Quantitative Economic Evaluations of HIV-Related Prevention and Treatment Services: A Review

Dr. Holtgrave and colleagues at the CDC set forth an extensive taxonomy of HIV prevention and treatment services and review reports of efforts to subject some of those services to formal economic evaluation. They find few services thus far to have been so evaluated, no evaluation to have focused solely upon behavioral outcomes and most economic evaluations to lack formal quantitative analyses

DYNAMIC ANALYSIS OF SOLAR HOT WATER SYSTEMS: THE CASE STUDY OF A DWELLING LOCATED IN ITALY

Abstract The present paper is aimed at the energetic analysis of a solar hot water system performed on a dwelling located in different cities in Italy, precisely, from north to south: Bolzano, Turin, Bologna, Rome, Brindisi and Trapani. The study is focused on a group of apartments, where the domestic hot water is provided by a solar system coupled with a storage tank and a recirculation loop; it is worth to mention that the recirculation loop is obligatory on this kind of plants. Therefore, a dynamic energetic study is carried out, assigned the hot water load profiles and the set parameters of the solar collectors with reference to the configurations here tested (flat plane and evacuated tube). Thus, dynamic simulations have been performed by means of TRNSYS simulations tool, setting different parameters: collector configuration and mass flow rate. Several ideas and results emerged from this study, such as the sizing process of the whole system, according to the variation of the solar fraction for all the analyzed scenarios. A digression with simulation results regarding a specific case concludes the paper. More specifically, the study of water temperature oscillations in winter and summer time with reference to the climatic data of Bologna has been carried out under particular operating conditions: i) the pump of the recirculation loop is powered all time (24 hours a day) ii) the pump is switched off during the night, except when the water temperature in the loop falls below a certain threshold temperature

Energy performance of a ventilation system for an apartment according to the Italian regulation

According to recent regulations on energy saving in buildings, all new structures should guarantee high-energy performance. To this aim, the building envelope should be equipped with insulated walls and high-efficiency windows. This approach leads to considerable thermal insulation, but at the same time, in the absence of a suitable ventilation system, it results in a worsening of indoor air quality. A healthy quality of life requires good indoor air quality; especially in places where people spend most of their time, adequate air exchanges should be guaranteed and indoor pollution reduced to "acceptable" levels. In the present work, we performed a dynamic simulation of a ventilation system for an apartment using a mathematical model, i.e., the Trnsys commercial code. The model has been applied to an apartment of 66 m2 inside a condominium located in Bologna (Italy), but can also be used for other types of buildings as well. The variation of energy request due to different measurements of volume flow rate was evaluated

A concentrated-parameter model for the validation of a tractor heating system during artificial winter conditions

In the present paper, a concentrated-parameter model is presented, in order to simulate the behavior of a climatic chamber suitably designed for testing tracked and wheeled tractors. Reference is made to standard-severe winter conditions (–18°C), i.e., the tractor dissipates thermal power in a climatic chamber that reproduces winter temperature and humidity conditions. The software package Matlab-Simulink is utilized and the system under investigation consists of 5 blocks. The dynamic modeling first covers a 10 hours period to reach the prescribed conditions for the climatic test chamber. Then, after this preparation period, the tractor’s engine is supposed to work. The simulations show that higher values of the adduction coefficient are preferable since they allow obtaining quickly, and with a lower heating power, the desired comfort conditions for the machine’s cabin

Hourly data for evaluating the carbon dioxide emission factor of heat pumps or other devices connected to the Italian grid

This data article includes an elaboration of carbon dioxide data available from three different online sources in the years from 2016 to 2019. The data article refers to the paper “Interpolating functions for CO2 emission factors in dynamic simulations: the special case of a heat pump” by the same authors. The data are provided on an hourly basis and are useful to determine the carbon dioxide emission of an electric heat pump or other devices connected to the Italian grid. The importance of the provided data is related to the possibility of having an accurate estimation of the CO2 emission when the device works for only a limited period of time during the year or day. Moreover, since the given data are provided in electronic format (.txt file or .xlsx spreadsheet) they are very useful to perform dynamic simulation using self-made or commercial software such as Trnsys, Energy Plus etc

The role of emitters, heat pump size, and building massive envelope elements on the seasonal energy performance of heat pump-based heating systems

The influence of emitters, heat pump size and building envelope thermal inertia was investigated on the energy consumption of a heat pump-based heating system with a numerical study performed with the dynamic software TRNSYS. An algorithm based on a Thermal Inertia Control Logic (TICL), which can exploit the capability of the building envelope to store thermal energy, has been applied. When the proposed algorithm is employed, the indoor air temperature set-point is increased when the outdoor temperature is larger than the bivalent temperature of the building-heat pump system. Different configurations of the heating system were simulated considering either convective (fan-coil) or radiant (radiant floor) emitters coupled to a variable-speed air-to-water heat pump. Simulations have been carried out considering a reference building derived from the IEA SHC Task 44 and evaluating the influence of the proposed control logic on both the heat pump seasonal energy performance and the internal comfort conditions perceived by the building users. The obtained results highlight how the introduced TICL can guarantee the use of downsized heat pumps, coupled to radiant emitters, with a significant enhancement of the seasonal performance factor up to 10% and a slight improvement of comfort conditions. On the other hand, when convective terminal units are considered the proposed logic is not effective and the overall energy consumption of the system increases up to 15%

The bin method to investigate the effect of climate conditions on the SCOP of air source heat pumps: the Italian case

The paper investigates the seasonal performances of electric air-to-water heat pumps specifically related to climatic conditions of the place where the heat pump is installed. The analysis is carried out using easily available weather data for some Italian towns differently located, and using the bin-method proposed by UNI/TS 11300-4. Two different types of heat pumps (on-off and inverter-driven variable speed compressor) are considered and comparisons between different types of heat pumps and different places of installation are performed. The analysis shows that the climate of the installation place is the most important factor that affects seasonal indexes of heat pumps; moreover, as expected, inverter heat pumps better perform than on-off ones