Fig. 3. Measurements of Indoor Temperatures in one week of winter( left) and leakage of building trough blower-door test( right) in the case 6.
On the other hand, adults occupants of each home were questioned about room use and a standard survey was applied to determine thermal satisfaction levels. More in-depth interviews were also carried out as well as daily following over the summer and winter periods to review occupation patterns and comfort perception and expectations. Firstly, this revealed diverse degrees of conformity amongst the family groups, with significant generational differences in habits and perceptions. Younger residents displayed a greater need for privacy and adequate thermal conditions. Overall, comfort levels in the homes were considered adequate but there was substantial disparity depending on the summer and winter seasons, the different rooms and storeys involved solar orientation and the activities taking place. Layout also proved important to comfort levels. Specific structured heating routines were identified( GARCIA et al, 2013).
Retrofit Studies
In the homes studied, the possibility of retrofitting to improve thermal performance was also assessed, using a strategy analysing solutions through dynamic simulation( GARCIA et al, 2014a). This was based on a baseline simulation with adjustments to the air change rate( to 1.6ACH) and adaptive comfort temperatures( 18 º C-24 ° C with 70 % RH) and occupancy rates( 40W / m2). These figures match regular conditions for the typology of the zone according the monitoring and surveys done, taking into account fuel costs for space heating in winter( the main domestic expense) converted to energy demand. The amount of total energy demand for heating in winter( May to October) in the homes studied was between 30 kwh / m2 to 80 kwh / m2, according age of construction( higher is older houses), that corresponds around 40 % of total energy demand per house. In line with recommendations from general studies and previous local experiences, the improvement alternatives that were considered by this study focused on increase air tightness and thermal insulation of the building envelope. Measures included sealing doors, windows and wall perforations, putting additional exterior protection on walls and ceilings and replacing existing single-glass windows with double-glazing. Other modifications, such as increasing or reducing window openings according to orientation, incorporating skylights or greenhouse and improving floor ventilation or insulation did not offer better performance results.
The budget of the solutions was calculated for each home according to market prices for materials and labour costs. An efficiency value was then determined in relation to the total cost versus equivalent saving in fuel expenses. General limit budget were then established for retrofitting, corresponding to 5 %, 10 % and 15 % of the commercial value of each home in order to offer different alternatives( 10 % corresponds to the state subsidy for this activity). The solutions
596 ZEMCH 2015 | International Conference | Bari- Lecce, Italy