Solar Air Heating Roofing and Siding for Government and ...americansolar.com/wp-content/uploads/2017/08/...– Better performing roof (longer life, better appearance, better fire protection)

American Solar, Inc. www.americansolar.com (703) 425-0923 1

Solar Air Heating Roofing and Siding for Government and Commercial Buildings

Prepared by

John ArchibaldAmerican Solar, Inc.

ASHRAE Roanoke 4/9/13


“Everybody knows”…..


It turns out……

HEATis the largest energy need across all US

buildings

“Everybody knows”…air conditioning drives electricity to the highest energy use in buildings

So, Why Solar Heat, …WHEN WE NEED COOLING?


Space HeatingCooling / Refrig

Lighting

Water Heating

Process Heat

Equipment

Others

Clothes DryingBoilers

NON-HEATINGLOADS

HEATINGLOADS

ENERGY USES IN RESIDENTIAL, COMMERCIAL, AND INDUSTRIAL BUILDINGS

THE LARGEST NEED FOR ENERGYIN THE U.S. IS FOR HEATING

Portions of all energy used in buildings and facilities, Source data: US Energy Information Administration

75°F

140°F

120°F

90+°F


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)


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.



Solar Air Heating Roofs Technology Description

• A Conventional Metal Roof • Sun light heats roof panels, OAT + 80F• Air under metal roof panel heats, OAT + 40-

80F• 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


• 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

How Solar Air Heating Roofs Are Installed: FDA Lab, Standing Seam Metal Over Metal

• 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


Laboratory Outside Air PreheatSolar roofing and siding preheating

outside air for 100% outside air buildings

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Monitored 11/19/08


•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.

Summer solar air temperatures

Solar Roof Air Temperatures Hill AFB, Utah

020406080

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Solar Air-Heating Metal Re-RoofOver Built Up Roof

Gaffney Fitness Facility Fort Meade, MD

•Solar re-roof funded by •DOD Environmental Security Technology Certification Program (ESTCP)


Technical Approach• Solar re-roof for

– Better roof – Solar heat air & water

• Solar Air Heating Metal Re-roof

– 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


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


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


• Matches Largest Energy Needs, for year round solar delivery– 68-72F Space (air) Heat, 40-120F 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

“Everybody knows”…hot water transfers more heat than hot air So, why Solar Air Heat for water heating?


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


Water Heating Performance, Ft. Meade

• 60 BTU/sqft roof/hr delivered• 30,000-80,000 BTU/sqft roof/yr delivered• Saves $0.35 - $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


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


• 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

“Everybody knows”…“Cool Roofs” are the way to go. So, Why a Hot Solar Roof?

Paul Ducharme, GovEnergy 2011


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


Solar Metal Siding



Solar Siding Hill AFB UtahBuilding 233 Aircraft Maintenance Hangar

13,000 sqft of Existing Brown Walls, SE & SW exposure


Solar Siding Hill AFB UtahBuilding 233 Aircraft Maintenance Hangar

13,000 sqft of Existing Brown Walls, SE & SW exposureHill AFB Bldg 233 Solar Siding

1/13-15/09

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SW solar SW Fan Amp OA T Space T SE Solar SE Fan Amp

17 fans~13,000 cfm~500,000 BTU/hr vsOAT~330,000 BTU/hr vs. T Space


• Solar Siding Hill AFB Utah

Hill AFB Building 1160Solar Heat Recovery From Siding

Weather: clear all day

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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


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


Economics and Incentives

• Eligible for Federal and State tax credits– Federal

• 30% tax credits, thru 2016• 5 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, www.DSIRE.org• VA- none, WV- residential 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, …..


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


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


John ArchibaldPresident

American Solar, Inc.703.425.0923

[email protected]

Documents

Solar Air Heating Roofing and Siding for Government and ...americansolar.com/wp-content/uploads/2017/08/...– Better performing roof (longer life, better appearance, better fire protection)