Document O141BLGQy3dEvY4bp9Gd2Yg9v
208
CHAPTER 14
1959 Guide
Table 1 .... Column-Type Cast-Iron Radiator
Accepted Saiittg per Section*
NelgM In.
One Cobnut
Two Cotwran
Three Column
SqFt
Btuh
Sq Ft
Btuh
Sq Ft
Btuh
16 1H 360
IS 2H 540
20
360 2
480
22
2H 540 3
720
23
m 400 2X
560
28 2
480 2H
640 3H
900
32
2* 600 3H
800 4H 1080
38 3
720 4
960 5
1200
45 5 1200 6 1440
Few Cotamn
Fbre Column
Six Column
Sq Ft
Btuh
Sq Ft
Btuh
SqFt
Btuh
13
16
18 3
720.
20
22 4
960
26
5
1200
7
32 6H 1560
38 8 1920 - 10
45 10
2400
1120
1680 2400
3 5
720 900 1080 1200
. * These ratines ere based oa steam at 315 F sad sir at TO F. They apply only to installed radiator* exposed is a normal manner; not to radiators installed
enclosures, (riUcs, or under shelves. For Bta per boor ratines at other temperatures, divide table values by factors found in Table 7.
enclosure for the convector fit as snugly as possible so that the air passing through cannot bypass the heating element.
BASEBOARD UNITS
Baseboard heat-distributing units are divided into three types: (1) radiant, (2) radiant-convector, and (3) finnedtube.1
Radiant-type baseboard is made of cast iron or steel. This type of unit emits a large portion of its heat output by radia tion. Units are sometimes suspended from the ceiling in rooms having little or no available wall space for floor mounted units. As the convected heat obtained from these units when mounted at the ceiling is less than when they are mounted at floor level additional length must be added as recommended by the manufacturer to allow for the reduc tion.
Radiant-convector type baseboard also is made of cast iron or steel. The units are provided with air openings at the top and bottom to permit circulation of room air over the wall side of the unit. The wall side of the unit has ex tended surface to provide increased beat output. A large portion of the heat emitted is transferred by convection. This type of baseboard having a greater output per linear foot than the radiant type is particularly adaptable where wall space is at a premium or the beat loss of the room is high.
Finned-tube type of baseboard has a finned-tube heating element that is concealed by a long low sheet-metal enclo-
Toble 2 .... Large-Tube Cast-Iron Radiators
SccfMoerf, cestwreo, tufaufor-type redfotore of Che large-tube partem, |bet b,
baring tabes approximately
in. in dmneter, 2} in. on center*.
of Tube*
Catalog
Rating
Height
per Section*
Width
Section Center
teg Height* to Tapping
Sq Ft Btuh
In.
h.
In. In.
m 420 20 2 480 23 3 2H 560 28 3 720 32 3M 840 38
2M 4K 2H 4h 2h 4M 2H 4H
2H 4M
VX 540 20 2% 600 23 4 2H 660 26
840 32
1020 38
2H 4K 2M 4h 2H 4M 2M iX
2H 640 20 3 720 23 5 3H 840 26
1040 32 5 1200 38
8-8M.
2Hd 2hd 2W 2W
. 2hd
4M 4M
4H
3 720 20 3M 840 23 6 4 960 26 5 1200 32
6 1440 38
9-10X
2X 4H
2K 4H 2X 4H 2M 2K iX
2* 600 14 7 3 720 17
3H 880 20
2X 3 214 3 2H 3 or4M
* These ratine* ere baaed on steam at 315 F and atr at 70 F/They apply only to hmtalled radixtore expoeed in * normal manner; not to radiator* installed bohind enclosures, grilles, or under shdvra. For Bta per hour ratines at other tem peratures, divide table value* by (actor* found in Table 7.
b Maximum eoembly 60 Beetlens. Lencth. eqoal* number of wetwna timet 3H in.
* Where treater than ctandard let heights are required, this dimension shall be 6 in., except for 7-tobe section*, in height* from 13 to 30 in., indnaive, for which this dimension shall be 4H in. Btdat<w may be furnished without let*.
d For 5-tube hospital-type radiation. this dimension i* 3 in.
sure or cover. A major portion of the heat is transferred to the room by convection. The output varies over a wide range depending on the physical dimentions and the materials used. When selecting this type of baseboard the designer should avoid using a unit with too high an output per linear foot. Baseboard performs best when units are so selected that they are installed along as much of the exposed wall as possible.
The basic advantage of the baseboard heat-distributing unit is that its normal placement is along the cold walls and under areas where the greatest heat loss occurs. Other advantages claimed for the baseboard heat-distributing unit are: it is inconspicuous; it offers a minimum of interference with furniture placement; and it distributes the heat near the floor. This last characteristic reduces the floor-to-ceiling temperature gradient to about 2 to 4 F deg, and tends to produce uniform temperatures throughout the room. It also makes baseboard heat-distributing units adaptable to base mentless homes, where cold floors are prevalent.*
Radiators, Convectors, Baseboard and Finned-Tube Units
209
Table 3 .... Small-Tube Cast-Iron Radiators
Heat 1063 calculations for baseboard heating systems are the same as those used for other types of heat-distributing
units. The procedure for designing baseboard heating sys tems is given in / = B = R Installation Guide No. 5.* Rat
ings for baseboard heat-distributing units' are expressed in Btuh per linear foot.
FINNED-TUBE UNITS
A finned-tube heat-distributing unit is a room-air beater
composed of a finned-tube element fabricated from mutaHto
tube to whicb metallic fins have been bonded. It does not
include a fin-tube type baseboard element provided with an
enclosure for replacement of. the conventional baseboard.
The finned-tube unit can be used with either
or
hot water systems. It has advantages for installation where
it is desired to distribute the heat along the entire outside
wall and thereby prevent down drafts along the walls in
buildings such as schools, churches, hospitals, and factories.
Normal placement of finned tube is along the walls where
the heat loss is greatest. If necessary, the units can be in
stalled in two or three tiers along available wall space to
meet the heating requirements. For hot water system instal
Table 4 .... Cost-Iron Wall Radiators
Appn.^,1.
Heat Output*
Height
Length or Width -Thkknem
Sq Ft
Btuh
13H
. 13x 22
13X 29
22
13H 29 13tf
3 6M \ 1560 3 8 1920 3 8 1920 3 11 2640 3 11 2640
. There rttS* berad oa steam *i 315 P and air at 79 P. They apply only
to installed radiator* expoeed to norma] manner, not to radiator*
be
hind enclosure*, (rills, or under *helve*. Far Bta per hour rating* at other tem
perature* divide table values by factor* found ia Tabla 7.
Table 5 .... Heat Emission of Pipe Coils Placed Vertically on a Wall (Pipes Horizontal) Containing Steam at 215 F and Surrounded with Air at 70 F
Btu per linear foot of cod per haw tnof linear feet el pipe)
Size of Pipe
1 In.
IX ftt.
IX In.
Single row..................... Two......................... Four................................ Six.............................
Eight..................................... Ten............................... Twelve.........................
132 252
440 567 651 732 812
162 312 545 702 796 907 1005
185 348 616 793 907 1020 1135
lations where two or three tiers are required, a sinuous water flow through the heaters is recommended because a header connection with parallel flow may permit the water to short circuit along the path of least resistance.
Protection of the heating element may be provided by open-type grilles fabricated of expanded metal or perforated materials covering the top and front of the finned-tube element. Covers and enclosures are also available to enhance the appearance and to increase heating efficiency.
A cover is a fabricated shield having at least a portion of the front skirt made of solid material. It can be mounted on the finned-tube element so that there is clearance be tween the wall and the cover, and the rear of the finned-tube element is not completely enclosed. A cover may have a top, front, or inclined outlet.
An enclosure is a shield of solid material installed so that the finned-tube element is completely enclosed at both front'and rear. An enclosure may have an integral hack or may be installed tightly against the wall so that the wall itself forms the back. An enclosure may have a top, front, or inclined outlet.
Finned-tube units are available in four tube tiras from 1 in. to 2 in. IPS with various fin arrangements. The resis tance to the flow of water or steam is rather low so that a