Document NNe3vkJ7vdJvqEmMvp5MoK6GR

.1954 Guide CHAPTER 20 476 Table 8. Determination of Free Area and Total Pressure Loss of Register for No Deflection of Air11-*>'*. ' Register Free Air in Square Inches {Upper value, in each group) Pressure Loss in Inches of Water Column (Lower value in each group) Distance prom Reqxstisr to Opposite Wall J Il9-21|2a-24|33-27128-80|31-84| 35-39 140-49 ( 80-59 |M9 ' l I || Distance prom Reoistss to Opposite Wall 380-419 -----------420-459 ------ ------460-499 119 0.02 149 0.02 171 0.02 * If register selected based on distance from register to oppor site wall is unsatisfactory on account of size or pressure loss, it is permissible to shift one or more spaces left or right in the tables to obtain a more suitable register. If requirements fall in blank space, select two registers in place of one and divide CFM capac ity between the two registers. b Total pressure (static plus velocity) loss is based on FLAT FACE ADJUSTABLE BAR TYPE and does NOT include stackhead. e Value? on the right of line A and A' should not be used in ap plications such as churches, auditoriums, and concert halls. d Values ori right of line B and B' should not be used in ap plication? such as residential work, motion picture theaters, court rooms and schools. 'For floor and baseboard registers where a velocity of ap proximately 300 FPM is used, the free area ~ --or ap proximately, Assume a pressure loss of .01, { Top nnv volume under 190 CFM use Table 7. 1460-1500 Forced Warm Air Systems 477. Table 9. Suggested Bonnet Pressure Inches of water Total CFM Through Any One Duct 800-1000 1000-1200 1200-1800 1800-2400 2400 to 3500 Suggested Bonnet Pressure In. Water 0.10 0.10 0.10 0.13 0.14 Total CFM Tbhouqh Any One Duct 3500 to 5000 5000 to 7500 7500 to 10,000 10,000 to 12,000 12,000 to 14,000 Suggested Bonnet Pressure In. Water 0.15 0.25 0.375 0.500 0.750 WARM AIR CEILING PANEL SYSTEMS Warm air ceiling panel heating systems utilize a false ceiling suspended 3)4 in. from the ceiling joists which have previously been covered on the bottom with sheets of plasterboard. Special hangers are used to suspend the false ceiling or heating panel from the joists. Steel supporting rods are installed through these hangers and metal lath is attached to the rods. The lath is then plastered to a thickness of M in., making a completely sealed air space above the-ceihng. Warm air is delivered' to this sealed spacethrough a standard warm air duct, installed in the usual manner: The air is then circulated over the entire ceiling being guided by sheet-metal baffles. After the air has passed over the ceiling' it is returned to the fur nace through a return air duct for reheating. The system is closed, and no air is introduced into the heated space from the panel. (See also Chapter 24, Panel Heating.) Because a warm air ceiling panel system involves a different type of ceiling construction, its installation is practically limited to new construc tion. Only automatically-fired and thermostatically-controlled furnaceblower units may be used with this system. The standard automatic heating controls consisting of a room thermostat, temperature limit con trol, blower control (fan switch), and primary control are all that are re quired. While warm air ceiling panel heating has particular advantages in one-story utility room houses, it can be just as effectively installed in one- and two-story houses with basements. Complete design and installation procedure is given8 in Manual 7-A of the National Warm Air Heating and Air Conditioning Association. WARM AIR PERIMETER SYSTEMS Perimeter heating is a method of heating residential and commercial buildings, with or without basements, in which warm air is (a) conveyed under the floor to warm the floor surface and (b) introduced into the rooms, preferably under the windows, at or near the floor, and delivered upward in diffused pattern blanketing the outside walls. The return air is collected through one or more grilles located high on the interior sidewalls or in the ceiling. Suggested procedures5 for the design and installation of warm air perimeter heating systems are given in Manuals 4 and 10 and in the ac companying work sheets10 of the National Warm Air Heating and Air Con ditioning Association. The furnace may be either the down-flow or the conventional up-flow type. For basement-less houses the down-flow type is preferred since it requires a minimum amount of floor area and ductwork, and eliminates