Selected Papers and Presentations
The following selection of papers and presentations outlines the past and current research activities of Dr. Richman. For ease of navigation, the media has been organized into various research themes. For each paper, the abstract has been posted. For more information on full text articles, please contact Dr. Richman. For a complete listing of papers, please refer to PDF fileDr. Richman's CV. update!!! update papers too!!! single list?
1) Sustainable Renovation: Principles and Practices (R. Richman)
A large portion of the housing stock needed to accommodate Canada’s population has already been built and represents a major environmental burden. In the past five years alone there have been over a million housing starts across Canada. But, because of a significant lack of attention to sustainable building designs this opportunity to address the environmental impact of residential housing through new construction has been squandered. Throughout the next twenty years, the existing Canadian housing stock (new and old) will require significant upgrades and renovations. There is an urgent need to look at how remedial actions through renovation might be able to transform existing energy and environmental inefficient buildings into more sustainable homes. My proposed research aims to create, develop and contribute to a new sector in low-impact home design focused on Sustainable Renovation Challenges, Principles, Validated Designs, and Outreach over the next ten years. Focus is initially placed on the Greater Toronto Area (GTA), representing a large majority of the existing Canadian housing stock.
2) Life Cycle Eneregy Use and Greenhouse Gas Emissions of Residential Dwellings (M. Bowick and R. Richman)
The residential building sector is responsible for approximately 15-20% of energy consumption (EC) and greenhouse gas emissions (GHGE) in Canada. Embodied and operational components of residential EC and GHGE are dependent on material and system choice, geographic location, and service life. Validated software packages are available to quantify these parameters individually and combine results to simulate the full life cycle EC and GHGE of a home constructed with common building materials. This provides an opportunity for designers and policy makers to more accurately predict the environmental impact of choices made when designing new or retrofit homes. This paper quantifies the environmental impact of design choices for a detached single family dwelling. A parametric analysis focusing on building envelope assembly, structural systems, mechanical/electrical systems, and geographic location within Canada is conducted to analyze the relative effect each on overall environmental impact. EC and GHGE for each permutation is researched, providing a metric to analyze various building designs.. A preliminary study on the embodied GHGE component of common residential building envelope and structural materials indicated material choice effects embodied life cycle GHGE of a dwelling by a factor of two. This effect translates into relatively significant changes in total life cycle impact of a dwelling. This unique analysis presents the preliminary stages an alternative rating system for residential buildings and could support Canada’s initiative on climate change mitigation through design and re-design of the Canadian housing stock.
3) Hour by Hour Analysis of Greenhouse Gas Emissions for a Near-Zero Carbon Condominium Design (D. Bristow, R. Richman, A. Kirsh, C. Kennedy, K. Pressnail)
Energy conscious building designs represent an important avenue for reducing greenhouse gas emissions associated with building operation. As it stands, the current method for measuring the building operation carbon footprint utilizes average greenhouse gas emissions rates from centralized grid electricity supplies in addition to historical climate norms. This traditional method ignores the impact of time varying demand and time varying emissions from peak electricity production and changing climate.
This research focuses on an hour by hour energy demand and greenhouse gas emissions analysis of a 105 unit, five storey condominium building design planned for construction in the city of Markham, Ontario (Canada). In an effort to reduce the carbon footprint of the building the design includes ground source heat pumps, reduced air leakage rates through the building envelope, a roof mounted photovoltaic array and vertical axis wind turbines. The hourly carbon footprint is processed in a building simulation using historical hourly climate data and historical hourly grid electricity production. The grid data is made available by the Ontario electricity grid operator while the weather data comes from a local weather station.
This paper presents the analysis results along with a comparison to the carbon footprint determined by using the traditional method. Results indicate that grid greenhouse gas emissions vary with a standard deviation of over 35% of the mean. The Greenhouse gas reduction from the photovoltaic array calculated from the hourly emissions factors is over 7% higher than the reduction calculated using the mean emissions factor.
4) Viability of Rammed Earth Building Construction in Cold Climates (S. Fix, R. Richman)
Rammed earth is a prolific construction technique for single and two storey buildings in dry, semi?arid to arid climates around the world. As global demand for low cost, sustainable residential buildings increases, it is important to analyze the viability of rammed earth construction in other climatic regions. This paper analyzes the feasibility of adopting rammed earth construction in a cold climate, with focus on the Canadian Prairie region. Existing research on thermal performance, air tightness, indoor air quality, moisture management, strength and durability is presented to develop the feasibility of this construction technique in the specific climate of the Canadian Prairies. Using this data, appropriate soil types found in various regions are located and specified. The hygrothermal performance of insulated rammed earth composite walls is simulated. Results show that rammed earth is a viable construction technique and that externally insulated rammed earth construction is optimal for low?rise dwellings in the Canadian Prairies. This is particularly evident in south and central Alberta, the majority of Saskatchewan, and southwestern Manitoba based on local soil suitability.
1) Low Energy Homes: The Economic Case for Building More Responsibly Now (A. Kirsh, K. Pressnail, R. Richman)
Residential heating and cooling accounts for approximately 10% of all energy used in Canada. Although significant improvements in residential energy use have been made in recent years, the technology already exists to build even more energy-efficient homes. In addition to comfort considerations and the environmental imperatives, there are persuasive economic reasons why better-built homes should be built now. This paper compares the construction and the energy costs of model homes: one home built to the prescribed minimum standard established by the Ontario Building Code and one home built to the R2000 standard. Given the relatively long life cycle of homes built today, and given the relatively high costs of retrofitting existing buildings, this paper shows that it is more economical to build better, more sustainable, homes now.
2) Low Energy Homes: Evaluating the Economic Need to Build Better Now
Residential heating and cooling accounts for approximately 10% of all energy used in Canada. Although significant improvements in residential energy use have been made in recent years, the technology already exists to build even more energy-efficient homes. In addition to comfort considerations and the environmental imperatives, there are persuasive economic reasons why better-built homes should be built now. This paper compares the construction and the energy costs of model homes: one home built to the prescribed minimum standard established by the Ontario Building Code and one home built to the R2000 standard. Given the relatively long life cycle of homes built today, and given the relatively high costs of retrofitting existing buildings, this paper shows that it is more economical to build better, more sustainable homes now.
3) Moderating the Impact of Sustained Energy Interruptions by Designing and Constructing Low Energy Homes (R. Richman, K. Pressnail, A. Kirsh)
Power failures lasting even one or two days can cause serious problems in modern homes. In addition to the discomfort experienced when the temperature inside the house drops, there is the possibility of water pipes within the home freezing, causing them to burst. This paper will show that, from the perspective of preventing such damage during winter storms, it is good practice to increase thermal insulation values. For the cities of Toronto, Edmonton, and Vancouver, a house will be modeled to the provincial building code. Another will be modeled to the Model National Energy Code for Houses (MNECH) issued by the Canadian government. A third will be built to a more sustainable, “advanced design”. The time taken for the temperature to drop to levels where water in pipes might freeze in each of these houses will then be examined and compared. A further comparison between the houses will be made to determine how much heat would be required to maintain the house at a reasonable temperature over an extended period of time (such as the 1998 Ice Storm, which killed 45 people in eastern Canada and the United States).
1) An Innovative Approach to Low Energy Building Performance Using Nested Thermal Envelopes (K. Pressnail, R. Richman, A Kirsh)
Given the environmental imperatives and escalating energy prices, there is an ever-increasing need to design and to build low-energy, more “sustainable” buildings. At a time when this need is growing, it is still challenging to design very low-energy buildings. Traditional approaches to achieving “net-zero energy” buildings in cold climates often involve designing an envelope that is more air-tight and contains more thermal insulation. However, this is not the only approach to minimizing energy use. The goal of this paper is to present an innovative construction technique for cold climates that may lead to relatively low-energy, more sustainable buildings. Using a single family home as an example, this paper shows that it is possible to achieve improved energy performance by designing and constructing nested thermal envelopes. Nested thermal envelopes consist of an insulated building within an insulated building - both designed to control heat, moisture and air movement. The perimeter building is designed as a traditional building while the core building, which is not exposed to the exterior weather, is not a conventional design. By using multiple thermal zones and thermal envelopes, the energy required for space heating can be reduced and the use of solar heat can be optimized. A Toronto home incorporating a nested thermal envelope was modeled and found to require 74% less heating energy than an equivalent R2000 home
2) Gemini House: An Innovative Design Using Nested Thermal Envelopes to Achieve Significant Reductions in Energy Use (E. Dixon, R. Richman, K. Pressnail)
There is a need to reduce and eventually eliminate our reliance on non-renewable energy sources. Although renewable energy technologies are promising, current sources cannot fulfill the increasing demands of industrialized countries. As a result, renewable solutions must involve significant reductions in energy consumption. A preliminary review of the energy supply mix in Ontario, Canada, reveals that renewable energy could meet home energy needs through a 75% reduction in demand. This paper presents a method of home construction that can achieve this energy goal. Known as ‘Gemini House’ it is an innovative design that optimizes building heat gains and losses through the use of nested thermal envelopes. The design incorporates one insulated building inside another to control heat, air and moisture transfer. A three-season perimeter area acts as a thermal buffer and heat recovery zone, while a core area is heated and cooled year round. This study compares a low-energy R2000 home to a Gemini Home located in Toronto, Canada and shows that heating load reductions of 75% or more are possible. Research conducted to optimize the design as well as investigate the impact of occupants on total energy use is also presented. Study areas include: (i) space proportions and construction detail modification, (ii) incorporation of passive energy-saving devices, and (iii) a parametric analysis of occupant behaviour. Preliminary results show that the Gemini House is capable of meeting and even exceeding the target 75% energy reduction.
1) A More Sustainable Curtain Wall System: Analytical Modeling of the Solar Dynamic Buffer Zone (SDBZ) Curtain Wall System (R. Richman, K. Pressnail)
Given the increases in both the environmental and economic costs of energy, there is a need to design and build more sustainable and low-energy building systems now. Curtain wall assemblies are engineered wall assemblies that are used widely in both high-rise as well as low-rise construction. These assemblies, show great promise – with the minimal modification outlined in this paper they can be built better now. Often ignored, spandrel panels that comprise a part of curtain wall assemblies can be natural solar collectors. By using a new simple, low cost method such as a Solar Dynamic Buffer Zone (SDBZ), solar energy can be efficiently gathered or excluded using the movement of air. Such a method can be used in both retrofit as well as new construction. This paper will introduce and outline a proposed SDBZ curtain wall system and present the results of analytical modelling. Using these results, a SDBZ system will be shown to be a more sustainable option for traditional curtain wall assemblies.
2) Laboratory Testing to Quantify Performance of the SDBZ Curtain Wall (R. Richman, K. Pressnail)
The recent rise in the environmental and economic costs of energy demands a need to design and building more sustainable building systems. Curtain wall assemblies show great promise - the spandrel panels within them can be natural solar collectors. By using a Solar Dynamic Buffer Zone (SDBZ) in the spandrel cavity, solar energy can be efficiently gathered using the movement of air. there is a need for a numerical model capable of predicting performance of this system. This paper presents the quantification of a prototype SDBZ curtain wall system through experimental testing in a laboratory environment. Results from the experimental testing were used to validate a one-dimensional numerical model of the prototype.
This research shows a SDBZ curtain wall system as an effective means of reducing building heating energy consumption. The numerical model showed good correlation with experimental results in the expected operating range of the system. Given the lack of published literature for similar systems, this research acts to validate a simple, innovative approach to collect solar energy that would otherwise be lost to the exterior using already existing components within a curtain wall. This research shows the SDBZ curtain wall has the potential to act as a significant solar collector.
3) More Sustainable Masonry Facades: Preheating Ventilation Air Using a Dynamic Buffer Zone
During sunny conditions, surface temperatures on masonry façades can rise to over 40 degrees centigrade above the ambient temperatures. Conventional wall designs minimize the benefits of this solar heat through the use of thermal insulation. However, air that is drawn from the outdoors, between the façade and sheathing, can be used to recover heat from the masonry. The system, which utilizes a Dynamic Buffer Zone (DBZ), acts as a solar air collector. This system can provide an effective way to preheat ventilation air at little to no extra cost while not compromising the architectural features of the masonry wall system. A numerical model was developed to predict the amount of heat recovery possible using a DBZ. The numerical model was verified by comparing results with a commercial computational fluid dynamics software package and by conducting laboratory experiments. Preliminary results indicate that the DBZ as a solar air collector can achieve as high as 33% daily solar efficiency and seasonal solar efficiencies of up to 27%. Since this system is low-cost, yet effective, it may offer designers an opportunity to build more sustainable masonry wall systems.