- G.W. Robinson Builder/Developer
|
Figure
14 G.W. Robinson home
in Cobblefield neighborhood. |
This builder, a leading member of the BAIHP program, takes
care to incorporate features and measures that enhance not
only the energy and resource efficiency, but also the indoor
air quality, safety, durability, and comfort, consistent
with the spirit of Building America.
Cobblefield Development
G.W.
Robinson committed to building the first “green
homes” community, as designated by the Florida Green
Building Coalition (FGBC), and to achieving Building America
standards in each home built (Table 13). Individual
home performance testing by Florida H.E.R.O. ensures that the
homes meet both program specifications. G.W. Robinson proudly
refers to these programs in weekly newspaper ads. (Figure
14)
Table 13 G.
W. Robinson Specifications |
Component |
Original |
Cobblefield |
Conditioned Area |
1,812 - 3,128 |
1,812 - 4,107 |
Hers Score |
~82 |
~89 |
Cooling and Heating |
SEER 10 air conditioner
and AFUE=80% gas furnace with standard thermostat |
System sized using Manual
J
SEER 12, 13, and 14 (depending on construction date,
higher seers more recent) and AFUE=90% gas furnace
with programmable thermostat and variable speed air
handler |
System Capacity |
|
Reduced capacity up to
2 tons; eliminated bonus room system by zoning main
system. |
Outside Air Ventilation |
None |
Passive, filtered ventilation
air. Ceiling fans in all bedrooms. |
Ducts |
Local conventional construction |
System
engineered using manual d, mastic sealed, and performance
tested to have cfm25out < 5% of AHU flow, coated
duct board |
Water Heating |
Conventional builder model
EF=0.56 gas water heater |
EF=0.60 gas water heater,
solar water heaters - Now instant |
Roof/Clg Assembly |
R-30 fiberglass |
R-30 cellulose and radiant
barrier |
Wall Assembly |
R-11 fiberglass |
R-13 cellulose |
Windows |
Double pane clear metal
frame |
Double pane Low-E metal
frame SHGC = 0.36 - Now vinyl with .28 SHGC |
Lighting |
Standard |
Air lock can lights |
Construction Process Innovations |
|
Statement of Work for each
trade. Load calculations and duct engineering done
with in-house design team. |
Durability And Green Features |
|
Low VOC interior paint,
15 year exterior paint, 30 year architectural shingles,
Enviro-scaping: saved trees, community wide reclaimed
water for irrigation, native plants grouped according
to water needs, wildlife habitats, no turf near house. |
Initial discussions between Florida
H.E.R.O. and the builder, sales manager, project manager,
and mechanical, insulation, and solar system subcontractors
resulted in the original decision to include batch solar
water heating and hydronic heating systems.
Florida
H.E.R.O. undertook a redesign of the air distribution system
for the Cobblefield homes to insure that ducts are properly
sealed with mastic and that the air handler closet (or
mechanical room) is sealed from the attic. Field tests
showed that leaks on the return side of the air handler
depressurized the mechanical rooms. When the ceiling was
not properly sealed, air from the attic was introduced
to the home, which diminished indoor air quality, increased
summer latent loads, decreased comfort, and increased the
home’s operating costs.
In response to an ongoing challenge to achieve a reasonably
air tight mechanical equipment closet, a new protocol shifted
installation of ductboard adjacent to the ceiling to rough-in
instead of finish mechanical, which allowed maximum accessibility
for the field technicians. Once the main supply and return
trunk line were stubbed out, the ductboard was custom cut
and installed over the ducts, then affixed to framing members
with nails or screws and plastic grommets. The duct line
seam between the ceiling and duct was sealed with pressure
sensitive tape and mastic and perimeter seams were caulked
after sheetrock installation. A flow hood CFM test on a Cobblefield
model found less than a 5% deviation from the anticipated
design flows.
Initially Florida H.E.R.O. recommended using hydronic heating
systems for the Cobblefield Development. Since the original
decision to include these systems, additional County requirements
for anti-scald mixing valves and automatic air vents have
added to the difficulty and precision of system installations.
Larger models also required bigger water heating units which
proved difficult to locate and costly. Installation irregularities
and inconsistencies, despite repeated training attempts,
exacerbated the situation and compromised the envelope tightness.
While the hydronic system offers many benefits, Florida H.E.R.O.
decided that the benefits did not justify the costs and problems
associated with installing these systems in this development.
Instead, a cost effective line of high efficiency (90% AFUE)
condensing natural gas furnaces will replace the hydronic
systems in all 17 models. This furnace style uses PVC for
the exhaust flue and to deliver outside combustion air directly
to the unit. This eliminates the need for high and low outside
combustion air vents in the furnace closet and insures the
maximum amount of system location flexibility. Changing the
heating system type did not affect the model duct designs.
Reducing Home Moisture After Plumbing Leaks
Florida
H.E.R.O. surveyed, performed diagnostic tests, and made
recommendations to G.W. Robinson on how to prevent moisture-related
problems in several water damaged homes. Two homes had significant
moisture problems with one home flooded several days before
it was scheduled to show in the 2002 Gainesville Fall Parade
of Homes. The "flood" in this home was likely a
result of a material failure in a kitchen sink supply riser.
The large plumbing leak, however, did provide researchers
with the opportunity to initiate and monitor the "drying
out" process.
Interior, exterior, and internal ambient moisture readings
enabled the monitoring of this situation with a goal of preventing
mold growth. To begin the process, all carpets and cabinets
were removed from the home and discarded. Two commercial
dehumidifiers and several fans were installed to reduce the
home's humidity. After 24 hours, moisture readings were taken
at a variety of points throughout the home. Wall surface
moisture readings ranged from 45% to 99%. After five days
of continuous drying, no surface moisture reading exceeded
10.9% at any point in the home. The process and procedures
employed seem to have been successful.
Eliminating
the effects of a plumbing line leak and the resulting water
damage proved more difficult in the second home where the
lasting effect of the water damage was mostly odor. Based
on recommendations from FSEC and Florida H.E.R.O., the
home’s water heater was disconnected, all water-damaged
sheetrock, wood, and insulation removed and replaced, and
the water heater reconnected. Though initially this fix seemed
to work, the smell eventually reappeared. Because the odor
was evenly distributed through the home, further investigation
determined that the odor source was most likely airborne.
The air handler, distribution system, and carpeting were
fogged with “May-Clean” solution, whose active
ingredients include "cleaning solutions and caustic
acids.” For now, this appears to have eliminated the
home's odor problem. The home was sold and now is occupied,
so additional data collection may be difficult.
High Bill Complaint
G.W.
Robinson's sales manager expressed concern that the model
center's monthly utility bills were significantly higher
then they expected - more than $300 a month! To locate the
source of this high electric usage, Florida H.E.R.O. arranged
a site survey with the mechanical contractor and conducted
a two-week temperature/humidity study. Since the home had
been individually performance tested for both whole house
infiltration and duct leakage rates, the detective work was
fairly simple. After determining that the mechanical equipment
was correctly functioning and properly charged, researchers
tested the flow rate of the outside air intake with an Energy
Conservatory exhaust fan flow meter. Higher than anticipated
readings, led researchers to test the return air plenum temperature.
With an indoor temperature of 77° and an outdoor temperature
of 93°, the air temperature in the plenum measured 84°.
The in-line damper was adjusted to reduce the volume of outside
air introduced.
While
investigating this problem, researchers also noted that
sales staff continually overrode the programmable thermostat,
typically after returning from lunch. Indoor temperature
readings as low as 71° were recorded in the model. All
findings were reported to the builder and subsequent measurements
have indicated that utility bills have dropped.
Standardized HVAC Installations: Florida H.E.R.O. Duct
Designs
Prior
to this, the distribution system was field “designed” by
the duct mechanic. Florida H.E.R.O. developed duct designs
for all of the community models. To insure that mechanical
design specifications are correctly interpreted by the HVAC
installer, Mr. Robinson has agreed to allow the mechanical
contractor to conduct a final review of all architectural
CAD drawings before each house project begins. With the designer
and installer in agreement on installation parameters, placing
the design emphasis on performance excellence and standardization
of supply and return register size, HVAC installation has
proven to be more timely and the installer’s profits
enhanced.
Florida Green Building Certification
Florida H.E.R.O. researcher Ken Fonorow met with University
of Florida Urban Horticulture Extension Agent, Wendy Wilber,
at the Cobblefield model center to survey and complete the
FGBC checklist required by the green certification process.
Green Features are listed in Table 13.
Fluorescent Lighting
Florida
H.E.R.O. used an infrared thermometer to demonstrate to
the builder the operating temperature differential between
an incandescent and compact fluorescent bulb. After viewing
operating temperature differentials of 75°, the builder
indicated an interest in replacing as many bulbs as possible
with CFL bulbs. The incandescent bulb measured 158°,
while the CFL bulb measured 83°.
“Green” or
sustainable housing is defined as energy efficient housing
with added features such as disaster resistance, improved
indoor air quality, universal design, resource efficient
products and materials, and low water landscaping. BAIHP
collaborates with the Florida Green Building Coalition
(FGBC), and other organizations to develop or define green
home standards, participate in educational programs, and
assist in demonstration houses and related activities.
Florida Green Building Program
BAIHP
staff has been extensively involved with the Florida Green
Building Program administered by the Florida Green Building
Coalition (FGBC), Inc. (www.floridagreenbuilding.org).
The intended result of this involvement has been to create
Building America homes that include additional “green” or
sustainable attributes like those listed above, and to
promote the incorporation of various Building America principles
to the home building community at large.
The
primary tool used to incorporate “green” concepts
into homes built by BAIHP partners is the Florida Green Home
Designation Standard, developed and maintained by the Florida
Green Building Coalition, Inc. with significant support and
technical assistance from BAIHP staff.
Several BAIHP partner builders have constructed homes that
have achieved the designation including Fallman Design and
Construction, Pruett Builders, the City of Orlando, and WCI
Communities. Each of these builders constructed at least
one certified home as a model or showcase to educate the
public about the benefits of green construction. In all homes,
BAIHP staff assisted with outreach, implementation, and certification.
The standard has been incorporated in affordable homes, with
several achieving the designation.
The standard also has proved useful to other Building America
teams when they work with Florida partners who are interested
in achieving green and sustainable housing. One example is
the Lakewood Ranch community in Sarasota/Bradenton, FL, which
recently began requiring all builders to build all homes
to the Florida Green Home Designation Standard. Much of the
technical assistance has been provided by CARB, but FSEC
staff has been involved with each builder to ensure minimum
requirements are achieved, and to assist with development
of submittal packages.
To increase awareness and interest in building homes to
Building America and green standards, BAIHP researchers have
made several presentations to local government decision-makers,
and staff. These were delivered to individual government
agencies and organizations such as Rebuild America. Presentations
have also been given at state and national conferences. The
presentations focused on how green homes benefit the community
at large, and how various developer, builder, and home buyer
incentives can be created to reflect these benefits, and
to reward individual efforts.
BAIHP staff developed and delivers training to individuals
interested in how to use the Florida Green Home Designation
Standard to achieve the outreach, implementation, and certification
phases of green housing. The course has been taught at least
biannually since 2001 and attendance averages 12 students
per class. The course is now required by the Florida Green
Building Coalition for anyone aspiring to certify homes to
the Florida Green Home Designation Standard. Several builders
and subcontractors have also attended the class to gain insight
on green construction.
National Green Building Program
FSEC staff members have been involved with the LEED Homes
Committee of the US Green Building Council. Efforts are underway
to work with local green building programs to formulate a
national standard. FSEC researchers have participated in
biweekly conference calls, and have attended 3 in person
meetings - one of which was hosted by FSEC in February 2004.
During the fifth budget period, BAIHP research received
media attention in the Orlando Sentinel for work with green
housing (See Appendix M for reproduction of articles):
- Orlando
Sentinel, Sunday, February 8, 2004. “The Green
Revolution: A Florida First. Part 1 of a 4-part series.” “Blueprints
for the home planet.”
- Orlando
Sentinel, Sunday, February 15, 2004. “The
Green Revolution: Interior Motives. Part 2 of a 4-part series.” “Health
worries hit home.” See Appendix M for reproduction
of articles.
- Orlando
Sentinel, Sunday, February 22, 2004. “The
Green Revolution: Applying Principles. Part 4 of a 4-part
series.” “Pioneer spirit.” See Appendix
M for reproduction of articles.
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