The manager may appoint a board of citizens qualified to act in an advisory capacity to the head of any department or office. The members of any such board shall serve without compensation and it shall be their duty to consult and advise with the director or other officer, as the case may be, but not to direct the conduct of the department or office. Recommendations of any such board shall be in writing and shall become a part of the records of the department or office to which they relate. The head of the department or office for which an advisory board is appointed shall be chairman of all meetings thereof.