Bristol Stickney, Cedar Mountain Solar — February 2006
Companion spreadsheet to the Potentials of Night Sky Radiation Cooling in New Mexico state report. Allows calculation of cooling energy and water savings for a user-defined house against all 11 New Mexico climate zones.
Enter values to model a specific house and NSRC system:
| Category | Variable | Default Value |
|---|---|---|
| Sample House | Floor Area | 1,800 sq ft |
| Heat Loss Rating | 5.64 BTU/sq ft/degree day | |
| NSRC Radiator | Radiator Area | 400 sq ft |
| Night Sky "U value" | 1.7 BTU/hr·ft²·°F | |
| Pump & Controls | 120 W | |
| Evaporative Cooler | Fan/Pump/Controls | 800 W |
| Cooling advantage over A/C | 3.6× | |
| Water use | 9.5 gal/kWh | |
| Air Conditioner | Fan/Compressor/Controls | 800 W |
| COP | 2.4 | |
| Power Supply | Electricity cost | $0.085/kWh |
| Power plant water use | 0.74 gal/kWh | |
| NSRC Performance | Avg overnight source temp | 73°F |
| Hours/night available | 10 hrs | |
| Air-dew temp correlation | 0.441 |
Annual cooling energy (kWh) and water (gallons) needed vs. saved using NSRC, for both A/C and evaporative cooling replacement:
| Zone | City | Cooling Degree Days | A/C kWh Needed | A/C kWh Saved by NSRC | % Saved |
|---|---|---|---|---|---|
| 1 | Red River | 0 | 0 | 0 | 100% |
| 2 | Chama | 37 | 46 | 39 | 85% |
| 3 | Gallup | 395 | 490 | 416 | 85% |
| 4 | Santa Fe | 537 | 666 | 566 | 85% |
| 5 | Farmington | 864 | 1,072 | 912 | 85% |
| 6 | Bloomfield | 878 | 1,090 | 926 | 85% |
| 7 | Corona | 392 | 485 | 412 | 85% |
| 8 | Silver City | 760 | 942 | 801 | 85% |
| 9 | Albuquerque | 1,269 | 1,573 | 1,275 | 81% |
| 10 | Truth or Consequences | 1,878 | 2,331 | 1,637 | 70% |
| 11 | Carlsbad | 2,153 | 2,668 | 1,555 | 58% |
Summary of inputs: 1,800 sq ft floor area, 10,152 BTU/degree day heat transfer rate, 400 sq ft radiator area. A/C EER 8.19, evaporative cooler EER 29.48.
Monthly average maximum temperatures (°F) for weather stations across New Mexico, period of record through 2004. Used to calculate cooling degree days for each climate zone.
Source: Bristol Stickney, Cedar Mountain Solar. Companion to Governor Richardson's Water Innovation Fund report PSC #05-341-1000-0035.
File: 2006-02-26-nsrc-new-mexico-cooling-calculator.xls