Ordre of Engineers Tripoli - Lebanon
UNDER FLOOR HEATING TECHNOLOGY
Eng. Wael Zmerly 02-11-2007
WWW.ZMERLY.COM
WHAT IS “FLOOR HEATING”
TO USE THE FLOOR AS A HEAT EMISSION SURFACE Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
2
Under Floor Heating Technology Eng. Wael Zmerly - 2007
HISTORICAL BACKGROUND
2000 years ago
Heating systems inspired by this idea were built by the Chinese, Egyptians and Romans. Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
3
Under Floor Heating Technology Eng. Wael Zmerly - 2007
HISTORICAL BACKGROUND
1900 At the start of this century floor heating appears in its present form. Hot water cycles inside a tube burred under ground.
In London in 1909, one of the Royal palaces was heated with this new system.
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
4
Under Floor Heating Technology Eng. Wael Zmerly - 2007
HISTORICAL BACKGROUND
1945 TO 1950 In Europe, from 1945 to 1950, over 100,000 homes were heated by this technique. Very soon, however, it was noted that the equipment was causing numerous physiological problems due to the following facts: Metallic pipes instead of plastic (long distance between pipes) No use of cement slab, High thermal inertia.
40ºC
The boiler temperature was 70ºC to 80ºC. The reason why the floor temperature was 34ºC to 40ºC. Which caused also some health problems. Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
5
Under Floor Heating Technology Eng. Wael Zmerly - 2007
THE NEW SYSTEMS
FROM 1970s • Use of Floating floors.
3 New values were added:
• More insulation, Low heat losses.
Low thermal inertia of the floor slab. Low surface temperature (28 - 29ºC). Uniform heat distribution.
• Plastic pipes, small pitches.
29ºC
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
6
Under Floor Heating Technology Eng. Wael Zmerly - 2007
ADVANTAGES Uniform heat distribution. Healthy conditions. Absence of air draughts. Safety. Space saving. Low noise Temperature reduction from feet to head. Lack of dryness due to low temperatures. Friendly to the environment. Efficient. Low operating cost. Reduction of roof thermal loses. Short-term depreciation. Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
7
Under Floor Heating Technology Eng. Wael Zmerly - 2007
INCONVIENIENTS
HEATING OUTPUT RELATED TO LIMITED AREA.
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
RELATIVLY HIGH THERMAL INERTIA.
8
Under Floor Heating Technology Eng. Wael Zmerly - 2007
HEAT AND COMFORT
RADIATOR HEATING Hottest part of the room is at ceiling level. Room temperature setting at 21ºC. Cold feet due to cooler convective air current.
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
FLOOR HEATING Coolest part of the room is at ceiling level. Room temperature setting below 21ºC (19). No draught. No cold feet. Less dust which can settle on walls, furniture and curtains. 9
Under Floor Heating Technology Eng. Wael Zmerly - 2007
HEAT REPARTITION 270cm
170cm
Floor heating Ceiling heating Radiators ext. Radiators int. Warm air 10cm
ºC
16
20
24
Thermal comfort Ideal curve Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
16
20
24
Warm air Radiators Radiators Floor heating Ceiling (external (internal walls) walls) radiant panel heating 10
Under Floor Heating Technology Eng. Wael Zmerly - 2007
APPLICATIONS RESIDENTIAL.
OFFICES.
INDUSTRIAL.
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
11
Under Floor Heating Technology Eng. Wael Zmerly - 2007
PANEL CONTAINEMENT STRUCTURES
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
12
Under Floor Heating Technology Eng. Wael Zmerly - 2007
LAYOUT Distribution manifold
Loops
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
13
Under Floor Heating Technology Eng. Wael Zmerly - 2007
LAYOUT
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
14
Under Floor Heating Technology Eng. Wael Zmerly - 2007
LOOP CONFIGURATIONS
variation
SINGLE SERPENTINE Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
15
Under Floor Heating Technology Eng. Wael Zmerly - 2007
LOOP CONFIGURATIONS
Floor temperature Variation
PARALLEL SUPPLY AND RETURN – COUNTERFLOW TYPE Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
16
Under Floor Heating Technology Eng. Wael Zmerly - 2007
LOOP CONFIGURATIONS
Floor temperature Variation
PARALLEL SUPPLY AND RETURN – SPIRAL TYPE Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
17
Under Floor Heating Technology Eng. Wael Zmerly - 2007
LOOP CONFIGURATIONS
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
18
Under Floor Heating Technology Eng. Wael Zmerly - 2007
MATERIALS
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
19
Under Floor Heating Technology Eng. Wael Zmerly - 2007
PIPES PEX – ALU - PEX
PEX with oxygen barrier
PIPE REEL Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
20
Under Floor Heating Technology Eng. Wael Zmerly - 2007
MANIFOLDS
For correct operation and maintenance of the system, manifolds must have: •Main on/off valves, •Panel on/off valves, •Micrometric panel regulating valves, •Automatic air vents, •Drain cocks. Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
21
Under Floor Heating Technology Eng. Wael Zmerly - 2007
MANIFOLDS
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
22
Under Floor Heating Technology Eng. Wael Zmerly - 2007
PERIFERAL INSULATION STRIP
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
23
Under Floor Heating Technology Eng. Wael Zmerly - 2007
INSULATION BOARD
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
24
Under Floor Heating Technology Eng. Wael Zmerly - 2007
INSULATION BOARD
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
25
Under Floor Heating Technology Eng. Wael Zmerly - 2007
INSULATION BOARD
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
26
Under Floor Heating Technology Eng. Wael Zmerly - 2007
EXPASION JOINTS
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
27
Under Floor Heating Technology Eng. Wael Zmerly - 2007
NETWORK TESTING •For 30 min at 150% of working pressure •For 90 min at double working pressure •Installation test •Same pressure during the pouring of thermal concrete
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
28
Under Floor Heating Technology Eng. Wael Zmerly - 2007
CONCRETE COMPOSITION
1m³of concrete contain
• 0,8m³ river sand • 0,4m³ gravel, 4 - 6mm grain size • 350 kg cement • 2,5 kg plasticizer • 250 kg water • 900 gr/m³ polypropylene fibers Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
29
Under Floor Heating Technology Eng. Wael Zmerly - 2007
CALCULATION PARAMETERS Ambient air temperature Outer diameter of pipe
Thermal resistance of the floor
Internal diameter of pipe
Thermal conductivity of slab
Thermal conductivity of pipe
Thickness of slab above pipe
Flow temperature of water
Panel surface
Center to center distance
Thermal resistance below panel
Underneath room temperature Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
30
Under Floor Heating Technology Eng. Wael Zmerly - 2007
REQUIRMENTS CENTER TO CENTER DISTANCE
MAXIMUM DESIGN WATER TEMPERATURE
HEAT OUTPUT REQUIRED
SURFACE TEMPERATURE OF THE FLOOR
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
The most frequently used grids are as follows: • 7,5 15,0 22,5 30,0 37,5 • 5,0 10,0 15,0 20,0 30,0 • 45 a 55°C with traditional boilers; • 40 a 45°C with district heating, condensing boilers, heat pumps; • 32 a 38°C with solar panels. Two aspects in consideration : • the lack of heat loss through the floors, • the heat contribution of any panels located on the floor above. To avoid uncomfortable physiological conditions, the surface temperature of the floor should be less than: • 29°C in continuously occupied environments, • 33°C in bathrooms, showers and swimming pools, • 35°C in perimeter areas or rooms rarely used.
31
Under Floor Heating Technology Eng. Wael Zmerly - 2007
REQUIRMENTS It is advisable not to be too high in order: TEMPERATURE DIFFERENCE OF • not to over-reduce the average temperature of the fluid, and thus the heat output of the panel; HEATING FLUID • to avoid surface temperatures which differ too much from each other, • Usually it is used below 8 ÷ 10°C PANEL FLOW
HEAD REQUIRED
LENGTH OF THE PANEL
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
Considering that the maximum flow of a panel is on average between: •200 ÷ 220 l/h, for pipes with Di = 16 mm •120 ÷ 130 l/h, for pipes with Di = 13 mm It is advisable that the difference between the preset head and that should be at least 200 ÷ 300 mm w.g. In domestic applications, it is advisable not to go beyond the commercial lengths of pipe rolls (120 ÷ 150 metres)
32
Under Floor Heating Technology Eng. Wael Zmerly - 2007
HEAT OUTPUT tp = surface temperature of floor, °C ta = ambient temperature, °C q = specific heat output (upwards) of panel, W/m2 In particular (at ambient temperature = 20°C), the maximum specific output which can be transferred by a panel is: • qmax = 8,92 . ( 29 – 20 ) 1,1 = 100 W/m2 in continuously inhabited environments. • qmax = 8,92 . ( 33 – 20 ) 1,1 = 150 W/m2 in bathrooms, showers and swimming pools. • qmax = 8,92 . ( 35 – 20 ) 1,1 = 175 W/m2 in perimeter areas or rooms rarely used.
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
33
Under Floor Heating Technology Eng. Wael Zmerly - 2007
CONTROL SYSTEM
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
34
Under Floor Heating Technology Eng. Wael Zmerly - 2007
CONTROL SYSTEM
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
35
Under Floor Heating Technology Eng. Wael Zmerly - 2007
BOILER ROOM
Mixing Valve Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
36
Under Floor Heating Technology Eng. Wael Zmerly - 2007
HEAT ACTIVATED BUILDING MASS
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
37
Under Floor Heating Technology Eng. Wael Zmerly - 2007
WALL HEATING
Radiant wall heating is one of the most comfortable form of heating available. Water circulating at 30-40ÂşC in pipes built into the wall provides gentle but highly efficient radiant heat.
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
38
Under Floor Heating Technology Eng. Wael Zmerly - 2007
CEILING HEATING
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
39
Under Floor Heating Technology Eng. Wael Zmerly - 2007
ELECTRICAL FLOOR HEATING
Order of Engineers – Tripoli - Lebanon ZMERLY & CO SARL.
40
Under Floor Heating Technology Eng. Wael Zmerly - 2007