Environmental Comfort Perception in the Alvorada Sustainable Low Cost House

Environmental Comfort Perception in the Alvorada Sustainable Low Cost House

(Parte 2 de 3)

10 yes no no no yes yes

All inhabitants have a rural origin, what explains some of the evaluations presented here, such as “the type of house proposal has an urban typology”. Most of the inhabitants consider that the yards are medium sized. However, two considered it small for their needs. In the backyard, half inhabitants usually have lines for hanging clothes, dog houses, vegetable gardens, flowers and fruit trees. One of the inhabitants built a storage/garage. Some of the interviewees do not do

HOUSE NR. 1 2 3 4 5 6 1 yes no yes no yes no 2 yes yes yes yes yes no 3 yes yes yes no no yes 4 yes no yes no no no 5 no no yes yes yes no 6 yes no no no no no 7 yes no no yes yes no 8 yes yes yes yes yes yes 9 no yes no no no no 10 no yes no yes no yes 1 no yes yes yes yes yes 12 B B B no no B 13 LR/K LR/K LR/K LR/K LR/K LR/K 14 yes yes yes yes yes yes 15 yes no yes yes yes yes 16 no yes yes yes yes yes 17 yes yes yes yes yes yes 18 yes no yes yes yes no

PLEA 2003 - The 20th Conference on Passive and Low Energy Architecture, Santiago – CHILE, 9 - 12 November 2003 any activity in this space. Others receive friends, drink chimarrão (typical Rio Grande do Sul herbal hot drink) or have lunches and dinners. In the front yard, the inhabitants grow spices, herbs and trees. Just two inhabitants use it as a children’s

play area and for gardening. These yards are the favourite spaces for the children.

The respondents' occupation varies widely: there is an odd-job man, a bricklayer, a shoemaker, a housewife and two others without a permanent job.

3.3 Thermal aspects

In relation to the residents' perception and satisfaction with thermal comfort, the following information was obtained:

1. hottest room in the summer, during the day; 2. hottest room in the summer, during the night;

3. coldest room in the winter, during the day;

4. coldest room in the winter, during the night. 5. preferred place in very hot days; 6. response action to very hot days; 7. response action to very cold days; 8.perception of the house thermal performance, in relation to the outdoor average the summer.

9. perception of the house thermal performance, in relation to the outdoor average in winter;

10. presence of draughts inside the house (in winter or in summer); 1. spots where draughts were noticed; 12. presence of excessive humidity inside the house; 13. spots where excessive humidity was noticed (mold); 14. period of the year when excessive humidity was noticed (summer or winter); 15. condensation noticed on internal surfaces; 16. spots where condensation was detected

The interviewees pointed out the bedrooms (BR1 and BR2) as being the hottest spaces of the house, both at night as during the day. In bedroom BR2, where daylight and ventilation comes from east, there are significant heat gains in summer, mainly during the morning, when the neighbouring houses are not shading the east wall. Due to the relative position of windows, doors and rooms, there is little possibility of cross ventilation when the room door is closed. The higher window, that could increase the movement of the air due to chimney effect, is located on the same wall as the lower one. Due to this, their efficiency is not the same as if they were on opposite walls.

The living room/kitchen (LR/K) is the room where ventilation works best, according to the interviewees.

This fact can be associated to the relative position of the windows and doors (D1, D3, W2 and W3), that provide good cross ventilation.

Most residents' prefer to stay outdoors in hot days, in the open area that is on the south side of the construction (BY). It reveals that the building thermal conditions are not satisfactory in the hot days of summer. When staying inside the house they need to use fans (during the night, for example), when they can afford them.

Table I, below, presents the answers from the interviews:

Table I: Perception of the residents on thermal comfort.

1 BR1 BR2 wholehouse BR1BR2 BR2 BR1 BR2

2 BR1 BR1 BR2 BR1BR2 BR2 BR1 BR2

4 LR/K LR/K * ** * *** 5 BY BY BY BY LR/K BY

6go toBY turn on thefanturn onthe fanturn on thefanopen thewindowsturn on the fan

7 close the house close the house close thehouse

**close the house turn on the eletric heater

8 muchhotter much lesshot thesame hotter muchless hot less hot

9 lesscold lesscold much lesscold **muchless cold***

10 yes yes no no yes yes

11D1 D3D1 D3D1 D3D3 W3 12 no no no no no yes

13 BR2 14all year

15 yes no yes no no ***

16 BYwall BY wall

* the interviewee did not make reference to any room of the house or he did not perceive differences among the rooms; ** the interviewee said that as he has been living in the house for only six months, he could not answer to the question; *** the interviewee said he did not know how to answer to the question.

In relation to the perception of uncomfortable heat inside the house, when compared to outdoors, four out of six respondents declared their house as being less hot or as hot as outdoors. From these four, three turn on the fan, which increases the tolerance to the hot indoor conditions in summer. Two other interviewees declared the house to be hotter than outdoors. Just one of them uses a fan in such situation.

In relation to the presence of draughts inside the house, four out of six interviewees identified its presence, mainly through the external doors (D1 and D3). These doors, in summer, guarantee a good ventilation of the living room/kitchen (LR/K). This lack of ventilation could explain the mould found in the east bedroom (BR2). However, of the six interviewees, just one pointed out the existence of excessive humidity in the east bedroom. This humidity could be associated to problems of rainwater infiltration in the south wall of the house. Of the six interviewees, two pointed out the existence of condensation in the east bedrooms (BR2), indicating the low ventilation in these rooms.

PLEA 2003 - The 20th Conference on Passive and Low Energy Architecture, Santiago – CHILE, 9 - 12 November 2003

Two out five interviewees considered the living room/kitchen (LR/K) the coldest room in winter. Three

interviewees did not indicate any room as being colder in the winter. It must be considered that four out of five interviewees already spent one winter living in the house. The presence of small gaps through the external windows and doors (due to construction flaws), leads to air infiltration and causes heat losses, in winter, even when the windows and doors are closed. At the same time, as in the region summer is harder to stand than winter, thermal comfort is also more difficult to achieve in summer. Thus, it is understandable that residents are more tolerant to winter conditions than in summer. In winter, the simple act of keeping the openings shut seems to supply the residents’ comfort needs. This perception could also be attributable to the north orientation of the windows. Only one of the interviewees declares to use an electric heater in winter. But, this fact can also be associated to the lack of economical conditions of most residents. As pointed out by the interviewees, it can be concluded that the house presents more unfavourable conditions in summer than in winter. Landscape in the settlement is quite bare (the plot, in general, has little vegetation to promote shade and to lower the temperature of the air). This fact also reduces the possibility of reception of fresh air from outside that would help lowering indoor temperatures.

3.4 Luminous Comfort

The residents were considered as meeting luminous/visual comfort, when able to develop their daily tasks, requiring good visibility, with no complaints. The house was considered as offering (natural) visual comfort when the user did not need to turn on the electric lights for the development of these tasks, during the period of the day (just needing to open the louvers of the windows).

For assessing luminous comfort, the following topics were considered in the interviews:

1. Need to turn on the lights, during the day

(state the room), in summer (even with the window is open); 2. Need to turn on the lights, during the day, in winter; 3. Use of curtains or other shading devices to avoid excess light entering a room;

4. Clearest room in summer;

5. Clearest room in winter;

6. Darkest room in summer;

7. Darkest room in winter; 8. Place where the interviewee accomplishes tasks that require a higher illumination level;

9. Type of activity requiring higher illumination level; 10. Room where children use to accomplish their homework.

Table IV, below, presents the results obtained with regard to visual comfort.

Table IV: Perception of the interviewed users on visual comfort.

(Parte 2 de 3)