The U.S. Food and Drug Administration is conducting market research for the potential future replacement of air handling units in Buildings 5B, 26, and 53C on the Jefferson Lab Campus. The place of performance is the National Center for Toxicological Research in Jefferson, Arkansas. If a contract arises, the period of performance would be 48 months after notice to proceed, with an estimated project magnitude of $25-$32 million. This is a sources sought announcement to identify capable businesses, including small businesses under NAICS code 236220, and is not a solicitation. Interested parties are encouraged to submit detailed capability statements.