Masonry Magazine January 1981 Page.20
PROJECTED HEADERS
# TYPICAL
# VENT
# COURSING
# MASONRY THERMAL STORAGE WALL
# COLLECTOR GLASS
# DIRECT GAIN
# 6 MIN.
# INSULATED
# CAVITY
# WALL
Locating Vents
FIG. 7
installed, if n' is less than n, plus 0.70. If the value of n' is greater than or equal to n, plus 0.70, the next larger whole number would typically be used as the number of sets of vents to be installed.
Both the vertical and horizontal spacing of vents will also affect performance. Top vents should be located as close to the ceiling as possible and the bottom vents as close to the floor as possible. The vertical distance between top and bottom vents should be at least 6 ft for full story height vented thermal storage walls.
The horizontal spacing of vents, s., may be determined by using Equation 2.
s=1/n,
(2)
Example. A 25-ft long vented thermal storage wall system 8 ft high is expected to supply about 35% of a building's heating load, SSF 0.35. Vent openings are formed by omitting one and one-half courses of standard modular brick vertically and two standard modular brick horizontally as shown in Fig. 7. Thus, the opening has a height of about 4 in. and a length of about 16 in. The dimensions of the vent opening satisfy the criteria of the length being approximately 4 times the height and the area being approximately 64 sq in. If other size brick are used, the courses and number of brick omitted to meet the area and height-to-length requirements of the vent opening will vary.
Using Equation 1, and F, 1.58 from Table 1 for a solar savings fraction of 0.35, the approximate number of vents would be:
n' 1.58 (25 × 8)/(16×4)
n,' = 4.94
Thus, n, is 5 sets of vents to be installed.
The horizontal spacing of vents may be approximated by using Equation 2.
s, 25/55 ft
The result is that the 25 ft long vented thermal storage wall should have 5 sets of top and bottom vents, each having an opening of approximately 64 sq in.. spaced horizontally at 5 ft o.c.
ATTACHED SUNSPACES
The typical details for direct gain thermal storage and thermal storage walls may be used for attached sunspaces with only modifications to the glazing details. Depending on the type of attached sunspace, the