CARMEC Study
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.
The CARMEC study is currently focusing on outdoor gas appliances and equipment, including grills, pool and spa heaters, outdoor fireplaces, and fire pits. As available, we would also like to measure methane emissions from tankless water heaters and indoor fireplaces that have vents accessible from the ground level.
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 currently looking for homes that meet these criteria:
- Located in the Greater Sacramento Area or the San Francisco Bay Area.
- Have two of the following:
(a) Outdoor grill connected to a natural gas line (NOT a propane tank) that is in regular use, such as twice per week
(b) Gas-powered heater for a pool or spa (hot tub) that gets used
(c) Any of the following gas appliances:
- Outdoor fireplace or fire pit that gets used
- Indoor fireplace that vents through the wall (NOT roof)
- A tankless water heater that vents at ground level
How long does this take?
Full participation may involve two visits to your home.
Methane Measurement Visit: A 3-hour visit for two field technicians to measure methane emissions from at least two of the gas appliances noted above and to set up devices to record their usage. In addition, the field team may also measure methane from your gas meter assembly.
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, 8:00 am to 6:00 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.
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 $60 gift card for completing the methane measurement visit.
If selected, they will receive an additional $50 gift card for completing about 2 months of monitoring their gas appliance usage.
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?
You can enter your information below, email us at [email protected], or call us at (833) 890-8100 to sign up.