USE OM - JANUARY 2017
55
5.1.6
Interpretation and Application of the Data.
5.1.6.1
Sensible Capacity Energy Balance. B
SH
, the sensible capacity energy balance, is
defined as follows:
𝐵
𝑆𝐻
=
𝑞
𝑠𝑟𝑖
−𝑞
𝑡ℎ𝑖
𝑞
𝑠𝑟𝑖
∙ 100
K1
Where;
q
thi
= sensible capacity as calculated in ASHRAE Standard 37 (7.3.4.1)
If blower is not powered then
q
sri
is calculated as follows,
𝑞
𝑠𝑟𝑖
= 𝐸
ℎ
∙ 3.413
K2
If blower is powered then
q
sri
is calculated as follows,
𝑞
𝑠𝑟𝑖
= (𝐸
𝑖
+ 𝐸
ℎ
) ∙ 3.413
K3
5.1.6.2
Application of Code Tester Correction Factors.
Each nozzle combination selection
shall be evaluated per Section 5.1.4 with at least three (3) unique air flow rates with the indoor blower
off.
5.1.6.2.1
If the energy balance,
B
SH
, for each air flow rate tested with a given nozzle
combination is within ±2.0% then no nozzle combination air flow rate correction is
required.
C
nz
= 1
K4
Where;
C
nz
= nozzle correction factor
5.1.6.2.2
If the energy balance,
B
SH
, for each air flow rate tested with a given nozzle
combination falls between either -2.1% and -4.0% or +2.1% and +4.0% then a nozzle
combination air flow rate correction factor shall be assigned to that particular nozzle
combination in that particular Room.
5.1.6.2.2.1
If a first order trend line reasonably matches the data (R
2
≥ 0.5) and the slope is less than 0.0025 %/SCFM the correction shall be
a single value at the mean of the test heat balances.
C
nz
= 1 +
B
SH
/ 100
K5
Where;
C
nz
= nozzle correction factor
R
2
=
1-(SS
Residual
/SS
Total
)
SS = sum of the squares of the curve fit errors
5.1.6.2.2.2
If a first order trend line reasonably matches the data (R
2
≥ 0.5) and the slope is greater than 0.0025 %/SCFM the correction shall