Hydronic Solutions for Low Energy Houses

Transcription

1 Hydronic Solutions for Low Energy Houses February 8, 2018 Burlington, VT Sponsored by: panel radiator TRV APPLIANCE! for space heating! and DHW presented by: John Siegenthaler, P.E. Appropriate Designs Holland Patent, NY DHW cold Copyright 2018, J. Siegenthaler all rights reserved. The contents of this file shall not be copied or transmitted in any form without written permission of the author. All diagrams shown in this file on conceptual and not intended as fully detailed installation drawings. No warranty is made as the the suitability of any drawings or data for a particular application.

2 Hydronic Solutions for Low Energy Houses Today's Topics: 1: Characteristics of low energy houses 2: Benefits of using hydronics technology for heating & cooling 3. Heat source options 4. Air-to-water heat pumps 5. Low water temperature distribution systems 6. System examples

3 Many hydronic systems are installed in large houses like these... Hydronics "owns" the upscale housing market in many areas of North America.

4 These systems often have complicated and expensive systems

5 Is this what it takes to operate a hydronic heating system???

6 The evolution of home heating system - from an architect s point of view...

7 Massachusetts Net Zero house Images: SolarToday magazine, Nov/Dec 2011 Mitsubishi mini-split heat pumps 1,800 square foot floor area, 12,100 Btu/hr design load R-46.8 walls, R-63 ceiling, R-20 basement,r-5 windows Heat recovery ventilator All electric house.

8 Net Zero house in Seattle SPECS 2,426 Square feet 4 Bedrooms 2.5 Baths Radiant heat Air-to-water heat pump SIP construction 9.5 KW PV system Source:

9 What are the characteristics of low energy houses that must be addressed during design of the heating system? Small design heating loads in the range of 10 to 15 Btu/hr/ft 2. (A 2000 ft 2 house at 10 Btu/hr/ft 2 is only 20,000 Btu/hr DESIGN load) Internal heat gains can have more significant impact on internal temperature. (room-by-room zoning is important to control overheating) Internal heat flow through open doors and uninsulated partitions helps equalize temperature differences. (difficult to maintain significant temperature differences between zones) DHW load may exceed design space heating load, and thus set the output requirement of the heat source. Heat Recovery Ventilation will be required due to low natural air leakage. Any large surface area radiant panels will operate at very low surface temperatures (71-75ºF). (Heated floors don t get as warm as they used to - they don t need to...) Image: SolarToday magazine, Nov/Dec 2011 Difficult to find a combustion type heat source with capacity well matched to load. (will need thermal mass to prevent short cycling) Monthly service charge associated with gas meter may be hard to justify based on fuel cost difference and usage. (consider all electric house) All net-zero houses will use solar PV system, and thus favor an all electric HVAC system.

10 What are the advantages of using hydronic heating in these houses? Superior comfort: Radiant panel heating is better match to human physiological comfort needs. It s not just about pushing Btus into a space to match heat loss. Simple room-by-room ( wireless ) zoning is possible with many heat emitter options. Don t have to leave all doors open for internal heat balancing. A limitation of single point heat/cool delivery such as wall cassette. Very low distribution energy required (A single ECM circulator operating on 10 to 40 watts supplies all heating distribution) Very non-invasive installation of small tubing (3/8 & 1/2 PEX, PERT, or PEX-AL-PEX) (Installing this tubing is like pulling electrical cable) Easily adapted to renewable heat sources) (solar thermal, hydronic heat pump, off-peak) In some cases a single heat source can supply heating and DHW (fewer burners, less vents, less fuel piping) Electric heat sources and water-based thermal storage is easily adapted to timeof-use rate structures. (thermal storage hardware already available) source: Wagner Zaun Architecture

11 Hydronic solutions for low energy houses Given that Houses are becoming smaller and more energy efficient (nominal 5 to 15 Btu/hr/ft 2 design loads). 2. More customers are looking into the possibility of using renewable energy sources. 3. Builders and buyers are looking for HVAC solutions - not hardware. 4. Hydronics is the enabling technology that underlies all thermally-based renewable energy systems. ENERGY EFFIC Question... Can the North American hydronics industry seize upon, and leverage the opportunity to provide heating (and cooling) solutions to the emerging market for low energy houses?

12 Why is the net zero housing market defaulting to mini-split heat pumps rather than hydronics? Training programs for net zero houses typically promote mini-split heat pumps as the only HVAC necessary. They discourage the complication of hydronic systems. Common suggestion for net zero houses. Install a ductless mini-split air-to-air heat pump, with 1 or 2 indoor wall cassettes, and leave the interior doors open for heat distribution. from Leave bedroom doors open during the day If you want to heat your house with a ductless minisplit located in a living room or hallway, you ll need to leave your bedroom doors open during the day. When the bedroom doors are closed at night, bedroom temperatures may drop 5 F between bedtime and morning. zerohomes.org If family members don t want to abide by this approach, or don t want to accept occasional low bedroom temperatures during the winter, then supplemental electric resistance heaters should be installed in the bedrooms. The COPs of cold climate heat pumps with inverter compressors is not discussed in detail. historicshed.com

13 What happens to the COP of ductless mini splits at low ambient air temperatures? Site 1 : COP = 1.1 at 0 ºF Site 4 : COP = 1.8 at 0 ºF

14 Low ambient air-to-water heat pump yields good performance at low ambient temperatures: At ambient = 0 ºF, and leaving 120 ºF, COP =2.04

15 Low ambient air-to-water heat pump performance COP = 2.04 at 0 ºF ambient and 120 ºF leaving water temperature. Heat pump heat output: 40,500 Btu/hr Heat pump power: 5817 watts COP HP+circulator = 40,500 Btu hr 3413 Btu = kw hr kw ( ) Higher than the measured COP of several ductless mini split heat 0 ºF ambient. Heat pump circulator: power: 200 watts Distribution circulator power: 25 watts Total power to system: 6042 watts

16 The energy source for net zero houses is electricity resistance heating (electric boiler) off-peak electric resistance w/ thermal storage air-to-water heat pump geothermal water-to-water heat pump (????) time-of-use! electric! meter 3-way! motorized! mixing! valve electric! boiler low temperature! distribution system storage! tank

17 Minnesota low load house (w/ electric boiler) Combined floor heating and panel rads Stained concrete floors Double stud wall construction 6KW (20,500 Btu/hr) electric boiler Wood stove (aux heat) source: Wagner Zaun Architecture TRV DiaNorm panel radiator 24"H x 36" W (model 22) BEDROOM 2 floor heating thermostat T2 48" sill 48" sill WOOD Circuit 1: 86+10=96' ENTRY T1 ELEC. BOILER MECH panel radiator master thermostat W/D W/H HRV floor heating manifold P/T station TRV DiaNorm panel radiator 24"H x 36" W (model 22) DiaNorm panel radiator 24"H x 24" W (model 22) BEDROOM 1 LIVING 12" tube spacing DINING wood stove 12" tube spacing 12" tube spacing KITCHEN Circuit 2: =168' Circuit 3: =180' Circuit 4: =139'

18 Minnesota low load house (w/ electric boiler) ISSUE: The floor slab will try to pull down the system water temperature - too low for panel radiators to function properly. SOLUTION: The Taco iseries motorized mixing valve senses water temperature upstream of panel, and modulates hot water to floor heat so that panel rads have 120 ºF water temperature available whenever they operate. TRV even though it's installed on the supply side, this is what the Taco instructions will refer to as the boiler inlet or boiler return sensor TRV TRV closely spaced tees 12D (P2) circulator w/ check valve closely spaced tees 30 psi PRV supplied with boiler Thermolec 6KW electric boiler (P1) 0-30 psi gauge reset line of Taco iseries valve (reset ratio setting =0.46) 130 purge valve Supply water temperature (ºF) Outdoor temperature (ºF) ºF outdoor temperature sensor 12D (P3) floor circuits Taco 3/4" iseries (reset) 3-way mixing valve (turn DIP switch 3 to ON for 120 ºF min)

19 If it s not net zero other energy sources are possible Natural Gas or Propane: low mass mod/con boiler with buffer tank high mass mod/con boiler - self buffering domestic water heaters - not recommended mod/con boiler! (low mass) air! separator thermostat flow-check purging! valve circulator PRV (30 psi) make up water P & T! relief! valve expansion! tank temperature! sensor to / from! heating load heat emitter(s) buffer tank water heater

20 What about fuel oil? It s possible, but a very hard sell based on volatile pricing, local fuel availability, fuel storage, venting, efficiency, public perception of oil. Smallest oil boilers (0.5 GPH nozzle) are about 60,000 Btu/hr output. A significant buffer tank will be needed to prevent short cycling. temperature! sensor to / from! heating load anti-condensation! 3-way! thermostatic! mixing valve oil-fired boiler buffer tank

21 Small hydronic wood stove - European thermostatic operator air vent w/ or w/o aux heat source air vent towel warmer radiator Space heat and DHW mod/con boiler dual isolation valve TRV aquastat! (close at 135 ºF)! (open at 125 ºF) (AQ1) 120 VAC PRV (T1) master! thermostat (S0) (UPS) (P1) swing! check! valve (P3) outdoor! temperature! sensor (S3) PEX, or! PEX-AL-PEX tubing hydronic! wood stove (P2) (S1) (P4) relay thermal! trap (HX1) (MV1) DHW (P5) (S4) manifold station (FS1) make up water thermal storage tank Tonwerk Wallnofer

22 The European approach for small loads... Combined space heating & DHW from single appliance. panel radiator TRV APPLIANCE! for space heating! and DHW ACV Rotex DHW cold

23 Combined space heating & DHW appliances from Europe Do you notice anything in common among these products? None of them look like a boiler or water heater... They all look like an appliance. They all have sufficient water volume to stabilize against short cycling the burner under light loading. This is what some North American systems look like.

24 What about geothermal heat pumps & hydronics in low energy houses?

25 Diminishing returns of higher COPs As home heating loads decrease due to better thermal envelopes, the difference in annual heating cost between heat pumps operating at seasonal average COPs that vary by perhaps 1.0 or less, decreases. Example house: 36,000 BTU/hr design load at 70ºF inside & 0 ºF outside Location: Syracuse, NY (6720 heating degree days) Total estimated heating energy required: 49.7 MMBTU / season Average cost of electricity: $0.13/kwhr Distribution system: radiant panels with design load supply temperature = 110ºF AIR-TO-WATER HEAT PUMP OPTION Based on simulation software, a nominal 4.5 ton split system air-to-water heat pump supplying this load has a seasonal COP = 2.8. Estimated installed cost = $10,600 (not including distribution system) GEOTHERMAL WATER-TO-WATER HEAT PUMP OPTION: Based on simulation using simulation software, a nominal 3 ton water to water heat pump supplying this load from a vertical earth loop has a seasonal COP = Estimated installed cost = $11,800 (earth loop) + $8750 (balance of system) = $20,550 (not including distribution system) Deduct for 30% federal tax credit: ($ -6165) Net installed cost: $14,385 (not including distribution system) Annual space heating cost: AIR-TO-WATER HEAT PUMP (COPave= 2.8) = $676 / yr GEOTHERMAL HEAT PUMP (COPave = 3.28) = $578 / yr Difference in annual heating cost: $98 / year Difference in net installed cost: $3,785 Simple payback on higher cost of geothermal HP: 3785 / years Without any subsidies the estimated difference in installed cost is $9,950 Initial difference in annual heating cost: $98 / year Draw your own conclusions.

26 Air-to-water heat pumps

27 Self-contained air-to-water heat pumps OUTSIDE INSIDE warmer climate application (water in outside unit) image courtesy of SpacePak OUTSIDE INSIDE Heating + cooling + DHW Pre-charged refrigeration system 2-stage operation for better load matching No interior space required No interior noise colder climate application (antifreeze in outside unit) antifreeze! protected! circuit to / from! load heat! exchanger

28 Split system air-to-water heat pump Heating mode: 1. condenser 2. circulator 3. expansion tank 4. aux element 5. controls Indoor unit Cooling mode: 1. evaporator 2. circulator 3. expansion tank 4. controls! outdoor unit OUTSIDE INSIDE! indoor unit image courtesy of Daikin Outdoor unit Heating mode: 1. compressor 2. evaporator 3. expansion device Cooling mode: 1. compressor 2. condenser 3. expansion device refrigerant! piping

29 Split system air-to-water heat pump Nordic air-to-water heat pump INDOOR UNIT compressor refrigerant-to-water heat exchanger reversing valve controls desuperheater (for DHW) OUTDOOR UNIT (major components) air-to-refrigerant heat exchanger fan

30 Bring your own condenser... ThermAtlantic Energy Products, Inc.

31 Bring your own condenser... Heating mode absorbed! (low temperature)! heat Heat pump routes heat to buffer tank Heat delivered from buffer tank to low temperature load air source heat pump! outdoor unit ON chilled water air handler OFF OFF controls manifold valve actuators zone! thermostats ON buffer tank open ON DX2W module electric! boiler ON! (supplemental)! zoned radiant! ceiling panels closed temperature sensor open

32 Bring your own condenser... Cooling mode Heat pump chills buffer tank rejected! heat Chilled water delivered to air handler for latent cooling, & mixing chilled water to radiant panels for sensible cooling air source heat pump! outdoor unit ON chilled water air handler ON ON zone! thermostats controls manifold valve actuators ON ON DX2W module electric! boiler OFF zoned radiant! ceiling panels (cooling mode operation) buffer tank partially! open partially! open mixed

33 33

34 Global air-to-water heat pump market: According to JARN (Aug 2015) 2014 global market: 1,745,000 air to water heat pumps sold (over 2 million in 2016) Japanese manufacturers [Daikin, Mitsubishi, Fujitsu, Hitachi, Samsung, LG, Toshiba] German manufacturers [Dimplex, Wolf, Viessmanm, Bosch,Vaillant] Canadian manufacturers [ThermAtlantic, Nordic] About 70% are split systems versus monobloc (self-contained). Performance of split versus monobloc systems is about the same 2014 China market : 987,000 units (12% increase over 2013) 2014 European market: 232,000 units (5% increase over 2013) #1 France, #2 Germany, #3 UK Still only about 2% of heat sources sold in Europe Due to low gas and oil prices, AWHP are subsided in Europe based on CO2 reduction targets, rather than energy efficiency. Many current models use inverter drive variable speed compressors for capacity control. Some use EVI (enhanced vapor injection) compressors.

35 LOW-AMBIENT Air-to-Water Heat Pump Systems

36 evaporator Standard refrigeration cycle outside! air fan! compressor outside! air condensor water out outside! air evaporator fan outside! air (main) TXV! thermal expansion valve water in EVI allows increased refrigerant mass flow into evaporator, & at lower entering temperatures. EVI enabled! compressor vapor injection port electronic expansion valve condensor water out water in EVI refrigeration cycle (main) TXV! thermal expansion valve refrigerant! "sub-cooler" sub cooled! liquid refrigerant solenoid valve

37 My own installation... February 2015 Upstate NY -23 ºF air temperature -29 ºF wind chill LAHP

38 Design objectives: 1. Be able to serve as heat source for building with 18,000 Btu/hr design load (via radiant floor heating). 2. Retain oil-fired boiler and allow simple manual selection of heat source. (flip of switch) 3. Provide zoned chilled water cooling for 1st floor office, and 2nd floor guest room. 4. Be equipped for BTU metering of energy from heat pump & KWHR meter of electrical energy to heat pump (to calculated COP, and EER)

39 Supporting the heat pump Treated lumber pedestal to keep unit above snow level Added 2 threaded rods w/ base flanges to stiffen pedestal

40 Piping details to keep condensate out of wall framing 1 FPT copper adapter 2 PVC sleeve wrap with electrical tape for tight fit 1 Chamflex hoses with offset to allow small movement foam sealant inside

41 high wall fan coil 1/2 FPT to propex adapter 1/2 MPT lines on air handler end of condensate drain hose HW-18-ECM 2.1 gpm flowrate) Heat ouput (Btu/hr) condensate drain direct through outside wall Entering water temperature (ºF)

42 Importance of low temperature distribution systems

43 Low temperature / low mass hydronic heat emitters

44 FUTURE PROOF your hydronic systems... Select heat emitters, and design hydronic distribution systems so that they can supply design load output using supply water temperatures no higher than 120 ºF. Even lower design load supply temperatures are preferred when possible. This is especially important when renewable energy heat sources are used.

45 Don t do this with ANY hydronic heat source! Heat transfer between the water and the upper floor surface is severely restricted!

46 Hydronic heat emitters options for low energy use houses Most CONVENTIONAL fin-tube baseboard has been sized around boiler temperatures of 160 to 200 ºF. Much too high for good thermal performance of low temperature hydronic heat sources. Could add fin-tube length based on lower water temperatures. BUT... Fin-tube output at 120 ºF is only about 30% of its output at 200ºF

47 Hydronic heat emitters options for low energy use houses Some low- temperature baseboard is now available

48 Panel Radiators Low water content and relatively light - fast responding Some can be fitted with thermostatic radiator valves for room-by-room zoning (WITHOUT ELECTRICAL CONTROLS) Some are thermal art - but bring your VISA card...

49 Hydronic heat emitters options for low energy use houses Panel Radiators One of the fastest responding hydronic heat emitters From setback to almost steady state in 4 minutes

50 Hydronic heat emitters options for low energy use houses Panel Radiators Adjust heat output for operation at lower water temperatures. As an approximation, a panel radiator operating with an average water temperature of 110 ºF in a room room maintained at 68 ºF, provides approximately 27 percent of the heat output it yields at an average water temperature of 180 ºF.

51 Adding low wattage fans to a low water content panel can boost heat output 50% during normal comfort mode, and over 200% during recovery from setback conditions At full speed these fans require about 1.5 watts each 30dB (virtually undetectable sound level) Allow supply temperatures as low as 95 ºF

52 Styles of panel radiators Ultra Low-Mass Panel Radiators Image courtesy of JAGA North America Microfan power consumption: (3 fans in group) 1. OFF: 1 watt (power supply) 2. Fans at normal comfort setting: 4 watts 3. Fans in boost mode: 5 watts

53 Fan-assisted Panel Radiators The NEO, just released from Runtal North America 8 tube high x 31.5 wide produces 2095 Btu/hr at average water temperature of 104 ºF in 68ºF room 8 tube high x 59 wide produces 5732 Btu/hr at average water temperature of 104 ºF in 68ºF room

54 Site built radiant CEILINGS Thermal image of radiant ceiling in operation Where: Heat output formula: q = 0.71 (T water T room ) Q = heat output of ceiling (Btu/hr/ft 2 ) Twater = average water temperature in panel (ºF) Troom = room air temperature (ºF)

55 Site built radiant WALLS

56 Site built radiant WALLS completely out of sight low mass -fast response reasonable output at low water temperatures stronger than conventional drywall over studs don t block with furniture Heat output formula: q = 0.8 (T water T room ) Where: Q = heat output of wall (Btu/hr/ft 2 ) Twater = average water temperature in panel (ºF) Troom = room air temperature (ºF)

57 System Examples

58 System using low mass mod/con boiler, buffer tank, and homerun distribution system The small insulated tank provides: Thermal buffering Hydraulic separation Air separation and collection Sediment separation and collection outdoor! temperatue! sensor TRV thermostatic! radiator valves! (TRV) on each! radiator TRV TRV TRV TRV TRV variable speed! pressure-regulated! circulator manifold! station indirect water heater buffer tank, also serves as hydraulic separator,! air separator, dirt separator Homerun distribution system to panel radiators Non-electric actuators on each panel radiator ECM-based pressure regulated circulator Buffer tank for zoned distribution system indirect tank for domestic water heating

59 What are the differences? outdoor! temperatue! sensor TRV thermostatic! radiator valves! (TRV) on each! radiator TRV TRV TRV TRV TRV variable speed! pressure-regulated! circulator manifold! station panel radiator TRV indirect water heater buffer tank, also serves as hydraulic separator,! air separator, dirt separator APPLIANCE! for space heating! and DHW Eliminate the DHW tank circulator. Pre-assembly versus on-site assembly. Single thermal mass component to stabilize both space heating and DHW delivery. DHW cold

60 System using high mass mod/con boiler and homerun distribution system panel radiator TRV thermostatic radiator valves! on each panel radiator TRV TRV TRV TRV TRV stainless steel! DHW heat exchanger ASSE 1017! anti scald! mixing valve hot water cold water domestic water! flow switch condensing! internal heat! exchanger 1/2" PEX or PEX-AL-PEX tubing pressure-regulated! variable speed circulator manifold station "high mass" mod/con! heat source purging! valve Homerun distribution system to panel radiators Non-electric actuators on each panel radiator ECM-based pressure regulated circulator Self buffering heat source Instantaneous water heating

61 Systems for a low energy Duplex in Ithaca, NY These systems are being installed in early 2012 as part of a DOE Building America research program coordinated through Steven Winter Associates. Design heating load on each side of duplex is about 18,000 Btu/hr

62 Systems for a low energy Duplex in Ithaca, NY Ithaca duplex, Side B, baseboard lengths based on 140 ºF supply water temperature at design load. 6 ft 5 ft 7 ft U-bend this end KITCHEN-B BEDROOM -2B BEDROOM -3B supply return supply return 1/2" PEX-AL-PEX (typical) DINING ROOM-B 5 ft LUX TX500E! thermostat TB2 U-bend LUX TX500E! thermostat TB1 this end BATH -B 3 ft LIVING ROOM-B 7 ft BEDROOM -1B 1/2" PEX-AL-PEX (typical) 5 ft U-bend this end 6 ft first floor second floor These BB lengths determined based on 140 ºF supply / 125 ºF return at design loads! 1 gpm flow in each circuit.! Series baseboard piping total baseboard:! first floor: 23 ft! second floor: 21 ft! TOTAL: 44 ft.

63 Systems for a low energy Duplex in Ithaca, NY (TS12) temperature sensor SECOND FLOOR BASEBOARD CIRCUIT baseboards shown piped with parallel connection of internal piping temperature sensor (TS13) BATH-A BEDROOM 1A BEDROOM 2A end manifolds supplied! by Emerson Swan with! 1/8" FPT connection at top! (typ. all locations on circuit) 3/4" copper to 1/2" PEX-AL-PEX! adapter Uponor (D ) 3 ft. H.E. baseboard 7 ft. H.E. baseboard 7 ft. H.E. baseboard 1/2" PEX-AL-PEX 1/2" PEX-AL-PEX FIRST FLOOR BASEBOARD CIRCUIT baseboards shown piped with series connection of internal piping temperature sensor KITCHEN-A LIVING ROOM-A DINING ROOM-A (TS10) (TS11) temperature sensor 7 ft. H.E. baseboard 11 ft. H.E. baseboard 5 ft. H.E. baseboard 1/2" PEX-AL-PEX 30 psi PRV supplied with Versa Hydro Unit. Pipe output to within 6" of floor drain 1/2" PEX-AL-PEX Caleffi Z54 3/4" CxC 4-wire zone valves 1/2" PEX-AL-PEX 1/2" PEX-AL-PEX internal (DHW) temperature reset line of distribution system Supply water temperature (ºF) set minimum supply! temperature to 100ºF! to expedite recovery! from setback Outdoor temperature (ºF) WATER TEMPERATURE! CONTROL FOR VERSA! HYDRO HEAT SOURCE temperature sensor cold water DHW temperature sensor temperature sensor (TS3) 3/4" baseboard tee (TS2) 3/4" copper (TS1) 3/4" copper Caleffi! ASSE 1017 listed! anti-scald! thermostatic valve! (max setting = 120ºF)! (install min. 3ft below! top of tank) gas meter W1 watt sensor 12D flow meter 12D (FM1) P&TRV 2" CPVC or polypropylene venting If CPVC venting is used recommend use of 2" KGAVT0501CVT concentric venting kit from HTP, Inc. HTP! Versa Hydro! Hydronic! Heating! Appliance Caleffi 1" Discal air separator Webstone! purge! valve 1" copper Extrol #30 expansion tank 12D 0-30 psi gauge outdoor! temperature! sensor temperature sensor Grundfos Alpha D 3/4" copper (TS4) (P1) flow meter (FM2) watt sensor W2 1" copper 1/2" copper make-up water this module is part of Versa Hydro unit 12D 3/4" copper cap 1" copper flow meter Caleffi A 1/2" feed valve! (FM3) 3/4" copper Webstone! purge! valve 12D (FM3) 12D 3/4" copper temperature sensor (TS5) 3/4" copper for 12 pipe diamters on! both sides of flow meter 12D 12D (FM4) flow meter temperature sensor temperature sensor (TS9) temperature sensor temperature sensor (TS8) (TS6) (TS7) 3/4" copper floor drain

64 Reverse indirect tank buffers space heating & significantly preheats domestic water (ZP1) (T1) Source: Turbomax tanks entire system filled with antifreeze solution OUTSIDE INSIDE (ZP2) (T2) point-of-use instantaneous water heater SPACEPAK (MV1) (S2) (SPC) (S1) ASSE 1070 valve DHW CW (P1) Solstice Extreme air-to-water heat pump (HP) flexible connectors reverse indirect water heater / buffer tank

65 Reverse indirect tank buffers space heating & significantly preheats domestic water DESCRIPTION OF OPERATION: (ZP1) (T1) Power supply: The Solstice heat pump, circulator (P1), and motorized valve (MV1) are powered by a dedicated 240/120 VAC 30 amp circuit. The heat pump entire system filled with antifreeze solution (ZP2) (T2) disconnect switch (HPDS) must be closed to provide power. The remainder of the control system is powered by 120 VAC 15 amp circuit. The main switch (MS) must be closed to provide power. The instantaneous water heater is supplied by OUTSIDE INSIDE a dedicated 240 VAC / 60 amp circuit. point-of-use instantaneous water heater Heat pump operation: Whenever the main switch (MS) is closed 120 VAC is passed to the multi-zone relay center (MZRC). The (MZRC) passes 24 VAC to SPACEPAK (S2) (MV1) (SPC) (S1) ASSE 1070 valve DHW CW the temperature setpoint controller (SPC) which monitor the temperature at sensor (S1) in the buffer tank. If the temperature at sensor (S1) is below 105 ºF, the (SPC) closes its contact, which completes a circuit between terminals 15 and 16 in the Solstice Extreme heat pump, enabling it to operate in heating mode. After a short time delay, circulator (P1) and motorized valve (MV1) will be (P1) supplied with 120 VAC from the heat pump. This establishes flow of the system s Solstice Extreme air-to-water heat pump (HP) flexible connectors reverse indirect water heater / buffer tank antifreeze solution through the heat pump. The heat pump verifies adequate flow using its internal flow switch, and when adequate flow is proven, starts the heat pump in heating mode. The 120 VAC supplied to (MV1) opens the valve 240 VAC 60 amp circuit instantaneous water heater heat pump disconnect switch (HPDS) (P1) (MV1) 240/120 VAC 30 amp circuit L1 L N L2 N Solstice Extreme heat pump (HP) (SPC) R C L1 (S1) sensor main switch (MS) 120 VAC / 15amp circuit (T1) (T2) (MZRC) (ZP1) (ZP2) N G allowing flow between the heat pump and the headers of the thermal storage tank. The system continues in this mode until the temperature at sensor (S1) reaches 125ºF, at which point the contacts in the setpoint controller (SPC) open turning off the heat pump, circulator (P1) and motorized valve (MV1). Space heating: Whenever the main switch (MS) is closed, 24 VAC is sent to thermostats (T1, T2). When either thermostat calls for heating its associated zone circulator (ZP1, ZP2) is turned on. Domestic water heating: Domestic water passes through the copper tubing coils suspended in the buffer tank. The tank temperature at sensor (S1) is maintained between 105 and 125 ºF. Domestic water passing through the coil will be preheated (or at time fully heated) as it passes through this coil. Any additional temperature rise of the domestic water is provided by the tankless electric water heater.

66 Cold climate air-to-water heat pump system 2 zones of radiant panel heating 2 zones of chilled water cooling 80 gallon buffer tank High efficiency variable speed distribution circulator Direct-to-load supply side piping (ZVH1) (ZVC1) OFF radiant panel mainfold station 1 (AH1) OFF radiant panel mainfold station 2 (ZVH2) (AH2) OFF HEATING MODE All piping and components conveying chilled water must be insulated and vapor sealed entire system filled with propylene glycol antifreeze solution OUTSIDE INSIDE (ZVC2) OFF (P2) SPACEPAK spring check valve (S1) (S3) temperature sensors (ORC) (SPC) (S2) outdoor temperature sensor Solstice Extreme air-to-water heat pump (HP) flexible connectors (P1) heated buffer tank

67 Cold climate air-to-water heat pump 2 zones of radiant panel heating 2 zones of chilled water cooling 80 gallon buffer tank High efficiency variable speed distribution circulator Direct-to-load supply side piping OFF (ZVH1) (ZVC1) (ZVH2) OFF (AH1) (AH2) COOLING MODE All piping and components conveying chilled water must be insulated and vapor sealed entire system filled with propylene glycol antifreeze solution OUTSIDE INSIDE (ZVC2) (P2) SPACEPAK spring check valve (ORC) (S2) (S1) (S3) temperature sensors (SPC) Solstice Extreme air-to-water heat pump (HP) flexible connectors (P1) heated buffer tank

68 Cold climate air-to-water heat pump system (AH1) (AH2) L1 L2 G R G L1 L2 G R G service switch (RC-1) service switch (RC-2) 240 VAC 15 amp circuit L1 L2 G 240/120 VAC 30 amp circuit L1 L2 N heat pump disconnect switch (HPDS) (P1) L1 L2 L N Solstice Extreme heat pump G (R2-3) heat (R1-2) (R2-2) L1 off cool main switch (MS) (R1-1) (R2-1) (MSS) Mode selection switch W Y 120 VAC / 15amp circuit RC RH G thermostat (T1) W Y RC RH G thermostat (T2) 24 VAC (ZVH1) M M (ZVC1) (ZVH2) M M (ZVC2) (P2) transformer 120/24 VAC (ORC) R R C (SPC) C (RC) (R1) (R2) (S1) (S2) sensors (S3) sensor N G Description of operation: Power supply: The Solstice Extreme heat pump and circulator (P1) are powered by a dedicated 240/120 VAC 30 amp circuit. The heat pump disconnect switch (HPDS) must be closed to provide power to the heat pump. The remainder of the control system is powered by 120 VAC / 15 amp circuit. The main switch (MS) must be closed to provide power to the control system. Both fan coils are powered by a dedicated 120 VAC / 15 amp circuit. The service switch for each air handler must be closed for that air handler to operate. Heating mode: The mode selection switch (MSS) must be set for heating. This passes 24 VAC to the RH terminal in each thermostat. Whenever either thermostat demands heat, 24VAC is passed from the thermostat s W terminal to the associated zone valve (ZVH1, or ZVH2). When the zone valve reaches its fully open position its internal end switch closes, passing 24 VAC to relay coil (R1). Relay contact (R1-1) closes to pass 120 VAC to circulator (P2). Relay contact (R1-2) closes to pass 24VAC to outdoor reset controller (ODR). The (ODR) measures outdoor temperature at sensor (S2), and uses this temperature along with it settings to calculate the target supply water temperature for the buffer tank. It then measures the temperature of the buffer tank at sensor (S1). If the temperature at (S1) is more than 3 ºF below the target temperature the (ODR) closes its relay contact. This completes a circuit between terminals 15 and 16 in the Solstice extreme heat pump, enabling it in heating mode. After a short time delay the heat pump (HP) turns on circulator (P1) and verifies adequate flow through the heat pump. After a short time delay the heat pump compressor turns on it compressor. The heat pump continues to operate until the temperature at sensor (S1) is 3 ºF above the target temperature calculated by the (ODR), or neither thermostat calls for heat, or the heat pump reaches it internal high limit setting. Note: Neither air handler operates in heating mode, regardless of the fan switch setting on the thermostats. Cooling mode: The mode selection switch (MSS) must be set for cooling. This passes 24VAC to relay coil (RC). normally open contacts (RC-1) and (RC-2) close allowing 24VAC from the air handlers to pass to the RC terminal in each thermostat. Whenever either thermostat calls for cooling, 24VAC is passed from the thermostat s Y terminal to the associated zone valve (ZVC1, or ZVC2). When the zone valve reaches its fully open position its internal end switch closes, passing 24 VAC to relay coil (R2). Relay contact (R2-1) closes to pass 120 VAC to circulator (P2). Relay contact (R2-2) closes to pass 24VAC to the cooling setpoint controller (SPC). The cooling setpoint controller measures the temperature of the buffer tank at sensor (S3). If this temperature is 60 ºF or higher, the (SPC) relay contact closes completing a circuit between terminals 15 and 16 on the Solstice Extreme heat pump (HP) enabling it to operate. Relay contact (R2-3) closes between terminals 17 and 18 in the Solstice Extreme heat pump (HP), switching it to cooling mode. The heat pump (HP) turns on circulator (P1) and verifies adequate flow through the heat pump. After a short time delay the heat pump compressor turns on it compressor and operates in chiller mode. This continues until the temperature at sensor (S3) drops to 45 ºF, or until neither zone thermostat calls for cooling, or until the heat pump reaches in internal low limit setting. The blowers in the air handlers can be manually turned on at the thermostats when the mode selection switch (MSS) is set to cooling. The blowers will operate automatically whenever either cooling zone is active.

69 Heating + Cooling +DHW towel warmer radiator air vent thermostatic operator Self-contained (2-stage) air-to-water heat pump w/ mod/con auxiliary boiler TRV dual isolation valve air vent Single thermal mass tank mod/con boiler Supplies: zoned space heating single zone cooling domestic hot water automatic aux boiler 2 stage or inverter drive heat pump very important to avoid short cycling in cooling mode. Solstice SE air to water heat pump PEX, or PEX-AL-PEX tubing OUTSIDE manifold station Entire system filled with propylene glycol antifreeze solution. INSIDE (P1) diverter valve AB variable speed circulator (P2) N.C. A B N.O. (DV1) spring-loaded check valves temp. sensor buffer tank (S1) (AH1) (P3) single zone air handler (S2) for cooling 2-stage temperature setpoint controller (SPH) (HX) (P4) (FS1) isolation and flushing valves for potable side of HX P&T DHW

70 Heating + Cooling +DHW towel warmer radiator air vent thermostatic operator air vent L1 240 VAC L2 N Electrical Wiring L1 main switch (MS) 120 VAC N TRV dual isolation valve (P1) L N (HP) Solstice SE heat pump (RH2-1) (P2) mod/con boiler (Rdhw-1) (P4) PEX, or PEX-AL-PEX tubing variable speed circulator (P2) 2-stage temperature setpoint controller (SPH) (RH1-2) (RB-1) (AH1) manifold station temp. sensor (S1) (P3) (HX) (FS1) isolation and flushing valves for potable side of HX P&T DHW (RH1-1) mod/con boiler (B1) (P3) 24 VAC T T transformer 120/24 VAC (Rdhw) OUTSIDE INSIDE (P1) diverter valve AB N.C. A B N.O. (DV1) spring-loaded check valves buffer tank (P4) Mode selection switch (MSS) heat off cool (S1) sensor off cool (FS1) R C stage 1 stage 2 (SPH) 2-stage setpoint controller (RH1) (DV1) Solstice SE air to water heat pump (AH1) single zone air handler (S2) for cooling (T1) W G Y master thermostat RC RH (SPC) (RH2) (RB) R C (S2) sensor

71 Heating + Cooling +DHW L1 240 VAC L2 N Electrical Wiring L1 main switch (MS) 120 VAC N (P1) L N (HP) Solstice SE heat pump (RH2-1) (P2) (Rdhw-1) (P4) (SPH) Tekmar stage setpoint controller (SPC) Tekmar stage setpoint controller (RH1-1) (RH1-2) (RB-1) mod/con boiler (B1) (AH1) T T (P3) Possible controller settings: 2-stage temperature setpoint controller (SPH) (used for heating mode only) stage 1 contacts close at 120 ºF, and open at 130 ºF (e.g., 125 ºF setpoint with 10 ºF differential centered on setpoint) stage 2 contacts close at 116 ºF, and open at 130 ºF (e.g., 123 ºF setpoint with 7 ºF differential centered on setpoint) Mode selection switch (MSS) heat off cool (S1) sensor off cool (FS1) R 24 VAC C stage 1 stage 2 transformer 120/24 VAC (Rdhw) (SPH) 2-stage setpoint controller (RH1) (DV1) 1 stage temperature setpoint controller (SPC) used for cooling mode only) contacts close at 60 ºF, and open at 40 ºF (e.g., 50 ºF setpoint with 20 ºF differential centered on setpoint (T1) W G Y master thermostat RC RH (SPC) (RH2) (RB) R C (S2) sensor

72 Heating + Cooling +DHW Description of Operation Please read this later in the PDF Heat Source Operation: When the main switch (MS) is closed, power is available to the line voltage and low voltage portions of the electrical system. 24VAC is applied to power up the 2-stage setpoint controller (SPH). This controller (SPH) measures the temperature at sensor (S1) in the upper portion of the thermal storage tank. If that temperature is below the user-set stage1 setpoint (in this case 125 ºF), minus half the user-set differential (in this case half the differential is 5 ºF), then the stage 1 contacts in (SPH) close. For space heating operation, the (DPDT) mode selection switch must be set to heat. This passes 24VAC to the RH terminal of the master thermostat (T1). It also allows 24 VAC to pass from the stage 1 contacts in the (SPH) controller to energize the diverter valve (DV1) and relay coil (RH1). Relay contact (RH1-1) closes between terminal 43 and 44 on the Solstice SE heat pump turning it on in the heating mode. Relay contact (RH1-2) opens between terminals 5 and 6 on the Solstice SE heat pump allowing it to operate in heating mode. An internal relay within the heat pump turns on circulator (P1). Heat from the heat pump flows to the upper header of the buffer tank. The heat pump and these associated devices continue to operate as described until sensor (S1)in the buffer tank climbs to a temperature of 130 ºF, or if the master thermostat (T1) stops calling for heat. If, during a call for space heating from master thermostat (T1), the temperature at sensor (S1) in the upper portion of the buffer tank drops to 115 ºF, the stage 2 contacts in the setpoint controller (SPH) will close. These contacts complete a low voltage circuit powered through the boiler, and enable the boiler to operate in a fixed upper temperature mode. The boiler turns on circulator (P3) through an internal relay. The boiler continues to operate until the buffer tank sensor (S1) reaches a temperature of (130 ºF), at which point the boiler turns off, and so does circulator (P3). Note: The boiler will operate in this mode regardless of whether the mode selection switch is set to heat or cool. This allows the boiler to maintain a suitable temperature in the buffer tank for domestic water heating even when the heat pump is operating as a chiller. Space Heating Distribution: When master thermostat (T1) calls for heat, 24VAC passes from its W terminal to energize the coil of relay (RH2). Contact (RH2-1) closes to pass 120 VAC to circulator (P2). This circulator is set to operate in constant differential pressure mode to provide the necessary flow to any panel radiator that does not have its thermostatic valve fully closed. Circulator (P2) will automatically vary its speed to maintain approximately constant differential pressure across the manifold station serving the panel radiators. The thermostatic valves on each radiator can be used to limit heat input as desired. Domestic Water Heating Mode: Whenever there is a demand for domestic hot water of 0.6 gpm or more, flow switch (FS1) closes. This passes 24VAC to energize the coil of relay (Rdhw). Contact (Rdhw-1) closes to pass 120 VAC to circulator (P4). Heated antifreeze solution flows from the upper portion of the buffer tank will flow through the primary side of heat exchanger (HX), and transfer heat to the cold domestic water flow through the secondary side of the heat exchanger (HX). When the demand for domestic hot water drops to 0.4 gpm or less, flow switch (FS1) opens. This turns off relay (Rdhw) and circulator (P4). All domestic hot water leaving the system passes through a thermostatic mixing valve to limit the water temperature to the distribution system. Cooling Mode: For cooling operation the mode selection switch (MSS) must be set to cool. This passes 24 VAC to the RC terminal of the master thermostat. If the master thermostat is set for cooling operation, and calls for cooling, 24VAC is passed to its Y terminal. From the Y terminal, 24VAC passes to energize the coil of relay (RB). A normally open set of contacts (RB-1) close to pass 120 VAC to the air handler (AH1) turning it on. 24VAC also passes from the Y terminal of the master thermostat to energize cooling setpoint controller (SPC). Once energized, (SPC) monitors the temperature of sensor (S2) on the inlet pipe to the air handler. If that temperature is above 60 ºF the contacts in (SPC) close. This completes a circuit between terminals 43 and 44 in the Solstice SE heat pump, turning it on in cooling mode. The heat pump turns on circulator (P1) through its internal relay. All necessary devices for cooling operation are now active. The system remains in cooling operation until either the cooling demand is removed at thermostat (T1), or the temperature at sensor (S2) on the air handler inlet drops to 40 ºF, at which point the heat pump, circulator (P1), and air handler (AH1) turn off.

73 Small hydronic wood stove application air vent thermostatic operator air vent towel warmer radiator mod/con boiler dual isolation valve TRV aquastat! (close at 135 ºF)! (open at 125 ºF) (AQ1) 120 VAC PRV (T1) master! thermostat (S0) (UPS) (P1) swing! check! valve (P3) outdoor! temperature! sensor (S3) PEX, or! PEX-AL-PEX tubing hydronic! wood stove (P2) (S1) (P4) relay thermal! trap (HX1) (MV1) DHW (P5) (S4) manifold station (FS1) make up water thermal storage tank Tonwerk

74 Small hydronic wood stove application mod/con boiler air vent thermostatic operator dual isolation valve towel warmer radiator air vent TRV L1 main! switch (MS) (R2-1) 120 VAC N DHW! circulator aquastat! (close at 135 ºF)! (open at 125 ºF) (AQ1) 120 VAC PRV (T1) master! thermostat recepticle (P4) hydronic! wood stove (S0) (UPS) (P1) swing! check! valve (P2) (S1) (P3) (P4) relay outdoor! temperature! sensor (S3) thermal! trap PEX, or! PEX-AL-PEX tubing (UPS) (AQ1) (P2) (S0) (P1) boiler loop! circulator variable speed! setpoint circulator (HX1) (FS1) (MV1) DHW (P5) make up water (S4) manifold station (R1-1) distribution! circulator thermal storage tank (P5) service! switch boiler (S1) (P3) auxiliary! boiler auxiliary! boiler! circulator transformer 120/24 VAC 24 VAC (FS1) R2 (T1) relay coil Tonwerk Spartherm master! thermostat (S3) (S4) sensors R1 (MV1) mixing! valve

75 Hydronic Heating for Low Energy Houses Summary: Energy conservation comes first Design around low supply water temperatures (120 ºF max for renewable heat sources) Use low mass heat emitters for fast response Radiant ceilings better choice than radiant floors Use homerun distribution system whenever possible Use ECM-based high efficiency circulators Provide thermal mass (buffer) to stabilize combustion heat sources against small zone load Integrate solar for DHW plus combisystems (drainback systems preferred) If system has thermal mass use external HX for instantaneous domestic water heating Evaluate service charge for gas meter on low load and net zero houses. (saving may not justify meter cost) If cooling will be needed, heat pump is a good choice Consider air-to-water heat pump against cost of geothermal heat pump Net zero houses will always have solar PV, so electric based heating is preferred. Keep system as simple as possible

76 Parting Thoughts Keep it neat...

77 Parting Thoughts Plan your tubing layouts...

78 Parting thoughts Don t get hung up...

79 Thanks for attending today s session Thanks also for today s sponsor recently released! 864 pages, full color textbook Please visit our website for more information Coming in 2018