Matthew Munson, Environmental Engineering ’17
Alyssa Schaedler, Architecture ’16
Table of Contents
II. Jacobson et al.’s Claims
III. Energy and Sustainability in Buildings
- Passive and Active Design
- Retrofitting Strategies
- Energy Usage and Costs
- Case Study
IV. Building Code and Policy
- Building Codes and Ratings
- Public Policy and Programs
Jacobson et al. claim that energy efficiency measures in buildings, appliances, and processes have the potential to reduce end-use power demand in the US by up to 23% by 2020. These measures include:
- improving wall, ceiling, and pipe insulation
- determining wasteful processes
- converting to LED light bulbs
- using more efficient appliances
- using hot water circulation pumps on a timer
- sealing leaks in windows, doors, and fireplaces
- converting to double-paned window systems
- utilizing passive solar heating and cooling techniques
- converting natural gas water and air heaters to heat pumps and rooftop solar heaters
- utilizing excess power generated to produce district heat through heat pumps and thermal stores
The Northeast Sustainable Energy Association (NESEA) writes,
“In the United States, the building sector accounts for nearly half of all energy consumption. It also produces nearly half of all greenhouse gas emissions, making it the largest single contributor to climate change. To shape the built environment is to shape the future not only of our cities and towns, but also of our planet.”
In order to account for this impact, we must do much more than implement the strategies listed above. This research is an investigation into the options available.
Jacobson et al.’s Claims
Jacobson et al. make five claims regarding residential, commercial, and industrial buildings in Examining the feasibility of converting New York State’s all-purpose energy infrastructure to one using wind, water, and sunlight (2013). In each point listed below, we investigate from where these claims are sourced.
- Energy efficiency measures in buildings, appliances, and processes have the potential to reduce end-use power demand in the US by up to 23% by 2020 (McKinsey and Company, 2009).
- Historically, efficiency programs targeting multi-family households have resulted in overall energy savings of approximately 20% (Falk and Robbins, 2010).
- For such households, the New York State Energy Research and Development Authority (NYSERDA) Home Performance with Energy Star program reportedly achieved annual savings of approximately 15% of average household electricity usage and over 50% of heating fuel savings for natural gas-heated homes (NYSERDA, 2011).
- Second, designing new buildings, neighborhoods and commercial complexes or retrofitting existing ones to use and store energy more efficiently has the potential to reduce significantly building energy required from the grid, transmission needs, and costs. Four methods of improving energy use and storage in buildings include: (1) extracting heat in the summer and cold in the winter from the air and solar devices and storing it in the ground for use in the opposite season, (2) recovering heat from air conditioning systems and using it to heat water or air in the same or other buildings,(3) extracting heat (or cold) from the ground, air, or water with heat pumps and using it immediately to heat (or cool) air or water,and (4) using solar energy to generate electricity through PV panels,to recover heat from water used to cool the panels, and to heat water directly for domestic use (Tolmie et al., 2012).
- The Drake Landing solar community is a prototype community designed primarily around the first method, that of seasonal energy storage (Drake Landing, 2012).
- Additionally, Jacobson suggests residential, commercial, institutional, and industrial buildings should be retrofitted with better insulation, more daylighting, solar hot water heating, seasonal energy storage, passive solar heating, and passive cooling in the summer. These strategies are discussed further below.
Energy Efficiency and Sustainability in Buildings
Ultimately, our goal was to validate Jacobson et al.’s claims in an effort to encourage engineers, policymakers, and the general population that converting to 80-85% Wind Water Solar (WWS) by 2030, and 100% WWS by 2050, is indeed feasible for New York State. Below we discuss the difference between passive and active design and the variety of retrofitting strategies available. We also analyze energy usage trends and costs.
Passive and Active Design
Passive design strategies use ambient energy sources instead of purchased energy like electricity or natural gas. These strategies include:
- natural ventilation
- improved insulation
- determining wasteful processes and appliances
- double-paned window systems
- seasonal energy storage
Active design strategies use purchased energy to keep the building comfortable. These strategies include:
- forced-air heating, ventilation, and air conditioning (HVAC) systems
- heat pumps
- radiant panels and chilled beams
- electric lights
- wind turbines
- photovoltaic panels
Hybrid systems use some mechanical energy to enhance the use of ambient energy sources. These strategies include:
- heat recovery ventilation
- solar thermal systems
- radiant facades
- ground source heat pumps
Source: Autodesk Sustainability Workshop
Retrofitting Strategies for NYS
|Direct gain||Solar radiation enters south-facing glazing and is then absorbed by and heats interior mass. During the cooling season, solar radiation can be blocked with appropriate shading devices or landscaping.|
|Indirect gain||System collects and stores energy from the sun in an element that also acts to buffer the occupied spaces of the building from the solar collection process. Thermal storage walls using masonry or water can be used, as well as thermal storage roofs.|
|Isolated gain||System collects and stores energy from the sun in a building element thermally separated from the occupied spaces of the building. Solar energy is captured in the collector element and redistributed from a storage component to the occupied building spaces.|
|Active solar thermal energy systems||System utilizes energy from the sun for domestic water or space heating. The major components include a collector, circulation systems that moves water or air from the collectors to storage, a storage tank, and a control system.|
|Ground source heat pumps||System uses the mass of the earth to improve the performance of a vapor compression refrigeration cycle, which can heat a building in the winter and cool it in the summer.|
|Cross ventilation||System establishes a flow of cooler outdoor air through a space, carrying heat out of a building. The effectiveness of this cooling strategy is a function of the size of the inlets, outlets, wind speed, and outdoor air temperature.|
|Stack ventilation||As air warms, it becomes less dense and rises, and cooler air replaces the air that has risen. This system of natural convection creates its own air current, but will only work when the outside air temperature is cooler than the desired inside temperature.|
|Evaporative cooling towers||Hot dry air is exposed to water at the top of the tower. As water evaporates into the air inside the tower, the air temperature drops and the moisture content of the air increases; the resulting denser air drops down the tower and exits through an opening at the base to the space.|
|Night ventilation of thermal mass||Mass materials moderate air temperature, reducing extreme swings of alternating hot and cold temperature. During the day, the building mass absorbs and stores heat. At night, outdoor air is circulated through the building.|
|Absorption chillers||An active design solution producing a refrigeration effect through use of a heat source. They consume less electricity than a vapor compression chiller, and do not require CFC or HCFC refrigerants.|
|Site analysis||Key issues include daylight, passive solar heating/cooling availability, water and stormwater runoff, acoustics, and air quality. Determination of temperature, humidity, solar radiation, rainfall and wind data is necessary.|
|Insulation materials||Types available include plastic foam board, spray-applied foam, magnesium silicate or cementitious foam, cellulose, fibrous batt and board, loose-fill fiber, mineral wool, cotton insulation, radiant barriers, perlite, and structural insulated panels.|
|Glazing||Glazing is used to admit daylight, admit direct solar radiation, and to allow for airflow. Important factors include U-factor, solar heat gain coefficient, visible transmittance, low emissivity, operable area, air tightness, and sound transmission loss.|
|Double envelopes||Double envelopes are transparent multiple-leaf wall assemblies used as a building façade. The outer leaf provides weather protection, and the intermediate space acts as a thermal barrier. They are used for natural ventilation, daylighting, and thermal insulation.|
|Lighting and Appliance Strategies|
|Green roofs||Green roofs are used for stormwater retention, increased thermal resistance, reduced urban heat island effect, and water and air quality mitigation. They also add to the aesthetic and functionality of a building.|
|Daylighting||Daylighting is simply the act of using sunlight to bring light into a building. It is renewable, efficient, and has to potential for coordination with electric lighting to reduce energy costs and consumption.|
|Plug loads||Plug loads represent the electrical consumption potential of all the appliances in a building in an attempt to use energy efficiently. Each watt of plug load contributes a watt of cooling load.|
|Air-to-air heat exchangers||These exchangers are mechanical devices designed to effectively transfer heat from one airflow stream to another. It reduces the significant waste of energy normally inherent in ventilation.|
|Energy recovery systems||System transfers sensible heat from one fluid to another fluid through an impermeable wall. System can be applied to industrial and production processes, and can recover heat from exhaust air ducts, boiler stacks, or waste water piping.|
|Photovoltaics||Systems produce electricity through the direct conversion of incident solar radiation. A PV cell provides direct current output, and can be used directly to power loads, stored in a battery, converted to AC power loads, or fed into an electrical grid.|
|Wind turbines||Wind turbines produce electrical energy from wind, a renewable resource. According to the American Wind Energy Association, a large wind project can produce electricity at lower cost than a new power plant.|
|Microhydro turbines||System generates electricity by tapping into a flow of water and harnessing the renewable kinetic energy in moving water. It is intended for on-site electricity generation and reduces the use of fossil fuel-generated electricity.|
|Hydrogen fuel cells||System produces clean energy through an electrochemical reaction between hydrogen and oxygen. On-site energy can be created with either proton exchange membrane fuel cells or phosphoric acid fuel cells.|
|Combined heat and power systems||Systems are specifically designed to recover waste heat from the electricity production process for use in heating, cooling, or process applications. The heat is usually recovered in the form of hot water or low-pressure steam.|
Source: The Green Studio Handbook: Environmental Strategies for Schematic Design, Second Edition. Alison G. Kwok, AIA + Walter T. Grondzik, PE (2011)
Current Energy Usage
1. Space & water heating
Most residential central heating systems rely on burning fossil fuels, which is both wasteful and harmful to the environment. Due to the naturally colder climate in New York State, space heating is used more heavily and frequently than air conditioning, making it the first priority in energy efficiency.
2. Appliances & lighting
Using appliances efficiently and conserving energy by using appliances on timers contributes greatly to reducing the electricity load of a residence. Each watt of plug load contributes a watt of cooling load, making conservation incredibly important. LED lights are beginning to become more popular, an excellent alternative to traditional lighting methods.
3. Air conditioning
Refrigerants used in air conditioning systems are known to cause ozone-layer depletion and contribute to global climate change. The typical air conditioning system in a home uses an enormous amount of energy, but this electricity can be supplied through solely WWS. There are also a number of passive design strategies that can be utilized for cooling.
NYS Housing Units: 8,126,026
NYS Households*: 7,234,743
Persons per household: 2.61
*A household consists of all the people who occupy a housing unit. A house, an apartment or other group of rooms, or a single room, is regarded as a housing unit when it is occupied or intended for occupancy as separate living quarters.
Source: US Census Bureau
The following table was obtained from Jacobson et al.’s study:
|Contemporary and projected end-use power demand (in terawatts)|
|Energy Sector||Conventional fossil fuels and wood 2010||Conventional fossil fuels and wood 2030||Replacing fossil fuels and wood with WWS 2030|
|NYS energy usage||Watts||Btu/yr||Cost|
|Buildings (total)||58 billion||1,734 trillion||$96.6 billion|
|Residential (45%)||26 billion||777 trillion||$43.5 billion|
|Commercial (55%)||32 billion||957 trillion||$53.5 billion|
~$6,000 per household, per year*
*Costs personally calculated according to price of energy
|Consumption by end use||Watts||Btu/yr||Cost|
|Air conditioning||1%||260 million||7.77 trillion||$432 million|
|Water heating||17%||4.42 billion||132 trillion||–|
|Appliances/lighting||26%||6.76 billion||202 trillion||$1.12 billion|
|Space heating||56%||14.6 billion||435 trillion||–|
|Heating fuel used|
|None/other||6%||1.14 billion||34.1 trillion||–|
|Electricity||8%||1.52 billion||45.5 trillion||$2.53 billion|
|Fuel oil||29%||5.51 billion||164 trillion||$1.22 billion|
|Natural gas||57%||10.8 billion||323 trillion||$3.29 billion|
|Cooling equipment used|
|Central air||20%||52.0 million||1.55 trillion||$86.3 million|
|None/other||27%||70.2 million||2.10 trillion||–|
|Window/wall units||53%||138 million||4.13 trillion||$229 million|
|Natural gas (residential)||$10.51 / thousand cubic ft||1 cubic foot of natural gas = 1,030 Btu|
|Natural gas (commercial)||$3.82 / thousand cubic ft||–|
|Electricity (residential)||$0.19 / kilowatt hour||1 kilowatt hour = 3,412 Btu|
|Electricity (commercial)||$0.15 / kilowatt hour||–|
|Fuel oil (average)||$43.10 / barrel||1 barrel of oil = 5,800,000 Btu|
|Commercial consumption by building type||Percentage in US|
|Hotels and restaurants||14%|
|Office consumption by end use||Percentage in US|
|Domestic hot water||4%|
Location: Syracuse, NY: Dawn Homes Management Actual
Situation: A 45-building complex with 520 individual units that utilizes outdated energy generation system, distribution as well as insulation, water usage, as well as lighting.
Solution: Rework the system so that 27 of the 45 buildings have their own boilers, this helped to eliminate the need for a distribution piping. As well as use Energy Star® certified CFL (Compact Fluorescent Lightbulbs) for all units, also upgrading the insulation insulation namely in the attics.
Gains: Not only is energy conserved by reducing the amount of piping needed to transport the heated water, but also generates a large amount of savings for the owner of the complex. These savings of $293,643 annually could be be utilized so that the tenants of the apartment complex are paying less for rent and then able to encourage local economic growth.
Long term savings:
NYSERDA Incentives: $941,400
Annual Gas Savings: 163,449 Therms
Projected Lifesavings: $3,053,231
Simple Payback: 4.7 years
Savings to Investment ratio: 3:1
“We wouldn’t have even considered this approach without guidance from the contractor. But it was the best approach, and it solved a lot of problems.” —Jessie Albert, VP of Operations, Dawn Homes Management Actua lNYSERDA
“The project was more expensive than we planned, but NYSERDA incentives made it worthwhile. Plus, the 25 percent improvement in energy use was compelling.” —Jessie Albert NYSERDA
As seen from Jessie’s point of view, even though there is a substantial initial cost involved with greening apartment complexes, it is favorable in the long term. Dawn Homes Management should serve as an example to other apartment complexes on how not only have substantial energy savings but do it in a cost effective manner. Furthermore, by evidence of their consolidation, there are people in the state of New York who know how to implement effective and efficient energy plans in order to save their clients money.
Average income of US Citizen: $54,063 (Source: US Census Bureau)
Percentage used on housing: 33% –> $17,840.29/yr (Source: personal calculation) spent on housing
Source: The Atlantic
Building Code and Policy
Building Code and Ratings
The IECC is an accepted benchmark that if incorporate, not only protects the environment but also reduces costs to the owner of the building. Generally, their are two codes that are most common in being implemented by the states and those are the 2009, and 2012 IECC codes. This building code is not a stagnant entity but is constantly being updated in order to take advantage of new technological techniques in order to not only save the environment but also save money for the person who owns the building.
It is approximated that by following the 2012 building code as oppose to the 2009 the average homeowner can save about $388.
According to the 2012 IECC, some of the standards include:
- That wall insulation have a at least an R-13+1 rating
- Pipes have R-3 insulation
A promising trend to take note of is that even though the most accepted building code if from 2009, the second most accepted is the more recent 2012 code. This helps to show that states are taking or at least demonstrating that they take the standards for these building codes seriously.
Source: Everblue Training
More changes can be seen by comparing and contrasting the 2009 IECC and the 2012 IECC building codes, furthermore additional changes can be noted by looking into the development of the 2015 IECC codes. Through consultation of HERS experts, you will be able to effectively gauge where your home/building stands in relation to the set standard. This standard should be in conjunction with the changing standards that are being updated every 3 years with the IECC standards. (Source: Residential Energy Services Network)
Currently, there is too little funding and too little manpower in order to implement, evaluate, and enforce building codes outside of fire and health codes. This is a major concern, if there is no funding in order to inspect that these buildings are meeting the standards that they are to meet, what is the point of the standards? (Source: New York Energy Code Compliance Study)
The Home Energy Rating System (HERS) is a building code certification recognized by the IECC (International Energy Conservation Code) and is thus an accredited standard by which to measure buildings efficiencies nationwide.
HERS is the standard nationwide in determining the energy efficiency of a home. It is calculated often in order to help ascertain the value of a household. When the efficiency is calculated, the value is assigned on the HERS in relation to a household standard.
Variables include walls, floors (if they are adjacent to a non-airconditioned/heated spaces), roofs, foundations, windows, doors, and water heating systems. These are just some of the variables taken account of in the rating system. (Source: Residential Energy Services Network)
Jacobson et al.’s claim of wanting all homes to achieve at least 23% reduction in end-use power by 2020 can only be achieved with the average building standard of 100 becoming 70 on HERS Index, which would lead to 30% more efficient homes. A more realistic situation would be if half of the current households met an index of 90 with the other half meeting an index of 70.
Suggestions for how to achieve these indices can be found in NYSERDA’s Build Better: A Guide to Energy Efficient Concepts for New Residential Construction. The contents of this guide can be found below.
Public Policy and Programs
- New York City Department of Environmental Protection (NYCDEP)’s Green Infrastructure Program
“New York City’s Green Infrastructure Program is a multiagency effort led by the Department of Environmental Protection. DEP and agency partners design, construct and maintain a variety of sustainable green infrastructure practices such as green roofs, rain gardens, and Right-of-way Bioswales on City owned property such as streets, sidewalks, schools, and public housing. Green infrastructure promotes the natural movement of water by collecting and managing stormwater runoff from streets, sidewalks, parking lots and rooftops and directing it to engineered systems that typically feature soils, stones, and vegetation. This process prevents stormwater runoff from entering the combined sewer system.” Read the report here.
- Urban Green Council’s Building Resiliency Task Force
“The Building Resiliency Task Force Report provides 33 actionable proposals for making New York buildings and residents better prepared for the next extreme weather event. Convened at the request of the City of New York following Superstorm Sandy, 200-plus task force members led by Urban Green were charged with making recommendations to improve building resiliency and maximize preparedness for future weather emergencies.” Read the report here.
- City of New York’s One New York: The Plan for a Strong and Just City
“The Mayor’s Office of Sustainability and the Mayor’s Office of Recovery and Resiliency oversee and implement the sustainability and resiliency initiatives in One New York: The Plan for a Strong and Just City. Together with our collaborators – the agencies, organizations, and New Yorkers who make our work a reality – we have made significant progress in just a few years. A changing climate, a growing population, aging infrastructure, and an evolving economy with increasing inequality pose challenges to our city’s success and quality of life. Recognizing that we determine New York’s future by how we shape our response to these challenges, Our work includes actions to mitigate climate change while also preparing for the risks it presents, ensuring quality of life for generations of New Yorkers to come.” Read the report here.
More information on specifically residential energy efficiency policy options can be found at the EPA’s website here.
Jacobson’s claim of reducing end-use power demand by 23% in New York State by 2020 through the use of wind, water, and solar energy appears to be technologically feasible. By examining passive and active design strategies for both retrofits and new construction, analyzing the associated costs with current energy consumption habits, and applying these findings to determine if these changes would be favorable, we conclude that not only are these changes feasible, but they are necessary in an effort to reverse our current trends in energy consumption as a society. Jacobson’s more general claims of converting to 80-85% WWS by 2030 and 100% WWS by 2050 are slightly more questionable. Indeed New York State has the ability to supply its buildings with solely WWS energy, but whether or not this is politically feasible is the ultimate factor.