Question

1. List at least two building energy rating systems and briefly explain from what aspects they evaluate the sustainability of a building

2. What is a net-zero energy building (NZEB)?

3. List at least eight technologies that can be applied to reduce energy consumptions in a NZEB

4. In your opinion, what are some main challenges for NZEB?

5. How do factors such as climates and building occupants affect the energy consumptions in a residential building?

6. Pick two NZEB examples (outside the class material and better to be under different climates) and describe the unique features they adopted to achieve minimal energy consumption

Answer 1

1. The two systems of building energy ratings are:- @) cumulative Energy demand It is a measure of energy, a building consumes. The assessment is carried out after every single year. However half yearly evaluations have been proposed in many countries. It is a single dimensional analysis considering energy flux. (b) Complete Quality assessment Systems It evaluates aspects like ecology, economic and soci - al aspects. Multi parameter system is the most common quality assessment systems. These systems truely, attra- cting the attention for sustainable evaluation of buildings. The aspects such as greenhouse gas emissions, energy consumptions, investment and equity etc. when a building consumes total quantity of energy on yearly basis and at the same time the quantity of energy consumed is created on the site, it is known as met rend energy building (NZEB). The created energy Should be purely renewable. This can be achieved by starting with efficient design. followed by Energy modelling. There are numbers of factors to achieve rero energy building. 3. The eight technologies that can be applied to reduce energy consumption in anet Zero Energy Buildings are:- photovoltaic cells ( wind turbines or site energy generation & (111) Solar water heaters (W) use of highly insulated door (V Heat recovery ventilation System (HRVS) (ull Ductless heat pumps (VI) High performance envelopes (1) Sun control and Shading device

4. Following are the some challanges to Net Zero energy buildings :- (a) while evaluating the energy need of the building a proper link establishment between the power generated and building loads is difficult. Balancing the supply and demand of energy is a huge issue as the energy generation is based on renewable sources (6) There will be a huge difficulty maintaining the economic side of net zero energy buildings People are not able to afford technologies because of its initial and operational costa There is a need of economical design and constru- ction of various energy providing source. Therefore, its a long journey of getting net energy zero buildings but at least something has been initiated and something has been done. 5. Energy consumption pattern changes from one howe hold to another and consequently attecting climate There is a relation that is predictable concerning the Occupants thermal comfort: Lifestyle of occupants of a residential building and uts demography, economy and its interaction witte building comfort features are outmost important bor evaluating the overall consumption and its effect on climatic behaviour. If the occupants uses comfort equipments like water heaters room heaters, Ac, fridges will lead to coal generated energy consumption rise which ultimately will increase the overal harmful emissions. Now a days solar cells are used on the rooftop of ren- dental buildings to general electrical energy but there is a huge disparity in the consumption and supply

6. The two examples of Net zero energy buildings are - @ passive House Ebner (styria) This building includes energy efficient features like solar panels, offsite thermal and wind energy generation. centres to meet the passive building standards. The matrials like staw, wood, loam rendering areted environmentally attached building materials used in the Construction. This building has mechanical ventilation systems which can recover almost 85% of energy (heat) 6 Technical University-sofia, University research Centres This building has improved infrastructure and hence building energy efficiency has been gone upto 40% VRF based cooling system, Low energy lighting system Heat pumps are some of the examples of building service system. 75% of the heat can be recovered in this university building.