NPFC - OO-A-373

AIR CONDITIONERS, SINGLE PACKAGE TYPE

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Organization:	NPFC
Publication Date:	27 May 1998
Status:	active
Page Count:	22

scope:

This specification covers space air conditioners, single package type units (referred to herein as "unit") consisting of an air-or water-cooled condensing assembly and means for simultaneous air circulation, ventilation, air cleaning, cooling, and dehumidification.

The units covered by this specification are classified by the following types, styles, classes and capacity, arrangement, and mountings, as specified (see 6.2):

Type SP-A - Single-package air-conditioner, air-cooled. Type SP-W - Single-package air-conditioner, water-cooled. Type SPY-A - Year-round single-package air-conditioner, air-cooled. Style A - Units with discharge plenum and grilles. Style B - Units with connections for duct-work.

Beneficial comments, recommendations, additions, deletions, clarifications, etc. and any data which may improve this document should be sent to: Commanding Officer (Code 15E2), Naval Construction-Battalion Center, 1000 23rd Avenue, Port Hueneme, CA 93043-4301, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

Class 1 - Cooling capacity up to 65,000 British thermal units per hour (Btu/hr) (19 050 watt (W)). Class 2 - Cooling capacity between 65,000 and 135,000 Btu/hr (19 050 and 39 565 W). Class 3 - Cooling capacity between 135,000 and 1,260,000 Btu/hr (39 565 and 369 270 W). Arrangement - Indoor or outdoor. Mounting - Vertical or horizontal, roof, floor, slab or ground, or other.

intended Use:

The units covered by this specification are single package type designed for a large office space or space consisting of several rooms with cooling capacity range from 1 ton to 75 tons. A general... View More

Type SP-A units are generally specified where condenser cooling water and drain facilities are not available.

Type SP-W units can be used in areas where there is a cooling tower or readily available water supply and drain facilities.

Type SPY-A units can be specified when heating of the office space to be conditioned is required. Where no water, gas, electricity or steam is available for heating, the appropriate type of heating coil or heat exchanger can be specified. Steam and hot water heating on outdoor rooftop-mounted units are usually available in sizes 20 to 75 tons. Larger models and small models are usually available in gas or electric heat only. Indoor vertical self-contained units are usually available in 3 to 80 tons cooling capacity and have provisions for electric, steam, or hot water heating but not gas heating. For steam and hot water coils, the following information should be supplied:

a. Velocity of air across coil face, feet per minute (ft/min) (metre per second (m/s) standard air.

b. Entering the dry-bulb temperature, °F (°C).

c. Water velocity range, ft/min (m/s) - hot water coil.

d. Entering water temperature, °F (°C), - hot water coil.

e. Steam pressure at coil, inlet, psi (kPa) - steam coil.

f. Maximum superheat in steam at coil inlet °F (°C), - steam coil.

Style A units can be specified where the conditioner can be discharged directly into the conditioned space. To accomplish this, the unit must be located either within the conditioned space, adjacent to the space, or on the roof over the space.

Style B units can be specified where duct work is necessary to supply the cooled air conditioned space. The unit is usually located outside the conditioned space and duct work is required to deliver the cooled air to the conditioned space, or where the unit is located in a conditioned space and connected to other spaces by duct work.

Many applications of unitary units require ratings under conditions other than standard rating conditions of ARI 360 (see 3.5.1.5 and 6.9). The following information of table I should be supplied by the acquisition authority to the contractor as indicated by the "X" in the applicable blocks.

Indoor unit components made of ferrous metals located in marine atmosphere should withstand 125 hours of 100 percent relative humidity per ASTM D 2247. Outdoor components made of ferrous and nonferrous metals located in marine atmosphere should withstand 125 hours and in severe marine atmosphere 500 hours of salt per ASTM B 117 (see 3.12.1 and 3.12.2).

All units rated less than 65,000 Btu/hr (19 050 W) with air cooled condenser and three phase power unit input, the SEER applies and the minimum should be not less than 9.7. Other units within the scope of this specification, the EER applies and the minimum EER should be not less than 10.0.

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