Serialnumberof panels

Ooka・Kikumoto Laboratory大岡・菊本研究室

Effect of insulation on indoor thermal comfort in a detached house with a floor heating system

Effect of insulation on indoor thermal comfort in a detached house with a floor heating system

1Background objective

• Vertical air temperaturegradient

• Cold draft• Local discomfort• Dust transport, indoor air

quality

Study on floor heating system ObjectiveIn a floor heating environment, the

relationship between thermal insulation

and thermal comfort？

Insulation performance

• Unnecessary heat loss andacquisition reduction

• Reduction of energy

required for air conditioning• Extended period without air

conditioning

2 Methodology (Simulation)• Simulation is a method of modeling and analyzing complex problems for real systems

using a computer

• A simulation was performed for a typical Japanese detached house by changing the

thickness t of the heat insulating material introduced to the ceiling / exterior wall / floor

• Heating period: Jan. to Feb., Nov. to Dec. Calculation step: 1 hour

3 Results・Mean air temperature• Compared with no insulation(case 0), MAT

was higher when there was insulation

• MAT rises as more insulation is introduced

• Increment of MAT was not linear

• The thicker the insulation, the smaller the

MAT increment with the previous case

4 Results・Floor temperature• Floor temperature was consistent with the change in

solar radiation

• Floor temperature increased compared to the condition

without insulation

• Floor temperature increased as the insulation thickness

was changed

5 Results・PMV/PPD

Warm Neutral Cool

• Predicted mean vote (PMV)

Indicator of thermal sensation felt by humans

• Predicted Percentage of Dissatisfied (PPD), Percentage of

people who feel dissatisfied or uncomfortable with their thermal

environment

• Case 0 without insulation had the lowest PMV and highest PPD

• The thicker the insulation, the higher the PMV value in all

rooms and the lower the PPD at the same time

• The increase and decrease of PMV and PPD became smaller

than the previous case

t=0mm t=50mm t=100mm t=150mm

25.1

19.519.4

13.6

11.211.4 11.4

9.29.3 9.38.48.5

Living Room

Bedroom

Children’s room (I)

Average result for each room of PPD (%)

Room

Mean air temperature Case 1 and

case 0

increment(℃)

Case 2 and

case 0

increment(℃)

Case 3 and

case 0

increment(℃)

Case 0 Case 1 Case 2 Case 3

断熱材0 mm

断熱材50 mm

断熱材100 mm

断熱材150 mm

Living Room 17.0 18.3 19.2 20.0 1.3 2.2 3.0

Bedroom 16.9 18.7 19.7 20.3 1.8 2.8 3.4

Children’s room I

17.0 18.7 19.6 20.3 1.7 2.6 3.3

Children’s room II

17.8 20.0 21.3 22.2 2.2 3.5 4.4

Floor temperature distribution in children’s room (II)

Warm +2 Slightly warm +1

Neutral 0

Cool -1 Cold -2

-0.1 0.1 0.3-0.5

Insulation thickness0 mm

Insulation thickness

150 mm

Insulation thickness 50mm

Insulation thickness100 mm

Average result of PMV in children’s room (II)

6 Conclusion• In a floor heating environment, thermal comfort can be

improved by increasing the thickness of the insulation material to some extent

17.518.018.519.019.520.020.521.021.522.022.523.023.5

0:00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00 12:00 0:00

断熱材 0 mm 断熱材 50 mm 断熱材 100 mm 断熱材 150 mm