Amount Of Insulation Research Articles

Disjoint Search for the Prices of Two Goods Consumed Jointly

The extensive literature on searching for price information deals almost exclusively with the search for the price of a single good. Casual empiricism shows that consumers buy more than one good and search for the price of more than one good before any single purchase. More importantly, not all of these goods are sold at the same store. Search theory should therefore consider the problem of multiple search in order to determine the robustness of conclusions based on a theory developed from the problem of search for the price of a single good. This paper reveals a number of insights that emerge when decisions taken in other markets are made explicit. Consider the situation facing the builder and designer of a new house. Among other things, the builder must decide on the amount of insulation and the method of heating before construction starts. The decision depends on the prices offered; hence the builder will search for an acceptable offer when prices are not known with certainty. If a low price for heat is found, then little insulation is needed because the cost of lost heat is relatively low. When relatively little insulation is needed, the potential savings from a lower price of insulation are also small. Therefore the builder may be willing to accept a relatively high price for insulation in the event of costly search and having already found a low price for heat. More generally, the price that would be accepted in one market depends on what has been found in the other market. The influence of one market on another is not clear. Consider another example. When a low price for heating is known, the cost, in terms of lost heat, of windows may be low. Thus the builder can' install more windows at a lower opportunity cost

Transient Voltage Protection for Induction Motors Including Electrical Submersible Pumps

Because it is not practical to build as much insulation into rotating equipment, induction motors are more susceptible to damage from lightning and system-induced surges than is stationary equipment. This is, unfortunately, true of submersible pump drive motors, where dimensional constraints further limit the amount of insulation that may be designed into the motor. The transient phenomena to which induction motors are likely to be exposed are addressed and the means for protecting induction motors from the damage such transients can cause are outlined.

Winter concreting in Canada

This paper deals with the pros and cons of concreting in sub-zero weather and the practice and theory behind the requirements of the Canadian standards for cold weather concreting. It gives the minimum protection period for initial curing to prevent frost damage and the amount of insulation required to meet the standards for various weather conditions. The problem of the thermal stress produced as the concrete cools under various degrees of restraint is dealt with in detail, and the cooling period required to avoid thermal stress cracks for various thicknesses of structures and weather conditions is given in graphical form. Examples of the use of insulation in slip forming and problems encountered in varying weather conditions are also included. Keywords: winter construction, concrete, insulation, curing, form work (construction), form removal, temperature, thermal shock, water–cement ratio.

Design criteria and operational guidelines for a pilotscale anaerobic digester

Design considerations for constructing a pilot anaerobic digester are presented. A 4.34 m 3 pilot digester was constructed using these criteria. Operational guidelines are presented. Also included is an iterative technique for sizing an internal heat exchanger, suggestions for selecting pumps, meters, and other equipment, and an electrical control system that permits automation of the entire system. The pilot digester operated successfully for more than 4 years with swine manure as a feedstock at a loading rate of 4 kg volatile solids per m 3 per day with a 15-day detention time at 35°C. Energy balances indicate that the overall energy efficiency of the digester is a function of ambient temperature surrounding the digester, amount of agitation, and amount of insulation.

Livestock Ventilation with Heat Exchange

ABSTRACT THE lack of heat in livestock struc-X tures is a problem in climates such as North Dakota's. The heat loss through ventilation plus the loss by heat leakage exceeds the heat pro-duced by the livestock at temperatures below about -16 C (+2 F). This varies with density of animals and amount of insulation. This paper reviews methods and problems of retrieving heat from exhaust air and presents the experience of using a double heat sink of rocks to reclaim this heat.

Insulated Forms and Thermal Shock in Winter Concreting

This paper deals with the problem of cracking due to the thermal shock of concrete. Safe temperature differentials between concrete and air are given with sample calculations in arriving at the values. The required amount of insulation is shown for various weather conditions to cure the concrete in accordance with the CSA specification. Assuming that the stipulated insulation is attached to the formwork, the safe stripping times to avoid thermal cracks are given for various thicknesses of structures under various degrees of restraint. The salient points are illustrated with practical examples, and the vital data are presented in graphical form to make it usable.

Efficiency of Energy Use in the United States

We described three uses of energy for which greater efficiency is feasible: transportation, space heating, and air conditioning. Shifts to less energy-intensive transportation modes could substantially reduce energy consumption; the magnitude of such savings would, of course, depend on the extent of such shifts and possible load factor changes. The hypothetical transportation scenario described here results in a 22 percent savings in energy for transportation in 1970, a savings of 2800 trillion Btu. To the homeowner, increasing the amount of building insulation and, in some cases, adding storm windows would reduce energy consumption and provide monetary savings. If all homes in 1970 had the "economic optimum" amount of insulation, energy consumption for residential heating would have been 42 percent less than if the homes were insulated to meet the pre-1971 FHA standards, a savings of 3100 trillion Btu. Increased utilization of energy-efficient air conditioners and of building insulation would provide significant energy savings and help to reduce peak power demands during the summer. A 67 percent increase in energy efficiency for room air conditioners would have saved 15.8 billion kilowatt-hours in 1970. In conclusion, it is possible-from an engineering point of view-to effect considerable energy savings in the United States. Increases in the efficiency of energy use would provide desired end results with smaller energy inputs. Such measures will not reduce the level of energy consumption, but they could slow energy growth rates.

Insulation and equipment for cold weather potato storages

A potato storage should have sufficient but not an excessive amount of insulation for maintaining the desired temperature and humidity. A vapor barrier on the interior surface of the walls and ceiling is essential for keeping the insulation dry and effective. The fans and air distribution system should be designed to meet the requirements during the various stages of the entire storage period. During cold weather a relatively simple inexpensive system may be used for automatically controlling the temperature and humidity inside a storage. The system can be installed in most existing storages with minor modifications.

Protection of the Ground from Thermal Effects of Industrial Plant

Synopsis Solutions have been obtained for the uniform thickness of insulation necessary to maintain a specified temperature below thermal plant of long-rectangular and circular plan, resting on the surface of the ground or sunk in the ground as a basement. A shape factor enables the solutions to be used for other simple shapes. Solutions are also derived for the heat-flow from the base of the insulated thermal plant. Examples are given. The amount of insulation required to ensure a safe ground temperature under high-temperature plant and under large cold stores is shown to be considerably greater than is used in practice. Numerous failures have occurred through the deleterious action of extreme ground temperatures. High-temperature plant requires protection of the ground by means of a ventilated cavity below a moderate thickness of insulation. A simple method of design is outlined, and the results of a successful application of this principle to a brick-kiln are shown. On a calculé quelle était l'epaisseur uniforme de matériel isolant nécessaire pour maintenir le sol à une certaine température sous des installations industrielles thermiques en forme de cercle ou de rectangle allongé, posées à ras du sol ou situées dans des souterrains. On a prévu un facteur-forme, permettant d'appliquer les calculs à d'autres constructions de formes géométriques simples. On a calculé également la chaleur transmise par la base d'installations thermiques pourvues d'une couche isolante. Ilest démontré que la quantité de matériel isolant nécessaire pour assurer la protection du sol sous des installations à hautes températures ou sous des installations frigorifiques est beaucoup plus grande que celle qu'on utilise couramment en pratique. Plusieures constructions ont été sérieusement endommagées par l'effet de températures extrèmes dans le sol. Les installations industrielles à hautes températures devront étre séparées du sol par une couche de matérial isolant d'épaisseur moyenne et par un espace ventilé. Les calculs s'effectuent suivant une méthode simple et un exemple est donné qui montre des resultats satisfaisants obtenus en appliquant ce principe à la construction d'un four à briques.

Joints, sealing ends and accessories for pressure cable

The general principles involved in the design of joints and sealing ends for pressure cable installations are discussed. Design standards based on experimental results are given, and practical methods of construction are described. An account is also given of the gas-control accessories of a pressure cable, including leak location methods. Special attention is given to the problem of voltage surges in relation to joints and scaling ends. It is shown that the voltage surges specified as representing service conditions are now a critical factor determining the amount of insulation. The relative economics of providing for the voltage surges by additional insulation or alternatively by surge diverters is examined.

Minimum Insulation Level for Lightning Protection of Medium-Voltage Lines

Lightning protection of wood pole lines is a problem of wide interest among operating companies. It is therefore timely to cite the experience of the Philadelphia Electric Company during the six year period, 1935–40, in successfully renovizing its 13 and 33 kv wood pole lines to reduce trouble. In 1935 this company was faced with the problem of determining how to materially reduce lightning trouble on a variety of pole top configurations at a minimum of expense. It had been shown by Andrews and Stroup1 that wood insulation could be employed effectively. However, no information was available to indicate what reduction in trouble could be obtained for various increases in insulation. The high ridge pin configuration proposed by these authors, while reported to be very effective, could not be applied to many of the existing line structures without making major changes in construction at considerable expense. There was therefore need for an investigation into the degree of protection afforded by lesser amounts of insulation. With this problem in mind, the author set out to make a detailed investigation of the performance of the various types of structures and to correlate their insulation strength with their rate of trouble.

Number of Feathers and Body Size in Passerine Birds

OTHER things being equal, the amount of heat lost by a warm-blooded animal is directly proportional to the surface area of that animal. The surface area, however, is not directly proportional to the weight, but varies approximately as does weight213. This means that the surface area per unit of weight is much greater in the small animal than in the large one, and ipso facto, that in homoiothermic animals the problem of maintaining body temperature above that of the environment is more difficult for small individuals than for large ones. Kleiber (1932) calculated that if a mouse. and a steer had the same heat production per gram of body weight, and if both were required to maintain the same temperature, the mouse would need a specific insulation twenty times that of the steer. The extensive data of Wetmore (1921), including 1,558 records of body temperature for 327 species of birds, indicate that small birds maintain temperatures just as high as those of larger species. For example, the mean temperature in ten species of Paridae (tits and chickadees) was 107.90 F., exactly the same as for fourteen species of Corvidae (jays, magpies and crows). Determinations of the metabolic rates of forty-five birds representing thirty-two different species ranging in size from 0.02 to 17.6 kilograms, made by Benedict, Giaja, Terroine and others, as summarized by Brody (1932, pp. 89-97), show that in birds, as in mammals, the metabolism per unit of body weight is highest in the smallest species and decreases with increasing body size. This indicates that maintenance of high temperatures by small birds is accomplished in part by an increase in the metabolic rate. However, the amount of insulation may also be an important factor. If this be so, the greater insulation needed by the smaller birds to maintain temperatures the same as those of large ones, which are from 30 to 120 F. higher than those of mammals, might be obtained by increased length of the feathers, but the resultant disproportion between size of body and length of feathers would probably interfere with flight and hence have little 'survival value.' Since the type of feather changes little within any one order, or group of birds, it is probable that any additional insulation needed by small birds is provided by an increase in the number of feathers per unit of body surface. On theoretical grounds, therefore, there should be many more feathers per unit of area in the Chickadee weighing eight to ten grams than in the Blue Jay of about ten times the latter weight. It follows that, since the surface area per unit of weight increases with diminishing body