Chirag Deb

Indian Institute of Technology Bombay | IIT Bombay · Centre for Urban Science and Engineering (CUSE)

Accurate building energy assessments are often limited by inaccurate assumptions about the buildings' properties and occupant behavior. Many assessment methods use assumptions instead of measured data because it is cumbersome, time-intensive, and cost-intensive to acquire up-to-date, on-site measured data. This work bridges this gap by presenting t...

A high-quality building energy retrofit analysis requires knowledge of building characteristics like the type of installed heating system. This means auditing the building in person or conducting a detailed survey, which is not readily scalable for many buildings. This paper presents a data-driven methodology to identify building characteristics fr...

The heat transfer coefficient (HTC) is a very important factor influencing the energy performance of a building. Recent studies have shown the importance of on-site measurements of the HTC in reducing the performance gap in buildings. However, its measurement setup and calculation procedures are known to be intense and complex. Due to this, many st...

In order to meet the ambitious emission-reduction targets of the Paris Agreement, energy efficient transition of the building sector requires building retrofit methodologies as a critical part of a greenhouse-gas (GHG) emissions mitigation plan, since in 2050 a high proportion of the current global building stock will still be in use. This paper re...

The current process of analysing building retrofit strategies relies on physics-based, thermal balance models. However, these models are oblivious to the significance of the input variables for devising the retrofit strategies. This leads to the process of exhaustive search for obtaining the cost-optimal retrofit strategy. On the contrary, this wor...

Indoor environmental quality (IEQ) can impact human health, well-being, and productivity. This paper reviews the couplings between IEQ which consists of thermal, acoustic, visual comfort, and indoor air quality, and parameters such as human comfort and productivity, with the overarching aim of ensuring a healthy environment while reducing energy co...

Buildings consume around 40% of total global primary energy and account for one-third of greenhouses gas emissions. In the context of rising average air temperature and growing reliance on air-conditioning for space cooling, energy efficiency in buildings is becoming increasingly important. This is of particular significance to the tropics where a...

Global energy concerns necessitate designing energy-efficient buildings. Many important decisions affecting energy performance are made at early stages with little information. Dynamic simulations support informed decision-making; however, uncertainty, high computational time, and expensive modelling efforts impair their use at early stages. This a...

This study presents a brief review on the current global trends in data-driven urban building energy modeling (UBEM) and explores the possibilities of applying data-driven UBEM to Indian cities. The existing research shows that availability of data that are required for UBEM is uncommon. This has led researchers to employ hybrid models that combine...

This study presents a black-box model to analyze retrofit strategies on the building envelope of a single-family residence in Switzerland. The model is a Long-short term memory-based Recurrent neural network (LSTM-RNN) developed on data from a wireless sensor network (WSN). The 39 measured variables are filtered using a two-step feature selection p...

Among other reasons, the low building retrofit rate in Switzerland is attributed to modeling barriers: a lack of accurate assessment of building energy performance in the pre-retrofit phase as well as the difficulty to model the energy performance in the post-retrofit phase. We propose a novel resistor-capacitor (RC) model that is calibrated with g...

Occupancy information is one of the crucial variables in modelling and predicting the energy use in buildings. However, the presence of occupants is often stochastic in nature. In the presented case of an institutional building, a substantial variation in the correlation between occupancy and energy consumption is found for different spacetypes dur...

Assembling the knowledge, tools, and skills to reliably determine the (Heat Transfer Coefficient) HTC of a dwelling was a main driver for Annex 71. However, research has been carried out in this area for several years. What has set this work apart was the idea of measurement of the HTC using cost effective data, such as smart meters and on-board de...

Retrofitting buildings is essential for improving the existing global building stock. Innovations in wireless sensor networks have provided new means for scalable and potentially low-cost solutions for evaluating optimal retrofit measures in a building. Building models are used to explore different retrofit options and to find effective combination...

In the building and construction sector, the mismatch between predicted and measured energy consumption is a well-known phenomenon called the performance gap. A promising approach to reduce the performance gap and thus improve the current building energy performance assessments are methods based on in-situ measurements. In this work, we present a b...

The thermal performance gap in buildings is defined as the difference between the theoretical and the actual energy consumption for heating, and is known to undermine energy retrofit strategies and policies. This study examines the performance gap in retrofitted buildings using the Swiss Cantonal Energy Certificate for Buildings (CECB) database, us...

The current retrofit rate in Switzerland is very low. Among other reasons this is attributed to a lack of knowledge about cost-optimal retrofit strategies. In this work we carry out a holistic cost-optimal retrofit analysis for a Swiss single-family house. First, currently popular retrofit measures including all incurring lifecycle costs are identi...

Building-related heating consumes 80% of final energy in the Swiss residential sector. Electrical resistance heating systems consumed 9.3 PJ and 7.9 PJ for space and domestic hot water heating respectively. This is 8.6% of the total electricity consumption in Switzerland. A successful retrofit action requires knowledge of energy consumed by these s...

This study aims to develop prediction models for HVAC related energy saving in office buildings. The data-driven modelling makes use of data gathered from several energy audit reports. These reports entail building and energy consumption data for 56 office buildings in Singapore. The two models are developed using Multiple Linear Regression (MLR) a...

This study aims to determine key building variables influencing energy consumption in air-conditioned office buildings. The study is based in Singapore which entails tropical climatic conditions. The analysis is based on assessment of several energy audit reports concerning pre- and post-retrofit data from 56 office buildings. A list of 14 building...

Thermal comfort aspects of indoor spaces are crucial during the design stages of building layout planning. This study presents a simplified tool based on thermal comfort using predicted mean vote (PMV) index. Thermal comfort simulations were performed for 14 different possible room layouts based on window configurations. ECOTECT 12 was used to dete...

Clustering algorithms have been successfully applied in analyzing building energy consumption data. It has proven to be an effective technique to identify representative energy consumption patterns as well as being a pre-processing step for other techniques. In this paper, we propose a clustering method based on k-Shape algorithm, which is a relati...

Energy consumption forecasting for buildings has immense value in energy efficiency and sustainability research. Accurate energy forecasting models have numerous implications in planning and energy optimization of buildings and campuses. For new buildings, where past recorded data is unavailable, computer simulation methods are used for energy anal...

In an increasingly competitive environment, a more efficient energy management is of utmost importance. However, despite the research on energy saving methodology and retrofitting analysis, these results and data does not allow different users to focus on what lies inside the management and strategy level. The Cockpit concept emerges as a strat...

Buildings consumes more than one-third of energy. Given the large number of occupancy in Institutional Buildings and the increasing need for more campus buildings and University infrastructure, the impacts of the urban heat island of University campus buildings can be felt more strongly. In this paper, we sought a smart energy consumption managemen...

Electricity load forecasting is crucial for effective operation and management of buildings. Support Vector Regression (SVR) have been successfully used in solving nonlinear regression and time series problems related to building energy consumption forecasting. As the performance of SVR heavily depends on the selection of its parameters, differenti...

This paper presents a detailed investigation and analysis of the energy consumption characteristics of three institutional buildings in Singapore. Building information, energy consumption data of the air-conditioning system, and energy consumption data of the plug loads were collected separately. Identification models are developed to predict the r...

This study presents an investigation and discussion on the energy performance of three ter-tiary institutional buildings in Singapore. Building information, energy consumption data of the airconditioning system, and energy consumption data of the plug loads were collected separately. MATLAB identification models are developed to simulate the real d...

This study presents building energy forecasting methodology for cooling load for three institutional buildings. These buildings belong to a university campus in Singapore. The daily energy consumption for cooling load is obtained for a period of two years and the daily variation is analyzed. The energy consumption is initially divided into five cla...

Air pollution and climate change increased the importance of renewable energy resources like solar energy in the last decades. Rack-mounted PhotoVoltaics (PV) and Building Integrated PhotoVoltaics (BIPV) are the most common photovoltaic systems which convert incident solar radiation on façade or surrounding area to electricity. In this paper the pe...

This study analyses the key principles in energy efficient lighting design for a commercial office building in India. Detailed assessment of the passive and active design features is carried out and is complimented by in-situ measurements and simulations. The results show that the building geometry, orientation & envelope is well planned to permit...

An attempt is made to present a new scale to study urban microclimates and outdoor thermal comfort using simple in-situ measurement data. For this purpose, six urban locations with distinct physical characteristics are selected in a metropolitan city, Chennai. At each location, three streets with diverse orientations (North–south; East–west and Nor...

Outdoor thermal comfort studies have gained momentum in the last couple of decades. The reasons may be attributed to increased urbanization and development and the resultant climate change leading to effects like the 'heat island'. Worldwide, there have been many initiatives to study these changing microclimates and its influence and interaction wi...

The recent Indian Railway budget proposes upgrading and development of fifty railway stations to world class standards. These stations act as crucial transport nodes for effective operation of the railway network and passenger well being. One of the important aspects regarding passenger satisfaction in these places is an acceptable thermal environm...

The use of the Physiological Equivalent Temperature (PET) to evaluate the thermal component of the outdoor microclimate is highlighted here.The increase in urbanization is loading urban areas with complex networks of built environments and human activity. The changes and developments in the built environment invariably affect the microclimate. The...