Recent trend of radiant cooling andheating panel in Europe and USProfessor Bjarne W. Olesen, PhD
International Centre for Indoor Environment andEnergy
Department of Civil Engineering
Technical University of Denmark
International Centre for Indoor Environment and Energy

Heating and Cooling of Buildings• Heating, cooling and ventilation systems play a significant
role in the energy use (42%) and for the indoor
environment quality in a building• The main purpose of these systems is to provide a
comfortable, healthy and productive indoor environment
for the occupants• These goals should however be achieved with the lowestpossible energy consumption.

COMFORT-PRODUCTIVITY
Building costs
People100
Maintenance 10Financing
10Energy1

Energy Demand-Energy EfficiencyEnergy Sources• As the resources of fossil fuels are limited and the use of nuclear
power is associated with several safety issues there is a worldwide

need for reducing the energy demand of buildings.
• Reducing the energy demand is much more efficient andsustainable than increasing energy sources• When constructing new buildings and renovation old buildings
the first priority is to decrease the energy demand

POSSIBLE ACTIONS• Decrease energy demands (building design)• Increase energy efficiency (HVAC systems)• Increase use of renewable energy sources(wind, solar, geothermal, biomass)• New energy sources (fuel cell)

The 20-20-20 EU policy by 2020
New policy for 2030 proposed
100%-1990

-20%

-20%

-40%

-27%

20%
27%
8,5%

Greenhousegas levels

EnergyUse

Renewables inenergy mix

Required reductions inenergy use in European
countries
2020 in relation to 2005

National overall targets for the share of energy from renewablesources in gross final consumption of energy in 20202005-2020
Belgium
2,2Bulgaria
9,4Czech Republic 6,1
Denmark
17,0
Germany
5,8Estonia
18,0Ireland
3,1
Greece
6,9
Spain
8,7
France10,3Italy
5,2Cyprus
2,9Latvia
32,6Lithuania
15,0
Luxembourg 0,9

13 %
16 %
13 %
30 %
18 %
25 %
16 %
18 %
20 %
23 %
17 %
13 %
40 %
23 %
11 %

2005-2020
•
•
•
•
•
•
•
•
•
•
•
•

Hungary
4,3 % 13 %Malta
0,0 % 10 %Netherlands 2,4 % 14 %Austria
23,3 % 34 %Poland7,2 % 15 %Portugal
20,5 % 31 %Romania17,8 % 24 %Slovenia
16,0 % 25 %Slovak Republic6,7 %14 %Finland28,5 % 38 %Sweden39,8 % 49 %United Kingdom 1,3 % 15 %Part of renewable energy sources(wind and bio-fuel) in Denmark(no nuclear)

The effect ofbuildingregulations

ANSI/ASHRAE/IES Standard 90.1-2013 -- EnergyStandard for Buildings Except Residential Buildings

Source: Pacific Northwest National Laboratory
11Advanced Energy Design Guides:
522,000 in circulation
Four 50% AEDGs

Being Implemented• 50% Grocery Stores– Quick Serve Restaurants– Places of Assembly• Under Discussion• Net Zero– K-12 Schools (2)– Quick Serve Restaurants– Places of Assembly– “Net Zero Ready” Guidance

www.ashrae.org/freeaedg

ZEB Concept
Over the course of a year, ifthe (on-site or source)
renewable energy produced ≥the energy used within theboundary, it is considered aZEB?

13

Energy Efficient Technologies• Indoor air quality– Reduce loads (pollution sources)– Heat recovery– Increase system efficiency– Natural ventilation-Hybrid ventilation– Air distribution (contaminant removal) effectiveness• Personal ventilation– Air cleaning• Thermal comfort– Reduce loads (building shell, solar screen, internal loads)– Increase system efficiency– Low Temperatur Heating- and High Temperature Cooling Systems– Use of building mass to reduce peaks (Thermo-Active-BuildingSystems (TABS))– Drifting indoor temperatures

Low Temperature Heating –High Temperature Cooling• Higher efficiency of boilers, heat pumps chillers• Lower distribution looses• Better use of renewable energy sources– Ground heat exchangers– Waste heat from processes– Dry coolers– Heat pumps• Low energy use for distribution• Low exergy
15

CONCEPTS OF RADIANT HEATING AND
COOLING SYSTEMS• Minimum 50% heat exchange by radiation• Heating - cooling panels• Surface systems• Embedded systems• Most recent development is the increasing
application world wide.

System types
Different installation concepts(thermally coupled or insulated form the building structure)17

Cooling panels

COMFORT• GENERAL THERMAL COMFORT– PMV / PPD, OPERATIVE TEMPERATURE• LOCAL THERMAL DISCOMFORT– Radiant temperature asymmetry– Draught– Vertical air temperature difference– Floor surface temperature

GENERAL THERMAL COMFORT• OPERATIVE TEMPERATURE– to = (hcta + hrtr)/(hc + hr)– to = 0.5ta + 0.5tr ( low air velocity)• ta = Air temperature• tr = Mean radiant temperature• hc = Convective heat exchange coefficient• hr = Radiative heat exchange coefficientSURFACE HEATING AND COOLINGHeat transfer coefficient

11,510,511,011,09,58,08,58,07,56,55,56,07,0
HeatingCooling

WallCeiling

Floor

W/m2K

Radiant Heating-Cooling Panels

Water temperature 16/18Co

Water temperature 32/28Co

ca. 60 W/m²

Room temperature 26 Co

Room temperature 20 Co

ISO 18555 Building Environment Design — Design, test
method, control and operation of radiant heating andcooling panel systems• Part 1: Definition, symbols, technical specifications
and requirements• Part 2: Determination of heating and cooling
capacity of ceiling mounted radiant panels• Part 3: Design of ceiling mounted radiant panels• Part 4: Control and operation of ceiling mounted
radiant heating and cooling panels

Control of radiant heatingand cooling systems• Radiant surface cooling systems shall include
controls to avoid condensation.
• This can be done by a central control of the supply
water temperature limiting the minimum watertemperature based on the zone with the highest dew
point temperature.
• If the supply water temperature is limited, thetemperature of the rest of system will be higher thanthe dew point, and there is no risk of condensation on
the pipes, and on the surface of the radiant system.
• Limiting the supply water temperature will lower thecooling power of radiant system at high indoor
humidity levels.
• Dehumidifying the ventilation air will result in lower
dew point temperature and will allow higher cooling
capacity of radiant system.

Residential Buildings• Middle and Nothern Europe– More than 50% floor heating– Mechanical Ventilation with heat recovery– Risk of over heating• Southern Europe– Increasing use of split-unit– Some Air ConditioningAirport Administration Düsseldorf

5.000 m2 cooling panels

Campus in Cologne

7.000 m2 gibson board cooling panels

Telecel Headquarters,
LisbonRenovation Deutsche Bank Frankfurt
Built 1984
Renovated 2006 for 200 mill. €Radiant ceiling panels
100kWh/m2 year
LEED-Platin and DNGB-Gold
Energy savings:• 67 % Heating,• 55 % Electricity• 74 % Water

Dutch Bank Buildings

Radiant cooling panels
Saudi Arabien

DOE-USADOE-USA

COOPER UNION NEW YORKFirst costs

Possible LEED Points• Energy – DOAS and radiant panel reduces energy 25-35%,
chiller without HCFC’s• Materials – radiant panels 100% recyclable and easily cancontain recycles• IEQ – increased ventilation effectiveness, thermal comfort,
controllability of system• Innovation credit – decoupling sensible and latent loads• Fast response time allows use of operable windows

Low Energy/Exergy Hydronic Radiant Heating and Cooling

Why?
• Water based systems• Low Temperature Heating - High Temperature Cooling• More economical to move heat by water:– Greater heat capacity than air– Much smaller diameter pipes than air-ducts– Electrical consumption for circulation pump is lower than forfans• Lower noise level• Less risk for draught• Lower building height• Higher efficiency of energy plant• Increased use of renewable energy sources