Installation; 15-1.How To Calculate The Necessary Heating Capacity - Mitsubishi Electric City Multi PWFY-P36NMU-E-BU Data Book

15. INSTALLATION

15-1. How to calculate the necessary heating capacity
15. INSTALLATION
Heating capacity calculation (Unit: °F/BTU/G)
A. For Air conditioning using such as Panel Heaters, Floor Heating and Fan coil units
Required total heating capacity
Safety factor;
B. For Sanitary use such as Shower and Bathrooms
Conditions
Tank inlet water Temp.;
Tank outlet water Temp.;
(Set Temp 23 °F)
Safety factor for Heat Loss;
Operating time;
For Shower;
For Bathrooms;
The conversion of water volume to
+
= G/day
Heating Capacity Calculation for sanitary usage
/ 1,000 x (
The conversion of M BTU to BTU
x 1,000 /
C. Total (A+B)
Total Heating Capacity
x (100%
D. No. of units required
Safety factor;
x (100%
A calculation example (Unit: °F/BTU/G)
A. For Air conditioning using such as Panel Heaters, Floor Heating and Fan coil units
Required total heating capacity
Safety factor;
B. For Sanitary use such as Shower and Bathrooms
Conditions
Tank inlet water Temp.;
Tank outlet water Temp.;
(Set Temp 23 °F)
Safety factor for Heat Loss;
Operating time;
For Shower;
For Bathrooms;
The conversion of water volume to
317
+ 63.4
= 234.6 G/day
Heating Capacity Calculation for sanitary usage
/1,000 x (
234.6
The conversion of M BTU to BTU
11.2 x 1,000 /
C. Total (A+B)
Total Heating Capacity
x (100%
68240
D. No. of units required
Safety factor;
x (100%
76674
* The value shown here is the rated capacity, and varies depending on the installation conditions.
MEES20K028
BTU
%
°F
°F
%
Hours
G/Person x Person =
G/Person x Person =
°F
x ( -
x ( -
-
=
+
%) +
%
+
%) / 39900BTU =
68240 BTU
10 %
50 °F
140 °F
15 %
8 Hours
16 G/Person x 20 Person =
2.1
G/Person x 30 Person =
°F
104
x ( -
x ( 113 -
-
140
8 =
+
10 %) +
20 %
+
20 %) / 39900BTU =
PWFY unit Tank
G (Water Temp. Condition
G (Water Temp. Condition
) / (
) / (
) / 2 =
BTU
x (100% +
units
units are required
317 G (Water Temp. Condition
63.4 G (Water Temp. Condition
50 140
) / (
50 ) / ( 140
) / 2 =
50 11.2
1400 BTU
1400 x (100% + 15
2.31 units
3 units are required
AIR TO WATER
4
7
3 3
3 3
°F)
°F)
- )
- )
M BTU / day
%) = BTU
104 °F)
°F)
113
50
- )
- 50 )
M BTU / day
%) = 76674 BTU
50