Solar Air Heating Roofing and Siding for Government and Commercial Buildings

Transcription

1 Solar Air Heating Roofing and Siding for Government and Commercial Buildings Prepared by John Archibald American Solar, Inc. ASHRAE Roanoke 4/9/13 American Solar, Inc. (703)

2 Everybody knows.. American Solar, Inc. (703)

3 Everybody knows air conditioning drives electricity to the highest energy use in buildings So, Why Solar Heat, WHEN WE NEED COOLING? It turns out HEAT is the largest energy need across all US buildings American Solar, Inc. (703)

4 THE LARGEST NEED FOR ENERGY IN THE U.S. IS FOR HEATING ENERGY USES IN RESIDENTIAL, COMMERCIAL, AND INDUSTRIAL BUILDINGS NON-HEATING LOADS Lighting Cooling / Refrig Space Heating 75 F Equipment Others Clothes Drying Boilers 140 F 90+ F Water Heating 120 F Process Heat HEATING LOADS Portions of all energy used in buildings and facilities, Source data: US Energy Information Administration American Solar, Inc. (703)

5 Which Solar Energy Systems Can Meet the Heating Needs? Specialized Add-on Solar Panels SolarWall -- $/sqft Solar Air Heating Panels -- $$/sqft Solar Hot Water Panels & Tubes /sqft (lo temp) $$/sqft (hi temp) Solar Electric (PV) PV Panels, Shingles, Tiles -- $$$$/sqft Conventional Metal Roofs and Walls $/sqft (existing, re-roof, or new construction) American Solar, Inc. (703)

6 Basic types of solar roofing Solar electric systems (PV)- most expensive, least productive, least economical, electrical connection regs, holes in the roof Solar water heating, Less expensive, more productive, economical, complicated plumbing, risk of freeze damage and leaks, liquid in the roof Solar air heating systems Least expensive, productive, pays for re-roof in few years, least complicated, built as conventional, weather tight metal roofs, with no holes. Simply pull heated air off the backside of a hot conventional metal roofing panel Deliver heated air to the building for many uses, heat air, heat water, heat equipment, etc. American Solar, Inc. (703)

7 American Solar, Inc. (703)

8 Solar Air Heating Roofs Technology Description A Conventional Metal Roof Sun light heats roof panels, OAT + 80F Air under metal roof panel heats, OAT F Simple fan and ductwork delivers heated air for uses in the building Space heat, water heat, outside air preheat, equipment heat, process heat (drying, etc.) Sloped Metal Roof gives better drainage and longer life than flat membrane/bur roof Cooler in summer from radiant barrier & insulation Equal to a Cool Roof Removal of old roof is not required Keeps building weather tight during install Reduces tear-off /transport /disposal costs American Solar, Inc. (703)

9 How Solar Air Heating Roofs Are Installed: FDA Lab, Standing Seam Metal Over Metal Labs with high outside air are most energy inefficient and expensive from heating costs Conventional metal re-roof over existing standing seam roof Ducts and fans added to pull solar heated air to building outside air intakes 10 lab buildings with 100% conditioned outside air Roofing contractor installs roof over sub-purlins and new solar siding Solar or HVAC contractor installs ducts, fans, controls American Solar, Inc. (703)

10 Laboratory Outside Air Preheat Solar roofing and siding preheating outside air for 100% outside air buildings T, Solar Roof (F) Temperature (F) T, Solar T, Attic T, Outdoor P, Fan Solar Insolation Solar Insolation (W/m^2) or Fan Power (W) T, Outdoor (F) T, Attic (F) P, Fa n Power (W) Solar Insolation (W/m^2) 0 5:30 6:05 6:41 7:17 7:53 8:28 9:04 9:40 10:15 10:51 11:27 12:03 12:38 13:14 13:50 14:25 15:01 15:37 16:13 16:48 17:24 18:00 18:35 19:11 0 Hour of Day Monitored 11/19/08 American Solar, Inc. (703)

11 Summer solar air temperatures High temperatures can be achieved even with light colored metal roofing Heat can be used for space heat, water heat, heat pump preheat, Air- Radiant floor, air conditioner re-heat, dehumidification, drying, paint booth preheat, etc. Temp, Deg F :00:00 07/10/09 Solar Roof Air Temperatures Hill AFB, Utah 12:00:00 07/10/09 23:00:00 07/10/09 11:00:00 07/11/09 23:00:00 07/11/09 11:00:00 07/12/09 Solar Roof Air Temp Outdoor Air Temp Indoor Space Temp 23:00:00 07/12/09 American Solar, Inc. (703)

12 Solar Air-Heating Metal Re-Roof Over Built Up Roof Gaffney Fitness Facility Fort Meade, MD Solar re-roof funded by DOD Environmental Security Technology Certification Program (ESTCP) American Solar, Inc. (703)

13 Technical Approach Solar re-roof for Better roof Solar heat air & water Solar Air Heating Metal Reroof Sloped gym roof and Sloped re-roof over portion of flat roof Warm solar air to preheat outside air for gym Solar air heats water via copper coil heat exchanger for showers/sinks American Solar, Inc. (703)

14 Technical Approach Solar roof installed over gym roof and projects over a portion of flat roof Solar air is sent to outside air intake to preheat outside air during winter Solar air preheats cold water under new sloped roof section Water preheat before entering hot water heater Exhaust solar air directed to building in winter American Solar, Inc. (703)

15 Outdoor Air Preheat Performance Solar air delivered to air handler outdoor air intake Solar air blown at air intake, no physical connection or flow/pressure balancing required at intake. ON-OFF control input from BAS when gym calls for heat Differential Temperature Controller turns solar fans ON- OFF based on delta Solar Air T > OAT American Solar, Inc. (703)

16 Everybody knows hot water transfers more heat than hot air So, why Solar Air Heat for water heating? Matches Largest Energy Needs, for year round solar delivery 68-72F Space (air) Heat, F Water Preheat, 0-50F Outdoor Air Preheat High temperature water not needed for low temperature preheat needs Easier to collect and move air Minimal air circuit enclosure unlike tight plumbing circuit No fluid leaks to worry about inside or outside the building envelope No freeze protection, antifreeze, minimal plumbing system integration Air-to-water heat transfer in a conditioned space Simple, - Fan, thermostat, (Optional heat exchanger and pump) Lower Cost, $5-25/sqft roof (roof $ credit) vs. $40-100/sqft hot water panels More Energy, 15-30% eff. heat recovery from entire roof vs 30-80% from 80sqft panels Downside: -Bigger ducts, more insulation that water based system American Solar, Inc. (703)

17 Water Heating with Solar Heating Roofs Water heating panels Mounted on and through the roof Sun-panel-glycol-copper-water Water in the roof Water tubes below metal panel roof Glycol for freeze protection Sun-panel-air-pex-glycol-copper-water Solar air heating systems Collect air for air-to-water heat exchanger Water only in conditioned space Sun-panel-air-copper-water Solar Assisted Heat Pump Water Heater for water temp to 160F Air-to-water heat pump High COP, 5-6 American Solar, Inc. (703)

18 Water Heating Performance, Ft. Meade 60 BTU/sqft roof/hr delivered 30,000-80,000 BTU/sqft roof/yr delivered Saves $ $1.25/sqft roof/year vs. gas at $1/therm Saves $0.90-$2.30/sqft roof/yr vs. $0.10/kwhr resistance heat, $3.50/gal fuel oil, or $2.50/gal propane American Solar, Inc. (703)

19 Winter Roof Heat Loss Performance Solar air layer and insulation raise old covered roof temperature by 25 degrees F at night compared to outdoor air temperature Cuts winter heat loss American Solar, Inc. (703)

20 Everybody knows Cool Roofs are the way to go. So, Why a Hot Solar Roof? Solar Roof gives 3 to 40 times more energy cost savings per square foot Heating Dominant in North Serves Largest Energy Need - Heat Your Always Heating Something, Somewhere Have it all Cool Roof with Solar Heat Recovery Paul Ducharme, GovEnergy 2011 American Solar, Inc. (703)

21 Summer Roof Heat Gain Performance Equivalent to a COOL ROOF for summer cooling load reduction Lowers and delays heat gain until past peak electric rate period American Solar, Inc. (703)

22 Solar Metal Siding American Solar, Inc. (703)

23 American Solar, Inc. (703)

24 Solar Siding Hill AFB Utah Building 233 Aircraft Maintenance Hangar 13,000 sqft of Existing Brown Walls, SE & SW exposure American Solar, Inc. (703)

25 Solar Siding Hill AFB Utah Building Hill 233 AFB Aircraft Bldg 233 Maintenance Solar Siding Hangar 13,000 sqft of Existing Brown Walls, SE & SW exposure 1/13-15/09 TEMP Deg. F fans ~13,000 cfm ~500,000 BTU/hr vs OAT ~330,000 BTU/hr vs. T Space 0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00 Hour of Day SW solar SW Fan Amp OA T Space T SE Solar SE Fan Amp American Solar, Inc. (703)

26 Solar Siding Hill AFB Utah Hill AFB Building 1160 Solar Heat Recovery From Siding Weather: clear all day 100 Air Temp Degrees F : :00 6:00 9:00 12:00 15:00 18:00 21:00 0:00 Time starting Midnight 3/23/08 south solar wall temp outdoor air temp Delta T (Wall - OA) American Solar, Inc. (703)

27 Energy & Environmental Benefits Benefits Lower Cost of Energy to the building Lower Life Cycle Cost Roofing (Outlasts 2.7 BURs) Expanded Renewable Energy Use Higher Insulating Value of Roof ( R-50 vs. R 20 BUR) More outside, fresh air to buildings at lower energy cost Lower Carbon Emissions Better performing roof (longer life, better appearance, better fire protection) Better roof drainage from steeper slopes Reduced tear-off, transport, and landfill of old roofs Recyclable roof material (steel, aluminum) Less petroleum use (vs. asphalt or plastic membrane roofing, transportation of waste) Rain water recovery simplified Mission sustainment heating source with low power use LEED Points American Solar, Inc. (703)

28 Energy & Environmental Benefits LEED Points Plays in up to 46 points out of 100, NC & Major Renovations, 2009 Sites - 2 Water - 6 Energy - 26 Materials - 7 Indoor Air Quality - 3 Innovation - 5 Regional - 4 American Solar, Inc. (703)

29 Economics and Incentives Eligible for Federal and State tax credits Federal 30% tax credits, thru year accelerated depreciation, vs. 39 for non-solar roof Roof and solar air & water system qualify in re-roof Air & water system only qualifies for new construction Principal designer of public building up to $1.80/sf meeting energy use reduction, thru 2013 States Varies, VA- none, WV- residential 30% American Solar, Inc. (703)

30 Light Commercial and Residential Various shapes & colors Shingle, tile, shake, slate, standing seam, clapboard, panel siding, etc. New solar applications Vent air heating, water heat, heat pump pre-heat, boiler air preheat, air-radiant floor heating, clothes dryer preheat, pool heat,.. American Solar, Inc. (703)

31 Other Solar Air Heating Applications Facilities uses of solar air heating From roofs, walls, ground mounted systems Cuts cooling and drying energy use Desiccant dehumidification, thermal drying Biological/Wastewater Treatment Process heating year round in all climates Speeds up processes in winter, more capacity Sludge drying American Solar, Inc. (703)

32 Solar energy looks better and does more than ever before! New aesthetics - shapes & colors New building integrated roofs & siding New solar applications Tax breaks & financing for commercial & government users Lowest cost roof Lowest cost solar Lowest cost energy American Solar, Inc. (703)

33 John Archibald President American Solar, Inc American Solar, Inc. (703)