LOWTEMPERATUREHYDRONICHEATINGFOR

COLDCLIMATES

TRAVISSMITHPRESIDENT

TANDTMOUNTAINBUILDERSINC

•  COLDCLIMATES–  REFERRINGSPECIFICALLYTOCLIMATESZONES6&7

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

80–100degreereturntemperatureisthe“sweetspot“forefficiency

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

HEATSOURCESELECTRICOPTIONS

•  AIRTOWATERHEATPUMPSDAIKINALTHERMACHILTRIXSPACEPAKSOLSTICEEXTREME

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

HEATEMITTERSTOWELBARWARMERSALUXURYITEM,VERYLOWHEATOUTPUT

MYSONTOWELBARWARMER,WITHTRV

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

SUMMARY

•  HEATEDCONCRETEFLOORSCANWORKINLOWENERGYHOMESIFDESIGNEDPROPERLY

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

NOTE:THISISNOTTHEONLYHEATSOURCEFORTHISBATH

MECHANICALROOM

PIPINGSCHEMATIC

ERVFANCOIL

500’“GEO”LOOPAROUNDFOUNDATION,ERVPRECONDITIONING

TIPSFORLOWERCOSTINSTALL

•  LIMITZONINGTOTHEBASICS•  USETRV’s•  USEFEWER,LARGERRADIATORS•  SITEBUILTMANIFOLDSWITHPEXFITTINGS(HOMERUNPIPING)

•  BRAZEDPLATEHEATEXCHANGER•  COULDBEINTHE$4-5SQFTRANGE+/-

DISCUSSION

•  ADDITIONALTHOUGHTSFORALOWERINSTALLEDCOST

•  WHENDOASHPsMAKEMORESENSE?

CREDITS

•  JOHNSIEGENTHALER:HYDRONICHEATINGFORLOWENERGYHOUSES

•  HEATTRANSFERPRODUCTS(HTP)