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
3.7 KW photovoltaic system which is off the grid. It uses 18
Sharp 208 panels
in 3 strings of 3 feeding to each of 2 Outback
MX60 Maximum Power Point Tracking (MPPT) Charge Controllers.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. 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 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 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. 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. 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. See http://alpeninc.com/windows/
for R values and specifications.
Renewable
products: The cabinets in the bathrooms, kitchen,
laundry and offices were made out of lyptus which is a renewable
wood. The cabinet manufacturer 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
saving electrical devices: Power strips to eliminate
phantom amps. Occupancy sensors.
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