Habitat for Humanity energy saving house by benbenzhou


Habitat for Humanity energy saving house

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									   Habitat for Humanity

 Energy Efficiency Team

                    Sponsor Contact:

                      Doug Taylor
                   Habitat for Humanity
                    420 S. First Street
                     (765) 423-4590

 Donnie Austin                     donnie@purdue.edu

  Doug Crook                      dcrook1@purdue.edu

Rosann Magnifico                 rosann@ecn.purdue.edu

  Brent Phillips                bphillip@ecn.purdue.edu

Matthew Selvey                     selvey@purdue.edu

  Brian Waller                    wallerb@purdue.edu

                      October 3 2000
Executive Summary

       International Habitat for Humanity works to provide quality, affordable homes to
low-income families. The final cost of the home is based upon the materials and the
quality of the techniques used in construction. In order to reduce the cost of owning the
home, the Energy Efficiency Team has conducted energy-utilization analyses of current
house plans and materials. It has been determined that low-income homeowners pay, as a
percentage, more for monthly utilities. This fact illustrates how important utility cost
information can be for a future Habitat for Humanity homeowner.
       The goal of the Energy Team is to reduce annual energy bills by incorporating
energy cost saving measures into Habitat for Humanity house plans. This is
accomplished by the purchase of new Energy 10 software, researching new energy saving
ideas, modeling these ideas, and modeling new Habitat for Humanity houses in Energy
       The Energy Team recently purchased Energy 10 version 1.3. This new software
is an upgrade to the previously owned version 1.2. The major improvement is the
Weather Maker package, which gives more control over the climate files. Other
improvements include corrections to errors in version 1.2 and improvements in other
areas. The newest version of Energy 10 will give the Energy Team more capabilities,
which will lead to better deliverables for the Habitat for Humanity organization.
       Several new ideas have been researched in the first half of the semester. These
ideas include a whole house attic fan, window insulation, and blown insulation. Now that
the team has a good idea of how these modifications will affect the energy use of the
houses and how to model them in Energy 10, they can be incorporated into the house
variants. The team has also looked into future energy costs to see how the modifications
will affect energy costs in the future.
       The first half of the semester was spent preparing for Habitat for Humanity
analyses. The team has learned to use the Energy 10 software and how to lower the
energy costs of the houses. The second half of the semester will be spent modeling the
modifications and providing quantitative
       The energy project was established with the goals of developing baseline utility
cost information and energy savings strategies for homes built by Habitat for Humanity
of Lafayette, Indiana (http://www.dcwi.com/~habitat). According to Habitat for
Humanity International’s website (http://www.habitat.org), low-income homeowners pay
(by percentage) more for utilities than middle and upper class homeowners do. This fact
illustrates the large benefit utility cost information and energy cost reduction can have for
current and future habitat homeowners.

       The baseline utility costs are provided to the web informational team throughout
the semester, and will be presented on their informative website. This website enables
potential homeowners the chance to see approximate utility costs associated with each of
the different houses offered from Habitat for Humanity. Since these utility costs are of
greater concern to lower income families, this information will help them recognize
different cost issues related to owning their own home along with cost issues of different
style houses.

       The other main goal stated for the team was the analysis of different energy
saving strategies for Habitat for Humanity homes. Potential energy savings strategies are
entered into an energy analysis computer program called Energy-10 [1]. This program
then estimates the amount of money a homeowner can save associated with utility costs
by implementing these strategies. The savings are then weighed versus the cost of
implementation, comfort factors, and current housing trends to determine if the energy
savings strategy is cost effective.

       The current semesters’ work involves updating all of the previous baseline
information along with the addition of four new houses. Once all of the baseline
information was set, three new energy strategies were performed based upon inputs from
Doug Taylor of Habitat for Humanity. These strategies included evaluating rolled
fiberglass insulation versus blown cellulose insulation, the advantages of attic fans, and
implementing different types of windows.
Description of Project Tasks
       The energy team has spent the last month preparing for future analysis. A newer
version of Energy 10 has been purchased to improve the energy analyses of Habitat for
Humanity houses. Research has been conducted to search for new energy conserving
ideas. In addition, the Energy team has looked to the future by looking at expected
energy rates and possible energy ideas for future analyses.

Overview of Energy-10
       The primary tool used to estimate the baseline utility costs and the energy savings
strategies is a software package called Energy-10. Energy-10 was produced through a
partnership of the Passive Solar Industries Council, the National Renewable Energy
Laboratory, the Lawrence Berkeley National Laboratory, and the Berkeley Solar Group.
Information about Energy-10 can be found at the Sustainable Buildings Industry Council
(SBIC) website, http://www.sbicouncil.org. It was designed as a tool to evaluate energy
usage and cost, and to provide energy saving suggestions for commercial, institutional,
and residential buildings. In order to perform an energy analysis of a house, specific
parameters need to be determined. By communicating with the project partner and
performing necessary tests these parameters were determined. After all of the elements
of the house have been put into the program, Energy-10 simulates a year of energy use,
using weather data of a selected city (in this case, Indianapolis, Indiana). The simulation
evaluates and predicts house energy usage and cost on an hourly basis based upon
inputted house designs, climatic data, and local utility costs. These variables are then
simulated, evaluated, and displayed in a series of user-friendly charts, graphs, and tables.
       We are getting an updated version of Energy-10, which has a few new aspects to
it. The new version of Energy-10 contains a program called WeatherMaker. With
WeatherMaker you can convert weather file formats, evaluate weather files in great
detail, and make new weather files for any of the weather stations in the United States.
Energy 10 version 1.3
       The big change in the new energy-10 software is that it comes bundled with
Weather Maker.     Weather Maker allows you to convert weather file formats, evaluate
weather files, and to create various weather files. This will enable the Energy Team to
create a specific weather file for Lafayette, as opposed to Indianapolis, which was used

       Minor changes in version 1.3 of the Energy-10 software are new features and
fixed errors.   Some new features include; building aspect ratio can now be specified, day
lighting operations are modified, opening screen is revised, and the help file has been
upgraded. Perhaps the most useful of these features, for our specific use, is the help file
upgrade. Because of the lack of detail in the manual, the help file answers many of our

Whole House Fans (a.k.a. attic fans)

One of our possibilities for modeling in Energy-10 was whole house fans. A whole
house fan draws outside air in through your screened windows and doors and blows it out
through your attic. The result is a mild cooling breeze that can lower skin temperature by
2 to 8 degrees. Whole house fans are practical and affordable and provide natural air-
conditioning. Whole house fans work well when outside temperature is below 82ºF. If
you already have air-conditioning, a whole house fan can be used to thoroughly ventilate
the house before the air-conditioning is turned on. This reduces air-conditioning
operating time and costs.

Whereas typical central air conditioners can cost about 20 cents per hour to operate, not
including maintenance, whole-house fans run for about three to five cents per hour. This
is often more than $100 savings per year.
Even if you have to use your air conditioner at times during the day, running the whole-
house fan at night helps. The circulating cool air draws heat out of the walls, furniture,
cabinets, etc. This will delay how soon the air conditioner must start the following day to
keep you comfortable.

With this rate of return, our only task left is to model the whole house fan in Energy-10.
Unfortunately this cannot be done. With the way Energy-10 is set up, we are currently
not able to model them. Without being able to model the fan, all that we are left with is
a good non-engineered suggestion for saving money in Habitat houses. And so because
we are working on engineering projects, we are at the end of this analysis.

Window Insulation
         Insulation helps to block the passage of heat, whether it's leaving your home in
the cold of winter or blazing in during summer days. Conduction refers to the heat that
passes from one molecule to the next as it makes its way through a solid wall. Therefore
the use of insulation is needed. The heat of the sun causes radiation heat. Windows lose a
lot of radiant heat unless they are equipped with a special coating. When warm air inside
rises, moving toward cooler air (convection), it eventually moves to the outside, warming
the outside air which, in turn, rises away from the house. Well insulated windows help
prevent heat loss due to convection.

                            Zone     Roofs      Walls     Floors
                             1        R19       R11        R11
                             2        R26       R13        R11
                             3        R26       R19        R13
                             4        R30       R19        R19
                             5        R33       R19        R21

Window Insulation Kits        &       Plastic Window Film Kit

Lowe's of Lafayette, IN
           (765) 448-1900

These clear plastic sheets are cut to fit and placed over windows to help guard against
cold drafts and radiation heat loss.
Inside Installation

    Clean your window trim to remove dust and grease. This will provide a good
     surface against which you can
    apply two-sided tape.
    Apply two-sided tape around the outside of the window trim. It may be necessary
     at the top to mount the
    tape inside of any brackets for curtain hangers. On the other hand, the plastic can
     be mounted outside of
    inset blinds. In other words, the blinds will be between the plastic sheet and the
     window. This shouldn’t pose
    a problem since inset blinds are installed inside the window trim.
    Cut the film approximately two inches larger than the window. Remove the
     protective paper from the
    two-sided tape along the top of the window and attach the film by stretching it
     and pressing it against the
    tape. Uncover the remaining tape around the window and attach the film all the
     way around.
    Use a hair dryer to shrink the film (consult the manufacturer’s directions). Using
     this process it is possible to
    remove wrinkles and creases, thereby leaving the film almost invisible.

Outside Installation

Plastic film kits are available for exterior installation as well. They may include
rolls of tacking strips or some other means of attachment. Some kits include
plastic moldings which can be permanently attached, allowing you to remove
or replace film whenever necessary. Installation is simple, and the kits include
detailed instructions. A general description of the procedure follows.

    Clean window trim to provide a good surface for tape adhesion.
    Cut the molding to fit around the window. Cut 45 degree miters at the
    corners so the pieces will meet to form 90 degree angles.
     Remove the molding inserts and attach the molding to the window trim
     with two-sided tape.
     Cut the film a couple of inches larger than the area encompassed by the molding
      strips. Temporarily tape it
     across the molding frame.
     Snap the molding inserts back into place. Do the top first, the bottom second and
      then the sides. Keep the
     film taut as you install the inserts. They will hold the film tight and firmly in
     You can leave the external film in place during the summer to decrease air-
      conditioning costs, or you can
     Remove and store it until the next winter.

Blown-in Insulation
        Blown-insulation is well suited for places where it is difficult to install other types
of insulation such as irregularly shaped areas, around obstructions and hard-to-reach
places. Installation is easier because it can be blown through holes drilled through the
wall without disturbing existing finishes. Professionals who are experienced at operating
the equipment to ensure proper density and complete coverage most commonly do

        There are three common forms for blown insulation that vary slightly: cellulose,
rock wool and fiberglass. The average installed price per R-value per square foot is about
1.2 cents for cellulose and rock wool and 1.3 cents for fiberglass.
        Due to the weight of the cellulose and rock wool insulation, parameters must be
met to prevent the ceiling drywall from sagging. Some manufacturers include weight
limit information with purchased insulation. Fiberglass is much less dense so it doesn’t
create a weight concern. The drawback is that fiberglass has more convective heat loss
because it is not as dense. The higher density also allows cellulose and rock wool to
settle and seal more around rafters and in corners.
       Rolled fiberglass insulation is well suited for existing and new walls, as well as
attics. The advantage of rolled fiberglass insulation, is that it is a quick and easy, do-it-
yourself installation. Rolled insulation is also a lightweight material. Rolled fiberglass
insulation contains an R-value of 2.3 - 2.5 per square inch.

Team Continuity Plan

       At the end of the semester, half of the Energy Team will be leaving. The
responsibility then falls upon the remaining team members. These members will be
comfortable with Energy 10 and the files associated with it. They will also be familiar
with previously modeled ideas and have new energy conserving ideas to model.

Project Roadblocks
       Numerous roadblocks have been encountered this semester. The newest version
of Energy 10 version 1.3 arrived on September 21, 2000. This was later than expected,
and delayed the evaluation of the software. The older version was used until the newer
version arrived. The Energy Team had only 1 returning member who was comfortable
using Energy 10, so the first month was spent learning the software package. This
includes navigating through the various input windows and inputting Habitat for
Humanity house models. Another roadblock was the architectural team and the house
plans. It was expected that the Energy Team would spend the first few weeks inputting
new Habitat for Humanity house plans. However, Habitat is in the process of hiring a
new architect. This will delay the house plans for at least a month. Finally, the insulation
analysis is on hold until the team meets with Corning Insulation. After the meeting, the
subject will be modeled in Energy 10 and the outcome will be reported.

Expected Semester Outcomes
        The Energy Team will complete several projects by end of the semester. The
Energy 10 software will be thoroughly examined. The Energy Team plans to document
how it differs from the previous version and its capabilities. Several analyses are
expected to be completed, including a window analysis, an insulation analysis, an
expected cost analysis, and a model of Habitat for Humanity houses in other climates.
Finally, the Energy Team plans to model any house plans provided by the Architectural

Team Organization
        The energy team consists of six-members, with a designated team leader. The
team leader, Doug Crook, acts as a representative for the energy team and meets with
representatives from the Architecture team and Web team to correlate progress of the
Habitat team as a whole.

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