California Residential Methane Emissions Characterization (CARMEC) Study
Lawrence Berkeley National Laboratory (LBNL) is leading a field study to gather data on methane emissions from natural gas appliances and distribution systems in California homes. Richard Heath & Associates, Inc. (RHA, now part of Resource Innovations) and other organizations are working with LBNL to recruit homes and conduct measurements for this research study.
In Spring 2025, we partnered with Self-Help Home Improvement Project (SHIPP) and Merced County Community Action Agency (MCCAA) to collect data from homes in the Redding and Merced areas. We thank the organizations and the people who participated and welcomed us into their homes.
Who is funding this study?
This research study is funded by the California Energy Commission (CEC).
Who can participate?
We are looking for households living in single-story houses with two or more residents that meet these criteria:
- Located in the Inland Empire, California.
- Have at least three gas appliances within the building structure, such as a furnace, a water heater, a cooktop (or stove/range), a gas fireplace, a clothes dryer, and others.
- One of the following: (a) or (b) or (c)
(a) Have at least one of the following gas appliances:
- Gas cooktop (or stove/range) with pilot lights
- Gas wall furnace that is direct vent (through the wall)
- Gas tankless water heater
- Indoor gas fireplace that is direct vent (through the wall)
- Outdoor fireplace or fire pit connected to a gas line
- Outdoor grill connected to a gas line (NOT a propane tank)
- Gas-powered heater for a pool or spa (hot tub)
(b) House is located in a SB 535 designated disadvantaged community.
(c) Household is self-report to qualify for low-income services or subsidies.
Our study is limited to single-story houses only. We may expand to include other types of homes (apartments, for example) and in other parts of California in future phases of our project.
How long does this take?
Full participation may involve three visits to your home.
Screening Visit: A 30-minute visit for a field staff to confirm that your home and gas appliances meet study requirements. Field staff will collect information and take photos.
Methane Measurement Visit: A 4-hour visit for two field technicians to visit your home to measure methane emissions from individual gas appliances and from your whole house.
Device Pickup: A 20-minute visit for a field staff member to return to your home to retrieve monitoring devices used to measure appliance usage, if selected.
All visits will be scheduled with you and will occur from Monday to Friday, 8 am to 6 pm. A responsible person who is 18 years or older must be present for each visit.
Are there any other requirements?
The person who receives us at the house must either be either the head of household, someone who owns or rents the property, or be at least 18 years old and authorized by the head of household to sign a consent form. It is also important that someone at the house during the visit knows how to operate the gas appliances.
What will we measure?
During the methane measurement visit, our field team will operate your gas appliances and measure methane (CH4) and carbon dioxide (CO2) concentrations using a gas analyzer. They will take photos and collect information about the gas appliances being measured.
In addition, they will install a large fan in an exterior doorway and blow air out of your house to measure how much methane is emitted inside.
Small monitoring devices will be used to record the usage of gas appliances for about 2 months. You will also be asked questions about how you use your gas appliances in your home and provide some basic information about your household.
Why measure methane?
Methane is an important greenhouse gas, but its sources are not well understood. This project aims to collect data to understand better the contributions from gas appliances and distribution systems in homes.
How will we use your data?
LBNL researchers will use data measured by the gas analyzer to calculate methane emissions from gas appliances when they are in use and when they are idle. Your data will be combined with other measurements collected from homes in California to estimate the contribution to our state's greenhouse gas emissions.
What will I learn from participating?
We plan to publish our analysis of de-identified results from this field study in 2026. You will not receive an individualized report from the measurements.
In the rare event (<1 in 1000 homes) that RHA finds an unsafe condition related to your gas appliances, RHA will notify you about the condition and advise you on actions to take. If necessary, RHA may call the gas company for assistance. For renters, this may also involve contacting the property owner as a standard practice of RHA.
What do I get for participating?
Study participants will receive a $20 gift card for completing the screening visit and a $80 gift card for completing the methane measurement visit.
In some cases, study participants may receive an additional $50 gift card for completing about 2 months of monitoring their gas appliance usage, if selected. A 20-minute visit by a field staff to retrieve the monitoring device is required.
IMPORTANT NOTICE: This incentive is NOT available to LBNL employees or federal employees. Participants are asked to let the research team know whether they are eligible to receive the study incentive or not.
Will others know that I participated?
Published results will only include general information about participating homes and their gas appliances, which are factored into the emission estimates. We will not disclose identifiable information, such as your name or contact information, to anyone.
While our field team will take photos for documentation, any identifying features will be removed from your images if they are used in publications.
Who can I contact to sign up?
Email us at [email protected], or call us at (833) 890-8100 to sign up.
