Heating and Cooling

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• Coordinator:• Karel Kabele, kabele@fsv.cvut.cz, CTU in Prague • Contributors:• Eric Willems, Erwin Roijen, Peter Op 't Veld, P.OpTVeld@chri.nl• Camilla Brunsgaard, cbru@create.aau.dk & Mary-Ann Knudstrup, mak@create.aau.dk, Aalborg

University, Per Kvols Heiselberg, ph@civil.aau.dk, Tine S. Larsen, Olena K. Larsen, Rasmus Lund Jensen (AAU)

• Arturas Kaklauskas, Arturas.kaklauskas@st.vgtu.lt, Audrius Banaitis, Audrius.banaitis@vgtu.lt , Vilnius Geniminas Technical University (VGTU)

• Marco Perino, marco.perino@polito.it, Gianvi Fracastoro, Stefano Corgnati, Valentina Serra (POLITO)

• Werner Stutterecker, werner.stutterecker@fh-burgenland.at, (FH-B)• Mattheos Santamouris, msantam@phys.uoa.gr, Margarita Asimakopoulos, Marina Laskari,

marlaskari@googlemail.com, (NKUA)• Zoltan Magyar, zmagyar@invitel.hu, Mihaly Baumann, Aniko Vigh, idesedu.pte@gmail.com (PTE)• Manuela Almeida, malmeida@civil.uminho.pt, Sandra Silva, sms@civil.uminho.pt , Ricardo Mateus,

ricardomateus@civil.uminho.pt, University of Minho (UMINHO) • Piotr Bartkiewicz, piotr.bartkiewicz@is.pw.edu.pl, Piotr Narowski, piotr.narowski@is.pw.edu.pl

(WUT)• Matthias Haase, matthias.Haase@sintef.no, (NTNU)• Karel Kabele, kabele@fsv.cvut.cz, Pavla Dvořáková, pavla.dvorakova@fsv.cvut.cz, (CTU – FCE)

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LECTURE 3

ACTIVE SPACE HEATING AND COOLING

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Heat emitters (radiators, convectors, tubular, radiant heating (stripes, panels), dark and light infrared radiant pipes, stoves).

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Heating equipment• Heat source - heat transfer medium

- heat emitter

• Classification of the systems– local– floor– central– district

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Heat emitters

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Fan convec tors N atura l

C onvec tors

B anks of P ipes O ff peak storage C olum ns R adiantpanels

P anels

R adiato rs

Heat emitters

Convectors

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NaturalFan-convectorsFloorWall

                 

Radiators

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Control limits

Panel radiatorP

Steel radiatorS

today Heat insulation (old buildings)

Heat insulation standard 1995 (new

buildings)

Heat insulation Standard 2000

Water content

radiator

Large mass = heating unresponsive low mass = responsive heating

G radiator G

Mass = storage

Responsive heatingcontrol important to make use of solar gains

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* radiator temperature, 200C room temperature

Radiation share

Convection share

Single panel radiator, without

convector

Radiator (modular)

Double panel radiator, with three convectors

Finned tube convector

Thermal output

Off-peak storage

• Static• Dynamic

• Convector• Radiator

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Air flow patterns

prof.Ing.Karel Kabele,CSc.

Radiant panels

• Low temperature• heaters max 110 °C (water, steam, el.power)

• High temperature• dark - about 350°C - radiant tube heating system

(gas)• light - about 800 °C - flameless surface gas

combustion13

Heat emitters• Design principles

– Heating output– Location– Covering - furniture– Connection to the pipe system– Type

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Heat emitters design

• Covering = changes in the output

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100% 87%110%95%

100% 100% 90% 85%

Connection to the piping system

SPACE HEATING AND COOLING

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Low-temperature radiant heatingHigh-temperature radiant cooling

• Underfloor, wall and/or ceiling heating/cooling

• Embeded surfaces• TABS• Snowmelt systems

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Low - temperature radiant heating• floor, wall and/or ceiling with embedded pipes or

el.wires in concrete slab– Temperature distribution

125BEE1_2008/2009 prof.Ing.Karel Kabele,CSc.

Ideal temperature

Radiators

Underfloor heating

Ideal temperature

Underfloor heating

Radiators

Radiant heating/cooling• Output

– Limited surface temperature limited output cca 100 W.m-2

• Energy savings – Lower air temperature lower heat losses

• Control– Low temperature difference autocontrol effect

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Underfloor heating

• History

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Low/high - temperature radiant heating/cooling

• Floor structure

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Insulating strip between wall and flooring

Finished flooringConcrete slab min 65mm

Thermal insulation20-80mm

Pipes

Humidity seal

Reinforcement

Supporting floor structure

Underfloor heating - structure

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TYP ATYP B

TYP C

Low - temperature radiant heating

• Technical solution– Pipe layout

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Underfloor heating - examples

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Wall heating• Embedded pipes - inner wall side

• Higher surface temperature on both sides

• Furniture layout

• Rooms with given use of space: swimming pools, entrance areas, corridors

• not possible or desirable to use conventional heating surfaces: prisons, hospitals,…

• Possibility to use the system for cooling

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Wall heating - Design process• determination of the areas, applicable to this type of heating;• determine the desired maximum surface temperature;• calculate the heat loss room analogy for underfloor heating

without losing the wall with wall heating;• verification of the achievable performance of surfaces and

temperature• compared to heat loss, or draft supplementary heating

surfaces.• select the type of wall heating, wet or dry system, pipe or

capillaries;• design spacing and temperature parameters of heat transfer

fluid;• hydraulic calculation.

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Wall heating - temperatures

• From the point of thermal comfort it is like radiators heating

• Maximum surface temperature 35 - 50 °C according to local conditions.

• For surface temperatures above 42 ° C can be painful contact.

• size of losses to the outside, impact on the neighboring room

• Some manufacturers recommend and design system for the surface temperature of 35 ° C

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Technical solutionA – pipes diameter 10-14 mm

• Wet• Dry

B – capillary mats

Pipes diameter 6 mm , rozteč 30-50 mm

• Wet

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• With or without phase change material• Cooling capacity can limit the use of system • Control of room conditions?

Thermally Activated Building Structures (TABS)

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Thermal activation of building structure (TABS)- National technical library (Prague)

30foto: Václav Nývlt, Technet.cz

Special caseHEATING OF THE BASEMENT OF ICE SURFACE

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Realization

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„Floor“ structureIce 50 mm

Concrete 240 mm

Cooling -16/-12°C; 160 W/m2

EPS 250 mm

Concrete 250 mm

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„Floor“ structure with heating system

Ice 50 mm

Concrete 240 mm

Cooling -16/-12°C160 W/m2

EPS 250 mm

Concrete 250 mm

Heating 10/8 °C; cca 10 W/m2

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Heating of outdoor surfacesSnowmelt systemPipe spacing 15-50cmTemperature 50-80°CUse of antifreezeThermal output according to the amout of snow

and outdoor temperature Large thermal inertiaMechanical resistance

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• Air heating/cooling systems – circulating, ventilating.• Integration of heating/cooling systems.

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