Short answer

Designers should prioritize achieving an operative temperature of approximately 28.0°C for elderly occupants in hot-humid, low-wind environments, ensuring the system can maintain a range between 26.4°C and 29.5°C for broad acceptability.

Field: Human Factors
Source: Indoor Air (2025)
Method: Quantitative survey and environmental measurement
Sample: 600 participants
Evidence: Strong effect

The neutral operative temperature for elderly individuals in hot-humid, low-wind environments is 28.0°C, with an acceptable range of 26.4°C to 29.5°C. This human factors research insight is drawn from a 2025 study published in Indoor Air. Using Quantitative survey and environmental measurement with 600 participants, researchers explored how this design variable affects real-world outcomes. The key design takeaway: Designers should prioritize achieving an operative temperature of approximately 28.0°C for elderly occupants in hot-humid, low-wind environments, ensuring the system can maintain a range between 26.4°C and 29.5°C for broad acceptability.

Study

Human FactorsNew This WeekStrong effect

Elderly thermal comfort neutral temperature is 28.0°C in hot-humid climates

The neutral operative temperature for elderly individuals in hot-humid, low-wind environments is 28.0°C, with an acceptable range of 26.4°C to 29.5°C.

Indoor Air · 2025

Key Findings

01The neutral operative temperature for the elderly in this climate is 28.0°C.
02The operative temperature range for 80% thermal acceptability is 26.4°C–29.5°C.
03The developed adaptive thermal comfort model accurately predicts local thermal comfort.
04There are gender differences in thermal comfort, with males preferring slightly cooler temperatures than females.
05Outdoor air temperature significantly influences the neutral temperature.

Application

Design takeaway

How to apply

When designing or retrofitting residential facilities for the elderly in hot-humid climates, use 28.0°C as a target operative temperature and ensure the system can accommodate a range of 26.4°C to 29.5°C.

Project actions

01When researching user comfort, consider the specific demographic (e.g., age, gender) and climate.
02Measure both environmental conditions and user feedback to establish comfort parameters.
03Explore adaptive comfort models that account for environmental and behavioral factors.

Method & Evidence

AimWhat is the neutral operative temperature and acceptable thermal range for elderly individuals living in naturally ventilated residential buildings in a hot-humid, low-wind climate during summer?

MethodQuantitative survey and environmental measurement

ProcedureA questionnaire survey on thermal sensation was administered to 600 elderly participants in naturally ventilated residential buildings during summer. Simultaneously, indoor thermal environment measurements were taken. Data was analyzed to determine neutral temperature and thermal acceptability ranges, and an adaptive thermal comfort model was developed and validated.

Sample600 participants

ContextResidential buildings for the elderly in a hot-humid, low-wind climate (Nanning, China) during summer.

Variables

IV["Operative temperature","Outdoor air temperature","Gender"]

DV["Thermal sensation vote","Thermal acceptability"]

CV["Climate (hot-humid, less-windy)","Season (summer)","Building type (naturally ventilated residential)","Participant age group (elderly)"]

Strengths & Limitations

Strengths

+Large sample size (600 participants).
+Combines subjective user feedback with objective environmental measurements.
+Development and validation of an adaptive thermal comfort model.

Limitations

The findings are specific to the climate and building types studied. Generalizing to all hot-humid climates or different building designs requires further investigation.

Reliability & validity

Reliability is supported by the use of standardized questionnaires and environmental measurement tools. Validity is enhanced by the large sample size, the inclusion of both subjective and objective data, and the validation of the developed model against measured data.

Think critically

How might the findings on gender differences in thermal comfort be addressed in a single-room design for a mixed-gender elderly couple?

Design Principles

"Design for the specific thermal comfort needs of vulnerable populations, considering climate and demographic factors."

Understanding the specific thermal comfort needs of the elderly is crucial for designing healthy and supportive living environments. This data directly informs HVAC system design, building insulation strategies, and the selection of materials to ensure occupant well-being and reduce potential health risks associated with thermal stress.

What This Means for Your Design

Older people in hot and humid places feel most comfortable when the indoor temperature is around 28°C, and a range of 26.4°C to 29.5°C is okay for most of them.

How to use in your project

1.Use the identified neutral temperature and acceptability range as a benchmark for evaluating thermal comfort in your design.
2.Cite the study when justifying design decisions related to temperature control and building envelopes for elderly users in similar climates.

Add to My Project

Quick Cite

Paragraph starter

This research indicates that for elderly individuals in hot-humid, low-wind climates, the neutral operative temperature is 28.0°C, with an acceptable range of 26.4°C–29.5°C. This suggests that design interventions should aim to maintain indoor temperatures within this specific range to optimize occupant comfort and well-being.

Source

Indoor Air

Evaluating Indoor Thermal Comfort of the Elderly During Summer in the Hot‐Humid and Less‐Windy Climate

journal · 2025

View source

Questions About This Research

What does the research say about elderly thermal comfort neutral temperature is 28.0°c in hot-humid climates?: Designers should prioritize achieving an operative temperature of approximately 28.0°C for elderly occupants in hot-humid, low-wind environments, ensuring the system can maintain a range between 26.4°C and 29.5°C for broad acceptability. Evidence: Indoor Air (2025).
Why does "Elderly thermal comfort neutral temperature is 28.0°C in hot-humid climates" matter for design?: Understanding the specific thermal comfort needs of the elderly is crucial for designing healthy and supportive living environments. This data directly informs HVAC system design, building insulation strategies, and the selection of materials to ensure occupant well-being and reduce potential health risks associated with thermal stress.
How can designers apply this research?: Designers should prioritize achieving an operative temperature of approximately 28.0°C for elderly occupants in hot-humid, low-wind environments, ensuring the system can maintain a range between 26.4°C and 29.5°C for broad acceptability.
What were the main findings?: The neutral operative temperature for the elderly in this climate is 28.0°C.. The operative temperature range for 80% thermal acceptability is 26.4°C–29.5°C.. The developed adaptive thermal comfort model accurately predicts local thermal comfort.. There are gender differences in thermal comfort, with males preferring slightly cooler temperatures than females.
What research method was used?: Quantitative survey and environmental measurement with 600 participants.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2025 journal from Indoor Air.
What should I do differently in my next project?: When designing or retrofitting residential facilities for the elderly in hot-humid climates, use 28.0°C as a target operative temperature and ensure the system can accommodate a range of 26.4°C to 29.5°C.
What are the limitations?: The study was conducted in a specific geographical location; findings may vary in other hot-humid regions with different building typologies or wind patterns. The study focused on naturally ventilated buildings, and findings might differ for air-conditioned environments.