Mark NFRA AQUA ECO Livret Technique page 5

2.0 Selection and design advice. [5]
In order to heat the room evenly, it is important to follow the steps below. These calculations
determine the type of panel, the panel length, distributors and the pressure drop. In connection
with the water side pressure drop and panel expansion, we advise you to keep the maximum
section length below 46 metres.
2.1 Signs and symbols
B = Width of the room
H = Height of the room
H = Installation height
m
K = Upper temperature
L = Length of the room
L = Section length
B
L = Total section length
tot
n = Number of radiation sections
sp
n = Number of pipes per group
m = Mass flow per pipe
pb
m = Mass flow per panel length
2.2 Steps to be followed
1. Determine the width, height and type of panel for the space. [5]
T = 65ºC
wi
T = 50ºC
wu
T = 18ºC (Temp. in the room)
omg
2. Determine the section length: [5]
L = L – 3m
B
L = 45 – 3 = 42m
B
NOTE!
Only 4 or 6 metre panels may be used.
42m is divisible by 6. This results in 7 panels, each 6 metres in length
See table [9]
3. Determine the installation height:
H = H – 0.5m
m
H = 5 – 0.5 = 4.5m
m
This is also the optimal distance from the centre point of each panel. [5]
q = Panel heat output per section length
Q = Heating requirement
T = Ambient temperature
omg
T = Water temperature in (feed)
wi
T = Water temperature out (return)
wu
∆T = Temperature variation
Q = Heat capacity per panel (table) [6]
pp
n = Number of panel lengths needed
pp
R = Pressure drop per pipe per metre of panel
Z = Distributor pressure drop
EN
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