ENERGY & WATER
Why is building energy and water use monitoring important?
From a small scale point of view, building energy and water systems traditionally are installed to primarily address user comfort, catering to the absolute need of every user. The AIA Architect's Guide to Integrating Energy Modeling explains how the traditional method of separating the design from the engineering has lead to a lack of integration between energy and building form.
"For much of the last century and in large part since architecture and engineering became separate professions, energy has typically been addressed at the building systems level, taking a back seat to many other drivers of the design and construction process."
(AIA_Architects Guide to Integrating Energy Modeling in the Design Process)
The AIA Architect's Guide to Integrating Energy Modeling In The Design Process explains how engineers arrive late to the project and size the energy load as a response to the desired building program, use, and aesthetics. This thought process, however, is driving up monthly power and water bills, reducing the overall budget the building owner has to invest in other areas of the building or site.
However, if energy and water use is monitored during design conception and during occupancy, utility costs on a monthly basis can be reduced significantly. This can be seen by taking a closer look at The Vancouver Island University Cowichan Campus Project in Duncan, BC, Canada.
"The combination of all the proposed energy conservation measures applied to the Cowichan Campus project were calculated to save approximately 250,000 kWhe per year over the ASHRAE baseline case and take 11.5 years to pay back. The financial grant allowed this payback to be reduced to less than eight years with a net present value of almost $125,000." (ASHRAE_Strategies for Sustainability_Smith)
From a large scale point of view, statistics show that the energy consumed by buildings is having a negative impact on the Earth, which in turn impact our health and the health of plants and animals long term. When looking at water usage, Paula Kehoe and Sarah Rhodes describe the situation the planet will be in, increasing the need for proper water monitoring in buildings:
"Worldwide, water consumption has tripled in the last 50 years. According to the United States Environmental Protection Agency (EPA), the United Nations estimates that the world’s population will exceed 9 billion people by 2050 and that the number of people living in urban areas will double, to more than 6 billion. Managing the supply and availability of water is one of the most critical natural resource issues facing the world, and new approaches to urban water supplies are urgently needed."
(Vision 2020 Water Efficiency_Kehoe Rhodes)
The amount of clean water used yearly by humans is impacting our water source quantities and qualities. Even the conventional process of recycling wastewater is energy intensive and not sustainable in a future scenario where the world's population could increase by over 2 billion people. In Sustainable Urbanism, Farr explains the issues regarding the conventional wastewater treatment process:
"In a conventional design, wastewater treatment imposes high capital and lifetime operating costs on a community while requiring significant investments in infrastructure and energy for long-distance transport. In this scenario, the wastewater is pumped to a large treatment plant that uses significant amounts of energy and chemicals for treatment and disposal" (Sustainable Urbanism_Farr_185-187)
Water monitoring is not just monitoring the water used in the building, but also addressing rainwater impacted by buildings so that it does not lose the natural relationships it has with the environment as the water feeds the environment and returns to its source.
"In a conventional design, wastewater treatment imposes high capital and lifetime operating costs on a community while requiring significant investments in infrastructure and energy for long-distance transport. In this scenario, the wastewater is pumped to a large treatment plant that uses significant amounts of energy and chemicals for treatment and disposal" (Sustainable Urbanism_Farr_185-187)
Water monitoring is not just monitoring the water used in the building, but also addressing rainwater impacted by buildings so that it does not lose the natural relationships it has with the environment as the water feeds the environment and returns to its source.
The AIA Guide to Integrating Energy Modeling in the Design process states that energy is a design problem. Do you agree or disagree with this statement? Why?
The fact that the design of a building can drastically impact the energy usage of that building leads me to believe that energy is a design problem. If energy use is not an integral part of the design of a building, the energy used to make a building function is going to be a reaction to the building design and location. Most of the time, this reactionary approach to power a building comes at a great cost to not only the building owners, but the environment. For example, the AIA Architect's Guide to Integrating Energy Modeling In The Design Process illustrates the side effects of sourcing a building's energy:
Nearly half of the energy produced by fossil fuels, natural gas, hydro and nuclear is wasted through inefficient production, transmission and transportation to the building. This inefficiency begs the question "why is energy not locally produced on a building by building basis?". In order for energy to be generated locally, it needs to be incorporated into the design of the building during the early phases of design. By incorporating how the building is powered into the other big-picture design questions force the building design to heavily pursue passive heating and cooling strategies in order to create as low demand as possible on electrical and mechanical systems. The AIA Architects Guide to Integrating Energy Modeling in the Design Process summarizes the importance of thinking of energy as a design problem by the following statement:
"A more holistic, collaborative approach to design will be vital as energy and operations costs rise and as energy targets are codified." (AIA_Architects Guide to Integrating Energy Modeling in the Design Process)
We have the technology to find the most optimal building envelope, orientation, massing and materials for the site location before the building is constructed. The following are several modeling tools that can be implemented before and after the building is in operation in order to optimize the building design to require the least amount of energy to function (Source: AIA_Architects Guide to Integrating Energy Modeling in the Design Process):
Nearly half of the energy produced by fossil fuels, natural gas, hydro and nuclear is wasted through inefficient production, transmission and transportation to the building. This inefficiency begs the question "why is energy not locally produced on a building by building basis?". In order for energy to be generated locally, it needs to be incorporated into the design of the building during the early phases of design. By incorporating how the building is powered into the other big-picture design questions force the building design to heavily pursue passive heating and cooling strategies in order to create as low demand as possible on electrical and mechanical systems. The AIA Architects Guide to Integrating Energy Modeling in the Design Process summarizes the importance of thinking of energy as a design problem by the following statement:
"A more holistic, collaborative approach to design will be vital as energy and operations costs rise and as energy targets are codified." (AIA_Architects Guide to Integrating Energy Modeling in the Design Process)
We have the technology to find the most optimal building envelope, orientation, massing and materials for the site location before the building is constructed. The following are several modeling tools that can be implemented before and after the building is in operation in order to optimize the building design to require the least amount of energy to function (Source: AIA_Architects Guide to Integrating Energy Modeling in the Design Process):
- Design Performance Modeling (DPM): Used during early concept design to aid in predicting building performance.
- Building Energy Modeling (BEM): Predicts building's energy use and savings and compares to a baseline
- Building Operation Modeling (BOM): Once building is complete, calculates building efficiency based on actual use.
- Project Resource Modeling (PRM): Provides a report on how the resources used to construct and operate the building is impacting the environment.
The Vancouver Island University Cowichan Campus Project is a great example of how energy usage was solved during the design phase. And by doing so, the finished building design incorporated several passive ventilation strategies to assist with heating and cooling the building and reducing the demand on electrical and mechanical systems. The diagram below included within the ASHRAE Strategies for Sustainability Article illustrate how operable windows, external shading devices, thermal chimneys and radiant in-floor heating piping (in other words, how the architectural elements of the building) act together to create an efficient, comfortable space year-round.
Also, the building incorporated locally generated energy source in geothermal heat pumps, using the earth as a constant heating and cooling agent.
"The central heating and cooling plant for the new building is a modular 60 ton (211 kW) high-efficiency water-to-water heat pump, which is connected to a vertical closed loop geo-exchange field. The ground source heat pump system provides heat in the winter and is used as a heat sink in the summer to provide cooling to the building while recharging the geo-exchange field. The near constant temperature of the ground, coupled with the loop field design, provide a steady source of heat and a sink for heat rejection throughout the year. " (ASHRAE_Strategies for Sustainability_Smith)
Also, the building incorporated locally generated energy source in geothermal heat pumps, using the earth as a constant heating and cooling agent.
"The central heating and cooling plant for the new building is a modular 60 ton (211 kW) high-efficiency water-to-water heat pump, which is connected to a vertical closed loop geo-exchange field. The ground source heat pump system provides heat in the winter and is used as a heat sink in the summer to provide cooling to the building while recharging the geo-exchange field. The near constant temperature of the ground, coupled with the loop field design, provide a steady source of heat and a sink for heat rejection throughout the year. " (ASHRAE_Strategies for Sustainability_Smith)
This ground sourced heat is distributed throughout the building by highly efficient in-floor radiant piping. During cool months, low-temperature hot water (about 110°F) flows through the piping system heating occupants from the ground up. In the hot months, relatively high-temperature chilled water (about 65°F) keeps occupants cool. The benefits of this system are not only the fact that the building uses locally sourced energy, but that this system is quiet in comparison to overhead HVAC supply ducts and it significantly reduces the size of the air-distribution system, providing monthly utility bill savings.
(ASHRAE_Strategies for Sustainability_Smith)
The ASHRAE Strategies for Sustainability Article summarizes the significance of this energy system by stating the following:
"A ground source heat pump system greatly reduces the demand on gas-fired boilers, which reduces the amount of pollutants affecting the environment and contributing to global warming. The greenhouse gas emissions are estimated to be reduced by 94.3 tons of CO2 per year over the Standard 90.1-2004 baseline, based on the results of the energy model. " (ASHRAE_Strategies for Sustainability_Smith)
This method would not have been possible if it was not incorporated into the design at an early phase. In other words, it only was implemented successfully because energy was seen as a design problem.
Is water a design problem? Why?
A case could be made that water is as much or even more of a design problem than energy! As seen above, water is essential in leading the ground source heat pump system to function efficiently.
When a site is cleared so that a building can be constructed, the environment surrounding the building is disturbed. The porous, natural earth that was once present to receive rainwater and filter it into groundwater has been replaced with hard, impervious surfaces. If not redirected through a proper building and site design the stormwater runoff can pollute nearby streams, increase soil erosion and sedimentation, cause flooding, and decrease groundwater supply. (Site Engineering for Landscape Architects_Strom_157-187)
One of the greatest opportunities when seeing water as a design problem is the ability to harvest rainwater and treat wastewater to be reused as non-potable water. A great example of this is the use of Eco Machine Technologies, which is described by Farr in "Sustainable Urbanism":
"With Eco Machine technologies, a neighborhood can use its own wastewater to create local green space for varied usage, to grow plants and ecologies that sequester carbon, and to produce clean, chemical-free water for reuse within the community. This can be done in a greenhouse facility requiring a very small above-ground footprint, with sub surface constructed wetlands serving a dual use as a park or orchard."
(Sustainable Urbanism_Farr_185-187)
This system using water and vegetation to filter and clean wastewater can also be used by the community for education, flower and fish production, water features and can be incorporated into the overall design of adjacent buildings.
In summary, water can be used as part of a locally sourced energy system, it needs to be redirected in order protect the surrounding environment and can be harvested, treated and reused as non-potable water for several building uses. These factors lead me to believe water needs to be addressed as a design problem and needs to influence the overall design of all buildings, especially given the statistics listed above regarding the future of population growth and current water consumption.
When a site is cleared so that a building can be constructed, the environment surrounding the building is disturbed. The porous, natural earth that was once present to receive rainwater and filter it into groundwater has been replaced with hard, impervious surfaces. If not redirected through a proper building and site design the stormwater runoff can pollute nearby streams, increase soil erosion and sedimentation, cause flooding, and decrease groundwater supply. (Site Engineering for Landscape Architects_Strom_157-187)
One of the greatest opportunities when seeing water as a design problem is the ability to harvest rainwater and treat wastewater to be reused as non-potable water. A great example of this is the use of Eco Machine Technologies, which is described by Farr in "Sustainable Urbanism":
"With Eco Machine technologies, a neighborhood can use its own wastewater to create local green space for varied usage, to grow plants and ecologies that sequester carbon, and to produce clean, chemical-free water for reuse within the community. This can be done in a greenhouse facility requiring a very small above-ground footprint, with sub surface constructed wetlands serving a dual use as a park or orchard."
(Sustainable Urbanism_Farr_185-187)
This system using water and vegetation to filter and clean wastewater can also be used by the community for education, flower and fish production, water features and can be incorporated into the overall design of adjacent buildings.
In summary, water can be used as part of a locally sourced energy system, it needs to be redirected in order protect the surrounding environment and can be harvested, treated and reused as non-potable water for several building uses. These factors lead me to believe water needs to be addressed as a design problem and needs to influence the overall design of all buildings, especially given the statistics listed above regarding the future of population growth and current water consumption.
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