UNIVERSITY OF PUNE

MASTER OF ARCHITECTURE (M.ARCH)

(ENVIRONMENTAL ARCHITECTURE)

TRAINING GUIDE 2013

SEMESTER III

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INDEX

Sr No CHAPTERS Page No

1INTRODUCTION TO ENERGY MANAGEMENT IN BUILDINGS, HVAC SYSTEM

2 ENERGY ANALYSIS OF BUILDINGS USING <VE>3 ENERGY MODELLING LIVE ACTIVITIES

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CHAPTER 1

ENERGY MANAGEMENT IN BUILDINGS

Commercial buildings utilise more than 42% of all electricity

produced, yet waste up to 50%. It is clear that looking at

innovative ways to manage energy use across the building

portfolio offers very substantial savings. Furthermore

organisations need to urgently adapt from ‘business as usual’

if they are to meet CSR targets, and comply with current and

future environmental legislation, whilst ensuring on-going

reliability and investment value of building stock. We believe

that the application of Virtual Building technology from

design, through construction & commissioning on into operation

and renovation/adaptation offers a 3D platform upon which

Smart building principles can be built. As such through our

consulting services we can furnish you with the analytical

information necessary to make decisions:

League table energy and carbon footprint ratings across your

building portfolio

Detailed surveys of when and where energy is wasted,

including hidden waste

A building portfolio energy reduction strategy that

maximises investment value

Tracked and verified financial savings from energy

conservation initiatives

Detailed accounting solutions that avoid Carbon Tax

penalties

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Existing Building Management Systems (BMS) frequently operate

inefficiently. We can not only identify how to make the BMS

perform better, but through advanced analytics help you

uncover hidden inefficiencies which when resolved can reduce

operating costs substantially. On a recent project we achieved

a 20% reduction on the annual energy bill without any capital

spend. If there is a need to refurbish, our state of the art

simulation technology can determine the best Energy

Conservation Measure by, for example, assessing the trade-off

between energy savings and costs. Or if the best course of

action is to de-commission and rebuild, we can provide a

sophisticated and integrated Virtual Building solution that

follows the design from conception, through rating and

regulation compliance, on into construction, commissioning and

operation. This ensures that optimal operation is achieved at

all stages and adapts as the building profile changes during

its lifecycle. In this way you can gain enormous benefits

throughout the whole design and subsequent operational

process.

HVAC SYSTEMS & ENERGY EFFICIENCY

Heating Ventilation & Air Conditioning refers to equipment,

distribution systems, and terminals that provide, either

collectively or individually, the heating, ventilation, or air

conditioning requirement to a building or a portion of

building. The HVAC system accounts for significant portion of

a commercial building’s energy use. Proven technologies and

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design concepts can be used to build energy efficiencies in

the system and generate significant energy and cost savings.

It also affects the health, comfort, and productivity of

occupants. Issues like user discomfort, improper ventilation,

lack of air movement and poor indoor air quality, and poor

acoustic design are linked to HVAC system design and operation

can be improved. The optimum HVAC design considers all the

interrelated building systems while addressing indoor air

quality, thermal comfort, energy consumption, and

environmental benefits. Optimizing both the design and the

benefits requires that the architect and mechanical system

designer address these issues early in the schematic design

phase and continually revise subsequent decisions throughout

the remaining design process. It is also essential that a

process be implemented to monitor proper installation and

operation of the HVAC system throughout construction.

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Above Figure – A Sketch of HVAC System

CHAPTER 2

ENERGY ANALYSIS FOR BUILDINGS USING <VE>

INTRODUCTION

In this chapter you will be shown how to populate a <VirtualEnvironment> project with thermal template data andconstructions in preparation for performing dynamic thermalsimulations (ApacheSim), thermal load calculations.

The session will explain the concept of the Building TemplateManager (BTM).Fast Accurate thermal simulation is now anessential part of successful low-energy, high-performancebuilding design.  ApacheSim is a central simulation processerwhich enables you to assess every aspect of thermalperformance as well as share results and input across a widevariety of other VE modules.

You will also look at the different Renewable Energyharnessing options under fuels data that can be assigned for agiven building model in Virtual Environment. To analyse thepotential for each and the benefits that one could achieve outof each.

You had earlier seen how to create a building model usingModelIT module of <VE>. Now you will be using the ApacheSimmodule of <VE> which is a dynamic thermal simulation programbased on first-principles mathematical modelling of the heattransfer processes occurring within and around a building.

ApacheSim is comprised of the following tools: Apache ApacheEngine Vista & VistaPro ApacheView ApachePro ApacheLocate

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Constructions Database

DATA ENTRY OPTIONS Extensive database of global weather Data detailing layer-by-layer thermo-physical properties of

building elements Comprehensive data on glazing systems including angle-

dependent transmissivity and absorptivity Sensible and latent gains from lights, equipment and

occupants Natural ventilation, mechanical ventilation and infiltration Plant operation profiles Plant efficiency and fuel characteristics Powerful facilities for assigning and editing time-varying

room data such as plant, casual gains and air exchanges Database of constructions

Configurable using Tabular edit function Time-series profiles Tabular Edit feature for Building Template Manager & NCM

(for UK Part L)

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MODEL CONSIDERED FOR ENERGY ANALYSIS

BUILDING TEMPLATE MANAGER

The Building Template Manager (BTM) is accessed via the <VE> Tools menu, or via the BTM icon.

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The BTM controls building level template information for a number of aspects of the project.

ACTIVITY 1: For a single Room Building model assign all theconstructions as per ECBC(Energy Conservation Building Code).Select Mumbai as the location. Consider the room to be anOffice. (Refer ECBC for the required values). Calculateadjusted SHGC for vertical glazing.

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ImportTemplates

Add Template DeleteTemplate

APpro ProfileDatabase

Step 1: Listing down ECBC requirements with respect toConstructions.

For the Warm & humid climate of Mumbai following shall beconsiderations as per ECBC

1. Roof Assembly: (ECBC Table 4.1)

Roofs24 hrs use building Other Buildings (day time)

Max. U-factorfor overall

assembly W/sq-m-K

Min R-valuefor

insulationalone sq-m-

K/W

Max. U-factorfor overallassemblyW/sq-m-K

Min R-valuefor

insulationalone sq-m-

K/WWarm & Humid

0.261 3.5 0.409 2.1

2. ECBC limits area of vertical glazing up to max of 60% ofgross-wall area. Other requirements area:

ECBC Table 4.3Vertical

Fenestration WWR<=40% WWR<=60%

Climate Max Ufactor Max SHGC Max SHGC

Warm & Humid 3.3 0.25 0.2

3. Minimum Visible Transmission of Glazing

ECBC Table4.5Transmissivity & Window Wall Ratio

Window Wall Ratio Minimum VLT0-0.3 0.27

0.31-0.4 0.20.41-0.5 0.160.51-0.6 0.13

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4. Opaque Wall Construction:

ECBC Table 4.2Opaque Walls

24 hrs usebuilding

Other Buildings(day time)

Climate

Max Ufactorfor

overallassembl

y

Min R-valuefor

insulation alone

Max Ufactorfor

overallassembl

y

Min R-valuefor

insulation

aloneWarm & Humid 0.44 2.1 0.44 2.1

5. Sky-lights:

ECBC Table 4.6Skylights (max 5% of gross roof area)

Max U-factor Max SHGC

Climate withCurb w/o Curb 0-2%

SRR2.1-5%SRR

Warm & Humid 11.24 7.71 0.4 0.25SRR – Sky-light roof ratio is ratio of total skylight area ofroof measured to the outside of roof, to the gross exteriorroof.

6. Overhangs for vertical fenestration to be used which dependson the Projection Factor. Projection factor is the ratio ofdistance from the window to the farthest edge of the overhang(H) and dividing that by the distance from the bottom of thewindow to the lowest point of the overhang (V). Also, anadjusted SHGC, accounting for overhangs and/or sidefins, iscalculated by multiplying SHGC of un-shaded fenestration by amultiplication factor (M). So there is a M factor for eachorientation and unique shading condition.

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Overhang "M''Factors for 4ProjectionFactors

Vertical Fin "M"Factors for 4ProjectionFactors

Overhang+Fin''M'' Factors

for 4 ProjectionFactors

ProjectLocation Or

ient

ati

on0.25

-0.

490.

5-0.

740.75

-0.

991.

00 +

0.25

-0.

490.50

-0.

740.75

-0.

99 1+

0.25

-0.

490.

5-0.

740.75

-0.

99 1+

Northlatitude 15deg orgreater

N0.88

0.8

0.76

0.73

0.74

0.67

0.58

0.52

0.64

0.51

0.39

0.31

E/W

0.79

0.65

0.56

0.5

0.8

0.72

0.65

0.6

0.6

0.39

0.24

0.16

S0.79

0.64

0.52

0.43

0.79

0.69

0.6

0.56

0.6

0.33

0.1

0.02

Lessthan 15degNorthlatitud

e

N0.83

0.74

0.69

0.66

0.73

0.65

0.57

0.5

0.59

0.44

0.32

0.23

E/W

0.8

0.67

0.59

0.53

0.8

0.72

0.63

0.58

0.61

0.41

0.26

0.16

S0.78

0.62

0.55

0.5

0.74

0.65

0.57

0.5

0.53

0.3

0.12

0.04

Step 2: Create a Model in ModelIT with weather file set toMumbai location and with 30% glazing on each wall and a sky-light which covers 3.6 % of gross roof area.

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Project location is 18.9° N latitude which is greater than15°. Site orientation is South as per the Building entry. Baseheight of window is approx 0.67 m height of window is approx1.5 m.

Step 3: Providing Overhangs for all the windows

The depth of overhang (Shade) is chosen as 0.1 m, length as 6m so that it covers the glazing, its height from the bottom ofwindow is 1.7 m (approximately), projection outwards is 1 m.

Hence the Projection factor for the Shade = 1/1.7 = 0.58 m

Hence the M-factors are : 0.8,0.65,0.64 for N, E/W,S windoworientations. So adjusted SHGC for the window would now be = Mx (SHGC of unshaded window).

Step 3: Assigning constructions as per ECBC

Create a new construction Template with the name ‘ECBCConstructions’ in the Building Template Manager’.

a) External Wall – The already assigned wall constructionmeets the ECBC standard

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Keeping ‘standard wall construction (2002 regs) for theexternal wall.

b) Roof – The already assigned roof construction meets theECBC standard

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c) Vertical Fenestration (windows) –

In place of SHGC, g-value has been shown for the windowassembly which is 0.64. This is greater than the 0.25

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specified under ECBC. Hence we will modify the constructionsuch that the value meets ECBC requirements.

Saving the glazing construction as ‘ECBC Glazing’.

d) Sky-light -

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The selected glazing construction for sky-light has a high g-value (SHGC) of 0.6457 which should be below 0.25. Hencemodifying the construction of sky-light as below:

Saving the construction as ‘ECBC Skylight’.

Step 4: Assign new constructions for vertical glazing & sky-light to the new template

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Click ‘Save’ and then Ok. Now we will assign the constructiontemplate to the model.

Step 5: Switch to ApacheSim & assign the newly createdconstruction template

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ACTIVITY 2: For the same model created in previous activity,calculate the Solar heat gain for the building. For the samemodel re-run the solar heat gain with default constructiontype to analyse any change. Also, find the yearly reduction inSolar gain as a result of the construction complying with ECBCas against non ECBC compliant (default construction).

Step 1: Calculate solar shading for the model with ECBCcompliant construction using SunCast

Making no changes in the existing model, calculate solarshading in SunCast

Step 2: Open ApacheSim & run the dynamic simulation for themodel and save result file as ‘ecbc run 1’

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Step 3: When in ApacheSim change construction template todefault

Step 4: Repeat Step 1 & Step 2 for the Model with non ECBCcompliant construction.

Step 5: Compare Results (Select both the result files and thensolar gain from variables)

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Clearly the model when assigned with ECBC compliantconstruction has reduced Solar gain as against with defaultconstruction.

Step 6: Yearly reductions in Solar gain

Click the Monthly totals button when in Vista after selectingthe two result files for the ECBC run and Non- ECBC run

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ACTIVITY 3: For the Model considered in Activity 1, calculatethe RE potential for the Building if area available for SolarPV is 50 sq-m. Also, comment on the feasibility of Wind powergeneration for the site.

Step 1: Open the project considered under Activity 1 &Selecting the ApacheSim application

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Step 2: Click on the Renewables button & add a PVS generatorPanel

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Step 3: Now add a wind generator Let the hub height be 20 mts and Rated Power be 100 kW.

Step 4: Run the ApacheSim Dynamic Simulation to analyse theenergy generation from renewables

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Name the results file as renewable run 1.aps.

Step 5: Select the required variables under the Energy tab &view the results for the model.

Energy Generation from Renewables is as below:

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Per day units generation on an average from PV = 24 kWhPer day unit generation on an average from wind energygenerator = 23.8 kWh

This suggests that for the given location both Wind and Solarare feasible options. But due to space constraint for theconsidered building wind may be a better option for RE.

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ACTIVITY 4: For a single room building model assign HVAC system such that the room temperature is maintained at 24°C during the occupancy hours. The occupancy hours are from morning 8:00 am to evening 6:00 pm on weekdays. Weekends are off. Also calculate the energy consumption and the air flow for the HVAC system.

Step 1: Considering the model that was created in Activity 1

Step 2: Open Building template manager and create an daily & weekly occupancy profile using APpro

Now, create a weekly profile by assigning the new daily profile to the weekdays & Always off profile to the weekends.

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Step 3: Defining Room conditions & assigning HVAC system to a new Thermal Template under BTM

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Step 4: Assigning the New Thermal template to the model room

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Step 5: Select ApacheSim & run ApacheSim dynamic simulation

Step 6: View results in Vista

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After selecting room, select the ‘Air temperature’ from the room variables and Dry bulb temperature from Weather

variables. Then select ‘Graph’ to view result. Step 7: Energy consumption for the HVAC system.

Under the Energy tab for the whole model, select System energyto view energy consumption for the HVAC.

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From the above data the total HVAC system energy = 24.9315 MW

Step 8: Air flow for HVACSelect ApSys air Supply under room variables and click on monthly totals

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This gives the per month air flow rate for the HVAC system forthe whole year. The total air supply to the HVAC is 469800 cumfor the year. But we may be interested in air supply flow for the HVAC during heating/cooling hours. For this click ‘Graph’ and then set a date.

This shows that 50 l/s is the constant Volume flow air supply from the HVAC system during its operational time.

ACTIVITY 5: Analyse the change in System cooling load as a result of the followinga) Room electric lighting level is increased from 300 lux to 500 luxb) Change in Room construction as below

ConstructionsU-Value(W/sq-m

K)External Wall 0.5

Roof 1

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a) Room artificial lighting level is increased from 300 lux to500 lux.Step 1: Opening already created model

Step 2: Select FlucsPro and design artificial lighting for themodel room.

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Step 3: Run Simulation for only artificial lighting and view results

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Results

The power density for artificial lighting for 300 lux design levels is 6.24 W/sq-m

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Step 4: Assign fluorescent lighting LPD in the internal gains tab when in BTM

Open BTM thermal template that is currently assigned to the model. Modify the Internal gains tab and assign Fluorescent

lighting ‘Max Sensible gain’ as 6.24 W/sq-m

Save the thermal template.

Step 5: Select ApacheSim & run a dynamic thermal simulation

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Step 6: Select FlucsPro and design artificial lighting for themodel room

This time design the Artificial Lighting for 500 lux lighting level

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Step 7: Run the Analysis calculation in FlucsPro to view the results

The Power density for 500 lux lighting level comes to be 9.75 W/sq-m

Step 8: Assign fluorescent lighting LPD in the internal gains tab when in BTM

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Save and run ApacheSim dynamic simulation for the 500 lux lighting level

Step 9: Run the ApacheSim dynamic simulation for 500 lux lighting level

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Step 10: Compare the Chillers load for the system

From the analysis you can observe that the Chiller’s energy consumption is reduced by 0.9689 MWh per year if 300 lux level

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lighting is provided for the model room in place of 500 lux levels.

b) Change in Room Construction

Step 1: Select Construction template under BTM

Step 2: Creating a Custom Roof Construction

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Step 3: Importing Exterior Wall construction from ‘System Constructions’ with required U-Value

Assign and then save the constructions to the New Constructiontemplate in BTM.

Step 4: Assign the new Construction Template to the model in ApacheSim & run dynamic simulation.

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Step 5: Change construction Template to ‘ECBC Constructions’ and assign it to the model. Run ApacheSim dynamic simulation for the model with changed construction

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Step 6: Comparing Vista results for the two runs.

Comparing ‘Room cooling plant sensible load’ for the two runs.

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It is clearly observed that the Room cooling plant sensible load has increased for the room with new construction where U-values of Roof & Exterior Wall is as below:

ConstructionsU-Value(W/sq-m

K)External Wall 0.5

Roof 1

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