In this article we intend to make a summary of the conclusions obtained by this interesting technical study made by Ecofys for the Construction Working Group Sustainable Fundación Entorno-BCSD Spain. In the same performs a dynamic simulation of behavior energy of various buildings for residential and tertiary use in different scenarios as well as a study of economic feasibility of the different improvement solutions proposals.
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Two types of buildings are analyzed, one for residential use multi-family house with 3 floors and another for tertiary use of offices with 14 floors, in two building periods different (buildings that are governed by the basic standard NBE-CTE-79 and in a second case by the Technical Code CTE-06), and in three different climatic zones Madrid (D3), Barcelona (C2) and Santander (C1), being the total number of 2x2x3= 12 different scenarios.
For each of the scenarios, the study raises the application of a series of improvement measures aimed at obtain buildings with a high energy rating, always starting from those hypotheses or situations that can be assumable and of course feasible both technically and economically in each of the situations. Said improvements are grouped into three groups: on the one hand, the passive solutions designed to reduce energy demand (step 1), on the other hand those solutions that imply the application of renewable energy (step 2) and finally introduce heating, cooling and/or high energy efficient lighting (step 3). These three steps make up the proposal that the study calls energetic triad. In this way, two cases are studied or energy concepts, the case CE 1 that includes only the measures of step 1 (reduce demand), and case CE 2 that includes the measures from steps 1, 2 and 3 (reduce +renewables +efficiency).
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EC CASE 1:
Improvement of the thermal insulation of facades (9 -10 cm.)
Improvement of the thermal insulation of roofs (12 cm).
Replacement of windows (New: frame U=2.2 with double glass)
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CASE CE 2:
Solar thermal energy covering a 60% contribution solar.
Replacement of existing individual boiler for DHW and heating by :
ACS: Individual gas heater.
HEATING: High-speed heat pump (COP= 3.2) efficiency.
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EC CASE 1:
Improved thermal insulation of facades (5-6 cm) compared to to that determined by the CTE.
Improved thermal insulation of roofs (4 cm) compared to that determined by the CTE.
Replacement of windows (New: frame U=2.2 with double glass)
CASE CE 2:
Solar thermal energy covering a 60% contribution solar.
Reference case with individual gas mixed boiler and individual air conditioning (EER =3), replacement is proposed by :
DHW and HEATING: Centralized biomass boiler.
COOLING: Centralized heat pump (EER=4) of high efficiency.
Cold and heat diffusion by underfloor heating.
EC CASE 1:
Improvement of the thermal insulation of facades (9-10 cm). Initial state without insulation.
Improved thermal insulation of roofs (12 cm). Initial state without insulation.
Replacement of windows (New, frame U=5.7 with double glass (U=1.4 and g= 0.42) with low emissivity layer,
initial state (frame U=5.7 and double glazing (U=2.7 and g=0.76).
Improvement with automatic ventilation system in hours nocturnal.
CASE CE 2:
RENEWABLE:
Photovoltaic solar energy on the roof.
AIR CONDITIONING:
Replacement of the existing centralized gas boiler and air-water chiller plant by:
Centralized biomass boiler and chiller plant air-water with higher efficiency.
EC CASE 1:
Improved thermal insulation of facades (5-6 cm) compared to to that determined by the CTE.
Improved thermal insulation of roofs (4 cm) compared to to that determined by the CTE.
Replacement of windows (New, frame U=2.2 with double glass (U=1.4 and g= 0.42),
initial state with hole transmittance value determined by the CTE.
Improvement by increasing the efficiency of the RITE of the heat recovery (44-85%).
CASE CE 2:
RENEWABLE:
Photovoltaic solar energy on the roof.
AIR CONDITIONING:
Replacement of the existing centralized gas boiler and air-water chiller plant by:
Centralized gas boiler with geothermal heat pump and underfloor heating (hot and cold).
LIGHTING:
Lighting regulation system.
Replacement of T8 fluorescent lighting by T5.
EXISTING MULTI-FAMILY HOUSING: Can be reached large energy savings, between 72% and 78%, so that the improvement measures that contribute the most to said objective are the thermal insulation of the façade and roof and the replacement of windows together with the implantation of energy solar thermal, which, as indicated in the document, is the as more reductions get .
NEW MULTI-FAMILY HOUSING: In this case the energy savings range between 24-39% of consumption of total energy of the house, being again the insulation facades and roofs together with the improvement of the windows the measures that contribute the most. However the achievable scenario would lead us to a building of maximum energy rating in all climate zones analyzed, so that important reductions are achieved of emissions, between 78-97%, which would be achieved by the inclusion of a biomass boiler for ACS and heating.
EXISTING OFFICE BUILDING: Can be reached savings of between 62% and 64% of energy consumption, so that the improvement measures that contribute the most to said objective are the thermal insulation of the façade and roof and the replacement of windows, together with the improvement of the system of air conditioning. The reduction of emissions reaches between a 64-67%, with the biomass boiler being the measure that most contributes. The building rehabilitated in this way can reach a energy rating B.
NEW OFFICE BUILDING: The rate of improvement in the energy consumption fluctuates between 57% and 63%, so that the improvement measures that contribute the most are insulation facade and roof thermal and the replacement of windows, and increasing the efficiency of the recovery system heating, lighting regulation and system improvement of air conditioning. Emissions can be reduced by between 52-55%, with the most important measure being the use of a geothermal exchange system as it generates a large increase in the overall efficiency of the air conditioning system. The newly built office building with these criteria you could achieve a B energy rating.
Regarding the feasibility study economics , presents conclusions and reflections very interesting, which are summarized in the following table:
Article prepared by José Luis Morote Salmeron (Architect Technician – Energy Manager – Google plus profile) Access to its website HERE, in collaboration with Home Repair Care .
