LOW TEMPERATURE HYDRONIC HEATING FOR COLD CLIMATES · hydronic heating for cold climates travis...
Transcript of LOW TEMPERATURE HYDRONIC HEATING FOR COLD CLIMATES · hydronic heating for cold climates travis...
HYDRONICHEATING
– USINGAFLUIDTOTRANSFERHEAT– MANYTYPESOFEMITTERS:PANEL
RADIATORS,FANCOILS,RADIANTFLOORS,WALLS,CEILINGS)
WHYHYDRONICHEAT
• HVACCONTRACTORSTENDTOOVERSIZEEQUIPMENT
• VERYQUIET• NOBLOWINGOFHOTAIR,STIRRINGALLERGENS
WHYHYDRONICHEAT• AGIVENVOLUMEOFWATERCANABSORBALMOST3500
TIMESASMUCHHEATASTHESAMEVOLUMEOFAIR,WHENTHEYBOTHUNDERGOTHESAMETEMPERATURECHANGE
8X12DUCT
¾”PIPE
OBVIOUSLYNOTCHINGA2X12JOISTTHISMUCHISUNACCEPTABLE
LOWTEMPERATURE
– SUPPLYTEMPERATURESOFLESSTHAN120(DEGREESF)– WHYLOWTEMPERATURE?ITTAKESLESSENERGYTOHEATWATERTOALOWTEMPERATURE.
– MAKESUSEOFSOLARCOMBI-SYSTEMSPOSSIBLE– CONDENSINGBOILERSANDWATERHEATERSONLYCONDENSEANDMAINTAINEFFICIENCYATRETURNTEMPERATURESOF130DEGREESORLESS.LOWERTEMPS=HIGHEREFFICIENCY
PASSIVEHOUSE• INHIGHPERFORMANCEHOMES,IT’STYPICALTOHAVEHEAT
LOADS,INCLIMATES6&7,OF10-30KBTU/HROFHEATLOSS.
• WHENSOURCINGABOILERTYPICALFORSPACEHEAT,THESMALLENDOFAVAILABILITYISAROUND60KBTU/HROUTPUT.
– “SMALL”BOILERSIZEOF+/-60KBTU/HR,WILLMODULATEDOWN3:1
– THELOWESTBOILERSETTINGCANEXCEEDTHEPEAKHEATLOAD!
SOLUTION
• COMBINEDDHWANDSPACEHEAT– ONEAPPLIANCEFORBOTH– THEMOSTCOSTEFFECTIVEWAYTOINTEGRATEHYDRONICHEATINGINALOWENERGYHOME
– THEEUROPEANSHAVEBEENDOINGTHISFORMANYYEARS
NOTE:THEDHWANDTHESPACEHEATINGSIDESAREHYDRAULICALLYSEPARATEDWITHAHEATEXCHANGER,NOTAN“OPEN”SYSTEM
SPACEHEATvs.DHW• WHENCOMPARINGSPACEHEATTODHW,ONANANNUAL
BASIS,DHWPRODUCTIONACCOUNTSFORABOUT30%OFTHEOVERALLENERGYUSE.(LOOSELY)
• CONCLUSION:ITDOESN’TMAKESENSETOFOCUSSOLELYONEFFICIENTSPACEHEAT,ANDNOTCONSIDERTHEPOTENTIALFOREFFICIENTDHWHEATING
DHW
SPACEHEAT
ELECTRICOPTIONS• HEATPUMPWATERHEATER????• THEUNITSCURRENTLYONTHEMARKETDON’THAVETHECAPACITYFORSPACEHEATINGANDDHWWATERHEATING
• POSSIBLYOKASASTANDALONEUNIT
• MAYWORKINMILDERCLIMATES,BUTTHENBUTDOESN’TPENCILOUTDUETOASHPSPLITSYSTEMS
ELECTRICOPTIONS
• RESISTANCE(ELECTRICBOILER)NOTIDEALFORCOMBISYSTEMNOTHERMALBUFFEROKFORSTANDALONEHYDRONICHEATBETTERTOSEPARATETHEDHWPRODUCTIONWITHANOTHERUNITTHISLITTLEBOXISTHEBOILER!FAIRLYINEXPENSIVE
GASFIREDCOMBI-APPLIANCESHTPPHOENIXWATERHEATER96%EFFICIENT,5:1TURNDOWNSEALEDCOMBUSTION,CONDENSINGWATERHEATER.NOTICETHEADDITIONALPORTSONTHETANKFORADDINGAUXILIARYHEATINGTHISDESIGNISTHEBESTOFBOTHWORLDS:
SUPEREFFICIENTCONDENSINGHEATEXCHANGER,WITH55GALLONSOFTHERMALSTORAGETOPREVENTSHORTCYCLING.ALSOIDEALFORAHOTWATERRECIRCULATIONSYSTEMNOTE:76%OFUTAH’SPOWERISGENERATEDBYCOALFIREDPOWERPLANTSAND19%GENERATEDBYNATURALGAS
GASFIREDCOMBI-APPLIANCESTANKLESSUNIT.PROS:MODULATESFROMTO12kTO120KBTU/HROUTPUT.(10:1!)FAIRLYINEXPENSIVECONS:HOTWATERRECIRC?
SOLARTHERMALCOMBI-SYSTEM
THESEUNITSFROMHTPFEATUREASOLARFEDHEATEXCHANGERINTHEBOTTOMOFTHETANK,THATPROVIDESTHEPRIMARYHEAT.THEBACK-UPHEATGENERATIONISGASFIRED.THISWILLPROVIDEALARGEPERCENTAGEOFTHEDHWFORTHEYEAR,BUTONLYASMALLFRACTIONOFTHESPACEHEAT.
HEATEMITTERS• BASEBOARDRADIATORS+/-$25LF,UNITSSHOWNARE$130WITHVALVES• LOWMASSDESIGNISIDEALFORLOWENERGYUSEBUILDINGS• RELIABLEHEATOUTPUTATLOWSUPPLYTEMPERATURES• NOFINTUBE!CANNOTPERFORMRELIABLYATLOWSUPPLYTEMPERATURES
MYSONRCVDÉCORSTYLEBASEBOARDRADIATORS
HEATEMITTERS
• PANELRADIATORS MANYDIFFERENTSTYLESPOSSIBLERELIABLEHEATOUTPUTATLOWSUPPLYTEMPERATURESTHESTANDARDINEUROPEGOODHEATOUTPUTPERSIZEOFUNIT
HEATEMITTERS
• FANCONVECTORS
MYSONiVECTOR
REMOTEFANCOILUNITSHIGHHEATOUTPUTONLOWWATERTEMPSVERYQUIETTHESEHAVETHECAPABILITYTOCOOLWITHCHILLEDWATERGIVENTHEHIGHEROUTPUTFEWERUNITSNECESSARY.+/-$1800EACHOUTPUTS@120EWTRANGEFROM6,710–16,776BTU.
THESECANHEATANENTIRELEVELOFAPASSIVEHOUSE
HEATEMITTERSKICKSPACEFANCONVECTORSFAIRLYINEXPENSIVEGREATFORKITCHENS,BATHS,LAUNDRYROOM,WHERETHEREISN’TTYPICALLYWALLSPACEFORAPANELRADIATOROUTPUTSOF2516–4629BTU/HR
MYSONWHISPAFANCONVECTORS+/-$250EACH
HEATEMITTERS
• SITEBUILTWALLS HIDDENFROMVIEWQUIETOPERATIONOUTPUTPERSQFTDEPENDENTONSUPPLYTEMPERATURE(TYPICALFORALLRADIANTPANELS)POTENTIALLYLOWERINSTALLEDCOSTTHANBASEBOARDANDPANELRADIATORSFLOORPLANLAYOUTSANDFURNITUREPLACEMENTSHOULDBECONSIDERED
HEATEMITTERS• RADIANTHEAT,
IMBEDDEDINCONCRETEPOUR
PROS:EXPOSEDCONCRETEFLOORSAREINFASHION,WITHIMBEDDEDHEAT,THEEMITTERISOUTOFSIGHT.MINIMALISTLOOKTHEMOSTCOMMONRADIANTINSTALLCONS:HIGHMASS,SLOWRESPONDING
HEATEMITTERSIMBEDDEDTUBING
THESEARENOT“BAREFOOTFRIENDLYFLOORSSURFACETEMPERATUREISONLY4DEGREESABOVEAMBIENT,THEYHARDLYFEEL“WARM”
REQUIRESALOWERSUPPLYTEMPERATURETOPREVENTOVERHEATINGINALOWENERGYHOME,VIAAMIXINGVALVE
NOTICETHETHICKNESSOFTHISSLAB,THISWOULDTAKE36HOURSTORESPONDTOTEMPERATURECHANGE!NOTIDEALFORALOWENERGYHOME!
RADIANTFLOORS• KEYPOINTSFORRADIANTFLOORSINLOWLOADBUILDINGS
KEEPTHEFLOORSURFACEDESIGNTEMPERATURELIMITEDTO4DEGREESABOVETHEINTENDEDROOMTEMPERATURETHISWILLCREATEANOUTPUTOF8BTU/HR/SFDONOTEXCEED12”TUBINGSPACINGTHECONCRETEFLOORWILLPROVIDESOMETHERMALSTABILITY,ANDISLIKELYTONOTSIGNIFICANTLYOVERSHOOTTHEDESIGNEDROOMTEMPERATURE,WHENSOLARGAINISAFACTOR.
HEATEXCHANGERS• THECORECOMPONENTTOHYDRAULICALLYSEPARATETHE
DHWFROMTHECLOSEDLOOPSPACEHEATINGSYSTEM.
TYPICALBRAZEDPLATEHEATEXCHANGER
SUPPLYTEMPERATURE• BRAZEDPLATEHEATEXCHANGER’STYPICALHAVE
ATLEASTA10DEGREEDELTAt• TOSUPPLYTHEEMITTERSWITH120DEGREE
WATER,THEHEATOUTPUTOFTHEAPPLIANCEMUSTBEAT130DEGREES,DEPENDINGONFLOWRATE
• THISDOESN’TACCOUNTFORDISTRIBUTIONLOSSESINHOMERUNPIPINGSYSTEMS
• INSULATETHETUBINGHOMERUNS• POTABLEWATERMIXINGVALVESBECOME
NECESSARY,130DEGREESCANSCALDONTHEDHWSIDE
• USECHECKVALVESONTHESEUNITSTOPREVENTTHERMALSIPHONING
ZONING• ROOMBYROOM?LEVELBYLEVEL?• THERMALZONESSHOULDBESEPARATEDBYLEVELSATA
MINIMUM(THISWORKSGREATINPASSIVEHOUSE)• ROOMBYROOMZONINGISTYPICALLYNOTNECESSARY,BUT
IT’SAGOODPRACTICETOSEPARATEAREASTHATRECEIVESIGNIFICANTLYDIFFERENTLEVELSOFSOLARGAIN
• RESULT=HAPPIERCLIENTS
ZONINGMETHODS
• USERINTERFACETHERMOSTATSTRV(THERMOSTATICRADIATORVALVES)NON-ELECTRICVALVES,THATREGULATETHERADIATORORBASEBOARDHEATER,BASEDONROOMTEMPERATUREANDUSERSETTING.EXTREMELYSIMPLE!
ZONINGMETHODS• MECHANICALROOMZONING
ZONEVALVES:OKWITHACENTRALPRESSUREREGULATEDPUMPCIRCULATIONPUMPS:TYPICALINAMODERNHYDRONICSYSTEM.NOTTYPICALLYNEEDEDFORALOWENERGYHOUSE
ZONINGMETHODSMANIFOLDMOUNTEDACTUATORSPROS:MANIFOLDSAREALREADYUSEDFOR(HOMERUN)DISTRIBUTIONPIPINGADDINGA24VACTUATORATEACHCIRCUITCREATESASIMPLEZONETHERMOSTATS,ANDACTUATORSWIREDTOAZONECONTROLISFAIRLYSIMPLEINSTALL
THESEARETHEACTUATORS
PUMPS
• VARIABLESPEEDCIRCULATIONPUMPS:THEKEYTOEFFICIENTDISTRIBUTIONANDPOWERCONSUMPTION
THESEECMBASEDPUMPSSENSEHEADPRESSUREANDADJUSTTHEOUTPUTBASEDONHOWMANYZONESARECALLINGFORHEAT
THEIDEALSYSTEM• THESIMPLESTSYSTEMWOULDUTILIZEONEVARIABLESPEED
CIRCULATORANDTHERMOSTATICRADIATORVALVES(TRV)ATEACHEMITTERLOCATION.
• JOHNSIEGENTHALERCALLSTHIS“HYDRONICSHEAVEN”
SUMMARY
• PANELRADIATORSANDBASEBOARDRADIATORSWORKGREATWHENPLACEDUNDERWINDOWS
• FURNITUREISN’TNORMALLYPLACEDTIGHTTOWINDOWS
• KICKSPACEFANCONVECTORSAREANOPTIONFORBATHS,LAUNDRYAREAS,ANDKITCHENS
• THEABILITYTOPLACEANDDISGUISEAHEATERUNDERTHECABINETTOEKICKISGREATUSEOFSPACE
PINEBROOKRESIDENCEPARKCITY,UTCLIMATEZONE6
• 3210sqq• DESIGNHEATINGLOADOF8BTU/HR/SF(PERMANUALJ)
• 25,680BTU/HRPEAKHEATLOSS• FAMILYOF4ASSUMEDUSEOF68GALLONSOFDHWPERDAY
• COSTOFSYSTEM,INCLUDINGWATERHEATER$7.50SF.MINUSCOSTOFWATERHEATER($3200)$6.52SF
SYSTEMSPECS
• HTPPHOENIX100kBTU55GALLONCOMMERCIALWATERHEATER
• GRUNDFOSMAGNAVARIABLESPEEDCIRCULATIONPUMP
• MYSONRCVDÉCORSERIESBASEBOARDRADIATORS• MYSONWHISPAKICKSPACEFANCONVECTORS• HOTWATERRECIRCULATIONSYSTEM
TIPSFORLOWERCOSTINSTALL
• LIMITZONINGTOTHEBASICS• USETRV’s• USEFEWER,LARGERRADIATORS• SITEBUILTMANIFOLDSWITHPEXFITTINGS(HOMERUNPIPING)
• BRAZEDPLATEHEATEXCHANGER• COULDBEINTHE$4-5SQFTRANGE+/-