2. High dusting to be rendered as needed.
D. WINDOW CLEANING
All exterior windows shall be washed on the inside and outside surfaces at frequency necessary to maintain a first class appearance.
A. Heating, ventilating and air conditioning equipment will be provided with sufficient capacity to accommodate a maximum population density of one (1) person per one hundred fifty (150) square feet of useable floor area served, and a combined lighting and standard electrical load of 3.0 watts per square foot of useable floor area. In the event Tenant introduces into the Premises personnel or equipment which overloads the systems ability to adequately perform its proper functions, Landlord shall so notify Tenant in writing and supplementary system(s) may be required and installed by Landlord at Tenants expense, if within fifteen (15) days Tenant has not modified its use so as not to cause such overload.
Operating criteria of the basic system are in accordance with the Massachusetts Energy Code and shall not be less than the following:
(i) Cooling season indoor temperatures of not in excess of 73 -79 degrees Fahrenheit when outdoor temperatures are 91 degrees Fahrenheit ambient.
(ii) Heating season minimum room temperature of 68 - 75 degrees Fahrenheit when outdoor temperatures are 6 degrees Fahrenheit ambient.
B. Landlord shall provide heating, ventilating and air conditioning as normal seasonal changes may require during the hours of 8:00 a.m. to 6:00 p.m., Monday through Friday (legal holidays in all cases excepted).
If Tenant shall require air conditioning (during the air conditioning season) or heating or ventilating during any other time period, Landlord shall use landlords best efforts to furnish such services for the area or areas specified by written request of Tenant delivered to the Building Superintendent or the Landlord before 3:00 p.m. of the business day preceding the extra usage. Landlord shall charge Tenant for such extra-hours usage at reasonable rates customary for first-class office buildings in the Boston Suburban market, and Tenant shall pay Landlord, as additional rent, upon receipt of billing therefor.