With the promotion in engineering worlds have adopted many techniques which give them alleviation and pleasance instead sing the factor how much energy and resources are being consumed. Like air conditioners if we talk has become the portion and package of life in these yearss and people on the other side are willing to pay high monetary value for it but what it can be mitigated by following natural airing ( NV ) which non merely would salvage energy ingestion and will conserve resources for the future coevals. As non- renewable resources are consuming, clime is altering across the Earth which has lead an dismaying menace towards wellness and environment due to the harmful emanations which in bend has made consciousness in improvizing energy efficiency in edifices and other residential flats.
Natural airing is the procedure in which the air is supplied in and removed through an indoor infinite by natural ways i.e. without any mechanical system. It works on the rule of airflow exterior of the edifice caused by the difference in force per unit area between the edifices and milieus to supply residents comfort and natural airing ( Green 2010 ) .
Natural airing has old historical importance from ancient times to modern epoch. As planetary variegation in footings of land, clime and civilization in relation to human demands has led to factors sing the designs. Talking about hot and waterless parts of Arabs traditional edifices have been modified to the beginnings of energy available which helps in cut downing humidness and enhanced natural airing. Wind backstop was introduced to accomplish residents comfort in the edifices for many centuries from early Pharonic periods ( Shorbagy, 2006 ) .
Heat capacity besides plays a critical function in natural airing. In comparing to rural countries, urban countries have high heat capacity because of denseness of stuffs being high and high thermic conduction as land is more populated and has less to none insulating bed above.
From the background surveies, figures have shown the fluctuation in acceptance of natural airing to being mechanical airing or even intercrossed ( mix of natural and mechanical airing ) . Orientation of the edifices, thermic multitudes, and thermic zone and buffer infinites all factors contribute to NV. In relation to the tallness of edifice, maximal width histories for maximal natural airing.
Coventry University situated in Coventry, UK is an oculus library due to its high energy efficient design spread over an country of 10,000m2. It to the full optimizes the daylight conditions for natural airing therefore salvaging energy ingestion on a mostly broad graduated table in comparing to air conditioned edifices.
In acceptance of natural airing many factors come into drama that may be proficient, fiscal or other psychometric conditions. In proficient facets, initial investing is an of import factor as to cut the energy ingestion of air conditioned edifices, initial substructure is needed. Peoples have general premise that how NV traveling to work over air learned conditions and has a fright in following as they might non puting money in incorrect undertaking. Many people are non sound plenty to hold any of ventilated systems in their houses because of their inability to purchase due to fiscal crises.
Natural airing has advantages over air conditioned edifices in footings of decreased running costs because of lower energy ingestion, less capital cost, lower conveyance energy in relation to fans, lower noise pollution which may happen due to air conditioners ( Jones, 2003 ) .
1.2 Literature Review
Energy Efficiency
Energy efficiency histories for the decrease of use of energy for the given activity in respect to warming, buoy uping or airing systems. The sum of energy consumed is in relation to how good the engineering is and how better organized and managed the edifice is. Basic factor on which energy efficiency depends is the design of the edifice and its components including walls, floors, foundation, doors and the roofs.
The edifice operation besides accounts for the energy being consumed and the stuff of what edifice is composed off. In commercial edifices the chief energy ingestion is by and large through warming and chilling systems and by implementing the automatic control or smart control energy ingestion can be significantly reduced.
Implanting energy efficient features into old edifices is bit hard as all the retrofitting will hold to be done and it will be cost orientated but in new building of the edifices it can be easy integrated and helps in achieving energy efficiency ( EPRI, 2004 ) . Carbon dioxide ( CO2 ) emanations are besides produced from the edifice sectors but they by and large go unnoticed as attending is chiefly to the major subscribers of pollution such as transit and industries.
1.3 Stairss for instance surveies
Ysbyty alltwen, porthmadog United Kingdom
This is a community infirmary which was completed in 2008.
The edifice is designed harmonizing to the topography, ecology and geology to supply the staff and patient with friendly curative environment of high quality. This edifice is designed around an internal winter infinite suitable for proposed natural airing and warming schemes.
The edifice incorporates many environmental friendly characteristics like:
Patient country is covered with big countries of glazing so as to supply plenty sunshine, natural airing and first-class natural positions to patients for speedy recovery.
In clinical countries a assorted method of airing is used which uses natural airing and where natural airing is non possible, mechanical airing is used.
For heating and hot H2O, a biomass boiler is used.
In the patient country, to carry through the warming demands a concrete construction is used which provides thermic mass for warming. For natural airing, the winter garden and light Wellss are used which create a pleasant stack ambiance.
To keep and command the environment in the edifice, a edifice monitoring system is adopted.
The edifice roof is designed to roll up and retain the rainwater. The site besides uses a rainwater fading system with a surface laguna.
The edifice design is really good and the edifice has achieved two awards for its perfect and sustainable design. The two awards are the national gold award and the national title-holder award.
Sunyani infirmary, Ghana
This infirmary was completed in 2003. This is the urban funded infirmary with 240 beds and was designed to supply long term value for money.
The infirmary design is such which uses local stuff and minimise the future care and costs. The site is gently aslant and provides regular cool airing and uses a green airing design for natural airing which restricts air conditioning to runing installations merely. This is achieved and maintained by utilizing the system of unfastened corridor with ‘shallow programs ‘ which are separated by big planted courtyards which ensures cross airing through adjustable glass blinds.
The infirmary designed is merely the individual floor, except the section of administrative offices. The large roof of the edifice overhangs and unfastened corridors are built to supply protection from the Sun and the rain.
The big land available was put into good usage by the infirmary and a human scaled edifice was made on the abundant land.
The edifice designed is engineering modest and technology installations have been provided as generic replaceable subdivision for pick maximization.
To attach the different section ‘s duplicate streets were designed and unfastened infinite is left for future enlargement of the edifice and streets.
The infirmary has achieved great success. The reappraisals in 2008 were conducted to gauge the effectivity and efficiency of design attack, low energy edifice, low care cost on clinical results and satisfaction study from visitants, patients and staff was really good and the infirmary has gone from 240 beds to 400 beds and was go toing five per centum more outpatients and pregnancy patients as was anticipated. The patients were to the full satisfied. The clinical and environmental success of the infirmary has lead to high degree of keeping of staff as this infirmary is in rural Africa and has besides lead to rapid addition in the figure of physicians and nurses.
Gateway 6th signifier college, Leicester, United Kingdom
This college was built in August 2009 and in UK this college is the most sustainable 1. The emanation rate of the college is 17.3 kilogram co2/meter square each twelvemonth which is more than half less than other conventional college edifices. The emanation of this college edifice is estimated to be two 3rd than the other old colleges. This college fits in the position of the metropolis as Britain ‘s first environmental metropolis.
The Uk public presentation certification mark has been given to the edifice with 28 ( B ) scores as compared to the other similar edifices with 46 mark.
The edifice is three floor and is 11,500 metre square and is designed to carry through the demands of 1500 pupils and besides has proviso for enlargement of suites at the rear.
The three floor constructing includes units for disposal, edifice and extra adjustment which is assessed through three storey street with besides path for primary circulation and path for dining and populating room infinite.
The edifice was designed by giving top precedence to energy creative activity and preservation and it is designed to transcend present statutory ordinances.
Controling solar energy and maximising twenty-four hours light – daytime detectors and adjustments devouring low energy are used to minimise the usage of electric illuming wherever possible. The in-between three storey street is shield from the southern side by brise-soleil. On the south side, solar energy commanding glass has been used.
Visible sustainability – it is non normally seen that edifice works is put on a show but in this instance it was put on a show to promote the college pupils to demo involvement in environment by utilizing seeable sustainability. Therefore, the energy Centre is established in forepart of the edifice at most outstanding public topographic point with large glazed mirrors offering the first-class position of biomass boiler. A large LCD show is located at the chief entryway to supervise the working of air current turbine and PV panels which is besides linked with the web site. All these characteristics and properties have attracted many pupils.
Biomass – french friess and wood was used as fuel foe the biomass boiler. As wood french friess were used ab initio, the fuel used was carbon impersonal and to the full sustainable. The biomass boiler attached with gas boiler generated 80 % warming energy and fulfilled the demand of hot H2O for domestic usage.
Natural airing – the full edifice was to the full ventilated of course and Windowss and instruments of the edifices were attached to constructing direction system which controlled temperature that is chilling and warming in the edifice. Most of the learning cods off of the chief atrium have exposed precast concrete board ceilings. This aid in commanding temperature alterations as it was provided with a thermic mass. Windows was linked to constructing direction system which controlled chilling at dark clip.
Photovoltaic glass and air current turbine – The photovoltaic laminate was used in the chief entryway of the edifice. Solar energy was besides enhanced by the combination of agreement of PV ‘S along with solar controlled glazing which generated energy. The site lift was used for the operation of air current turbine. A big sum of energy for the college was produced by the PV ‘S and turbine. In trim times, this system continues to bring forth and supply energy back to national grid by salvaging costs of energy for the college.
Sustainable drainage – many figure of armored combat vehicles and swales were made for H2O storage on the site due to hapless drainage system and as the dirt was clay impermeable dirt which absorb small H2O.
Reaping of rain H2O – the rainwater is collected and stored in armored combat vehicles of 8400 litres which was used for blushing lavatories in the instruction unit. Not merely this, steps are besides made to utilize rain H2O for fire brigade whenever necessary.
Suitability of natural airing system
Narrow program edifices or holding a floor home base breadth of 15m.
Open program layouts with really less external air and noise pollution.
When patterning usual airing, take into study auxiliary buildings refering it as they will change the effectivity of the air current hitting the constructing to craft the force per unit area derived functions needed. So, the demand for NV arises from carefully understanding the conditions of the topographic point and demand needed ( Heiselberg, 2002 ) .
Research inquiries
From the research field description the inquiry that arises is as: how natural airing in air conditioned edifices can achieve energy efficiency? As the NV edifices after twentieth century has been based on the construct of air flow in and around the edifices and so more specific inquiries could be formulated.
How the design of the edifice and natural airing are related to each other?
Can natural airflow be used as possible factor in planing a edifice?
Purposes
To calculate out what work has been already done in doing air conditioned edifices more energy efficient by improvizing Natural Ventilation and what else can be added to it farther.
To do certain the maximal usage of daylight conditions for the lightning in edifices.
To entree the energy demand and besides sing the combined heat and power with renewable energy of the edifice
Aims
To give clear understanding between how alteration in clime and different edifices situated with regard to topographic points respond to energy demand and balance.
To show the part made by the passive ( orientation, types of Windowss ) and active ( absorption hair-raiser ) techniques in effectual energy dissipation in edifices.
Analyzing the quality of air, thermic comfort and minimisation of possible dead musca volitanss by following natural airing.
Methods
To measure natural airing certain parametric quantities like automatic control, smart control and edifice direction systems needs to be understood clearly. The edifice operations about account 40 % of all energy ingestion in Europe ( Allard, 2002 ) .
Automated control system in relation to mechanical and natural airing can cut down the CO2 emanation to big extent and led to ecofriendly environment. As compared to the traditional HVAC systems which consumes big sum of energy and histories for C dioxide production, adaptative natural systems are cheap to put in, care cost is low and maintains a sustainable hereafter. Automated programmed Windowss can be used proportionately to open at their ain when a given set of C dioxide degree is reached in the room.
The use of natural-ventilation agreements is often endowed as a standalone solution. As this can manipulation airing in a constructing, there could be conditions whereas it is in fight aboard auxiliary HVAC works – aboard wasteful consequences. One illustration is possessing Windowss to supply new air as warming or air conditioning works is running ( Santamoris, 2005 ) .
Such struggles lead to inefficient and excessive usage of power and can to boot hold a negative brush on the early connexion monetary value, as put ining a temperature detector for the heating agreement and a distinguishable temperature detector for the natural-ventilation agreement is unnecessarily expensive. Making natural-ventilation controls an built-in part of an finished BEMS declaration non simply reduces the early investing monetary value but to boot ensures that all building agreements are working effectually aboard on another.
Besides the supply bond encompassed aboard reciting and put ining a natural-ventilation agreement can be rather disconnected, alongside disparate design and connexion parties involved.
To besiege such a scenario, possessing a seamless solution from a lone supplier – that to boot takes on the design agent – is most good. This will safeguard the most energy-efficient methods are retained as transporting comfort to users ( Rees, 2012 ) .
To technically optimise the usage of Natural Ventilation research focuses on tracking three public presentation standards ( Livermore, 2000 ) ;
Energy nest eggs,
Occupant comfort and
Indoor-air quality ( IAQ )
The aim is to suitably prove and supervise the edifice to rate the public presentation of installed NV under different controlled schemes.experimental model would be in three stages: –
Testing set up
Data aggregation
Datas analysis
The focal point of Phase I is the finding of what NV constituents and schemes to prove, how those trials will be implemented through a testing matrix, and how each control will be developed to track trials developed in the experimental matrix.
Phase II describes a agency for roll uping informations through edifice detectors, informations acquisition package or other beginnings ( i.e. , conditions Stationss or tenancy comfort studies ) and forming them in a database.
After finishing trials, Phase III utilizes energy analysis and standardization to find public presentation standards for each scheme and find the best Nevada scheme for the edifice. These schemes will be implemented in an automated control and will be retested for confirmation.
1. Introduction
For any state to be socially and economically developing the of import parametric quantity is energy. Energy is besides critical factor in sing and measuring result of the proficient systems on the environment as it is straight related in footings of the emanations to assorted impacts across the Earth environmentally which further includes particulate affair, smog, nursery gases and clime alteration. Construction industry is considered to be the major and critical consumer of energy and other natural resources globally ( T.E.Uher, 1999 ) .
The significance of the handiness of nursery gases and energy ingestion is good described during the edifice operation. But, still holding the cognition for energy being consumed in assorted fabrication procedures that may be constructing stuffs there are other stages like transit of the edifice stuffs, collection into edifices and besides the extinction of the edifice is non counted during the energy use when edifices are determined ( J. Adnot, 2004 ) .There is a important changeless rise in Thailand ‘s energy strength. Its energy ingestion in 2001 was accounted 3.06 EJ, which rose six times from 0.53EJ which they used to devour 20 old ages back. The building rate of edifices is besides increasing in Thailand. There was 35 % addition in the buildings of new edifices numbering 268,000 in 2005 as compared to the twelvemonth 2002 which has added to the high energy strength of Thailand and besides accounted a portion of 43 % of ingestion of electricity yearly ( EIA, 2008 ) .
To do the energy sector better Thailand authorities has enacted the Energy Conservation and Promotion Act in 1992 with which the accent was laid on extenuating the energy ingestion rate under 10 % yearly from 13 % ( Chirarattananon etal. , 2004 ) .
Attempts were put frontward in preservation of energy in assigned industrial and commercial edifices in mention to the edifice codifications which were introduced as a portion for this plan, but merely the operation stage was under focal point by these steps and did n’t give much consideration to other stages runing on the edifice accounting for energy nest eggs. So, to cut down the energy ingestion by edifices other stages would be given consideration as a future end for energy efficiency in state. Therefore, energy appraisal of the life rhythm of edifice is necessary.
Life rhythm analysis ( LCA ) is a portion of ISO 14040 which involves pull offing environment under specific criterions set up for different activities associated with it. It deals with how a procedure goes through different phases from its beginning to its extinction. Here LCEA will be relevant as energy efficiency of the edifice is assessed and energy is merely the critical parametric quantity discussed under. So, a much detailed survey of the available energy to edifices can be made. LCEA can non be compared to the LCA as it is broader in measuring the environment. Despite it, LCEA makes determination easier for energy efficiency sketching the information required for a measure by measure process to cut down ingestion of energy from edifices sector.
The edifices sector provides chances in an country in urban development for increased energy preservation. Particularly energy usage of edifices becomes important when referenced towards Thailand ‘s purpose for energy security. In Canada, the comparative LCEA of three different structural systems has besides been conducted of wood, steel and concrete mixture on three-story edifice covering about 4620m2 of country. The energy required for operation and destruction of a low energy edifice in USA and Sweden has besides been assessed and in Japan, sum of energy consumed every bit good as the pollutants emitted due to constructing building has besides been examined ( C. Thormark, 2001 ) . However, in instance for Thailand no survey exists on the LCEA of office edifices in Thailand. The purpose of this thesis hence is to show and discourse the usage of LCEA in mention of a typical office edifice in Thailand.
The aims of this survey are to find the corporal energy coefficients of stuffs used in edifice stuffs utilized in Thailand ; to measure the LCE ingestion of a typical office edifice ; to analyze different life rhythm stages and ; to supply information which may be effectual and can be used as footing for constructing energy efficiency policies in the state.
2. Research methodological analysis
Assorted types of commercial edifices exist in Thailand like hotels, infirmaries, educational institutes, offices, and section shops so to be aligned with the aim to accomplish, a typical commercial edifice demands to be chosen. Office edifice stock has the largest portion in the electricity ingestion in Thailand and histories for 43 % of the entire electricity being consumed in the state harmonizing to Department of Alternative Energy Development and Efficiency ( DEDE ) . So the office edifices were of much involvement as what measures need to take up to cut down the energy cost by take downing the electricity ingestion by execution of any policy or any research consequences which would be of any benefit in better economic development and energy security in Thailand. The edifice construction in Thailand is about similar and has same envelope construction comprising of strengthened concrete and concrete wall system. So the consequence result can be applied to other edifices after analysis in Thailand.
The instance survey edifice is located at 14 & A ; deg ; N latitude in the Bangkok territory of Thailand and was eight-story in tallness. Humidity outside was calculated mean of around 65-70 % . The average temperature fluctuation was from minimal 23 & A ; deg ; C-27 & A ; deg ; C to maximum 30 & A ; deg ; C-34 & A ; deg ; C. Operating energy required to run the edifice system is obtained from the national grid. HVAC system is located centrally to chill the edifice. For the indoor runing conditions set point temperature of 22-24 & A ; deg ; C was set up and degree of humidness inside the edifice was around 50-60 % . Changeless supply of fresh air was provided to the residents of the edifice by air managing system at rate of 5l/s for the airing. The lightning system of the edifice was full manual. The LCEA of studied edifice was based on the presumed life of 50 old ages and stuffs composing the edifice construction consisting chiefly steel, concrete were taken into consideration. The entire gross country of the edifice was 60,000 M2. The ceiling tallness of the edifice was 2.9 m with edifice ‘s gross volume accounting 9, 12,000 M3. The foundation construction was built from concrete slabs, interior and exterior walls were composed of brick and combination of drape wall. Flooring was finished with all right ceramic tiles and roof country was level and made of concrete.
3. Life rhythm energy appraisal ( LCEA ) methodological analysis
Two types of methodological analysiss exist for LCA one is based on the procedure and other is based on the economic input end product LCA ( EIO-LCA ) . For the LCA which is procedure based all the activities are in relation to the all the life rhythm operations get downing from cradle to sculpt. Process based analyses are really result oriented and requires immense computations and informations to measure and due to this it makes it more wastage of clip and cost inefficient. Due to fluctuating design parametric quantities of two edifices the consequence result is non that easy predictable. Therefore, to take the fuss of LCA procedure to be used EIO-LCA was created. Merely drawback of this method found was incapacity of supplying Pr & A ; eacute ; cised consequences due to collection of merchandise in high degree but the attack is rather comprehensive.
A different figure of issued came up when making the LCA of an office edifice due to tremendous construction of edifice, life of the edifice and different stuffs embedded inside the edifice. Additionally, singularity of every edifice leads to less standardisation of the production procedure as compared with most of the goods manufactured. Therefore, the whole scenario of edifices complication construction urges the usage of other LCA methodological analysis.
With the add-on of pros of procedure and input end product based LCA a new loanblend is formulated.
EIO-LCA can give ready to hand cognition sing the merchandises which come under IO class and remainder can be taken attention by the procedure based LCA. Thus, for analyzing this edifice, a heterogenous LCA was used. To analyze and give elaborate information sing the edifice stuffs EIO-LCA was used.
3.1 Embodied energy
Data was made available from authorities databases of Thailand for ciphering the edifice stuffs embodied energy strengths. The antecedently described method is used here and it uses parts made by the energy sectors in relation to the edifice stuffs sectors. National mean monetary values of assorted stuffs obtained from Thailand authorities to bring forth the energy consumed in the end product of a individual unit was multiplied by the energy strength from the sectoral sector. Then, by obtaining these values the entire initial embodied energy per stuff was verified after multiplying with values of entire stuff which reached the building site. Different stuffs wastage factors were besides obtained ( MOC, 2012 ) .
Energy required for the building comes from the electricity in usage for running the electric machines, Diesel fuel utilized by the heavy equipment ‘s and transit of the of the stuff on the site
Activities include site readying, structural and envelope installing, mechanical, electrical equipment installing, and interior coating. Process-based LCA was applied for this stage. Datas on the building procedure of the survey edifice site are site specific. The chief edifice elements which formed portion of this edifice infrastructure were columns, floors, stairwaies, roof, walls, Windowss, and coatings. Items such as fitments, healthful fixtures, contraptions, plumbing, electrical and external points were excluded from the survey due to the trouble associated with obtaining these informations. All informations relevant to building machines, energy demand and equipment used on-site, and transit distances of building stuffs to the building site were obtained. These were later aggregated with the energy ingestion for the transit of edifice stuffs to the building site from their assorted points.
3.2 Operational energy
Operating energy of the edifices includes energy used for chilling and air flow, illuming and machines process, and H2O beginning. Merely energy was found in the studied constructing. Process-based LCA was utilized to calculate out the edifice ‘s operating power demand. This was calculated by measuring cognition on mechanical and electrical devices manner and design demands as good because the awaited usage sample on the devising ( each twenty-four hours utilization 8h/ 5 day/week ) . As the edifice age is less than a twelvemonth and was new at the clip of research, so records for its existent electricity ingestion exist for a this period merely. The consequences of energy ingestion determined by analyzing the edifice were matched with current available records for the electricity. The assessed results showed a great correlativity therefore verifying the computations with electrical energy consumption informations. Life span of the stuffs of which edifice is made up was used in ciphering the energy required in the care stage and subsequent procedure was followed in gauging the energy demand in industry.
3.3 Building terminal
The concluding phase of a edifice ‘s life involves destruction. The traditional destruction method usually involves disposing off stuffs into a landfill site. Electrical power ingestion at this phase is chiefly ensuing from the process of destruction equipment. Due to absence of informations around the electricity demand of the destruction process in Thailand, secondary inside informations were taken into consideration and applied ( UNE, 2003 ) . 51.5 MJ/m2 of energy was used to pulverize concrete edifice obtained in the signifier of Diesel fuel. From the available informations it was assumed that 0.846 ton/m2 of waste would be generated from the destruction of the edifices.
As the edifice under research is located in the cardinal country of Bangkok so transit distance to the landfill site located 50 kilometer on the fringe of Nonthaburi was assumed. The Diesel operated truck utilizing energy around 2.78MJ/ton kilometer was used in transporting the destruction stuffs. Last but non least the entire energy required in destruction stage was summed up by the energy used by the destruction machinery and the energy used by the dump truck in transit of the stuffs ( Chini, 2003 ) . So, entire life rhythm energy was calculated by the equation given under: –
LCE=EEi + EErec+ ( OE-building life-time ) ( J )
Where LCE: life rhythm energy ;
EEi: initial corporal energy ;
EErec: recurrent embodied energy ( for future care ) and
OE: entire one-year operational energy.
Table 2.
Embodied energy coefficients of cardinal edifice stuffs.
Material
MJ/kg
MJ/kg
Ceramic tile
2.2
2.5
Granite
0.7
Brick
1.86
0.97
Gypsum
3.31
4.4
Aluminum ( Virgin extruded )
216.5
191,227
Plywood
8.5
10.4
Cement sand screed
0.2
0.1
Glass
17.1
15.9
Concrete ( ready mix 17.5 MPa )
1.3
1.0-1.6
Steel support
11.1
8.9
Structural steel
22.1
35
Steel wire
13.3
12.5
Bulk cement ( dry procedure )
3.6
5.8
Mortar
1.2 ( Fine ) , 1.4 ( LWB )
2
Paint ( oil )
81.5
88.5 ( H2O ) , 90.4 ( general )
95.4 ( polypropene ) , 98.1 ( dissolver )
Sand
0.1
0.1
It was determined that the corporal energy coefficients were good in co-relation with other surveies on same stuffs with mere divergences. This divergence for some stuffs could be associated to figure of parametric quantities that embrace technological effectiveness and quality of informations. As an illustration, brick bring forthing in Thailand has become ascertained to normally be inefficient and technologically deprived. Therefore, on ciphering the corporal energy value of bricks manufactured in New Zealand and the 1s used in this survey showed a big difference due to the hapless efficiency of the kiln techniques deployed in Thailand ( Lensink, 2005 ) . Discrepancies within the typical methodological analysiss and plan boundaries used for the computations within the analysis are { to boot } extra parts to be cause for these fluctuations.
The LCE associated with the edifice under survey is 2.2 – 106 GJ within following 50 old ages over entire floor country of 60,000m2. LCEA showed Operation stage accounted for around 80 % of the entire life stages in energy ingestion. Significant portion of 16 % energy ingestion was found from the industry stage by LCE. All other stages were non of much part to edifices LCE profile.
375 TJ was the initial corporal energy of the office edifice calculated and is besides responsible for fabricating all other stuffs used in edifice. The extent of initial corporal energy 6.7 GJ/m2 in relation to the commercial development runing from ( 3.4-19 GJ/m2 ) was unvarying ( Pullen, 2000 ) . Over a span of 50 old ages the one-year mean energy ingestion was 0.87 GJ/m2. Over analysing the edifices operational and corporal energy, towards the terminal of the edifice it has been found that merely embodied energy histories for 15 % of the energy used in operational stage, which in bends is rather valuable as it equals to requirement of the operational energy for 11 old ages. Concrete and steel were present in high sums and steel and concrete portions were 42 % and 35 % severally of the IEE. As the edifice was made of strengthened concrete construction so the sum of steel and concrete stuffs was high in the edifice.
From the measures of the major resources utilized for in edifice doing 80 % of the content is concrete followed by steel and bricks as 5.5 % and 13 % severally. Nonetheless, for the ground that steel has much higher corporal energy as compared to that of bricks, its portion for IEE is greater. Subsequently, concrete supplies ( including bricks ) and steel shared around 93 and 5.6 % severally in the full merchandise mass from the edifice assessed.
The mean one-year energy ingestion ( AEEC ) of 0.85GJ/m2 for the life span of edifice was aligned with consequences obtained. In the referenced research, AEEC of commercial edifices scopes from.5 to 1 GJ/m2 in Australia and was found to be 0.77 GJ/m2. A criterions or variable usually utilised for measuring electrical usage throughout the edifices ‘ process would be the energy index, expressed in KWh/m2/yr and was assessed 238. This was when compared with clearly located office edifices decision was found that it lies in the margin for low rise edifices and other denominated edifices by the Thailand authorities, and besides similar to some other Asiatic states.
During the analysis of the current energy ingestion within the operational stage of the edifice showed that the air conditioning was highest in energy usage of ( 6796 KWh/m2 ) followed by office equipment and illuming burden of ( 1996 KWh/m2 ) and ( 1887 KWh/m2 ) severally. The portion of air conditioning system was found to ( about 57 % ) was close plenty when compared with office edifices 51 % of Thailand edifice database ( DEDE, 2005 ) .
4. Appraisal of possible energy salvaging steps
To cut the energy ingestion of the edifice Numberss of criterions were formulated foremost being to raise the set point temperature of air conditioning system. Even though the advisable indoor temperature set point is about 26 & A ; deg ; C but many surveies revealed that the temperature comfy for human organic structure is higher in parts of Torrid Zones as worlds have the ability to acquire accustomed to diversifying clime and other psychological fluctuations. In respect to people of Thailand many surveies have shown that people in Thailand can populate at a temperature higher than the people from West comfortably. Therefore, from the satisfaction degree of workers, the set point of air conditioned systems can be 28 & A ; deg ; C for the one working in these conditions and can be 31 & A ; deg ; C in edifices where workers are working natural ventilated conditions.
Implementing the concluding consequences of the placement as an implicit in premise, the influence of an addition in the set-point temperature was examined in the air conditioned system. On farther analysis it showed that by increasing the temperature by 1 & A ; deg ; C in the system a lower limit of 7 % decrease will be shown in the average energy ingestion. This consequence proved to be in conformity with consequence formulated by ( Yamtripat et al, 2005 ) . So by altering the set point from 24 to 26 & A ; deg ; C, 1.14 – 106 kWh/yr of electricity would be saved and this in bends is equal to its one-year operational energy by seven per centum on application of this premise in whole of Thailand
The scheme supplied the opportunity of make up one’s minding the possible once-a-year energy personal nest eggs for Thailand topographic point of work developing stock depending on its electrical power ingestion 12,349.87 GWh/yr ( DEDE, 2004 ) . Using the belief which the indoor set-point temperature is enhanced by two & As ; deg ; C by Thailand ‘s overall workplace building stock list, an correspondent computation showed that 978 – 106 kWh/yr of electrical energy may really good be achieved to the part.
Yet another reasonably basic no-cost possibility assessed with a fact of turning off the electrical burden and lightning for about one hr during the tiffin interruption in consequence to salvage energy and is besides predicted that air conditioned airing would besides non be under operation within this clip. By making so there would be no consequence on the thermic comfort and the acting activities of the residents. Switch overing off the edifice system for this period of clip has been experimented in office edifices in Thailand with the permission sing residents comfort degree and has proved critical in extenuating the ingestion of energy ( Chirarattananon, 1998 ) .
Despite the fact that same aim can be achieved by other available picks like better efficaciousness and tenancy detectors, it should be mentioned as purpose of this rating is to happen out the grade of extenuation of the energy that can be achieved. Further it was assumed that if for one hr the air conditioned and other equipment ‘s running in the office are turned off during the whole twelvemonth 12.54 % of one-year energy of the edifice accounting 1.8 – 106 kWh/yr would be saved and if this could be projected for all the office edifices in Thailand the energy ingestion will be reduced by 1.1 – 104 GWh/yr.
Major portion of the electricity ingestion in the edifice is fundamentally the air conditioned systems and HVAC system running centrally chiller H2O system and which can be replaced with high efficaciousness and lesser capacities of hair-raisers. The elaborate option for hair-raiser to be replaced is down below: –
Technical informations for hair-raiser scenario.
Water-cooled centrifugal compressor ( & A ; gt ; 300 ton )
Capacity ( kW/ton ) base instance
Capacity ( kW/ton ) replacing option
Chiller 1
0.65
0.45
Chiller 2
0.64
0.45
Chiller 3
0.63
0.45
Chiller 4
1.32
0.45
Chiller 5
1.32
0.45
An appraisal on the electricity usage with the building utilizing the replacement options for the hair-raisers was carried out plus the effects obtained in contrast with that of the base state of affairs. The terminal consequence indicated that by using the permutation pick of hair-raisers instead than the base constellation, a 17 % lessening in operational energy might be achieved and this besides saves enormous sum of energy. Thus efficient energy equipment in doing of office edifices should be given consideration.
Windows can significantly absorb and convey sunshine which in bends increases the chilling edifices chilling burden. So, to cut down the energy and solar ingestion heightening Windowss public presentation was besides considered in edifices. The ratio of window to palisade in the edifice studied was 0.5. As larger window country is used as a sale aim in bulk of Thailand the window wall ratio lies within the scope of 0.3-0.5 for edifices used as offices. So it was calculated if in given edifice wall window ratio is changed to 0.45 and 0.35 there would be a lessening in operational energy by 2 % and 6.24 % severally.
Glazing and make up one’s minding appropriate choice of the size of Windowss used in the edifices can assist in cut downing the heat transmittal still keeping equal entry of visible radiation and positions within the edifice. So, based on this choice of window size and glazing stuffs in usage different stuff was used in topographic point of the basal stuff and consequence was evaluated.
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Specification
Base instance
Option A
Option B
Thickness
6 millimeter
6 millimeter
External window glass 6 millimeter
Shadowing coefficient
0.29
0.26
0.26 ( sum )
U value ( W/m2 K )
5.24
4.6
1.1 ( Ar filled )
SHGC = SC – 0.87
0.253
0.226
0.226
Visible light coefficient of reflection ( % )
16
8
14
Visible light transmission ( % )
9
41
30
Solar energy transmission ( % )
6
33
15
Solar energy coefficient of reflection ( % )
12
7
11
Beginning
Bill of stuffs
A
Bacillus
Base instance = Heat Strengthened Blue Reflective glass SS514 ; Option A = Heat Strengthened Gray Reflective glass SS514 ; Option B = High public presentation Blue double glazed unit with 16 millimeters argon filled pit, 6 millimeter clear interior glass.
The result advise that by utilizing solution A as an option to the base, keeping the ratio of window-wall ( WWR ) at 0.5, a cut down of approximately 0.6 % while in the edifice ‘s operating electricity demand could perchance be accomplished. While utilizing the exact WWR, option B performed good by take downing 3.7 % of the operational energy of the office edifice in comparing to current state of affairs
Recycling recovered doing elements with the conclude of day-to-day life of the development is doubtless an topographic point the topographic point come-at-able decreases can be received while in the LCE profile of edifice ‘s via a decrease during the original corporal electrical power needed for production devising constituents. Recycling is used below given that the general thought for reuse and stuffs recycling. The prospective positive facets of recycling are salvaging of all-natural uncooked constituents and verve at the same clip as lowering of landfill room.
Recycling the stuffs recouped at the clip of destruction of the edifice is an facet where edifices LCE profile can be reduced by cut downing the corporal energy required in the initial stage of fabrication stuffs for the edifice. Reprocessing is utilized here as the finished believed for reuse and physical recycling. The possible benefits of recycling are salvaging of natural stuffs happening of course, energy and besides cut downing country under landfill. Though, the grade of plus varies reliant on physical sort and signifier of recycling. A possibility ca n’t be denied to cut down corporal energy of the edifice by recycling the stuffs recovered at the edifices end life.
Energy saved was calculated on the footing of the old methodological analysis delineated and concluding consequence obtained showed reprocessed stuffs over the life span of the edifice reduces initial embodied energy up to 9 % and 1.49 % over the life rhythm of the edifice.
At the terminal life of constructing it is normally taken down and consequences in the big balls of bricks and other concrete stuffs which leads to formation debris and which is by and large disposed of to open sites in Thailand and are non recycled, which in bends have the ability to be recycled. But, in recent times due to progressing engineering and scientific discipline much attending is given to recycling of rubble. Datas from the European states suggest that what which was considered to be waste because of built-in value is now been considered to be importance as rubble obtained from the dismantled edifice can be used as a replacement in topographic point for virgin sum in utilizing as route base, paving ingredient which will salvage energy spent in fabricating concrete from it. Besides the energy wasted in excavation and processing to do concrete would be saved.
To give clear scenario of what potency does recycled rubble have by replacing virgin aggregate the contents of waste obtained from the destruction of edifice were utilised and proportions of different stuffs in the waste was measured by utilizing an equation below: –
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Qx=A-Gav-Px=Qp-Px ( J )
where Qx: measure of destruction waste stuff ten in dozenss ;
A: gross country of edifice in M2 ;
Qp: undertaking destruction waste generated in dozenss ;
Gav: mean waste coevals rate ( 18.99 kg/m2 for new non-residential edifices ) ;
Post exchange: mean composing of waste stuff x in % .
The undermentioned premises were made based on information obtained, ( a ) procedure energy for the production of one ton of virgin sum = 51.3 MJ/ton ; ( B ) procedure energy for the production of 1 ton of recycled sum = 37.1 MJ/ton.
4.1 Analysis of energy salvaging schemes
In footings of extenuating the operational energy of the edifice an rating of certain steps were undertaken and were applied and the most dependable and efficient method was holding an effectual HVAC system. Second was the stopping electricity supply sporadically and 3rd was the WWR decrease heightening energy salvaging for approximately 2 % . As disingenuous value of the edifice with bigger window size is liked in Thailand so little WWR would non be of much credence, the following best method of salvaging energy by 3.69 % would be usage of lower solar heat addition coefficients with higher public presentation of the dual glassy unit.
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The terminal consequences obtained when set together and besides sing the fact the potency of recycled stuffs in cut downing the initial corporal energy of the edifice a sum of about 45-50 % of the energy can be saved. If the office edifices in Thailand would run under the conditions formulated above a big sum of entire energy can be reduced up to 3.1- 103 GWh/yr equivalent to 28 % could be achieved.
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Introduction
Based on the LCA of the air conditioned edifice above similar edifice of the same dimension was studied for ciphering energy efficiency of the natural airing of the edifice as baseline. Some alterations were made to confront the challenges lifting in mensurating the natural airing. The overall agreements and constructions of the natural ventilated edifice were same as of the commercial edifice and much of the concern was given to the energy, airflow and temperature.
Office edifice is located at distance of 300 metres from the mechanical ventilated edifice studied above in Bangkok. The edifice is good spaced, with about 25- 35 metres between edifices. The country fundamentally falls in the tropical part of the Earth. The fluctuation in temperature was from 22 -31 & A ; deg ; C at the clip of survey. The edifice has an country around 2650 M2 about and is three narratives in tallness and is surrounded by the edifices runing under mechanical ventilated conditions.
Building has unfastened infinite on all the 3 floors get downing with first floor on the south side, 2nd floor had both south and north confronting unfastened infinites and last floor with north side unfastened. The first floor is closed from all sides of the edifice and is by and large used as conference hall towards the north side. As sometimes due to increase in temperature this floor has the ability to be cooled automatically but this is done by and large on hebdomadal footing and for few hours. The office country opens in chief entryway along east to west way of the edifice.
The edifices building description is given below in the tabular array: –
Construction
Materials
Thickness, millimeter
Glazing
Argon filled double tinted glass window glass
29
North roof
Vapor membrane and roofing board
82
South roof
Fiber insularity
155
Insulated panels
Aluminum panels
214
Brick Fa & A ; ccedil ; ade
Fill insularity and pit wall
410
Table: Construction stuff Description ( DEDE, 2005 )
Orientation and U-value of the edifices are given below the tabular array:
Orientation
Fa & A ; ccedil ; ade type
Area M2
U-value W/m2 K
North
Brick fa & A ; ccedil ; ade
80
0.46
Glazing
230
2.2
South
Insulated panels
84
0.46
Glazing
228
2.2
East
Brick fa & A ; ccedil ; ade
264
0.46
Glazing
110
2.2
West
Brick fa & A ; ccedil ; ade
262
0.46
Glazing
102
2.2
Table: Area and U-value of edifice ( DEDE, 2005 )
The airing operated in the edifice was buoyancy-wind driven and besides the fan assisted airing tonss were in consequence. At each floor of the edifice, on north and south frontages there were six sets of two occupant monitored Windowss, a larger window incorporating the smaller window. Venetian blinds were included in the design of the edifice to cut down the blaze from Suns which were manually operated depending upon the demand of the resident to allow daylight entry to edifice. As these blinds were placed to cover the upper windows they hinder the sum of air come ining or go forthing the edifice when they are all the manner down.
A series of Windowss shutter normally termed as louvres were used in series by stack mercantile establishment and are besides manually controlled. The louvres are opened if the fans are runing. The edifice is occupied by the residents on each degree and there are about 26 people on each floor. Energy efficient lamps are located in the edifice. By analysing the energy being consumed and other equipment ‘s usage habitation of the edifice can be figured out. The elaborate information was collected from every floor of the edifice in measuring the energy ingestion of the edifice.
Window Airflow Ratess
Awning type Windowss were pivoted to the top and would by clash pull of flexible joint integral. A method for finding the airflow rate was developed as the foundation for natural airing is the air drawn from outside ambiance to supply comfort degree and fresh zephyr as motion and velocity of air current is extremely unsure. To mensurate the exact sum of air current come ining the edifice a device was made non merely to do design of window understood easy but besides to keep balance in the airflow rate. To hold an effectual country for Windowss, a rectangular window transition was installed alternatively of the geometry of awning window which was more complex to understand.
Following information was calculated for the air current velocity and effectivity of gap of window was measured.
Time ( sec )
Speed of air ( m/s )
Air volume ( M3 )
Volume flow ( m3/s )
Effective gap ( M2 )
Effectiveness of window ( % )
9
0.476
1.6
0.183
0.366
31
