Study On The Effect Of Indoor Thermal Environment On Cardiovascular Health Of The Elderly In Rural Areas In Cold Regions

With the improvement of living standards and medical level,the trend of population aging is accelerating,and the aging of the population has become a major challenge faced by many countries.Indoor thermal environment is closely related to human health.The human body maintains thermal balance with the surrounding environment through temperature regulation.However,the elderly population’s ability to regulate body temperature declines,making them a vulnerable group under thermal environment exposure.In this article,the indoor living environment parameters,cardiovascular physiological parameters,and thermal comfort of rural residential areas in cold regions were studied through surveys,field measurements,and statistical analysis.The impact of indoor thermal environment on the thermal comfort level and cardiovascular health of the elderly was analyzed.Furthermore,a prediction model for hypertension based on room temperature was established using stepwise regression and Bayesian fitting methods.A comprehensive evaluation model for improving residential environments and preventing hypertension was developed by combining the De ST-h simulation and optimizing rural residential building energy consumption.This study investigated rural residential buildings and their residents during the heating season in Weifang,China.The results of the survey showed that rural residential buildings are mainly composed of brick and concrete walls with a simple form of envelope structure and poor thermal performance.The primary heating method used in these homes is coal-fired heating,which is generally provided in the bedrooms and kitchens through decentralized heating systems.The thermal environment comfort is poor,and there is a significant difference in physiological and subjective responses to temperature changes between elderly and young individuals.Field measurements were conducted,and the basic human body temperature regulation model was used to simulate and experimentally verify the skin temperature on the back of the hand,resulting in experimental results that conform to the basic theoretical law.Through the analysis of the partial correlation between various cardiovascular physiological parameters,the age,BMI,and indoor temperature of the subjects,it was found that systolic blood pressure,pulse pressure,and heart rate have a significant negative correlation with indoor temperature,while blood flow velocity and skin temperature on the back of the hand have a significant positive correlation with indoor temperature.Diastolic blood pressure has no significant correlation with indoor temperature.By stepwise regression analysis,it was found that for every 1 ℃ decrease in indoor temperature,systolic blood pressure increased by 1.05 mm Hg,pulse pressure increased by 0.53 mm Hg,heart rate increased by 0.99 bpm,blood flow velocity decreased by 1.54cm/s,and skin temperature on the back of the hand decreased by 0.13 ℃.When the indoor temperature was below 18 ℃,the proportion of elderly people whose pulse pressure exceeded the normal value of 60 mm Hg was 98.7 %.When the indoor temperature was between 18-22 ℃,the proportion of residents with abnormal cardiovascular physiological parameters was the lowest.This study explores the quantitative prediction of the relationship between indoor temperature in rural residential buildings and the incidence of hypertension among residents.The indoor temperature-hypertension prediction model shows that as indoor temperature decreases,the predicted incidence of hypertension gradually increases.The impact of low indoor temperature on the predicted incidence of hypertension is significantly higher among older people than among younger people.Compared with the incidence of hypertension at the lowest indoor temperature of 1.3 ℃,the incidence among older people at 24 ℃ is reduced by 43 %.The benefit model of preventing hypertension by improving the residential environment shows that optimizing the thermal performance of the building envelope and raising the indoor temperature not only reduces energy consumption for heating but also lowers the medical expenses for treating hypertension.The combined benefits of building energy-saving and the nonenergy benefits of reducing the incidence of hypertension improve the economic benefits of residential buildings.Furthermore,the longer the residential building is used,the higher the economic benefits.This study proposed corresponding indoor thermal environment control strategies based on the temperature-based hypertension prediction model to provide scientific guidance for reducing the risk of cardiovascular diseases in elderly rural residents.Furthermore,it improved the health of elderly rural residents and the economic benefits of housing by combining optimization and renovation of building energy efficiency.