Products
Used
I wanted to try many different
energy efficient and green building materials. As a believer
that these practices should be mainstream, I used standard products
such as from big box stores whenever possible such as no formaldehyde
insulation, zero VOC adhesives and paint, energy efficient exterior
doors, and 1.6 gallon flush toilets. Other products were purchased
from companies specializing in ecofriendly products such as
the low VOC polyurethane product.
Photovoltaic
System:
We have a
5.6 KW photovoltaic system which is off the grid. It uses 27
Sharp 208 panels
in 3 strings of 3 (roof top) feeding to each of 2 Outback
MX60 Maximum Power Point Tracking (MPPT) Charge Controllers
and 3 strings of 3 (pole mount) feeding to a FLEXmax
60. We have a 48 VDC system with an Outback
VFX3648 inverter in a Ready Watt Half Rack Power Center.
I chose roof mounting so that our lightening protection system
would cover the panels. I can push snow off of only about 1/2
of the panels from the roof-top deck. The fixed pitch of the
panels is that of the roof (33 degrees) which is less than ideal
for our latitude but more importantly not steep enough for snow
to fall off rapidly. We therefore installed the pole mount at
a 65 degree angle to shed the snow in the winter. My 48 VDC
battery bank is relatively small but relies on some sun almost
everyday. We have 16 Trojan
L16P batteries. Assuming each battery holds 350 amp hours,
there should be approximately 17 kwH of storage at 50% battery
capacity. The battery box is obviously homemade out of plywood
with a plastic lining and a Zephyr Power Vent battery fan. I
was eligible for an off the grid rebate from XCEL Energy until
October of 2006 and most of the original system was installed
(15 of 18 panels) by that time. I received a $7800 Solar Rewards
Renewable Energy Credit rebate from XCEL Energy.I also qualified
for a $2000 2006 federal residential energy credit.The pole
mount installed in October 2009 will qualify for a tax credit
from the federal government. The system performs well and has
occasionally gotten more than rated wattage thanks to the high
altitude (9600 feet).
Solar
Hot Water: 
Again
wanting to roof mount panels, I installed the maximum amount
of square footage of solar hot water panels (200 sq feet in
5 10' x 4' panels) on the covered porch which has a greater
pitch than the rest of the house (40 degrees). We have a 380
gallon storage tank which has a maximum temperature of 170
degrees F. This provides essentially all of the domestic hot
water and some of the space heating with radiant in floor
heat. The solar hot water system was installed by Industrial
Solar Technology (now Novan Solar), Golden, CO. There
are 2 Takagi T-DK20
on demand propane hot water heaters. One is for domestic hot
water and uses preheated water passing through the storage
tank. If the heater is off or the temperature of the water
is above the setpoint, the heater will not turn on. The radiant
infloor heat uses the preheated water passing through the
storage tank until it falls below a setpoint and then switches
over to water heated by the Takagi. The solar hot water system
qualified for a $2000 2006 federal residential energy credit.
Thermal
Mass: The passive solar gain relies on thermal mass
including exterior and interior walls of 6" concrete
slab (these are plastered but not covered by inside insulation,
4" floor concrete slab, and slate tile floors. The masonry
fireplace and the laminated pine deck floor in the loft also
add some mass. This thermal mass leaves the temperature of
the house relatively stable. Without heat in the winter, the
temperature drops about 4 degrees F overnight.
Insulation:
The house is well insulated with 4 inches of foam on the exterior
of the concrete slabs (R20) and 2 inches of foam below the
slab, 12" structural insulated panels on the roof (R42),
and energy efficient doors and garage doors. The exterior
doors are Therma-tru smooth-star fiberglass with a solid polyruethane
foam core (R13.6 for solid doors-less with glass). The garage
doors are Overhead Door 494 (R17.5).
Windows:
Windows use heat
mirror technology were made by Alpen Windows, Boulder,
Colorado now called Serious Windows. The frames are fiberglass
which is energy efficient and the glass is air filled. East
and South windows are HM-88. North and West windows are TC-88.
Renewable
products: The cabinets in the bathrooms, kitchen,
laundry and offices were made out of lyptus which is a renewable
wood. The cabinet manufacturer Custom
Cupboards earned environmental stewardship certification.
The floors in the kitchen, laundry room, powder room, master
closet and toilet area are engineered bamboo floating floors.
The use of carpet was limited to maximize the thermal mass
effect of the floors and to facilitate heat transfer from
the radiant infloor heat (slate over concrete). A wool blend
with jute back was used. The underlayments used under the
carpet and bamboo floor have a low R value for heat transfer
from the radiant infloor heat. Recycled rubber tiles were
used on the decks and the room over the garage.
 Lyptus
cabinets and bamboo flooring.
 Recycled
rubber tile on roof deck.
Appliances:
Energy star appliances were used including the refrigerator,
washing machine and dishwasher. See my comments regarding
appliance selection.
Masonry
fireplace:
 
A Tulikivi
masonry fireplace was installed between the kitchen and the
dining room. This soapstone fireplace is fired up once or
twice a day and radiates heat all day. It is rated to heat
1500 square feet. The open floor plan allows this to heat
up most of the house.
Air
quality : The passive ventilation of the house works
very well with low living/dining room windows and clerestory
windows at 3rd floor level. A Standex ERV300DC was installed
but was not well planned and really only adequately ventilates
the 2nd floor. It draws about 95 watts so it uses quite a
bit of electricity with 24/7 operation. The home is very tight
and is in a high risk area for radon so the initial radon
level was very high at 38.7 pCi/L. Use of the ERV alone resulted
in a radon level of 37.9 pCi/L. I caulked between the concrete
walls and concrete slab and used RadonSeal Deep-Penetrating
Concrete Sealer on the concrete slab floors without much improvement.
I used a very good radon mitigator, Accredited Radon Reduction
Techniques, who was patient with my experimentation and had
many good suggestions. See description radon
mitigation. I found that DC fans gave best performance
per watt and fortunately found RAM/GAM
Engineering Services, a supplier of radon mitigation fans
in the Denver area. They use Ebmpapst
R1G175 series motors and mount them in a fan housing.
I use RAM/GAM's 24VDC fan and had them mount a 12VDC Ebmpapst
R1G175 motor in a fan housing for direct use with a spare
solar panel.
Low
VOC products: No particle board was used in construction,
cabinets or furniture. Plywood used was exterior grade which
outgasses less than interior grade plywood. Sherwood Williams
Zero VOC paint was used as well as low/zero VOC adhesives.
Timber-Tek Crystal Urethane (VOC 168 gms/liter) was used on
tongue and groove pine on ceilings and loft floor, doors,
and mouldings.
Energy
efficient products: Only compact fluorescent and
LED lighting used. Energy star fans throughout the house.
Energy star computers and monitors.
Energy
saving electrical devices: Power strips to eliminate
phantom amps. Occupancy sensors.
|
