Effect of location on the predicted performance of a heat-pump water heater

A heat pump water heater (HPWH) extracts energy from the air in the environment. The question arises as to how this energy extraction would affect the house HVAC system if the HPWH were located in a conditioned space of a household. A second question concerns the savings obtained by locating the HPWH in an unconditioned space such as a garage or basement. A computer study of these effects was carried out. Since geography, house construction, type and efficiency of HVAC system, and hot water usage will all affect the effective performance, some of the variables were fixed and some were allowed to vary in the study. The effect of locating the HPWH in the conditioned spaces of houses with a high performance heat pump as well as resistance, gas, and oil heated houses with a high performance electric air conditioner was studied. Bin data for each of 18 US cities were used as input weather data. The monthly inlet supply water temperatures to the water heater f each of the 18 cities are given. Results of the calculations for the various combinations of HVAC systems are given. (MCW

Experimental plan for the fuel-oil study

An up-to-date assessment of the Weatherization Assistance Program (WAP) is being performed by the US Department of Energy WAP Division and the Oak Ridge National Laboratory. Five studies form the evaluation. Major goals of the Fuel-Oil Study are to estimate the fuel oil saved by the WAP in the Northeast during the 1990 and 1991 program years, identify and quantify non-energy impacts of the WAP, assess the cost effectiveness of the WAP within this submarket, and assess factors which may cause savings and cost effectiveness to vary. The study will only analyze single-family houses in the nine states in the Northeast census region and will be carried out over two heating seasons (1990 and 1991 WAP program years). A split-winter, pre- and post-weatherization experimental design with a control group will be used. Houses will be monitored over one winter. Energy conservation measures will be installed in the weatherized houses in January of each winter by the local WAP subgrantee. One hundred twenty five weatherized houses and 75 control houses will be monitored over the 1990--1991 winter; a different set of 200 houses will be monitored over the 1991--1992 winter. The houses will be evenly distributed among 25 subgrantees. Space-heating fuel-oil consumption, indoor temperature, and outdoor temperature data will be collected for all houses. Fuel-oil delivery data will be collected for each house monitored over the 1990--1991 winter for at least a year before weatherization. The delivery data will be analyzed to determine if the accuracy of the study can be improved by collecting fuel-oil delivery data on a larger sample of houses over the 1991--1992 winter. Detailed survey information will be obtained on all the houses. This information includes descriptive details of the house and its mechanical systems, details on household size and other demographics, and occupant answers to questions regarding comfort, safety, and operation of their space-heating system and house

Transformações da terra: para uma perspectiva agroecológica na história Transformation of the land: towards an agroecological perspective in history

O artigo discute a constituição do campo da história ambiental, que se deu nos anos 70 em meio aos debates sobre a crise ecológica e a eclosão do movimento ambientalista. Esta história não aceita a noção de que as sociedades humanas não produzem alterações ambientais significativas, e interpela as condições específicas dessa interação recorrente. O sistema agroecológico representa um dos casos mais típicos de rearranjo da atividade humana sobre os ecossistemas naturais, em uma relação complexa de interação entre plantas nativas, vegetação forasteira, fertilidade dos solos e diversas práticas agrícolas. O itinerário dessas mudanças é essencial para se compreender a história do ponto de vista ambiental<br>This article discusses the formation of the field of environmental history which originated in the 1970s in the middle of the debates on the ecologic crisis and the emergence of the environmental movement. This history rejects the notion that human societies do not cause significant environmental alterations and analyzes the specific conditions of that recurring interaction. The agroecologic system is one of the most typical cases of the intervention of human activity on natural ecosystems in a complex interaction between indigenous plants, exotic vegetation, fertility of the soil and diverse agricultural practices. The roadmap of these changes is essential to understand history from the view point of the environment