Reference Buildings

The reference building has a floor area of 1000 m2 (height: 6 m). It is facing south and has a flat roof. The floor slab consists of 20 — 60 cm concrete with integrated underfloor heating system and 10 cm of insulation underneath. Four different reference cases were defined corresponding to typical insulation and usage scenarios for industrial buildings. The used building parameters can be found in Table 1.

Case 1

Case 2

Case 3

Case 4

Poorly insulated, high air exchange rate

Poorly insulated

Standard

High internal gains

Building construction

U-Value Walls

W/(m2 K)

0.584

0.584

0.233

0.233

U-Value Roof

W/(m2 K)

0.350

0.350

0.184

0.184

U-Value Floor

W/(m2 K)

0.307-0.364

0.307-0.364

0.307-0.364

0.307-0.364

Area (Windows and Doors)

m2

88

88

88

88

g-value Windows

0.589

0.589

0.589

0.589

U-value Windows

W/(m2 K)

1.4

1.4

1.4

1.4

Internal Gains

People (8-18 h), Mon-Fri

15

15

15

15

Light

W/m2

5

5

5

5

Machine Operation (8-18 h), Mon-Fri

kW

0

0

0

8

Air Exchange Rate

h-1

0.6

0.3

0.3

0.3

The so-called “Standard” reference building (Case 3) in the table is a relatively well insulated building with wall sections consisting of 160 mm of mineral wool insulation and 2 mm of sheet metal on both sides, for the roof 200 mm of mineral wool insulation was assumed. The windows are standard double-glazed insulating windows.

However, in retrofit situations, industrial buildings are often not very well insulated (sometimes not insulated at all). Therefore, a poorly insulated reference building was also defined with only 60 mm of mineral wool insulation in the walls and 100 mm in the roof (Cases 1 and 2). The air exchange rate in industrial buildings is especially difficult to estimate. It varies strongly depending on the number and duration of door openings. For this study, a standard air exchange rate of 0.3 h-1 was assumed. Case 1 includes an increased air exchange. In addition, another case with 8 kW of waste heat (e. g. of machine operation) during working hours was considered (Case 4).