Analysis of thermal comfort in nursing homes in Mediterranean continental climate

This project is part of the coordinated programme which aims to analyse the thermal comfort of elderly people in Residential Centres located in the cross-border cooperation area of Spain-Portugal and to predict which thermal conditions are acceptable or preferred for this group of people. 

The project 1. Analysis of thermal comfort in nursing homes in Mediterranean continental climate is planned in 4 stages: 

Stage 1: Selection of centres to be studied 

Selection of 5 representative centres. 

Stage 2: Fieldwork 

Data collection began in February, just after the contract was signed and the equipment was purchased.

Collection of field data (indoor and outdoor conditions of the common areas of the centres) (monitoring) and subjective assessment (ST wind chill) of its residents over an entire year (survey). 

Monitoring

Monitoring of dry temperature (Taext) and relative humidity (HRext) outside, dry temperature (Ta) and relative humidity (HR), average radiant temperature (Trm) and air velocity (Va) of occupied spaces.

Satisfaction survey

The necessary information from each of the surveys is summarized in:

Basic information on the person surveyed: sex, age, body mass index, length of residence, height and weight.

Clothing level (clo) and metabolic rate (met) at the time of the survey.

3. Thermal sensation (ST), Preference (P) and Acceptability (A) and adaptive behaviour. Wind chill is expressed on the 7-point Ashrae scale, preference on the three-point scale, and acceptability on two points. The questionnaire options are listed in the table below.

Stage 3: Data analysis and development of the thermal comfort model

In order to determine the model of thermal comfort for older people, both the characteristics of the respondents and the satisfaction data obtained from the surveys and the indoor and outdoor environmental conditions will be analysed beforehand. Both residents and carers will be analysed.

Data analysis

Visualization through a histogram of the indoor and outdoor dry temperature and indoor and outdoor relative humidity. Relationship between the variables (age, weight, height and body mass index, clothing rate and metabolic rate) and thermal sensation (ST). Relationship between variables (Age, weight, height and body mass index, clothing rate and metabolic rate) and To. Relationship between variables (Va, PMV, ST) and To. Relationship between variables (clothing rate and metabolic rate) and Text.

Verification of the thermal comfort model of the expected average vote.

Check the PMV model and the adaptive model.

Development of a statistical model of thermal comfort for the elderly

On the basis of the data collected, the statistical model of thermal comfort based on the adaptive model shall be determined and checked for validity in naturally ventilated and forced ventilated buildings. The results obtained from residents and carers will also be compared.

2. Activities to date and milestones achieved 

1st Stage: Selection of centres to be studied. 

The selected centres are representative of the Mediterranean continental climate. The centres belong to Sanitas Mayores and are located in: 

2.1. Centre 1. La Seu 

2.1.1. Residents' building and routine 

It is located in the centre of Valencia. It was built in 1927 to be a convent. In 1997 structural reforms were made and it was fitted out as a residence, whose current occupancy is 150 residents. The building is divided into 5 floors. The PB consists of: 3 rooms (room for recreational activities or workshops, room "Serranos", room "La Seu"), a dining room, a gym and 5 rooms. From floors P1 to P4 there are the rooms, all of them with the same distribution except the P4 which only has 10 rooms. It should be noted that it is the only residence where the floors are not sectored by level of cognitive impairment and all activities are carried out in the PB. There are no dining rooms or rooms on the room floors. For this reason, three shifts are established for meals. 

Below is an estimate of the hours that are usually used according to activity or space: 

- Gymnasium: facing the street. With little natural light. About 10 people. Individual treatments with two physiotherapists from 10:30 to 11:30. 

- Ludic activities/workshops room: next to the gym. Orientation to the street. About 10 people. Morning and afternoon activities. During the first week of experimental campaigns it was observed that in the afternoon the sample oscillates between 3-4 people and the activity is cinema. Therefore, it cannot be measured. 

- Sala "La Seu": facing the courtyard. 3 very different spaces with U-shaped sofas. There is a lot of heat. During the initial visit, it was decided to carry out different data collection due to the magnitude of the room and the different characteristics of the different spaces. The capacity was estimated at around 50 people (about 10-12 residents per sector). Based on the experimental campaigns, the auxiliaries recommended not to position the measuring equipment in the middle of each sector because it could suffer damage. In addition, the residents in this room present a significant impairment of cognitive status. 

- Serranos" room: facing the courtyard. It also consists of 3 spaces, but not as different as in the "La Seu" room. A maximum occupancy of 50 people is calculated (about 10-12 per sector). Around 12 noon, all the residents of the second and third meal shifts are seated (talking with colleagues or reading). In the afternoon and from 17h, you can start the surveys. 

- Dining room: Between street and patio. There are 3 shifts, of which it is recommended to attend the second one and carry out the surveys when the residents are eating dessert. The capacity of the room is estimated at about 50 people, but due to the short period of time to develop the surveys, you can only ask about 5 people (considering between 2-5' per survey). In terms of comfort, a high thermal contrast (cold sensation) is detected. 

- Snack: offered by the assistants from 15:30 to 17:30 and goes by groups (shifts) and rooms. 

2.1.2. Air-conditioning and ventilation installation 

The air conditioning system is all water with two pipes with a boiler (heating) and a heat pump (cooling, although it could work for heating). A single closed circuit with a pump and a reserve pump. 

The rooms and PB are air-conditioned with fancoils. The P4, being in contact with the roof, the fancoils are not sufficient and there are also individual splits per room. In fact, in some rooms there are only splits and the corridors are not air-conditioned. The most characteristic data to take into account are the following: 

- Hours of operation of the fancoils: from 7:00 to 22:00 

- Setpoint temperature: between 20 and 22oC 

The building does not have forced ventilation. Room windows and corridors open in the mornings to ventilate. During the experimental campaigns, air currents are experienced throughout the day. In reference to DHW, there is an independent boiler and three accumulators located in the PB. 

2.2. Centre 2: Mas Camarena 

2.2.1. Residents' building and routine 

The building of "Mas Camarena" is located in Bétera and was built in the year 2000 as a residence, unlike the rest of buildings that have undergone remodeling to adapt them to their purpose. With a capacity of around 115 residents, this centre is made up of a P-1, a PB and 3 floors. Details are shown below: 

- P-1: kitchen and laundry services. 

- PB: occupational therapy rooms and workshops, gymnasium, hairdressing salon, offices and doctor's office. 

- P1, P2, P3: rooms and dining room per floor. 

- P1: elderly disabled residents (45 residents) 

- P2: residents with good cognitive status (45 residents) 

- P3: disabled young people (25 residents) 

The dining room and lounge floor are now the same space. The double and single rooms are spread over the floors. At the timetable level, from 9:00 to 10:00 breakfast is given in the dining room on each floor in two shifts. Lunch is also fixed in two shifts: One group from 12:30 to 13:30 and another from 13:30 to 14:30. The snack is established from 16:30h. 

The gymnasium used to be the cafeteria. In terms of construction, windows can be seen on two facades, facing the street and the courtyard. There are usually two physiotherapists. As far as timetables are concerned, there are two groups: from 11:00 to 12:00 and another from 12:00 to 13:00. Each group 12-13 people (including people from the CD). 

The occupational therapy room has large windows facing the inner courtyard. When there is no activity, it is estimated an occupation of about 7 people. When there are activities about 20 people. 

2.2.2. Installation of air-conditioning and ventilation 

The Mas Camarena centre has an air water system with a main condensing boiler for heating and DHW and a support boiler only for heating, a main chiller and a support boiler. 4 cooling circuits: north zone, east zone, west zone and basement. It also has an Air Treatment Unit (ATU) on the roof providing air to all the fancoils of the building. 

On the room floors there are about 4 fancoils (long corridor, short corridor, dining room and lounge). Now the dining room and living room are a single space and sometimes just a fancoil is enough. In the PB there are 5 units of fancoils. Some of these share rooms (offices, meetings, reception, etc.). The PB gym is air-conditioned through a Split. It is not known why, but it could be due to the fact that this space had previously been the cafeteria. The rooms only have heating through radiators (one in the room and another in the bathroom of the room except the P3 that there are splits. The most significant data to contemplate are the following: 

- Opening hours: 24 hours in winter until the end of February. Then heating from 19:00 to 8:00 (turned on at night). 

- Setpoint temperature: 24ºC. 

2.3. Centre 3: Holy Family 

2.3.1. Residents' building and routine 

The Sagrada Familia building is located in Barcelona and the year of construction is unknown. This centre is divided into 5 floors. In the PB are the common areas (two living rooms - one used as a library and the other as a television room; dining room; offices; and reception). In the P-1 there is the services section (doctor, hairdresser etc) as well as the gymnasium and occupational therapy/workshop for guided group activities (about 15-20 people). As for the distribution of the rest of the floors, the following aspects stand out: 

- P1, 2 and 3: rooms, living room and dining room. Residents live on the ground floor, as they have a low cognitive state or do not have mobility (some are in bed). 

- P4 and 5: rooms with living room, but without dining room. Residents come down to the PB to eat and for leisure activities. More autonomous residents. With a total of 116 rooms, these can be individual or shared on each floor, reaching a total of 145 residents (P1: 26 residents; P2: 26 residents; P3: 29 residents; P4,5,6: 66 residents) apart from the 6 in the day centre. 

On an indicative level, the timetables by spaces or activity are as follows: 

- From Monday to Friday there are always activities in the gym from 10:00 to 13:00. 

- On Tuesdays and Thursdays the residents go for a walk from 11:30 to 13:00. 

- From 14:00 to 15:30 everyone takes a nap or rests in bed or living rooms. 

During the morning there are continuous activities. From 17:00 to 19:00 domino groups meet in the library room of the PB. In the television room, the majority of residents are usually asleep and half of the room has a low cognitive state, it is difficult to identify which resident could be surveyed. At a general level, it is estimated that there are 15 or 20 people per room. It should be noted that all windows are south-facing and if the curtains are not drawn, the temperature of the balloon could be highly affected when direct solar radiation enters. 

- The snack is at 16:30 in the rooms of the BP for residents with mobility or good cognitive status, but is not mandatory. In this time slot there are also usually family members. 

2.3.2. Air-conditioning and ventilation installation 

Two-tube all-water system with two boilers and two chillers and fancoils for each room and room. A condensing boiler with high efficiency is the one that is working constantly. For consumption peaks, a support boiler is used with lower output, but large (older) capacity. All fancoils hang from the same circuit and have 3 speeds. The set point temperature is 22oC for the whole building. The control, which is centralized from the reception computer, is set by floor time and on/off mode. Occasionally it could be modified per room. Several operating times are distinguished from the fancoils: 

- PB: from 7:30 to 22:00. Heating is almost always on all day. 

- Rooms without people in bed throughout the day: from 7:00 to 10:00; from 13:00 to 14:30; and from 19:00 to 22:00. 

In relation to ventilation, there are 7 heat recuperators that are linked to each floor and some additional for the kitchen and dining rooms. At the level of natural ventilation, windows open in the morning. 

2.4. Center 4. Provença 

2.4.1. Residents' building and routine 

The Provença residential centre is located in Barcelona and has 124 residents distributed over 6 floors + PB. On the PB floor there are the offices, the gymnasium for individualised treatments with physiotherapy, the hairdressing salon and the reception. Residents do not move from the floor to which they belong and there is usually a constant occupancy of about 22 per floor and about 7-8 per activity. In addition, they are distributed by degree of cognitive state. For this reason, we can highlight that from plants P4 to P6 are users with good cognitive status. 

Each floor consists of: a dining room; a living room where group activities are carried out (physiotherapy or occupational therapy) and snacks; rooms. In general, the chambers are double (A and B). The activities take place throughout the day on all floors (from 10 a.m. to 7 p.m.). The space chosen can be the living room on each floor or areas with multipurpose use such as the dining room on the P4. There is no cafeteria. 

2.4.2. Installation of air conditioning and ventilation 

Two-tube all-water system with 2 condensing boilers (for room radiators, common room fancoils and DHW) and a chiller (for common room fancoils). There is no refrigeration in the rooms. 

The radiator circuits are distributed in zones: north-west and south-west, while the fancoils have only one circuit for the whole building. The hours of operation, with no possibility of modification, are: 

- Hours of operation radiators: from 6:00 to 9:00, from 13:00 to 16:00 and from 19:00 to 24:00. These times are so because they serve the rooms and residents are in the rooms when they wake up, for siesta and when they go to sleep. 

- Operating hours fancoils: from 10:00 to 19:00. Setpoint temperature: 22oC in winter. Each fancoil has its own stop and on thermostat, but it is controlled by the maintenance technician. 

In relation to the ventilation, the forced one is emphasized in all the building and it is regulated by means of a CO2 sensor located in the P4. However, the maintenance technician ensures that the building consists of two ventilation systems (one for plants P0 to P3 with heat recovery and one for plants P4 to P6 with input fan and extraction fan). In this system there is no heat recovery due to roof space issues. 

2.5. Centre 5. Tarragona 

2.5.1. Residents' building and routine 

The centre of Tarragona, with a glass roof and a large inner courtyard, was built in the 1960s for the Little Sisters of Charity and was renovated between 2003 and 2008. At the end of the summer, an extension is planned (elevator and to destine the floor of offices to rooms). This building is also characterised by being the most vertical of all (11 floors) as well as having a large sectorisation according to the cognitive state of the residents, as detailed: 

- 9 floors of rooms. P5-P9 have the same distribution (shared double chambers) and the users have a good cognitive level. From P4 down, the rooms are single rooms with shared bathrooms and the main users show a high level of cognitive impairment. However, the physiotherapists and the psychologist reported during the experimental campaign that there are P3 patients who could well answer the questions asked in the survey. 

- PB: dispatches and reception. 

- P-1 common areas (cafeteria, physiotherapy room, cinema room, occupational therapy room or workshops, music therapy room, library and day centre). Each floor has a dining room where breakfast, lunch and dinner are served. Snacks are served in the cafeteria on the P-1. 

In terms of routines, the following schedule is established: 

- 7:00 get up / 9:00 have breakfast 

- 10:15: physiotherapy activity with one or two professionals. In the activity room there are about 30 people and the duration would be about 15 minutes. In the gym, the time of activity is reduced since it is about 15 people with individualized treatments. 

- 11:15: cognitive stimulation activity with the educator, psychologist, animator or TASOC in the therapy room of the P-1. About 15-20 people. Estimated duration is about 45 min. 

- 13:00: Lunch (one hour). Each floor has its own dining room. 

- 16.30h-17:00: snack in the house/cafeteria for the autonomous profiles (80 people) (about 30 minutes). 

- 17:30: recreational activity in different rooms of the P-1 (cinema, bingo, board games, etc.) (from 20 to 25 people). 

2.5.2. Air-conditioning and ventilation installation 

The air conditioning is based on splits. 

2nd Stage: Fieldwork

Data collection began in February, just after the contract was signed and the equipment was purchased.

2.6 Monitoring 

For monitoring the dry temperature (Ta) and relative humidity (HR) of the occupied spaces, average radiant temperature (Trm) and air speed (va) the Delta Ohm HD 32.3 was purchased.

For the dry temperature (Taext) and relative humidity (HRext) outside, the data from the weather stations closest to the building will be used.

For each monitored room, a table was generated with the mean, deviation, minimum and maximum of all the monitored variables.

Table 1. Format for collecting monitored data.

2.7 Satisfaction survey 

In order to carry out the satisfaction survey, different ways of collecting residents' perceptions were analysed. After some tests, it was found that the most reliable method was to use images to determine both Thermal Sensation, Acceptability and Preference.

The reference values of the UNE-EN-ISO-7730:2005 were used to characterise the level of clothing of residents and their activity.

For the collection of information from residents, their level of clothing, activity and thermal sensation, the following template was used:

2.8. Experimental campaign

For each climatic period, three experimental campaigns were planned for each centre. In each centre, around 5 spaces were monitored (common areas, gymnasium, dining room, etc.). For about 15 surveys were obtained. In total 25 spaces monitored approximately 375 surveys for each climatic season.

To date the experimental winter and spring campaign has been carried out. The following table shows the number of surveys carried out in each centre, reaching a total of 1516 (872 in winter and 644 in spring).

Stage 3: Data analysis

The comfort model and the comparison with other models cannot be developed until all the monitored data of the different climatic seasons are available.
However, in order to check the reliability of the data collected, some correlation graphs between variables and models have been made with a sample of the data obtained.

2.8. Analysis of results

A first analysis with the data obtained in the experimental winter campaign in the center of Sagrada familia we obtain that the residents have a different level of thermal sensation to the caretakers.

We obtain a significance value lower than 0.05, therefore we accept the null hypothesis and we accept that the two subgroups behave differently in relation to the thermal sensation.
A first analysis has also been carried out to check whether the thermal sensation of the residents depends on the monitored space.

We obtain a value of significance greater than 0.05, therefore we reject the null hypothesis and accept that the two subgroups behave in the same way in relation to the thermal sensation, and with which the thermal sensation does not depend on the space where the monitoring was carried out.

On the other hand, an analysis of correlation between the quantitative variables was carried out:

The Preference depends inversely on the Thermal Sensation. When residents perceive a thermal sensation of heat, they prefer a cooler environment. This result confirms that the neutral thermal sensation (ST=0) can be the comfort ST.

The Thermal Sensation depends on the Operating Temperature. The operating temperature, which is the average between the ambient temperature and the radiant temperature, also has a level of correlation with the outside temperature. In this case it can be seen that although the set temperature is always the same (23oC), the operating temperature oscillates depending on the outside temperature.

A linear regression has also been carried out between the ST and the operating temperature or a high correlation. It can be seen that in order to obtain a neutral ST (ST=0) with an operating temperature of 23.2ºC.

The comfort model has also been calculated in relation to the average outdoor temperature through the Griffith model and we obtain the following adaptive comfort model:

Tc = 0,086 - Trm + 22,103

A comfort model (ST) has been made taking into account all the monitored variables and we have obtained the following expression:

ST = -6,852 + 0,18 - Hrint + 0,186 - Top + 1,161 - Act

Finally, contrasting the model obtained with those existing in the ASHRAE- 55 and EN-15215 standards, we have obtained the following regressions:

It is observed that the neutral temperature of the model obtained with experimental data is lower (22.6ºC) than those of the models of the regulations (about 23ºC). These results
shall be validated with the entire sample (all 5 centres).

On the other hand, the slope of the straight line indicates that the thermal sensitivity of the elderly is lower than what the models of the standards consider. For a PPD of 20% the temperature oscillates 3ºC while according to the regulations this value is at 1ºC. These results make it possible to foresee great differences between existing models and those that are really necessary for older people.

At the moment they are only a first approximation waiting to analyse all the extermental data grouped together.