Methods

Investigations were conducted in an almost full-scale test apartment built in- side a laboratory hall. The test apartment consisted of an entrance hall con- necting four rooms designated living room, bedroom, kitchen and bathroom.

In the apartment human occupancy was simulated through controlled emis- sions of CO2 and water vapour. Two adult occupants were assumed to fol- low the 24-hour routine outlined in Table 1. The table also gives emission rates for water vapour resulting from the occupants' activities like cooking or showering. Finally, N2O was dosed in the living room in order to simulate emission of contaminants from building products and furnishings.

Four scenarios, each with a different ventilation strategy, were investigated. The scenarios are described below whereas the test apartment, the installed equipment and the measurement procedures are described in detail in the following chapters.

Scenario 1

In this scenario ventilation complied with current Danish Building Regula- tions which stipulate a continuous mechanical extraction rate of 20 l/s from a kitchen and 15 l/s from a bathroom; in total 35 l/s for an apartment. Outdoor air was supplied through permanently open outdoor air inlets in living room and bedroom. Moisture and pollution loads are given in Table 1.

Scenario 2

This scenario was characterised by a somewhat low basic ventilation rate and a high manually controlled forced ventilation rate in the kitchen. The ba- sic continuous mechanical extraction rate was 10 l/s from the kitchen and 10 l/s from the bathroom; in total 20 l/s for the apartment. In the morning and in the early evening there was a forced mechanical extraction rate of 70 l/s from the kitchen. Outdoor air was supplied through permanently open out- door air inlets in the living room and the bedroom. Moisture and pollution loads are given in Table 1.

Scenario 3

This scenario was characterised by a basic ventilation rate somewhat higher than in Scenario 2. The forced ventilation rate was manually controlled in the kitchen and demand controlled in the bathroom. The basic continuous me- chanical extraction rate from the kitchen was 15 l/s and the manually con- trolled forced extraction rate was 50 l/s. In the bathroom the basic continu- ous mechanical extraction rate was 10 l/s and the demand-controlled forced extraction rate was 20 l/s. Outdoor air was primarily supplied to the occupied room (living room or bedroom). Humidity sensors were installed in the living room, the bedroom and the bathroom. Moisture and pollution loads are given in Table 1.

Scenario 4

In this scenario the ventilation in the apartment was fully demand-controlled. In the kitchen the basic extraction rate was 10 l/s and the forced extraction rate was 50 l/s. In the bathroom the basic extraction rate was 10 l/s and the forced extraction rate was 20 l/s. Like in Scenario 3, outdoor air was primar- ily supplied to the occupied room. Moisture and pollution loads are given in Table 1.

Table 1. Moisture and pollution loads over a 24-hour period.

Time Bedroom Living room Hall, kitchen, bathroom

00:00-01:00 15 gH2O/h 2 persons:

50 gH2O/h/person

20 l CO2/h/person

60 gH2O/h/person

15 gH2O/h Contaminant emission

Hall:

15 gH2O/h

01:00-07:00 2 persons:

25 gH2O/h/person

12 l CO2/h/person

15 gH2O/h

15 gH2O/h Contaminant emission

Hall:

15 gH2O/h

07:00-08:00 15 gH2O/h 15 gH2O/h

Contaminant emission