 |
|||
|
|
|||
|
|
|||
| ||||||||||
|
|  MIL-B-62152A(AT)
3.5.10.1 Heater. The main system shall provide filtered, fresh, and recirculated airflow
through a common duct system. The duct system shall disperse air through louvered vents below
the sash of all side windows or through fin tube ducting installed at the ceiling center or at the
junction of the floor and both side walls, and extending the entire length of the bus passenger
area. A dash system shall furnish heat in the area of the driver, windshield, and door.
Engine-coolant hot water type heater(s) shall be provided. The capacity of the heating system
shall maintain the inside bus temperature at a minimum of plus 70F, midway between floor and
ceiling, in ambient outside air of minus l0F, with no passengers inside and air control at
100 percent recirculation. The temperature gradient between floor and ceiling shall not exceed
10F. Blower capacities shall provide a ventilating airflow of at least 1200 cubic feet per minute
(cfm). The system shall be provided with thermostatic controls. The system shall also be capable
of providing 20 percent fresh air and 80 percent recirculated air or 100 percent recirculated air
with controls for proportioning the amount of fresh air from 0 to 20 percent.
*
3.5.10.2 Defroster. Defroster outlets with suitable connections and independent
blower(s) shall be furnished. The independent blower(s) shall have a rating of not less than
250 cfm, and shall be installed to provide a flow of heated air to the full windshield at not less
than 30,000 British thermal units (Btu) per hour. An adjustable auxiliary fan shall be provided on
top of the dash with a guard. The windshield defrosting system shall conform to SAE J381 and
SAE J382.
3.5.10.3 Ventilator. A manual, adjustable, flow-type ventilator opening shall be provided
at the front of the bus. The outside openings for heaters and ventilators shall be so located as to
minimize entry of fumes, road dust, rain, or road wash and shall be covered in such a way as to
prevent clogging in bad weather.
*
3.5.10.4 Air conditioning. The vehicle shall be equipped with the manufacturer's
standard air conditioning system. The manufacturer shall furnish to the engineering department
of the procuring activity the rated capacity at the specified conditions of the entire unit, either by
air measurement or the flow meter method. The air conditioner shall have a cooling capacity of
not less than 72,000 Btu per hour and shall be capable of maintaining not more than 80F dry
bulb and a 68F wet bulb temperature and an effective temperature of 74F inside the bus when
the ambient temperature is 95F dry bulb. The humidity shall be not less than 30 percent and not
more than 60 percent. Inside temperature shall be measured midway between floor and ceiling at
the front, middle, and rear seats with no passengers in bus and not more than 6F wet bulb
30
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals