Cold Weather Performance (Sandia Crest Data)

Lowest mean temperatures are in January and February at 20°F. Average daily winter shelter temperature will be 20°F + 18°F=38°F. On sunny days the solar heating system will add an additional 6,000 Btu/day or another 16°F to 38°F base temperature for an average shelter temperature of 54°F. When temperatures are colder shelter temperatures will also be lower. If more heat is required the solar heating systems can be easily up sized to meet the demand.

During extremely cold, cloudy weather the thermal mass of the water with the shelter provides 184, 320 Btu's of heat as it freezes. This heat is enough to guard the shelter from subfreezing temperatures for 10 days at -17°F temperatures. At times when the weather is colder than normal and additional heat is required, a 300 watt electric heater is provided for back up.

Warm Weather Performance (Sandia Crest Data)

Internal shelter temperatures will be in the high 60's to low 70's. Lower elevations-6,500 ft. -Shelter temperatures will be in the high 70's to be 80's. A 2000 BTU thermo-electric air conditioner is offered as an option.