Miguel A. Campano

Method for the Economic Profitability of Energy Rehabilitation Operations: Application to Residential Dwellings in Seville☆

Abstract This work proposes a method based on a computer model to assess the economic profitability of energy rehabilitation operations in the envelope of a block of residential dwellings (Virgen del Carmen) in Seville (Southern Spain). The work evaluates the influence that certain hypotheses of interventions in the opaque part of the envelope exert on the annual energy demand: better insulation of the facade, interior partitions, roof and ground floors, in addition to its semi-transparent part: improvements in the airtightness of the building openings, the glass windows, and the thermal conductivity of its frame. These interventions arise from strict compliance with the Spanish regulatory framework. This model has been designed for the context of a Mediterranean climate, (mild winters and hot summers). The simulation tool Design Builder 3.4.0.041, which uses the calculation engine Energy Plus 8.1, has been selected to generate the computing model and establish its energy demand. The amortization of the economic costs of rehabilitation is quantified by the net present value (NPV) index, in accordance with the savings in the bills of energy consumption due to the reductions in demand for heating and cooling in the building, thereby obtaining an amortization period which exceeds 22 years.

Validation of a Dynamic Simulation of a Classroom HVAC System by Comparison with a Real Model

Schools require thermal comfort in their classrooms , but some uncertainty arises as how their HVAC systems will actually provide it, especially given their high internal loads and mechanical ventilation diffusion. Thus, it is necessary to resort to computational fluid dynamics (CFD) for developing predictive models; nevertheless, the reliability of the simulation tool has to be verified, so the main objective of this work is to define and perform the validation process of a thermal dynamic simulation tool by comparison with a real room. A validation protocol has been detailed for dynamic simulation tools, in medium-sized spaces with high internal loads, by comparing with the measured air temperature values of an existing standard classroom, according to ISO 7726:2002. The chosen standard classroom for this comparison belongs to “Eca de Queiros” secondary school of Lisbon (Portugal). To that effect, 80 thermocouple sensors were used for the characterization of its indoor thermal behaviour. A mean bias error (MBE) of 0.21 °C was obtained, with a maximum standard deviation of 0.47 °C, which is under the maximum limit of ±0.5 °C established by this standard. The application of this methodology for validating the Design Builder software proves the reliability of this tool in such type of venues.

Practical Application of ICT Solutions for Energy and Water Savings at Condominium Level

EnergyTIC project has made available easy ICT ́s solutions for domestic end users in order to involve the social housing residents as an active part of water and energy efficiency. In this paper we analyze a proposal for a methodology designed to apply these single home ICT technologies in the whole-building energy layer. Our approach treat to take advantage of the the system currently in operation at single-dwelling level in order to involve users in the same building as clusters of the energy and water savings at building level. An on-line continuous benchmarking process between buildings in the same area will be used as the main tool of our procedure.