Q. How do you convert watts into BTU's?
A. Watts x 3.412 |
Q. How do you convert BTU's into watts?
A. BTU's x 0.293 |
Q. What is DT 50°C?
A. It is the difference in the mean water inlet and outlet temperatures, 75°C and 65°C respectively, and the room air temperature 20°C. It is calculated as follows,
Flow Temperature 75°C
Return Temperature 65°C
Room Temperature 20°C
75+65 = 140°C
140/2 = 70°C
70-20 = 50°C |
Q. What is DT 56°C?
A. It is the difference in the mean water inlet and outlet temperatures, 82°C and 71°C respectively, and the room air temperature 20°C. It is calculated as follows,
Flow Temperature 82°C
Return Temperature 71°C
Room Temperature 20°C
82=71 = 153°C
153/2 = 76.5°C
76-20 = 56°C |
Q. What is DT 60°C?
A. It is the difference in the mean water inlet and outlet temperatures, 90°C and 70°C respectively, and the room air temperature 20°C. It is calculated as follows,
Flow Temperature 90°C
Return Temperature 70°C
Room Temperature 20°C
90+70 = 140°C
160/2 = 80°C
70-20 = 60°C |
Q. How do I calculate the water content and dry weight of the radiators I'm choosing?
A. The required data is located in the following sections
Horizontal panels on the same page as the heat emissions.
Columns on the data chart page.
Vertical Panels under heat emissions the first page.
Radiavectors(Low Level) on the same page as heat emissions.
LST's see horizontal panels.
Bathroom radiators on same page as the heat emissions |
Q. How do I calculate the pressure drop in a radiator ?
A. Look up the resistance diagram for the radiator in the correct section for a horizontal panel look up the resistance diagrams in the horizontal section etc.
Draw a vertical line up from the flowrate axis (this is the flowrate through the radiator in Litres per hour) until you intersect a diagonal line then draw a horizontal line across to the pressure drop axis.
Read the value and this will give you the pressure drop across the radiator in Milli-Bar.
There is a worked example with each resistance diagram.
Please note that the resistance diagrams are logarithmic. |
Q. How do I calculate the flow rate through a radiator ?
A. the following formula is used to calculate the flow rate through a radiator
-------------------------Q = M x C x deltaT-------------------------
where
Q is the output in watts (W)
M is the flow rate in Litres per second (l/s)
C is a constant 4187
deltaT is the difference in the flow and return temperatures
litre/sec x 3600 = Litre /hr,
What is the flowrate of a radiator with an output of 1000W with a flow and return temperature of 90°C and 70°C respectively?
M=Q/(C x deltaT) = 1000/(4187x20)=0.01194 l/s
for l/hr we multiply by 3600 = 42.99 l/hr. |
SITE PROBLEM
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