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www.bradfordwhite.com | Built to be the Best
| To Find A Wholesaler Call 800.523.2931
2010, Bradford White Corporation. All rights reserved.
EcoStor2 SC Solar Indirect System Double-
Wall Single Coil Gas Backup Models
Uses gas burner for backup when solar energy
does not meet hot water demand
Electronic temperature sensor in upper portion
of tank allows maximum use of solar power
Double wall heat exchanger located in lower
portion of tank optimizes heating performance
and provides protection between surroundingwater and heating fluid
Atmospheric venting provides easy replacement
for existing water heaters
EcoStor SC Solar Indirect System Single-Wall
Single Coil Electric Backup Models
Single-wall heat exchanger provides fast and efficient
water heating from the solar collector
Available with single or dual electric element for backup
Dual element models can provide a full tank of hot
water when solar heating is not available
EcoStor DC Solar Indirect System Dual
Coil Heat Exchanger Backup Models
Dual heat exchanger design provides superiorinstallation flexibility
Allows combination heat source systems to
operate independently or simultaneously
Top heat exchanger coil is single-wall; lower
heat exchanger coil is double-wall
Typical applications: solar, boiler, wood burner,
geothermal or space heating
EcoStor2 SC Solar Indirect System Double-
Wall Single Coil Electric Backup Models
Double-wall heat exchanger allows heated water from
a solar collector to flow through the coil and provides
additional protection required in certain municipalities
and applications
Available with single or dual electric element for backup
Dual element models can provide a full tank of hot
water when solar heating is not available
Solar Saver Models
For open system applications
where water from a solar
collector is pumped into tank
Directly heats the potable water
(no internal heat exchanger coil)
Alternate collector supply and
return connections provided for
installation flexibility
EcoStor2 SC Solar Indirect System
Double-Wall Single Coil Eco-Defender
Gas Backup Models
Uses the Eco-Defender Safety System Ultra
Low NOx gas burner as backup when solar
energy does not meet hot water demand
State-of-the-art radiant burner
reduces NOx emissions by 75%
Incorporates the latest advances in
technology to meet the most stringent air
quality requirements for allowable NOx
emissions in the country
EcoStor2 SC Solar Indirect System
Double-Wall Single Coil Power Vent
Gas Backup Models
Same design features as atmospheric
vent models but with a powerful, quiet
blower motor for venting flexibility
All EcoStor models feature an Integrated
Mixing Device that allows for higher
stored water temperatures and sensor
wires for solar thermistor connections.
With so many types of solar water
heating solutions to choose from,
Bradford White is
now the center of
your solar system!
For full details onthe entire line of
Bradford White solar
water heaters, ask your
Bradford White representative or
wholesaler for the Solar Water
Heating Solutions Brochure.
Circle 403
http://www.bradfordwhite.com/http://www.bradfordwhite.com/http://www.bradfordwhite.com/8/8/2019 Solar Heating 0410
3/20
Choose FlexSure
solar tubing for a stellarconnection between solar thermal panels
and your hot water storage tank.
FlexSure Flexible Stainless Steel Tubing Systems
Titeflex Corporation603 Hendee Street Springfield, MA 01104
BENEFITS OF FLEXSURE SOLAR TUBING
Continuous runs allow for bending aroundcorners and obstacles
Minimal energy loss through tubing because
of high R-value insulation
Closed cell elastomeric EPDM insulation
Tough cover stands up to installation conditions
316L corrugated stainless steel tubing
Self-flaring, reusable fitting: No special
tools required
Pre-insulated tubing saves time and money Made in the USA
Call 1-888-353-9471 or visit www.flexsure.net
Circle 400
http://www.flexsure.net/http://www.flexsure.net/8/8/2019 Solar Heating 0410
4/20Spring 2010 Solar Heating Report2
SolarHeatingReportSpring2
010
4
Features4 On The Cover: The Italian Job
The challenges of installing solar radiantheating in an 800-year-old mill.
9 Thermal Handoffs, Part 1Inside the fundamentals of heat exchangers insolar thermal systems.
12 Photovoltaic = Sexy SolarThermal Solar = Not So MuchThermal solar systems can do a big job at a
relatively low installed cost.
Departments
15 Information Showcase15 Solar Heating Products16 Reader Service Card
13
4
Bradford White Corp. (215) 641-9400 www.bradfordwhite.com 403 IFC
IAPMO (909) 472-4100 www.iapmo.org 404 7
PAW (508) 943-4240 www.paw.eu 406 14
Stiebel Eltron Inc. (800) 582-8423 www.stiebel-eltron-usa.com 405 BC
Taco Inc. (401) 942-8000 www.taco-hvac.com 401 3
The Noble Co. (231) 799-8000 www.noblecompany.com 407 6
Titeflex Corp. (888) 353-9471 www.flexsure.net 400 1
Viega (800) 976-9819 www.viega.com 409 13
Viessmann Mfg. (800) 288-0667 www.viessmann-us.com 402 IBC
Zuwa (508) 943-6000 www.zuwa.de 408 8
ADVERTISER PHONE WEBSITE RAC PAGE
SolarHeatingReport
AD INDEX15
Contents
12
15
http://www.bradfordwhite.com/http://www.iapmo.org/http://www.paw.eu/http://www.stiebel-eltron-usa.com/http://www.taco-hvac.com/http://www.noblecompany.com/http://www.flexsure.net/http://www.viega.com/http://www.viessmann-us.com/http://www.zuwa.de/http://www.zuwa.de/http://www.viessmann-us.com/http://www.viega.com/http://www.flexsure.net/http://www.noblecompany.com/http://www.taco-hvac.com/http://www.stiebel-eltron-usa.com/http://www.paw.eu/http://www.iapmo.org/http://www.bradfordwhite.com/8/8/2019 Solar Heating 0410
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www.taco-hvac.com
Great warm-ups.
The Taco Family of Solar Products
Domestic water heating is the #2 user o energy in
most parts o the country. Thats why homeowners
are warming up to solar. With Taco Variable
Speed Solar Pumps with integral controls, system
perormance can increase by as much as 20%.
Our Solar X-Pump Blocks patent-pending designincludes a variable speed solar diferential control,
collector circulator, storage tank circulator and
brazed-plate heat exchanger or system isolation,
all in a single unit. The Solar Pumping Station
is a complete closed loop system. With just 5
connections 2 to the collector(s), 2 to the storage
tanks heat exchanger, and 1 to the expansion tank
the installation is done!
Flexible applications.
All Taco solar products work beautiully with any
solar thermal application: open or closed loop, drain-back, 1 or 2 storage tanks and more. And each is a
snap to install. Its solar everyone can warm up to.
Circle 401
http://www.taco-hvac.com/http://www.taco-hvac.com/http://www.taco-hvac.com/8/8/2019 Solar Heating 0410
6/20Spring 2010 Solar Heating Report4
People request solarthermal systems for theefficiency and energy
cost savings you can achieve with anintegrated thermal system that pro-vides domestic hot water, space andpool heating that its a sustain-
able technology is a bonus, says BillShady, P.E., owner of Santa Cruz,Calif.-based Sustainable Designand Project Management. Savingmoney over the long term helps savethe planet by investing in renewableenergy technologies today.
Shady speaks from vast experi-ence on the subject. His solar begin-nings date back to the early 1980swhen he obtained an associatesdegree in solar energy technology.He went on to get his bachelors
degree in mechanical engineering
before starting Sustainable Designand Project Management, a con-sulting mechanical engineeringfirm, in 2002.
By 2005, he had three projectengineers and was doing primar-ily HVAC design as a consulting
mechanical engineer; almost 95percent of that work was radiantand hydronic heating.
From the outset, solar thermalintegration was a feature that wewere known for, Shady explains. Irealized there was an opportunityto apply a lot of the technologieswed been using in commercialbuildings to small-scale residentialprojects. The manufacturers wereseeing that as well.
The firm now has clients all
over the country and the world.
Thats how Shady ended up in Italyto work on a unique job.
One of his American clients,Bob Smith, fell in love with anItalian island he discovered in themiddle of the Mediterranean Sea.Over the years, Smith continued
to visit the island, eventually pur-chasing several connected proper-ties that include an 800-year-oldhouse, a 20-acre organic wineryand an olive orchard. He wanted tomake his property sustainable andenergy-independent but wasntsure how to go about it.
He contacted radiant heatingpanel manufacturer Warmboard,which recommended Pacific SolarRadiant, Inc., a business Shadystarted in 2006 with Greg Cross,
a plumber who wanted to branch
The Italian Job
by Kelly Faloon [email protected]
The challenges of installing solar radiant heating inan 800-year-old mill on a tiny Mediterranean island.
The mill's roof is plumbed for rainwater catchment, providing a large part of the domestic water supply.
PhotoscourtesyofBillShady,SustainableDesignandProjectManagement.
mailto:[email protected]:[email protected]8/8/2019 Solar Heating 0410
7/20Spring 2010 Solar Heating Report 5
out into mechanical contracting. Westarted a design-build company fromscratch, he says. The only customersback then were my design clients. Theprojects were very far apart geographi-cally, because that was the nature ofmy design practice.
Smith hired the firm after discov-ering that it specialized in the integra-tion of solar thermal radiant hydronic
heating and cooling, domestic hotwater, swimming pool and spa heating as well as its experience traveling toremote locations.
We Do Things Differently Here:The first task for Shady and his crewwas to investigate the site and thegeography to understand the obsta-cles and challenges of the project.They studied climate data and satelliteimages through Google Earth.
The process included learningabout the history of the area. It was
thought the house Smith bought wasoriginally a mill built by the Moors inthe 12th century. The most commonbuilding style has a domed roof madeof cut and stacked volcanic lava stone,plastered on both sides. The mill istypical of island architecture for thisperiod and continues to this day, evenwith new homes. The domed roofsare all plumbed for rainwater catch-ment that flows by gravity into a lavarock cistern that is also plastered. Itprovides a large part of the domestic
water supply.
Smith wanted Shady to design anoff-grid system that includes water col-lection and water treatment, electricalpower, heating and possible cooling.
Since we had designed and builtprojects with similar energy sources,we knew we had to source as manyproducts from the European Union
as possible in order to minimize thechance of being stuck out in the mid-dle of the Mediterranean Sea with thewrong parts, Shady explains. Themost challenging aspect of the designwas finding controls and pumps thatwere different dimensional units, andmotors that were European voltage.
The team was finally able to source
the materials from Great Britain andItaly and had them shipped to theUnited States.The solar thermal andradiant floor heating systems wereassembled in Pacific Solar Radiantsmanufacturing facilities in SantaCruz and shipped in containers tothe island. The electrical systemsprovided by Sandbar Solar andElectric, the electrical contractor
that designed the PV electrical, wereincluded in the shipments.But the project did encounter a few
obstacles. The first one came when thecontainers were detained in customsin Palermo, Italy. There were questionsabout documents and whether thesystem components bore the requiredCE (Conformitee European) mark.Most of them did, since they weremanufactured in Europe. Smith hadhis attorney deliver the technical fileto Italian Customs and the containers
were finally cleared.In late April 2008, the Pacific SolarRadiant crew of six men flew to Romeand then to the island to begin con-struction. Thats when the next chal-lenge presented itself.
If getting our crates through cus-toms wasnt challenging enough, get-ting them up the hill to the mill was anequally daunting task, since most of theroads were designed for donkey cartsand maybe the odd Fiat, Shady notes.
They hired a truck with a crane to
remove the crates from the contain-
People request solar
thermal systems for the
efficiency and energy cost
savings you can achieve
with an integrated
thermal system that pro-
vides domestic hot water,
space and pool heating
that its a sustainable
technology is a bonus.
Bill Shady, P.E., ownerof Sustainable Design and
Project Management
Left: Bill Shady, P.E., and the Pacific Radiant Solar team installed the home's solar thermal and PV systems, the radiant heating and cooling systems and
the hydronic water heating system. Right: The site before the solar thermal and photovoltaic panels were installed. The solar systems were fabricated inCalifornia before being transported to the island.
8/8/2019 Solar Heating 0410
8/20Spring 2010 Solar Heating Report6
ers; it showed up an hour late with twoflat tires. They rented cars, which tooka bit of a beating, in order to fetch oddparts from the local hardware store.
The final obstacle occurred whenthey met with the Italian constructioncontractor and his crew. Everythinghe and our foreman had agreed upona year earlier was forgotten, Shadysays. Their construction methods andtools were outdated and somewhatprimitive. None of us spoke Italian andthey spoke no English.
So, the crew picked out the guywith the best English Alfredo, whogrew up on the island and knew whereto find everything the crew needed.Even with our careful packing, wewould have been lost without him,Shady states.
The Particulars: Due to the highcost of propane and the cost to trans-port the multiple tanks up to the mill,Shady and his team decided to design ahigh solar fraction. Solar fraction is thepercentage of annual expected energy
use that the collector array generates.A high solar fraction normallymeans that at certain times of theyear, usually summer in the NorthernHemisphere, you generate more than you need for domestic hot waterand space heating, Shady explains.Serving the pool where you wouldotherwise burn fuel is the best way toshunt. If there is no pool, then someform of low-energy-use dump of heatis required. This gives you the highesttrue solar fraction.
The mild Italian climate and theminimal load in the summer led thePacific Solar team to the installationof a shunt fan assembly to relieve solargain from the system. The addition ofa heated swimming pool in a futurephase of the project will keep the shuntto a minimum.
Additionally, five 16-tube SundaSeido 1 evacuated-tube collectors areinstalled on a low-profile ground-mount array, piped to a 50-gallondomestic water heater and a 200-gal-
lon insulated storage tank. All solar
The Italian Job
Radiant floor heating and cooling is distributedthroughout the home with PEX tubing in a groovedsubfloor. The radiant cooling system draws waterfrom the rainwater collection cistern.
Circle 407
Antifreeze & Heat Transfer Fluid
Non-Toxic - made with 100% FDA
G.R.A.S. ingredients
Extended Temperature Range
(up to 325oF)
For Applications such as Solar Heating,
Hydronic Heating and Water-Based
Heat Extraction Systems
NOBURST Freeze Flow Burst
HD Point Point Point
100% -60F -70F -100F
75% -60F -60F -100F
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35% 0F -10F -60F
Noble Company produces a variety of antifreeze products including NOBURST -100 and NOBURST AL
for Aluminum systems. The finest raw materials (including deionized water) contribute to Nobles high
quality. The company also markets refractometers, test strips, inhibitor boost, and other accessories tohelp ensure system performance.
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9/20Circle 404
http://www.iapmo.org/http://www.iapmo.org/8/8/2019 Solar Heating 0410
10/20Spring 2010 Solar Heating Report8
fluids are closed loop and all thermalstorage is domestic hot water. Radiantfloor heating is distributed throughUponor TruFlow manifolds with ther-
mal actuators and five zones of control.Composite PEX-al-PEX tubing wasinstalled in the Warmboard thermalsubfloor for heating and cooling.
Controls for the project wereKanmar injection-mixing controllerswith pumps supplied by Wilo andGrundfos. The innovative Wilo Stratos
Eco is the first known application ofthe pump in the region, Shady says. Itprovides heating with the bare min-imum use of valuable solar power
stored in the battery system or used asit is being generated. The Kanmar tem-perature controllers are also variablespeed, thereby limiting the power used
and maximizing the wire-to-waterheating efficiency of the system.
Cooling is accomplished througha heat exchanger in the radiant floorloop that draws water off the rainwatercollection cistern and cools the watergoing into the home down to a com-fortable 67 degrees F for passage intothe interior of the building.
The home is continually condi-tioned in the wet and windy winterseason beginning in October andcontinuing into late spring by the
solar thermal array. In order to moni-tor the system remotely, a Sensophoneremote monitoring system with a cel-lular data modem allows alarms to callout and the users to call in to downloadtemperature and climate data in realtime to diagnose potential problems.
An Engineered Solution: AfterShady returned from Italy, he began towork on a simple, engineered systemthat could be installed in remote loca-tions the ClimateRight System. Itsan easy-to-install system that evolved
from the design and engineeringwork he has done over the past eight years, including the extremely long-distance Italian project. Its factory-built and factory-tested in Oregon andCalifornia; all a contractor needs todo is rough in the utilities with astandardized, dimensioned wall-hungtemplate, bolt it to the wall and makethe final connections.
And while he believes solar thermaland solar radiant systems will continueto gain in popularity, Shady says the
economic climate today is a hindrance.He wants to change that by having afinancing option that contractors canoffer their customers, making it easierfor them to buy the product.
People love to do these projects,they just dont have the money, heexplains. The biggest factor in grow-ing the solar thermal business is theopportunity to lease the equipment.When I offer a customer a completelyengineered product and I can offerfinancing, thats when this thing is
going to take off.SHR
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The Italian Job
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11/20Spring 2010 Solar Heating Report 9
Most of the solar domestic water heatingsystems now deployed in the United Statesuse antifreeze to protect the collectors and
exposed piping from freezing. The antifreeze absorbsheat in the collectors and conveys this heat to the hotside of a heat exchanger. This heat conducts through
the metal wall of the heat exchanger and passes intowater on the other side of this wall.
Like most things hydronic, the performance of heatexchangers can vary widely, and that performance canhave a profound effect on the overall energy yield of asolar thermal system.
Two Flavors: Heat exchangers for solar thermalsystems are classified as either internal or external.An internal heat exchanger usually takes the form ofa helical coil made of stainless steel or copper. Thecoil is suspended within the lower portion of a stor-age tank essentially the same configuration foundin most indirect water heaters. Figure 1 is a schematic
showing a typical internal heat exchanger in a solarwater heating system.Heat moving from the coils external surface to the
cooler water is transferred by natural convection. Inthis situation the word natural implies there is nopump or other device to create vigorous water flowacross the coils external surface. This significantly lim-its the rate of heat transfer relative to a heat exchangerwhere flow is forced across both sides. To compensate,some internal heat exchangers have large surface areasand may use fins or other extended-surface detailingto further increase surface area and enhance the rateof heat transfer.
An external heat exchanger has forced flow throughboth sides. Forced flow produces higher rates of heattransfer relative to natural convection. This allows arelatively small heat exchanger with forced flow totransfer heat at the same rate as a significantly largerinternal coil.
Figure 2 shows how an external heat exchanger istypically used in a solar water heating system. Noticethat two circulators are required: one for the collec-tor side and the other for the tank side of the heatexchanger. When the tank contains domestic water, thetank-side circulator must have a stainless-steel, bronzeor engineered polymer volute to prevent contamina-
tion of the water.
Thermal Handoffs,Part 1
by John Siegenthaler, P.E.
sola
rcolle
ctor
array
storage tankll / purgevalves
expansiontank
air ventw/ shut off
valve
PRV
internal heat exchanger
Inside the fundamentals of heat
exchangers in solar thermal systems.
Figure 1
-
8/8/2019 Solar Heating 0410
12/20Spring 2010 Solar Heating Report10
An Effective Approach: Heat exchanger perfor-mance is often expressed as effectiveness, which isdefined as follows:
To calculate effectiveness, you need to first deter-mine:
a. The actual rate of heat transfer across the heatexchanger.
b. The maximum possible rate of heat transferacross the heat exchanger.
The actualrate of heat transfer can be determinedbased on the flow rate, specific heat and temperaturechange of fluid flowing through either side of theheat exchanger. Figure 3 provides the formulas andnomenclature to calculate the rate of heat transfer
across the heat exchanger.
Where:Qactual = actual rate of heat transfer across heat
exchanger (Btu/hr.)8.01 = unit conversion factorDh = density of fluid through hot side of heat
exchanger (lb./ft.3)Dc = density of fluid through cool side of heat
exchanger (lb./ft.3)ch = specific heat of fluid through hot side of heat
exchanger (Btu/lb./degrees F)ch = specific heat of fluid through cool side of heatexchanger (Btu/lb./degrees F)
fh = flow rate of fluid through hot side of heatexchanger (gpm)
fc = flow rate of fluid through cool side of heatexchanger (gpm)
T = temperatures at locations shown in figure(degrees F)
The maximum possible rate of heat transfer throughthe heat exchanger can be calculated as follows:
Where:(8.01xDxcxf)min = the smaller of the two fluid
capacitance rates. This can be found by calculating theproduct (8.01xDxcxf) for both the hot and cool sideof the heat exchanger and then selecting the smallerof the two.
Thin = inlet temperature of the hot fluid (degrees F)Tcin = inlet temperature of the cool fluid (degrees F)
As the size of the heat exchanger increases relativeto the rate of heat transfer, its effectiveness approaches
the theoretical limit of 1.0.
e=effectiveness = e =actual heat transfer rate
maximum possible heat transfer rate
Thout
Thin
Tcin
Tcout
fcfh
hot side cool side
orQ
actual = (8.01 Dc cc ) fc Tcout Tcin( )
Qactual = (8.01 Dh ch ) fh Thin Thout( )
Qmax 8.01 D c f min Thin Tcin
Thermal Handoffs, Part 1
Figure 3
solar storage tank
differentialtemperature
controller
sola
rcolle
ctor
array
expansiontank
pressure relief
valve
collectorcirculator
air ventw/ shut off
valve
ll / purgevalves
tankcirculator(bronze or
stainless steel)
external heat exchanger
-Figure 2
8/8/2019 Solar Heating 0410
13/20Spring 2010 Solar Heating Report 11
Heres an example. Consider a heat exchanger in a solarthermal system operating at the conditions shown in Figure 4.
The fluid in the collector loop is a 40 percent solutionof propylene glycol. The fluid on the cool side of the heatexchanger is water. Here is how you determine the rate ofheat transfer across the heat exchanger and its effectiveness.
Start by finding the fluid properties of both the 40percent propylene glycol solution and water at the aver-age temperature of each fluid as it passes through the heatexchanger. These can be found in reference books on heat-ing or, in the case of antifreeze solutions, referenced fromspecifications at the manufacturers Web site.
For the 40 percent propylene glycol solution:D = 64.0 lb./ft.3
C = 0.91 Btu/lb./degrees F
For water:D = 61.8 lb./ft.3
C = 1.00 Btu/lb./degrees FNext, calculate the actual rate of heat transfer across the
heat exchanger. This can be done using data from eitherflow stream. In this case, data from the flow stream throughthe hot side of the heat exchanger (using the 40 percentpropylene glycol solution) is used:
Then determine which side of the heat exchanger has theminimum fluid capacitance rate (e.g., calculate the product
(8.01xDxcxf) for each flow stream and determine which issmaller).For the hot side of the heat exchanger:
For the cool side of the heat exchanger:
The fluid capacitance rate on the hot side of the heat
exchanger is the smallest.
The next step is to determine the maximum possibleheat transfer across the heat exchanger. This corresponds toa thermodynamic limit in which the outlet temperature ofthe fluid with the lower fluid capacitance rate approaches
the inlet temperature of the other fluid stream. It is deter-mined by multiplying the minimum fluid capacitance rateby the difference in temperature between the entering hotfluid and the entering cool fluid.
Finally, determine the effectiveness of the heat exchangerunder these conditions.
In the next issue, well look at how the effectiveness of aheat exchanger affects the overall energy yield of a solar ther-mal system. As you might expect, the higher the effectiveness,the higher the solar fraction. But as usual, the numbers pro-vide a more complete story and also guide design decisions.
About the author: John Siegenthaler, P.E., is principalof Appropriate Designs, a consulting engineering firm inHolland Patent, N.Y., and the hydronics editor for Plumbing& Mechanical and pme. E-mail him at [email protected]. More than 200 of Johns articles on hydronic systemdesign are now available in the Hydronics Know How IIDVD collection. To order, go to http://store.bnpmedia.com/
store/aec_online/index.html.
Qactual (8.01 Dh ch ) fh Thin Thout (8.01 64.0 0.91) 4 130 120 18,660Btu/hr
hot side cool side
130F4 gpm
120F
6 gpm
110F
116.3F40%
propylene
glycol
water
(8.01 D c f)40%PG (8.01 64.0 0.91 4) 1866Btu
hrF
(8.01 D c f)water (8.01 61.8 1.00 6) 2970Btu
hrF
Qmax 8.01 D c f min Thin Tcin [8.01 64.0 0.91 4] 130 110 37,320Btu/hr
e =Qactual
Qmax=
18,660
37,320 0.50
Figure 4
SHR
Copyr ight2009,BNPMedia. AllrightsReserved.Theoriginalpurchaserofth isDVDmaymakeoneprintedcopyofthearticles itcontains forpersonaluse. N oon e is a l l owe d t o c r e a te o r distributeadditionalcopiesoftheseart ic les ,either inpr intorelectron ic form,withoutwrittenperm issionfromBNPMedia. Tos ecurepermissioncontac tBNPat248-362-3700or www. PMmag.com.
Requires AdobeAcrobat Reader
(version 3.0 orhigher)
JOHNSIEGENTHALERS
HYDRONICS
KNOWHOW
II PMPlumbingMechanical&
Over 200 of John's articles and
columns from the last 12 years
of PM and PM Engineercovering
everything from heat loss to
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fully searchable files.
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14/20Spring 2010 Solar Heating Report12
Ican relate to the lack of respectand attention that thermalsolar systems experience in the
marketplace as well as within our
state and federal governments. Asa teenager, my best buddy was thisgood-looking, smooth-talking guyand standing next to him, I kind ofblended into the wallpaper. I wasntugly and/or dull but next to mybuddy, the ladies couldnt see myattributes. So goes it for thermalsolar systems!
Photovoltaic (electricity-gener-ating) solar systems have become thesexy solar systems in the press andin the legislatures around our coun-
try. Dont get me wrong, producingelectricity via the suns energy isawesome and deserves attention. Myconcern is that thermal solar systemsmay not be getting the attentionthey deserve and, thus, opportuni-ties may be missed.
Thermal solar systems that gen-erate hot water for domestic use aswell as supplemental heat are gener-ally a fraction of the cost of a PV sys-tem. Although thermal systems cantcreate an income-generating source
as photovoltaic can, I dont believe itis realistic for average homeownersto think they will be getting checksfrom their local electric utility forthe unused kilowatts that a residen-tial PV system could generate. Smallresidential PV systems are just that small and as a result cant gen-erate income and fulfill unrealisticexpectations of potential buyers.
On March 31, 2009, the governorof New Jersey enacted the ResidentialDevelopment Solar Energy Systems
Act, which requires residential home
builders to offer a solar energy optionto potential home buyers in projectsof 25 or more units. I believe ther-mal solar systems are the best choice.TSS can be installed by properlytrained plumbers and HVAC install-ers. Sixty vacuum tubes or four flat-plate panel collectors can do most,if not all, of a typical domestic hotwater requirement for a four-personfamily, as well as supplement low-temperature heat (approximately 30percent) and high-temperature heat
(approximately 10 percent).
Thermal solar collectors aremuch more efficient than PV col-lectors. Depending on the collector,a solar thermal system can convert50 to 70 percent of the suns energyinto hot water. Photovoltaic collec-tors convert somewhere between 12to 15 percent of the suns energy intoelectricity. Hot water can be storedat low- or no-usage periods in aninsulated tank with less than onedegree of heat loss per hour.
PV systems large enough to pro-
duce more electricity than the home
by Gerry Wagner
Photovoltaic = Sexy Solar
Thermal Solar = Not So MuchThermal solar systems can do a big job
at a relatively low installed cost.
Gerry Wagner, training manager at The Wales-Darby Learning Center, teaches his studentsthe many benefits of thermal solar systems compared to photovoltaic systems.
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Viegas ProPress system is the fastest, most reliable
way to join metal piping in commercial, residential
and industrial applications.
You can rely on Viegas ProPress system to back you up in an
emergency. Thats why hospitals have entrusted their piping
systems to Viega. With Viegas patented Smart Connect
feature you can make connections in less than seven seconds.
During pressure testing, water and air flows past the sealing
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ProPress features and benefits:
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When
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Viega The global leader in plumbing and heating systems. www.viega.com 1.800.976.9819
Circle 409
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16/20Spring 2010 Solar Heating Report14
can use can be connected directlyto the grid and excess kilowattssold to the local utility. However, itsmore typical in small PV systems that
electricity may be stored in a battery,or a series of batteries, which requirespace, maintenance and can be veryexpensive.
Thermal solar systems have verylittle maintenance issues. A circulatoris virtually the only moving part andit, as well as the other system compo-nent parts, are familiar to all plumbersand HVAC technicians because a TSSis a traditional hydronic system. Theonly thing different is, instead of aboiler and/or water heater, the panel
is your heat source. Thermal solar is asimple system that can do a big job at arelatively low installed cost comparedto complicated PV systems.
In my role as the training managerat The Wales-Darby Learning Center,I have plumbers and HVAC techni-cians calling me daily to ask when
our next solar class is scheduled.I have learned to ask the question,You do understand our class is forthermal solar and not photovoltaic?
Unfortunately, I have found thatpeople are using the word solarin an all-encompassing way. Earlyon, I had a few guys in my class ask,When are we going to talk aboutsystems that produce electricity? Itbrought me back to my younger dayswhen I would get phone calls frompretty girls asking me if I thoughtmy buddy liked them. Ugh!
There are signs that the spotlightis starting to shine (pun intended) onTSS. The feds finally came around and
raised the $2,000 limit on tax creditsrelated to residential TSS installationsand put it in line with what had beenstandard for PV systems (up to 30 per-cent of installed cost) since the enact-ment of the 2005 Federal Energy Act.
Eventually my good-looking,smooth-talking friend moved away
and I started to get some attention(and I stress some) from the femalepopulation.
Hang in there, thermal solar fans.
Im proof that every dog has hissunny day!
This article was previously publishedin sister publication Supply HouseTimes January 2010 issue.
Gerry Wagner has been in theHVACR industry for 29 years, the last18 with the manufacturers representa-tive firm Wales-Darby Inc., Warren, N.J. He is now the training manager
at The Wales-Darby Learning Center,where he brings his unique combina-tion of experience, both in the fieldand in the classroom, as well as humor,communication skills and love of theHVACR industry to life. You can con-tact Gerry at 732/907-1763, [email protected]. SHR
Photovoltaic = Sexy SolarThermal Solar = Not So Much
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mailto:[email protected]:[email protected]:[email protected]://www.paw.eu/http://www.paw.eu/http://www.paw.eu/mailto:[email protected]:[email protected]8/8/2019 Solar Heating 0410
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Stiebel Eltron Thermal SolarWater Heating SystemStiebel Eltron SOLKITs 2 and 3 are nowEnergy Star-rated and have OG300 sys-tem certification from the Solar Rating
and Certification Corp. Each solar closed-loop system includes flat-rate collectorpanels and mounting hardware, a stor-age tank with heat exchangers, a pumpstation with expansion tank and varioustemperature/pressure gauges, pressurerelief and check valves, and a control-ler unit with corresponding sensors. Afive-year warranty is also included.www.stiebel-eltron-USA.com. 800/582-8423.Stiebel Eltron USACircle 410
solar i.s.{information showcase}
solar products
STORAGE TANK AND WATER HEATER: SolarUsage Nows S.U.N. Equinox Heating Systemis a combination hot water storage tank andinstantaneous water heater that provides100 percent of domestic hot water andspace-heating needs while placing a specialemphasis on water hygiene. Solar UsageNow. www.sunequinox.com. Circle 411
DRILL PUMP: Zuwas Unistar 2001 series drillpump is ideal for refilling solar collectorsand features a light aluminum body, dryself-priming from 10 feet and flow rates of8, 16 and 24 gallons per minute. The pump isavailable in stainless steel and different im-peller materials for different fluids (not forgasoline). Zuwa. www.zuwa.de. Circle 412
SOLAR TRILOGY: Taco introduces all-in-one solar pumps, components and controls to fita wide variety of solar thermal applications. The Solar Pumping Station combines all fea-tures needed for a closed-loop water heating system (five connections to make). TheSolar X-Pump Block combines a stainless-steel, flat-plate heat exchanger with two bronzecirculators and a solar differential temperature control in one compact package. The Vari-able Speed Solar Pump line includes circulators with integral solar differential temperaturecontrols. Taco. www.taco-hvac.com. Circle 413
SOLAR THERMAL COLLECTORS: SolarsSmart received formal SRCC (SolarRating and Certification Corp.) industrycertification of its Smart 10, 15 and 20Solar Thermal Collectors. The collectorsare designed for use in domestic hotwater, radiant home heat and swimmingpool heating applications and are con-structed to perform under a wide vari-ety of weather conditions. Solars Smart.www.solars-smart.com. Circle 415
SOLAR THERMAL COMBISYSTEMS:Caleffi released its 6th edition ofidronics, a semi-annual design
journal for hydronic professionals,on solar thermal combisystems.The journal provides informationto assist those designing solarcombisystems. Caleffi also hasstate-of-the-art hardware to sup-port installation of the systems.Caleffi. www.caleffi.us. Circle 414
http://www.sunequinox.com/http://www.zuwa.de/http://www.taco-hvac.com/http://www.solars-smart.com/http://www.caleffi.us/http://www.caleffi.us/http://www.solars-smart.com/http://www.taco-hvac.com/http://www.zuwa.de/http://www.sunequinox.com/8/8/2019 Solar Heating 0410
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You may also respond to ads in the Solar Heating Report via the Reader Action
Card in the August issue of Plumbing & Mechanical (that SHR was bound into).
STORAGE TANK: Rheems SolPak systems fea-turing Marathon storage tanks combine thelongevity of the Rheem Marathon electric
water heater with the energy savings of anactive solar water heating system. This newoption for SolPak provides homeowners ac-cess to a high-efficiency storage tank witha lifetime leak-free guarantee. Rheem.www.rheem.com. Circle 418
INTERNAL TEMPERATURE SENSOR: SolarSkies Mfg. offers an option to maximize theefficiency of its solar collectors. The new
internal temperature sensor well allowsfor a more accurate internal temperaturemeasurement of the collector, allowing thesystems controller to respond quicker andcollect more Btu per day. Solar Skies Mfg.www.solarskies.com. Circle 417
CIRCULATION PUMP: PAWs FlowCon FA(U.S. version) is for use in a closed-loop
design only. The circulation unit is usedon the primary circuit of solar heatingsystems to control temperature in the hotwater storage. The pump inside the unit isactivated by the signal from the differen-tial temperature regulator. PAW GmbH &Co. KG. www.paw.eu/us. Circle 416
solar products
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