Cold Outdoor Research Articles

Study of Selected Characteristics of 8-Cell HHO Generator Using Various Concentrations of NaOH Solutions

The aim of the contribution is to carry out the study of the conditions of HHO gas production. All of the measurements were executed on dry cell HHO generator made of 8 stainless electrodes with NaOH solution as an electrolyte. Three concentrations of NaOH solutions (5%, 10% and 20%) were used and the changes in volt-ampere characteristics, efficiency and hourly volume performance were monitored and results were processed and compared. The KOH solution is considered as a best available electrolyte from the perspective of stability and moreover it is more suitable in cold outdoor conditions. However, the NaOH solution provides higher maximum efficiency of HHO gas production. Some recommendations to increase the efficiency of the generator are described in the conclusion.

Effects of outdoor temperature on changes in physiological variables before and after lunch in healthy women

Previous studies of autonomic nervous system responses before and after eating when controlling patient conditions and room temperature have provided inconsistent results. We hypothesized that several physiological parameters reflecting autonomic activity are affected by outdoor temperature before and after a meal. We measured the following physiological variables before and after a fixed meal in 53 healthy Japanese women: skin temperature, systolic and diastolic blood pressure, salivary amylase, blood glucose, heart rate, and heart rate variability. We assessed satiety before and after lunch using a visual analog scale (100 mm). We recorded outdoor temperature, atmospheric pressure, and relative humidity. Skin temperature rose significantly 1 h after eating (greater in cold weather) (P = 0.008). Cold weather markedly influenced changes in diastolic blood pressure before (P = 0.017) and after lunch (P = 0.013). Fasting salivary amylase activity increased significantly in cold weather but fell significantly after lunch (significantly greater in cold weather) (P = 0.007). Salivary amylase was significantly associated with cold weather, low atmospheric pressure, and low relative humidity 30 min after lunch (P < 0.05). Cold weather significantly influenced heart rate variability (P = 0.001). The decreased low frequency (LF)/high frequency (HF) ratio, increased Δ LF/HF ratio, and increased Δ salivary amylase activity imply that cold outdoor temperature is associated with dominant parasympathetic activity after lunch. Our results clarify the relationship between environmental factors, food intake, and autonomic system and physiological variables, which helps our understanding of homeostasis and metabolism.Electronic supplementary materialThe online version of this article (doi:10.1007/s00484-014-0800-1) contains supplementary material, which is available to authorized users.

Development and characteristics of a method for self-contained ice production using cold outdoor air in winter

This paper proposes a new method of ice production using a simple insulation lid and a self-contained ice production. Results of experiments in a freezer showed that ice could be produced with three proposed containers. It was possible to produce ice using a flat-plate-type simple insulation lid with the 1-ton and 0.5-ton containers. It was also proven that self-contained ice production was possible using a cap-type simple insulation lid with the 135-kg container. Outdoor experiments were also conducted. It was confirmed that ice could be produced outdoors and shown that the production method for ice intended for space cooling with a mixture of snow and water was effective. Furthermore, a method of production for high-value-added clear ice was proposed based on the outcomes of indoor and outdoor experiments. It was confirmed that all the items of the relevant standards were satisfied as a result of water quality examination of edible ice and ice intended for space cooling.

窓の断熱改修が住宅の温熱環境と高齢者の生活および健康に及ぼす影響に関する研究

This study was conducted to investigate the effects of installing well-insulated windows on the residential indoor thermal environment and the thermal comfort and health of occupants. We conducted measurement of thermal environments, occupant questionnaire about thermal comfort and surveys on physical activities of the elderly, before and after inner windows were added to inhabited houses. The survey was carried out for eight old wooden houses with elderly occupants in Yamagata City and surrounding areas. The results of our measurement and survey revealed that window renovation reduced the impact of cold outdoor air temperature on indoor thermal environment and improved thermal comfort in winter. Further, steps per day of the elderly significantly increased after renovation.

Skin temperature measurement using an infrared thermometer on patients who have been exposed to cold

The aim of this study was to determine if the skin temperature of febrile children is affected by the child's exposure to cold outdoor temperatures immediately prior to the taking of that temperature. A total of 150 febrile and non-febrile children (aged 3-10 years) who had walked to the hospital's pediatric emergency department and were thus exposed to outside cold weather were enrolled in the study. Using infrared thermometry, forehead and chest skin temperatures were simultaneously measured every 2 min during the first 14 min after presentation. Temperatures were recorded and differences between the two measurements were calculated. By the fifth evaluation (10 min from the first reading), skin temperatures from forehead and chest had equalized. Determination of fever from the body parts that had been exposed to cold environmental conditions may cause contradictory results if taken while the child is still chilled from exposure to the cold. For accuracy, children should be acclimated to the indoor temperature before taking body temperature readings. Acclimation takes at least 10 min after coming in from cold weather outside.

PP76 Exploring Barriers and Solutions to take up of Interventions to Address Fuel Poverty: A Health Impact Assessment of Fuel Poverty Policy in England

BackgroundFuel poverty – whereby households are unable to keep warm at reasonable cost – is an on-going problem within the UK. There are known health impacts of living in cold...

Thermal performance optimization of free cooling systems using enhanced latent heat thermal storage unit

Free cooling systems use phase change materials (PCMs) to store outdoor cold during the night and to supply it to the indoor environment during the day when the need for cooling increases. This work presents a numerical investigation of the performance enhancement of a free cooling system using a latent heat thermal storage (LHTS) unit employing multiple PCMs. The PCM storage system consists of several flat PCM slabs arranged in layers with a passage in between for the heat transfer fluid (HTF). Using the effective heat capacity method, the process of melting and solidification of the PCM is predicted. The energy storage effectiveness (as a new performance parameter for LHTS units) and coefficient of performance (COP) of the system are calculated. These two performance indicators are used to optimize the system. The suitability of both methods for optimization purpose is discussed indicating the superiority of the energy based (COP) method.

Predicting backdrafting and spillage for natural-draft gas combustion appliances: A validation of VENT-II

VENT-II is a computer program designed to provide detailed analysis of natural-draft and induced-draft combustion appliance vent systems (i.e., furnace or water heater). This program is capable of predicting house depressurization thresholds that lead to backdrafting and spillage of combustion appliances; however, validation reports of the program being applied for this purpose are not readily available. The purpose of this article is to assess VENT-II's ability to predict combustion gas spillage events due to house depressurization by comparing VENT-II simulated results with experimental data for four appliance configurations. The results show that VENT-II correctly predicts depressurizations resulting in spillage for natural draft appliances operating in cold and mild outdoor conditions but not for hot conditions. In the latter case, the predicted depressurizations depend on whether the vent section is defined as part of the vent connector or the common vent when setting up the model. Overall, the VENT-II solver requires further investigation before it can be used reliably to predict spillage caused by depressurization over a full year of weather conditions, especially where hot conditions occur.

Analysis of Cold Protective Clothing’s Design and Market - Functional &amp; Structural Design

Relationships of cold protective clothing design and market were explored for apparel function and structure, and cold protective clothing company product to successful meet market demand. People require a large number of outdoor cold protective clothing that makes a chain of market, designer, consumer and manufacturer. They are not only focus on apparel functional comfort but also garment style preference structural design. Sophisticated new technologies are available to the apparel industry to create automated custom-fitted clothing, using 3-D body scanning and software designed to automate patternmaking to effectively improve productivity [1]. Currently, the quantification of fit is complex and ambiguous and objective methods. The purpose of this study was to explore the cold protective clothing manufacturer should have the necessary conditions on function and structure for the market demand.

Impediments to energy-efficient ventilation of German dwellings: A case study in Aachen

Manual ventilation of dwellings in winter consumes excess heating energy, as cold outdoor air replaces warm indoor air. The German government promotes ‘shock-ventilation’ (Stoßlüften), where all windows are opened simultaneously, fully and briefly, to minimise energy wastage. However, the predominant design of windows in Germany's housing stock mitigates against this strategy, as these windows open inwards while their indoor ledges provide ideal storage for pot-plants and other objects, blocking normal opening. An alternative window setting, long periods of trickle-ventilation, can consume up to 20 times as much energy as shock-ventilation. This paper reports a pilot study of household ventilation capabilities and practices in the German municipality of Aachen. A statistical analysis indicates 29% of dwellings have sufficiently unimpeded windows to facilitate shock-ventilation, while householder interviews reveal reasons for reliance on trickle-ventilation, including convenience and underestimation of its energy consumption. Analysis of results using ‘social practice theory’ suggests three possible policy interventions to improve energy-efficiency of ventilation. The results suggest the need for a nationwide study to quantify energy wastage through mismanaged ventilation, not least because of its possible cost to the country, of several billion Euros annually, and the millions of tonnes of CO2 emissions it most likely causes.

Evaluation of the effects of low temperature on performance of standard non-electric medical equipment at −21.5 °C (−6.7 °F) – A descriptive study on a real life challenge in the prehospital setting

Aim of the studyTo our knowledge, there are no previous reports on the performance of medical equipment in cold conditions. The aim of this study was to evaluate the performance of several plastic, single-use medical equipment exposed to cold outdoor temperature. MethodsMedical equipment such as endotracheal tubes, suction catheters and intravenous lines were exposed to outdoor temperature of −21.5°C (−6.7°F) for 15min. After 15min the equipment underwent a manual stress test resembling normal prehospital use. ResultsAfter 15min in −21.5°C (−6.7°F) during the stress test several equipment exhibited significant changes in properties as compared to room temperature. Mainly, loss of flexibility and connectivity was observed. Examples of these were fractures of endotracheal tubes and suction catheters, and permanent airway adapter loosening from a respirator breathing circuit. ConclusionPlastic medical equipment has poor tolerance of cold conditions. Loss of equipment performance and properties could result in relevant harm to the patient. Retaining the equipment, e.g. in a closed backpack slows the rate of temperature decrease.

Feasibility Study on Energy Saving Effect and Economical Benefit of Ice Production Method using Cold Outdoor Air in Winter

Feasibility Study on Energy Saving Effect and Economical Benefit of Ice Production Method using Cold Outdoor Air in Winter

Model-based Optimal Control of Outdoor Air Flow Rate of an Air-Conditioning System with Primary Air-Handling Unit

This paper presents a model-based outdoor air flow rate optimal control strategy for multi-zone variable air volume air-conditioning systems with the primary air-handling units. An adaptive optimisation algorithm is adopted for optimising the set point of the outdoor air flow rate to minimise the energy cost, which could compromise the energy consumption of the primary fan and the cooling energy saving by the cold outdoor air. The primary fan energy consumption can be predicted using a simplified incremental fan model and the main parameters of this model are identified online. The cooling energy saving by the outdoor air is estimated online using the enthalpies of the air streams. The lower limit of the outdoor air flow rate is determined by a CO2-based adaptive demand-controlled ventilation strategy using the dynamic multi-space equation to maintain the satisfied indoor air quality (IAQ). Tests were conducted to evaluate the performance of the control strategy applied to a practical building system in simulation environment. The results show that the proposed optimal control strategy can reduce energy consumption significantly, while maintaining a satisfactory IAQ.

Condensation Problems in Precast Concrete Cladding Systems in Cold Climates

Abstract The use of precast concrete panels as a cladding material can provide an economical and attractive method to enclose contemporary buildings. In cold climates, improper detailing or inappropriate construction of precast clad walls can result in widespread water problems due to condensation forming within the wall construction. Condensation may form at the interior of the wall assembly due to inadequate protection against air flow through the wall, such as exfiltration of warm, moist indoor air, or by infiltration of cold outdoor air reaching the interior wall components. The condensation within the wall assembly can also be caused by water vapor diffusion into the wall from the building interior. In addition, inadequate separation and/or insulation between precast panels and adjacent cladding components, such as windows, curtain wall, or metal framing components, can result in surface condensation on these wall elements. The moisture from condensation can cause extensive damage to finish materials, including insulation and gypsum wallboard; can result in corrosion and deterioration of metal components, such as structural connections and metal wall framing; and may result in mold and mildew. This paper will (1) present examples of precast clad building wall construction where significant condensation problems have occurred; (2) discuss typical causes of condensation in precast clad buildings in cold climates; (3) review design considerations to reduce the potential for condensation in new buildings; and (4) present repair methods to address condensation in existing buildings.

The Prevalence and Characteristics of Brown Adipose Tissue in an (18)F-FDG PET Study of Koreans.

The object of this study was to evaluate the prevalence and characteristics of brown adipose tissue (BAT) in Korean subjects using (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET). Six thousand and five consecutive (18)F-FDG PET/CT scans of 5,115 patients (3,007 females and 2,108 males, mean age 53.5 years) were retrospectively reviewed. We characterized the nature of BAT, such as its location, and we assessed the influence of sex, age, body mass index (BMI), and temperature on BAT. The prevalence of BAT in Koreans in a single (18)F-FDG PET/CT scan in average conditions was 1.07%. The BAT detection rate was higher in females than males (1.32% vs 0.73%), and also with younger age (7.94% vs 0.73%), lower BMI (BMI with BAT, 21.1 vs BMI without BAT, 23.15) and cold outdoor temperature (1.65% vs 0.49%). The most frequent location of BAT was the supraclavicular area (left, 0.91%; right, 0.88%) and ventral neck area (left, 0.62%; right, 0.63%). The characteristics of BAT in Koreans are not different from those described for Caucasians. However, the low prevalence of BAT in our study might be related to some scan condition like ambient temperature, but further study is needed.

Low-temperature baseboard heaters with integrated air supply – An analytical and numerical investigation

The functioning of a hydronic baseboard heating system with integrated air supply was analyzed. The aim was to investigate thermal performance of the system when cold outdoor (ventilation) airflow was forced through the baseboard heater. The performance of the system was evaluated for different ventilation rates at typical outdoor temperatures during the Swedish winter season. Three different analytical models and Computational Fluid Dynamics (CFD) were used to predict the temperature rise of the airflow inside the baseboard heater. Good agreement between numerical (CFD) and analytical calculations was obtained. Calculations showed that it was fully possible to pre-heat the incoming airflow to the indoor temperature and to cover transmission losses, using 45 °C supply water flow. The analytical calculations also showed that the airflow per supply opening in the baseboard heater needed to be limited to 7.0 l/s due to pressure losses inside the channel. At this ventilation rate, the integrated system with one air supply gave about 2.1 more heat output than a conventional baseboard heating system. CFD simulations also showed that the integrated system was capable of countering downdraught created by 2.0 m high glazed areas and a cold outdoor environment. Draught discomfort in the case with the conventional system was slightly above the recommended upper limit, but heat distribution across whole analyzed office space was uniform for both heating systems. It was concluded that low-temperature baseboard heating systems with integrated air supply can meet both international comfort requirements, and lead to energy savings in cold climates.

Focus on materials

Focus on materials

Moisture Convection Performance of External Walls and Roofs

Full-scale laboratory measurements were taken and 2D simulations were performed to determine the moisture convection performance of the joint of an external wall and an attic floor. Both the measured and simulated results showed that the building fabric is locally sensitive to exfiltration airflow as moisture convection could cause a remarkable increase in the moisture accumulation rate on the inner surface of the sheathing. The results prove that in modern houses with balanced ventilation, where the positive pressure caused by the stack effect cannot be easily controlled, it is essential to control moisture convection by good airtightness and the use of assembly solutions with improved hygrothermal performance, such as the case with mineral wool sheathing that was tested. The simulated results showed that the use of a constant moisture excess value instead of the profile did not cause any inaccuracy in the moisture content. At the same time, the use of the constant outdoor temperature over a long time period did change the hygrothermal performance, which became significantly more critical when simulated with variable outdoor temperatures. The laboratory measurement and simulation results show that in a cold climate, for the assemblies being studied with mineral wool sheathing, leakage rates of 0.1—0.2 L/(s·m) at a 10 Pa pressure difference may be used as performance criteria for moisture convection in a two-storey house with dimensioning moisture excess 4 g/m 3 and a cold outdoor climate. Previous studies on the leakage characteristics show that these leakage rates are easily achievable in practice with careful workmanship.

Study of ventilation cooling technology for telecommunication base stations in Guangzhou

Telecommunication base stations (TBSs) in Guangzhou, China are used in large numbers, and have high heat density, a long cooling season and high energy consumption. To make full use of natural outdoor cooling resources, a new ventilation cooling technology (VCT) is proposed. As the heat from the telecommunication equipment can be dissipated directly by outdoor cold air, the runtime of the air conditioners can be shortened by VCT, resulting in notable energy savings. Based on field investigation of a typical TBS, VCT was studied systematically. The results show that the application of VCT to the TBSs in Guangzhou is feasible, the energy saving for VCT is about 49% and the payoff period is less than two years. Obvious economic and social benefits will be achieved, provided that VCT can be broadly applied. Also, computational fluid dynamics simulation results indicate that optimization of airflow organization has a strong influence on heat dissipation efficiency for VCT.

Timing of bud set in Picea abies is regulated by a memory of temperature during zygotic and somatic embryogenesis

It has been shown previously that height growth and bud phenology are influenced by the temperature during zygotic embryogenesis in Picea abies. To test whether this phenomenon operates within individual plants, clones produced through somatic embryogenesis were used. Seeds were from a full-sib family produced in both a cold (outdoor) and a warm (inside a glasshouse) environment. Embryogenic clones derived from mature zygotic embryos from both crossing environments were cultured at 18, 23 and 28 degrees C during the proliferation and embryo maturation steps. After the second growing season in a glasshouse, plants from the warm seed production environment were taller and had significantly later bud set. For the first time, it is also shown that plants are influenced by the in vitro temperature during somatic embryo development. The warmer the temperature, the later the plants formed terminal buds. The differences were similar to those produced by a provenance separation of 4-6 degrees of latitude. The results indicate that there exists a mechanism in P. abies that operates during embryo development and adjusts the timing of bud set in accordance with the temperature conditions in which the mother tree lives. This in turn counteracts negative effects of gene flow among populations located along altitudinal and latitudinal gradients.