Michael Albert Lenzi, 42, the information manager of the solar heating and cooling demonstration program at the Department of Housing and Urban Development, died Thursday at Johns Hopkins Hospital in Baltimore. He had a viral infection of the heart.

Mr. Lenzi joined HUD in 1976 as the information director of its solar program. He is credited with organizing its National Solar Heating and Cooling Information Center, which includes traveling exhibits and mail and telephone operations. The center is a main source of information concerning solar heating and cooling in the United States.

Mr. Lenzi was born in Brooklyn. He graduated from Buckness University in 1959 and moved to Washington in 1961.

His career here was in public relations and information and he worked in both the public and private sectors. He worked first for the Internal Revenue Service and then for the Federal Aviation Administration.

He was employed by a private public relations firm in 1962 and 1963 and then joined the Army Times Publishing Co., where he was managing editor of the Military Market Magazine.

In 1965, Mr. Lenzi joined the Journal of Home Building of the National Association of Home Builders. He later worked as a free-lance photographer and writer and spent three years working for a public relations and advertising firm. In the early 1970s, he returned to the home builders association as its director of industry promotion. He worked for a real estate firm in Tarpon Springs, Fla., before joining HUD in 1976.

Mr. Lenzi's marriage to his wife, Sarah, ended in divorce.

Survivors include two children, Lisa, of Boulder, Colo., and Michael, of Washington.