The Plan Collection is pleased to feature Passive Solar home designs.

The Northern Lights is a proven winner! The heating and cooling bills have averaged 32 /month in a similar home built in 1990 in North Carolina. It has been featured in Fine Homebuilding and Solar Today, as well as other energy publications. Click on the image to the right for floor plans and other images. Below you'll find all the technical information for the home including energy performance, solar features and energy conservation information. Check back with us in the future for more passive solar and alternative construction home designs.

Project Description: Gordon and Barbara Plumblee Residence

Architect: Debra Rucker, AIA, Energetic Design, Inc.
HVAC/Energy Consultant: Harry Boody
Contractor: Rex Terrell
Location: Burlington, North Carolina
Size: 1 story, 3 bedroom, 2170 ft² (202 m²)
Year completed: 1990
Construction Cost: $186,000 (1990)
Heating Degree Days: 3825
Cooling Degree Days: 1300

ENERGY PERFORMANCE

	Reference	Plumblee Residence	Percent Reduction
Auxiliary heating load	25,000 Btu/ft2/yr	8000 Btu/ft2/yr	68 percent
	(284 million joules/m2/yr)	(91 million joules/m2/yr)
Auxiliary cooling load	11,000 Btu/ft2/yr	5000 Btu/ft2/yr	55 percent
(125 million joules/m2/yr)	(57 million joules/m2/yr)
Total	36,000 Btu/ft2/yr	13,000 Btu/ft2/yr	64 percent
(409 million joules/m2/yr)	(148 million joules/m2/yr)

Notes:The heating load in the Plumblee home, given energy efficiency improvements but before accounting for the passive solar heating contribution, is 12,000 Btu/ft²/yr (136 million joules/m²/yr). Passive solar heating meets 33 percent of this load, providing 4000 Btu/ft²/yr (45 million joules/m²/yr) and reducing the total auxiliary heating load to 8000 Btu/ft²/yr (91 million joules/m²/yr). An electric heat pump provides auxiliary heating and cooling.

These calculations give approximate values for purposes of comparison of the Plumblee home with typical design and construction practices in the same location.

SOLAR FEATURES

• South-facing glass: 206 ft² (19.1 m²) of vertical glazing
• Appropriate overhangs on all south-facing windows
• Thermal mass in brick chimney and brick pavers over concrete in direct sun
• Minimal west and north windows, tree and porch-roof shading on west and east sides

ENERGY EFFICIENCY/CONSERVATION FEATURES

• R-30 ceiling (fiberglass batts and blown-in insulation)
• R-17 walls (2x4 stud construction, fiberglass batts, .5 in. [1.3 cm] rigid insulation on exterior)
• R-19 floor (fiberglass batts in floor over crawl space)
• Sealing package (approximately .4 air changes per hour)
• Double glazed low-e windows (.85 shading coefficient)
• Airlock entries

CONSTRUCTION COST COMPARISON

Added initial cost for solar/efficiency features:

Energy Conservation Features*	$4000
Low-e glazing, added window area	$1000
Total added cost	$5000

* This includes larger-volume and higher-quality ductwork, extremely high-quality insulation installation, rigid exterior wall insulation, aluminized vapor barrier, a high-quality air filtration system, high standards for sealing and caulking and a high-efficiency heat pump. It also accounts for the savings from reducing the size of the heat pump.

HEATING/COOLING COST COMPARISON

Reference Case (estimated)		Plumblee Home (actual)	Savings
Heating	$800	$230	$570
Cooling	$400	$130	$270
Total	$1200	$360	$840