FIGURE 12. |
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• When communicating with the outdoors through horizontal | FIGURE 13A. |
ducts, each opening shall have a minimum free area of |
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1 square inch per 2,000 BTU per hour (11 cm2/kW) of | Water Piping |
total input rating of all equipment in the enclosure. See | |
Figure 13. |
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• When ducts are used, they shall be of the same cross- |
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sectional area as the free area of the openings to which |
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they connect. The minimum short side dimension of |
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rectangular air ducts shall not be less than 3 inches |
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(76.2 mm). See Figure 13. |
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FIGURE 13.
•Louvers and Grilles: In calculating free area, consideration shall be given to the blocking effect of louvers, grilles or screens protecting openings. Screens used shall not be smaller than 1/4 inch (6.4 mm) mesh. If the free area through a design of louver or grille is known, it should be used in calculating the size opening required to provide the free area specifi ed. If the design and free area is not known, it may be assumed that wood louvers will be
•Special Conditions Created by Mechanical Exhausting or Fireplaces: operation of exhaust fans, ventilation systems, clothes dryers or fi replaces may create conditions requiring special attention to avoid unsatisfactory operation of installed gas utilization equipment.
•Alternatively, a single permanent opening may be used when communicating directly with the outdoors, or with spaces that freely communicate with the outdoors. The opening shall have a minimum free area of 1 square inch per 3,000 BTU per hour (8.3 cm²/kW) of total input rating of all equipment in the enclosure. See Figure 13A.
HOTTER WATER CAN SCALD:
Water heaters are intended to produce hot water. Water heated to a temperature which will satisfy space heating, clothes washing, dish washing, cleaning and other sanitizing needs can scald and permanently injure you upon contact. Some people are more likely to be permanently injured by hot water than others. These include the elderly, children, the infirm, or physically/mentally handicapped. If anyone using hot water in your home fits into one of these groups or if there is a local code or state law requiring a certain temperature water at the hot water tap, then you must take special precautions. In addition to using the lowest possible temperature setting that satisfies your hot water needs, a means such as a *mixing valve should be used at the hot water taps used by these people or at the water heater. Mixing valves are available at plumbing supply or hardware stores. See Figure 14. Valves for reducing point of use temperature by mixing cold and hot water are also available. Follow manufacturer’s instructions for installation of the valves. Before changing the factory setting on the thermostat, read the Temperature Regulation section in this manual.
FIGURE 14.
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