The warden shall manage the Connecticut Correctional Institution, Somers, subject to the direction of the Commissioner of Correction, and he shall keep all the prisoners employed in such labor as the commissioner orders, during the term of their imprisonment. He shall also keep a record of any punishment inflicted upon a prisoner, showing its cause, mode and degree, and a like record of the conduct of each prisoner. Any prisoner sentenced to a term of imprisonment prior to October 1, 1976, may, by good conduct and obedience to the rules of said institution, earn a commutation or diminution of his sentence, as follows: Sixty days for each year, and pro rata for a part of a year, of a sentence which is not for more than five years; and ninety days for the sixth and each subsequent year, and pro rata for a part of a year, and, in addition thereto, five days for each month as a meritorious time service award which may be granted in the discretion of the warden and the commissioner for exemplary conduct and meritorious achievement; provided any serious act of misconduct or insubordination or persistent refusal to conform to institution regulations occurring at any time during his confinement in said prison shall subject the prisoner, at the discretion of the warden and the commissioner, to the loss of all or any portion of the time earned. Said commutation of sentence shall apply to any prisoner transferred from the Connecticut Correctional Institution, Somers, to the John R. Manson Youth Institution, Cheshire. When any prisoner is held under more than one conviction, the several terms of imprisonment imposed thereunder shall be construed as one continuous term for the purpose of estimating the amount of commutation which he may earn under the provisions of this section. The commissioner may employ prisoners outside the institution walls, within the state, under the charge of some officer of the institution. He shall provide for the prisoners suitable food and clothing and suitable implements and materials for their work, and shall provide for the relief of any sick or infirm prisoner, and the cost thereof shall be paid by the state from funds appropriated and available for such purpose and, if the prisoner is hospitalized the cost thereof shall be paid as provided in § 18-52a. The warden shall superintend the labor and conduct of the prisoners, and, when requested, shall communicate to the commissioner any information in his knowledge respecting the prison.