Forrest Michael Meggers

Princeton University | PU · School of Architecture

This research aims to make Building Automation System (BAS) data more accessible to building occupants by better visualizing them in a 3D environment. Current 3D solutions require a high-level of expertise, customization and integration that prohibit adoption, especially for small and medium scale projects. We developed a streamlined workflow based...

This research aims to better understand the radiant environment of an interior space located in the tropical climate that is cooled by Radiant Ceiling Panels (RCPs). To do so, we have designed a highly instrumented 177m ² office testbed in Singapore installed with RCPs, Dedicated Outdoor Air System (DOAS) and Fan Coil Units (FCUs). An 11-day experi...

Three decades of building performance standards have resulted in a meaningful reduction in energy consumption in commercial buildings, but limited improvement in thermal comfort has been observed. ASHRAE Standard 55, the primary reference used to design and operate “comfortable” buildings, specifies six thermodynamic factors that must be addressed...

Modern remote temperature sensing in the form of infrared imaging has become a widely used and important technique, with the ability to measure and characterize important but unseen Radiant heat. As more Long-wave Infrared (LWIR) detectors come to market aiming to meet a wide array of needs and goals, there is a need to differentiate and appraise L...

The psychrometric chart is the most common data visualization technique for the designers of thermal comfort systems worldwide. From its humble roots as means of expressing the characteristics of air in building systems design, the use of the chart has grown to include the representation of the zones of human thermal comfort according to both conve...

This research proposes a Computation in Design (C-in-D) framework for design practices to consider the adoption of computational technologies in their design process. Examples of computational design technologies include but are not limited to computational algorithms, the Internet of Things (IoT), reality capture and digital fabrications. We devel...

Cities today encounter significant challenges pertaining to urbanization and population growth, resource availability, and climate change. Concurrently, unparalleled datasets are generated through Internet of Things (IoT) sensing implemented at urban, building, and personal scales that serve as a potential tool for understanding and overcoming thes...

Radiant systems are an energy-efficient method for providing cooling to building occupants through active surfaces. To assess the impact of the radiant environment on occupants in space, we develop a ray-tracing simulation, which accounts for longwave radiation. Thermal radiation shares many characteristics with visible light, and thus is highly de...

We introduce and demonstrate new measurement and modeling techniques to fully resolve the spatial variation in shortwave and longwave radiant heat transfer in the outdoor environment. We demonstrate for the first time a way to directly resolve the shortwave radiant heat transfer from terrestrial reflected and diffuse sky components along with the s...

It is widely accepted that most people spend the majority of their lives indoors. Most individuals do not realize that while indoors, roughly half of heat exchange affecting their thermal comfort is in the form of thermal infrared radiation. We show that while researchers have been aware of its thermal comfort significance over the past century, sy...

Advancements in multi-agent, autonomous, and intelligent robotic systems over the past decades point toward new design and fabrication possibilities. Exploring how humans and robots can create and construct collectively is essential in leveraging robotic technology in the building sector. However, only by making existing knowledge from relevant tec...

Cooling a sample of a material until condensation is observed is a standard technique for accurately measuring the dewpoint and associated relative humidity in a volume. When conducting an experiment with a membrane-assisted radiant cooling panel, we found that membrane surface temperatures were difficult to measure directly. Instead, the onset of...

Urban building energy modeling is an important field in the current decade due to the rising rate of urbanization, specifically in developing countries. The UN environment is promoting urban level space cooling approaches in the upcoming smart cities of India. Rourkela is a tier-2 steel township included within the ‘smart city’ mission in India and...

In November 2018, following the Grenfell Tower tragedy in London, the Ministry of Housing, Communities & Local Government (MHCLG) introduced an amendment to the Building Regulations 2010, which outlined stricter rules banning the use of combustible materials defined by the new Building Regulation 7(2). This change had a significant impact since ear...

A data-driven simulation technique is proposed for the calculation of the 3-dimensional radiant temperature distribution across a room with the aid of a ray tracing method. The proposed simulation accounts for interreflections of radiant heat fluxes from surfaces reflective in the longwave range within the indoor environment. The simulation provide...

A radiatively cooled translucent building skin is developed for desert climates, constructed out of pockets of high heat-capacity liquids. The liquids are contained by a wavelength-selective membrane enclosure, which is transmissive in the infrared range of electromagnetic radiation but reflective in the shortwave range, and therefore prevents over...

Radiant cooling-assisted natural ventilation is an innovative technical approach that combines new radiant cooling technology with natural ventilation to increase fresh air delivery into buildings year-round with minimal energy cost and improves air quality. Currently, the standard paradigm for HVAC (heating, ventilation and air conditioning) is ba...

Instruments measuring the outdoor radiant environment are limited spatially. They aggregate observations to singular points, eliminating variations from surrounding surface temperatures. Computational methods can characterize the heterogeneous outdoor radiant environment, but spatial validation with accurate tools remains difficult. We use two nove...

This research proposes the use of membrane-assisted radiant panels to improve the thermal comfort of naturally ventilated spaces in hot and humid climates. These radiant panels are capable of conditioning naturally ventilated spaces, which is impractical with conventional mechanical cooling systems. For conventional systems, a permeable envelope wi...

This research proposes the use of membrane-assisted radiant panels to improve the thermal comfort of naturally ventilated spaces in hot and humid climates. These radiant panels are capable of conditioning naturally ventilated spaces, which is impractical with conventional mechanical cooling systems. For conventional systems, a permeable envelope wi...

This paper describes an open data set of 3,053 energy meters from 1,636 non-residential buildings with a range of two full years (2016 and 2017) at an hourly frequency (17,544 measurements per meter resulting in approximately 53.6 million measurements). These meters were collected from 19 sites across North America and Europe, with one or more mete...

Significance In this paper, we present results from a radiant cooling pavilion, demonstrating a method of cooling people without cooling the air. Instead, surfaces are chilled, and thermal radiation is used to keep people cool. A thermally transparent membrane is used to prevent unwanted air cooling and condensation, a required precursor to deployi...

This paper describes an open data set of 3,053 energy meters from 1,636 non-residential buildings with a range of two full years (2016 and 2017) at an hourly frequency (17,544 measurements per meter resulting in approximately 53.6 million measurements). These meters are collected from 19 sites across North America and Europe, and they measure elect...

Significance Wheat is the most important food crop worldwide, grown across millions of hectares. Wheat yields in the field are usually low and vary with weather, soil, and crop management practices. We show that yields for wheat grown in indoor vertical farms under optimized growing conditions would be several hundred times higher than yields in th...

In this research we have developed a 3D city model of Princeton University campus for the Campus as Lab (CAL) program using openly available 3D data. The sources include the official open data portal from the United States Geological Survey, OpenStreetMap and Google Maps. The 3D city model is used as a tool for visualizing and analyzing multidiscip...

A roof aperture lined with hydrogel membrane is proposed for combined evaporative and radiative cooling in the desert climate. In order to determine the design, materials and predicted performance of this device, several types of digital simulations and physical experiments were performed. The proposed full-scale prototype, planned to be built and...

Thermal radiation, being the infrared spectrum of electromagnetic radiation, shares many characteristics with visible light, and thus is highly dependent on surface geometry. Much research effort has been dedicated to characterizing the behavior of visible light in the built environment and its impact on the human experience of space. However, long...

Dynamic solar shading has the potential to dramatically reduce the energy consumption in buildings while at the same time improving the thermal and visual comfort of its occupants. Many new typologies of shading systems that have appeared recently, but it is difficult to compare those new systems to existing typologies due to control algorithm bein...

In this paper, we present results from a world-first radiant cooling pavilion, demonstrating a method of cooling people without cooling the air. Instead, surfaces are chilled and thermal radiation is used to keep people cool. A thermally-transparent membrane is used to prevent unwanted air cooling and condensation, a required precursor to deploying...

In this paper, we present results from a world-first radiant cooling pavilion, demonstrating a method of cooling people without cooling the air. Instead, surfaces are chilled and thermal radiation is used to keep people cool. A thermally-transparent membrane is used to prevent unwanted air cooling and condensation, a required precursor to deploying...

For thermal comfort research, globe thermometers have become the de facto tool for mean radiant temperature, tr, measurement. They provide a quick means to survey the radiant environment in a space with nearly a century of trials to reassure researchers. However, as more complexity is introduced to built environments, we must reassess the accuracy...

To better understand the extent of how the air temperature and mean radiant temperature may vary both spatially and temporally in a radiantly heated space, we conducted a seven-day experiment in the architectural laboratory at School of Architecture, Princeton University. The primary intent of this paper was to decouple the measurement of the air t...

For full access (before February 12, 2020), visit https://authors.elsevier.com/a/1aHm21M7zG%7EOya

Air conditioning demand is projected to increase rapidly over the next 50 years, particularly in already hot and humid climates. Radiant cooling can be an energy efficient strategy to mitigate comfort energy demand with high air temperatures, thereby reducing both sensible and latent loads in spaces. We have built an outdoor radiant cooling pavilio...

In a conventional indoor environment, thermal comfort is supplied by an air based distribution system. This system is controlled by an air temperature (and occasionally humidity) sensor, and the role of radiation in thermal comfort is often overlooked. In a typical indoor environment, slightly less than half of the heat occupants shed to maintain t...

Architectural surfaces constantly emit radiant heat fluxes to their surroundings, a phenomenon that is wholly dependent on their geometry and material properties. Therefore, the capacity of 3D scanning techniques to capture the geometry of building surfaces should be extended to sense and capture the surfaces' thermal behavior in real time. We pres...

The IEA EBC Annex 64 – LowEx Communities was a three year international research project which aims to demonstrate the potentials of low exergy thinking on a community level as energy and cost efficient solutions to achieve 100 % renewable and GHG emission-free energy systems. Central challenges are the identification of promising and efficient tec...

The inherent geometric and material dependence of radiant heat transfer can be leveraged to improve system efficiency and thermal comfort. Unlike in air-based systems, non-uniform temperature distribution can be highly controlled and beneficial in radiant systems, where temperature perception can be manipulated locally. An experiment was devised wi...

For thermal comfort research, globe thermometers have become the de facto tool for mean radiant temperature, tr, measure- ment. They provide a quick means to survey the radiant environment in a space with nearly a century of trials to reassure researchers. However, as more complexity is introduced to built environments, particularly with radiant he...

We present a makeover of the psychrometric chart using a new color-shading method that allows the chart to be considered comfortable based on the variation of non-air related comfort parameters such as mean radiant temperature, air movement, and the transitional behavior of occupants. These representations allows us to think outside the thermal com...

We can use the concept of exergy to analyze a human body as a heat emitter: while generating heat continuously, the body remains at roughly the same temperature through physiological responses such as shivering, sweating, breathing thus raising/decreasing the core and/or skin temperature to maintain effective heat dissipation. Existing literature p...

Borehole heat exchangers (BHEs) are often used to harvest geothermal energy at shallower depths. The standard increase in temperature with depth is generally ignored. Without high quality electricity generation as with enhanced geothermal systems (EGS) there is a lack of financial incentive for drilling deeper for higher temperatures. This temperat...

Although passive building envelope systems dominate contemporary building design, active building envelope (ABE) research, development, and deployment are rapidly growing and present many new ways to address building energy efficiency at the façade level. This paper presents a comprehensive review on the state-of-art-research on ABEs for improving...

In this study, we enhance the understanding and design of a radiant cooling technology for outdoor comfort in tropical climates, originally proposed by R.N. Morse in 1963, in this journal. We investigate a type of radiant cooling methodology whereby the cold temperature source is physically separated from the outdoor environment by an insulated enc...

The globe thermometer has been considered a reliable instrument to quantify mean radiant temperature (MRT) since Bedford & Warner isolated its readings from air movement in their 1934 paper so that radiation could be quantified. Recent expanded use of radiant heating and cooling systems has presented new challenges for the usage of globe thermomete...

Discouraged by the high-cost and lack of connectivity of indoor air quality (iAQ) measurement equipment, we built a platform that would allow us to investigate what kinds of iAQ evolution information could be collected by a low-cost, distributed sensor network. Our platform measures a variety of iAQ metrics (CO2, HCHO, volatile organic compounds, N...

LowEx Communities - Optimised Performance of Energy Supply Systems with Exergy Principles

The satisfaction of occupants with an indoor environment supplied by a conventional central VAV air-conditioning system was compared to a novel system represented by decentralized ventilation units and a network of passive chilled beams. In parallel with occupant survey measurement of indoor air quality (IAQ) parameters was conducted with the devel...

This study focuses on the inference of characteristic data from a data set of 507 non-residential buildings. A two-step framework is presented that extracts statistical, model-based, and pattern-based behavior. The goal of the framework is to reduce the expert intervention needed to utilize measured raw data in order to infer information such as bu...

In order to deal with corrosion, crossover and desiccant utilization issues encountered in commercially available liquid desiccant systems, we develop and characterize the performance of a hydrophilic nonporous membrane-based liquid desiccant absorber. The liquid desiccant is an alkoxylated siloxane mixture, a modified silicone oil for enhanced moi...