Benefits of Floor Heating Control
Individual Room Temperature Control In Hydronic Floor
Heating Applications – Simulation Studies, August 2003
Danfoss Floor Heating Hydronics
Benefits of Floor Heating Control
Personal Thermal Comfort
 Room temperature is a main factor for personal thermal comfort
 The desired room temperature depends on activity, clothing, and personal ”taste”
 Desired temperatures varies for each room in the house
Bathroom ~ 23 C°
Kitchen ~ 20 C°
Bedroom ~ 17 C°
Living room ~ 20 C°
2
Benefits of Floor Heating Control
How Do We Achieve Optimal Personal Thermal Comfort ?
 In order to achieve the desired temperature in each room
it must be possible for the user to define/set the
temperature in each room
 It must be possible to differentiate temperatures between
the rooms, - e.g. typically the user wishes the bathroom to
be warmer than the bedroom
 The heating system should at all times supply the correct
amount of energy needed to each room so that large
fluctuations resulting in the room being too warm or too cold
is avoided
 Optimal comfort is achieved when the user has exactly
the temperature desired in each room of the house
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Benefits of Floor Heating Control
Individual Room Temperature Control
°C temperature
Desired temperature in bathroom
Desired temperature in living room
Desired temperature in bedroom
Hour
Temperature without individual room control
Temperature with individual room control
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Benefits of Floor Heating Control
Individual Room Temperature Control – Conclusion
 In order to fulfill the desire for optimal personal thermal comfort it is necessary to utilize
Individual Room Temperature Controls of your heating system
5
Benefits of Floor Heating Control
Individual Room Temperature Controls
 Precise regulation of the temperature corresponding to
the specific set-point chosen for each room by the user
 Individual Room Temperature Controls adjust heat flow
depending on user pattern, free heat through windows,
appliances, etc.
 Optimal personal thermal comfort
 Individual Room Temperature Controls adapt heat output
to heat loss in each room
 Minimized costs with regard to energy
consumption/saving
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Benefits of Floor Heating Control
The Simulation Studies
 Danfoss has carried out simulation studies in order to clarify
the importance of Individual Room Temperature Control of
the heating system with regard to:
 Personal thermal comfort
 Energy consumption
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Benefits of Floor Heating Control
The Simulation System: IDA Indoor Climate and Energy 3.0
 IDA Indoor Climate and Energy 3.0 is a general-purpose
modeling and simulation tool for modular systems where
components are described with equations
 IDA Indoor Climate and Energy 3.0 is a new generation
tool for simulation of thermal comfort, indoor air quality and
energy consumption in buildings
 More than 900 registered users, mostly HVAC designers
but also educators and researchers
 First version was released in May 1998. Version 3.0,
released in November 2001, marks a major development
step with
several significant improvements
8
Benefits of Floor Heating Control
The Simulation System: IDA Indoor Climate and Energy 3.0
 IDA Indoor Climate and Energy 3.0 is developed by the company EQUA in close cooperation with a network of academic institutions, each contributing through expert
usage and model development:
 Royal Institute of Technology , Stockholm, Sweden
 Building Services Engineering, Sweden
 Helsinki University of Technology, Heating, Ventilating and Air-Conditioning, Finland
 Hochschüle für Technik+Architektur, HLK Engineering, Luzern, Switzerland
 University of Kassel, Department of Building Physics, Germany
 Norweigan University of Science and Technology, Dept. of Refrigeration and Airconditioning,
Norway
 For more information please refer to the EQUA homepage http://www.equa.se
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Benefits of Floor Heating Control
System Control Methods
 Automatic control of flow temperature using an
electronic weather compensator
 With individual room temperature control
 Without individual room temperature control
 Manual control of flow temperature by occupant
operation of self-acting flow regulator
 With individual room temperature control
 Without individual room temperature control
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Benefits of Floor Heating Control
Automatic Control of Flow Temperature Using an Electronic Weather
Compensator
 No occupant interaction on the heating system during heating
season
 Apartment with 6 rooms
 No reference room control
 Doors to bathroom and bedroom closed and the other doors open
 Flow control to each room is on/off with a dead-band of 0.25 °C
 Minimum operative temperatures registered in the rooms equals
desired temperatures
 Flow temperature is adjusted to ensure desired indoor
temperatures at a coldest day of -12°C
 Thermal comfort related to tube layout is not included in the study
 Only energy consumption in association with room heating is
considered - efficiency of the energy producing and delivering system
is not considered
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Benefits of Floor Heating Control
Manual Control of Flow Temperature by Operation of Self-acting Flow
Regulator
 The occupant checks the flow temperature with regular intervals
and change the set-point of the flow temperature regulator if the
deviation between proposed value and present value of the flow
temperature is more than 2°C
 No occupant interaction on the room thermostats during heating
season
 Apartment with 6 rooms
 Doors to bathroom and bedroom closed and the other doors open
 Flow control to each room is on/off with a dead-band of 0.25 °C
 Minimum operative temperatures registered in the rooms equals
desired temperature
 Flow temperature is adjusted to ensure desired in-door
temperatures at a coldest day of -12 °C
 Thermal comfort related to tube layout is not included in the study
 Only energy consumption in association with room heating is
considered - efficiency of the delivering and energy producing
system is not considered
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Benefits of Floor Heating Control
Settings For Both Simulations
 Heating season: 9 months (September to May)
 Set-point temperatures
 Living room
 Corridor
 Bedroom
 Bathroom
 Kitchen
 Childrens room
(degrees Celsius)
20°C
20°C
17°C
23°C
20°C
20°C
 Measured results
 % of time during heating season, where operative
temperature deviates with less than 1 celcius degree
from set-point temperature
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Benefits of Floor Heating Control
Automatic Control Of Flow Temperature Using An Electronic Weather
Compensator
Living room
Corridor
Bedroom
Bathroom
Kitchen
Childrens room
0
10
20
30
40
50
% of time during heating season, where
operative temperature deviates with less than
1 celcius degree from set-point temperature
Without individual room temperature control
With individual room temperature control
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60
70
80
90
100
Benefits of Floor Heating Control
Manual Control of Flow Temperature by Operation of Self-acting Flow
Regulator
Living room
Corridor
Bedroom
Bathroom
Kitchen
Childrens room
0
10
20
30
40
50
% of time during heating season, where
operative temperature deviates with less than
1 celcius degree from set-point temperature
Without individual room temperature control
With individual room temperature control
15
60
70
80
90
100
Benefits of Floor Heating Control
Conclusions: Personal Thermal Comfort
 Significantly improved personal thermal comfort with individual room temperature
controls
 Individual Room Temperature Control is optimal in combination with both electronic
weather compensator and occupant interaction for regulation of flow temperature
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Benefits of Floor Heating Control
Results on Energy Consumption
Pre-setting
of manifold
valves
Without
room
temperature
controls
With
room
temperature
controls
Reduction
in energy
consumptio
n
Automatic
– using an electronic weather compensator
Yes
8372 kWh
7392 kWh
12%
Automatic
– using an electronic weather compensator
No
9550 kWh
7390 kWh
23%
Manual
– occupant operation of self-acting flow
regulator
Yes
9009 kWh
7552 kWh
16%
Manual
– occupant operation of self-acting flow
regulator
No
10412 kWh
7681 kWh
26%
Flow temperature control
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Benefits of Floor Heating Control
Conclusions: Energy Consumption
 Significant energy savings can be achieved with Individual Room Temperature Controls
 15-25%
 Significant energy savings can be achieved in combination with both electronic weather
compensator and occupant interaction for regulation of flow temperature
 The simulation results support independent research by e.g. M. Bauer, University of
Stuttgart, who shows possible energy savings of approx. 20-40% for similar applications
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Benefits of Floor Heating Control
Simulation Data:
Automatic Control Of Flow Temperature Using An Electronic Weather
Compensator
Heating season: 9
months
(September to May)
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Set-point
temperatur
e
(oC)
% of time during heating season, where
operative temperature deviates with less than
1oC from set-point temperature
Without room
control
With room control
Living room
20
70%
98%
Corridor
20
9%
100%
Bedroom
17
0%
67%
Bathroom
23
46%
91%
Kitchen
20
2%
99%
Childrens room
20
0%
97%
Benefits of Floor Heating Control
Simulation Data:
Manual Control of Flow Temperature by Operation of Self-acting Flow
Regulator
Heating season: 9
months
(September to May)
20
Set-point
temperatur
e
o
( C)
% of time during heating season, where
operative temperature deviates with less than
1oC from set-point temperature
Without room
control
With room control
Living room
20
30%
96%
Corridor
20
9%
97%
Bedroom
17
0%
56%
Bathroom
23
30%
98%
Kitchen
20
7%
92%
Childrens room
20
2%
88%