state’s nitrogen oxide pollution, creating a “significant barrier” to meeting state climate targets and federal air quality standards.

Nitrogen oxide is a precursor to ozone — a molecule crucial to shielding the earth from ultraviolet radiation high up in the stratosphere. But on the ground level, ozone pollution is linked to adverse health outcomes, including respiratory disease and infection, cardiovascular harm and even premature death.

“Connecticut has been failing to meet federal limits for ozone for many years,” Louis-Prescott said. “That essentially means that Connecticut residents are breathing unhealthy levels.”

“We’re talking about a major cost to residents’ health,” Louis-Prescott added. “(To) put into perspective the magnitude here, in 2017, in Connecticut alone, fossil fuel equipment in buildings caused (an estimated) 116 premature deaths that year, according to (an RMI analysis based on a model produced by) Harvard researchers.”

The report said the health risks disproportionately impact communities of color, stating that “The city of New Haven, for example, which has a population of roughly 60% people of color, routinely experiences ozone levels so high that it received an ‘F’ grade for ozone in the American Lung Association’s 2023 State of the Air report.”

Louis-Prescott said that further analysis estimates the cost of building pollution on human health at $520 million annually — a cost that Connecticut could avoid.

“We are living with these fossil fuel polluters in our homes and in our workplaces, and they’re contributing to the ozone and outdoor air pollution in Connecticut, they’re contributing to health impacts for residents, and they’re contributing to climate change in a really significant way, and we don’t need to live with these appliances,” Louis-Prescott said. “We have the opportunity to upgrade to superior non-polluting electric heat pumps instead, and Connecticut policymakers can help us do that.”

Charles Rothenberger, a climate and energy attorney for Save the Sound, said that while the Connecticut Department of Energy and Environmental Protection is developing the state’s Comprehensive Energy Strategy there is a “real opportunity” to improve the efficiency and reliability of residential energy systems while reducing pollution.

The report calls for DEEP to use the state’s Comprehensive Energy Strategy to develop zero-pollution air quality standards for HVACs and water heaters and mandate that all furnaces and water heaters sold in Connecticut in or after 2030 are pollution-free. The report’s authors said the goal is to facilitate a gradual shift to cleaner heat systems.

Jennifer Jennings, the executive director of the Connecticut Heating and Cooling Contractors Association, said she is cautious of a statewide mandate.

While the CHCC is a fuel-neutral association that does not promote one fuel source over another, Jennings said she “certainly caution(s) people anytime you’re sending the masses in one direction.”

“We really want to see a lot more renewables. I think the direction of the industry collectively from manufacturers is going in that direction anyway. But when you apply a mandate that’s going to come down from the state, (which is) interest group driven, I think you have to caution that,” Jennings said.

One of Jennings’ concerns is how residents will continue to heat their homes during power outages or grid failures.

“When you look at creating massive use of electricity, you have to stop and say ‘What happens when that energy source fails?’ ” Jennings said. “Look at California, look at Texas. It’s not that this hasn’t happened already, (with) other states (having) problems or overburdening the grid.”

Jennings said that while electric heat pumps, specifically ductless systems, are “a wonderful option” and “have come leaps and bounds in terms of technology,” they are not viable for all homes.

“Every application here in Connecticut is very unique. We’ve got some homes that are several hundreds of years old, and contractors going to work with them to make sure the cleanest, most efficient, cost-saving options (are) available for them,” Jennings said.

Jennings said that all heating systems, regardless of the fuel source, are regulated through state, federal, industry and ASHRAE standards. She also pointed out that “electric” doesn’t always mean “clean.”

“It’s paramount that champions of any fuel regulations understand how electricity is actually produced,” Jennings said. “When you look at the power grid and you understand how power is created, it’s less than 7% here in Connecticut that’s actually renewable. Greater than 50% comes from natural gas. So even as we push people to be on, say, ductless heat pumps, as this (report) talks a lot about, where are you getting your supply from?”

Jennings emphasized how fuel trends fluctuate based on energy costs and state rebate initiatives. If the state continues to push for system conversions or mandates electric heat pumps, Jennings said she is concerned about how the current contractor shortage and other workforce challenges will meet the demand.

According to the report, 85% of Connecticut homes use heaters that burn fossil fuels.

While getting these residences to convert to electric heat pumps may seem like a mammoth undertaking, Rothenberger looks to Maine’s transition as an example of successful policy in action.

“They have surpassed their target of installing 100,000 heat pumps across the state two years early, and have doubled down on their target to install 175,000 more by 2027 — and this is in a state with only about 600,000 homes,” Rothenberger said. “Clearly it’s getting consumer acceptance.”

When asked to comment on the report’s calls for a 2030 pollution-free mandate, DEEP said in a statement that the agency is “grateful that advocates are analyzing and proposing solutions to address the state’s public health and air pollution challenges and welcome the opportunity to evaluate how we might implement solutions in partnership with the legislature.”

“The impacts of climate change here in Connecticut have been deeply felt this summer, as recently as last week, from destructive rains and extreme flooding, to extreme heat and wildfire smoke,” DEEP Media Relations Manager Paul Copleman said.

“To achieve Connecticut’s climate goals of reducing statewide emissions 45% by 2030 and 80% by 2050, relative to a 2001 baseline, homes and businesses must significantly reduce emissions in a manner that helps manage costs for communities with the highest energy burdens and poor health impacts.”

Copleman said that DEEP already has an energy efficiency and demand management investment plan, programs for homeowners to minimize energy-related costs and fuel usage, and efforts to address “barriers, such as mold and asbestos that inhibit the completion of residential weatherization and energy efficiency measures, and further clean energy deployment.”

“We have a number of initiatives in place, but need to do more,” Copleman said.

Rothenberger said environmental advocacy groups plan to work with the state legislature to develop specific standards and incentives for updated heating systems.

“I think the timing is particularly apt not only because we’re in the middle of that (DEEP) Comprehensive Energy Strategy planning process, but also because of the unprecedented amount of funding that’s available to help households and businesses with this transition,” Rothenberger said.

Residents can receive up to $15,000 in combined incentives from Energize Connecticut for converting to electric heat pumps. By 2024, federal incentives will provide up to $8,000 in rebates to low-income homeowners who install electric air-source heat pumps, according to a press release announcing the new report.

The report also found that Connecticut households could save 35% on their heating bill by transitioning to an electric heat pump and another 10% by switching to a heat pump water heater.

Rothenberger said that educating residents on the benefits is key.

“Highlighting the opportunities around replacing those equipment with cleaner, less polluting options, is really critical so that people know that there are alternatives and they’re not just automatically thinking, ‘Well, I just want to replace this (fossil-fuel) furnace or this heater with whatever the newest model is,’ ” Rothenberger said. “Consumers can actually do good for the environment while also doing good for their household budget.”