Range Of Outdoor Temperatures Research Articles

Daily indoor-to-outdoor temperature and humidity relationships: a sample across seasons and diverse climatic regions.

The health consequences of heat and cold are usually evaluated based on associations with outdoor measurements collected at a nearby weather reporting station. However, people in the developed world spend little time outdoors, especially during extreme temperature events. We examined the association between indoor and outdoor temperature and humidity in a range of climates. We measured indoor temperature, apparent temperature, relative humidity, dew point, and specific humidity (a measure of moisture content in air) for one calendar year (2012) in a convenience sample of eight diverse locations ranging from the equatorial region (10 °N) to the Arctic (64 °N). We then compared the indoor conditions to outdoor values recorded at the nearest airport weather station. We found that the shape of the indoor-to-outdoor temperature and humidity relationships varied across seasons and locations. Indoor temperatures showed little variation across season and location. There was large variation in indoor relative humidity between seasons and between locations which was independent of outdoor airport measurements. On the other hand, indoor specific humidity, and to a lesser extent dew point, tracked with outdoor, airport measurements both seasonally and between climates, across a wide range of outdoor temperatures. These results suggest that, in general, outdoor measures of actual moisture content in air better capture indoor conditions than outdoor temperature and relative humidity. Therefore, in studies where water vapor is among the parameters of interest for examining weather-related health effects, outdoor measurements of actual moisture content can be more reliably used as a proxy for indoor exposure than the more commonly examined variables of temperature and relative humidity.

Experimental thermal performance of a solar source heat-pump system for residential heating in cold climate region

Abstract Solar source heat pump systems present tremendous environmental benefits when compared to the conventional systems for residential applications. In addition to not exhausting natural resources, their main advantage is, in most cases, total absence of almost any air emissions or waste products. In order to investigate the performance of a solar source and energy stored heat-pump system in the province of Erzurum, an experimental set-up was constructed, which consisted of twelve flat-plate solar collector, a sensible heat energy storage tank, a water-to-water plate heat exchanger, a liquid-to-liquid vapor compression heat pump, water circulating pumps and other measurement equipments. The experiments were carried out from January to June of 2004 and, the collector efficiency ( η c ), the heat pump coefficient of performance (COP) and the system performance (COPS) were calculated. In these months performed of the experiments, the outdoor temperature range varies from −10.8 °C to 14.6 °C. This study shows that the system could be used for residential heating in the province of Erzurum having the coldest climate of Turkey.

The Influence of Air Circulation, Jet Discharge Momentum Flux and Nozzle Design Parameters on the Tightness of an Upwards Blowing Air Curtain

Air curtains are used to eliminate airflows through doorways (doorway tightness). In this paper the impacts of air circulation, jet discharge momentum flux and nozzle design parameters on the tightness of an upwards blowing air curtain are presented. The tightness values were measured using a tracer gas decay method in the laboratory hall. Measurements were undertaken for two nozzle widths, 30 mm and 120 mm, and for two different discharge angles, 10° and 30°. According to the study, the upper limit for the tightness of the upwards blowing air curtain is 80%. The difference in tightness between a recirculated and non-circulated air curtain is significant, being 20%. The selection of the jet design parameters can be undertaken fairly freely as long as the force balance at the doorway is valid. When the jet discharge momentum is optimal, the effect of the nozzle width, discharge angle and discharge velocity on the tightness of the air curtain is small. To keep the tightness level of the air curtain high enough, regardless of outdoor temperature fluctuation, a jet velocity controlling system is recommended. In the typical outdoor temperature range for Finland (-30°C to +10°C), the lack of a jet velocity controlling system reduces the tightness of the air curtain by 20 to 60% depending on the nozzle width and discharge angle. When selecting the jet design parameters by the moment of momentum principle in a relatively tight building (n50-value < 4.2 1/h), it is recommended to use a value of 0.6 - 0.7 times the doorway height for the stack neutral pressure height in order to achieve an airtight air curtain and to avoid the breakthrough phenomenon.

Colorless Operation of WDM-PON Employing Uncooled Spectrum-Sliced Reflective Semiconductor Optical Amplifiers

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We demonstrate a low-cost wavelength- division- multiplexed<?Pub _nolinebreak=""?> passive optical network based on colorless uncooled spectrum-sliced reflective semiconductor optical amplifiers. In this network, we achieve bit-error rates of better than <emphasis><formula formulatype="inline"><tex>$10^{-10}$</tex> </formula></emphasis> over 32 100-GHz-spaced channels from 0 <emphasis><formula formulatype="inline"><tex>$^{\circ}$</tex></formula></emphasis>C to 60 <emphasis><formula formulatype="inline"><tex>$^{\circ}$</tex></formula></emphasis>C in 155-Mb/s transmissions. The penalties due to dispersion effect and Rayleigh backscattering interference over 25 km are almost negligible. We also present colorless operations over 16-channel coverage in outdoor temperature range. </para>

Effect of Refrigerant Flow Control on the Heating Performance of a Variable-Speed Heat Pump Operating at Low Outdoor Temperature

An experimental study was conducted to investigate the effect of electronic flow control on the performance of a variable-speed heat pump. A heat pump with two different expansion devices (capillary tube and electronic expansion valve) was tested in a psychrometric calorimeter over a range of outdoor temperatures from −15 to 7°C. Heat pump performance was first optimized with respect to charge for each expansion device through cycle-matching tests. Parametric tests also were conducted by changing compressor speed and opening angle for the electronic expansion valve at each outdoor temperature. The refrigeration cycle characteristics of the electronic valve were illustrated using pressure-enthalpy diagrams. Performance enhancement was also analyzed in terms of superheat, heating capacity, and energy efficiency ratio (EER). Comparison of the capillary tube and electronic valve indicated that the superheat significantly improved when using the electronic valve. Also, unit showed larger heating capacity and EER with the electronic valve than with the capillary tube except when the compressor speed was above 95 Hz. Enhancement of heating performance became larger as outdoor temperature decreased.

A low-power integrated tuner for cable telephony applications

This paper describes an integrated tuner for cable telephony in a 0.35 /spl mu/m, 27 GHz SOI BiCMOS technology. The IC integrates a complete dual-conversion signal path including upconverter, downconverter, variable-gain amplifier, LO synthesizers with fully integrated voltage-controlled oscillators, gain control circuitry, as well as digital calibration and interface circuits. It accepts signals in the 200-880 MHz band and produces a 44 MHz IF. Drawing 168 mA from a 3 V supply, the tuner system has a worst case noise factor of 7.3 dB, system phase noise below -78 dBc/Hz at a 10 kHz offset, spurs below -42 dBc for 137 5 dBmV input channels, a gain of 60 dB, and gain control range of 68 dB. The 13 mm/sup 2/ IC meets specifications across an outdoor temperature range of -40/spl deg/C to 100/spl deg/C in production lots.

Heart rate response to industrial work at different outdoor temperatures with or without temperature control system at the plant

Different outdoor temperatures, the association between indoor temperature control at the workplace and working heart rates of industrial employees were evaluated. The subjects, 6,016 male and female employees in 21 industrial plants in Israel, were screened for cardiovascular risk factors between 1985–87 (The CORDIS Study). The data collected included resting heart rate, working heart rate (based on one hour ambulatory ECG), outdoor temperatures, temperature control (TC) status of the plant, workload, age and health-related habits. At outdoor temperatures below or above 22–28°C, subjects working in plants with TC had lower mean working heart rate HR (- 2 bpm) than those working in plants without TC (p < 0·0004 after adjustment for confounders). No statistically significant differences in mean working HR were found between subjects working with TC (at all the outdoor temperatures) and those without TC within the outdoor temperature range 22–28°C. Based on working heart rate, indoor temperature control in industrial plants appears to moderate the cardiovascular strain in working subjects during both cold and hot days.

Static and dynamic low-temperature crack resistance of the steels and weld joints of the metal structures of load lifting machines

The results are given of experimental investigations of the static and dynamic low-temperature crack resistance of 1OKhND, St-38-b2, 09G2S, St20, and VSt3sp steels and weld joints of the metal structures of load lifting machines in the 203–293 K range of outdoor temperatures. The ductile-to-brittle transition temperatures are given. The temperature relationships of mechanical properties and stress intensity factors in static Kc, dynamic Kcd, and cyclic loading Kfc are established. The results may be used in calculations of residual strength and residual life of metal structures with cracks.