Mestek VERTICAL STEAM HOT WATER HEATERS Instrukcja Użytkownika

Understanding Hydronic SystemsMestek Institute, June 16, 2014© Copyright 2014, J. Siegenthaler, all rights reserved. The contents of this file sha

common piping and !heat source have!HIGH FLOW RESISTANCEONONlarger circulatorsmaller circulatorP=22 psibackseated!flow checkP=17psicommon piping and !h

70758085909510010511070 60 50 40 30 20 10 0 -10supply water temperature (ºF) Outdoor temperature (ºF) reset linedesign load conditionno load condition

Determine the size of a buffer tank that will absorb 48,000 Btu/hr from the heat pump while increasing in temperature from 90 ºF to 110 ºF, during a h

image courtesy of Mestek• Provide adequate space for air flow• Respect prevailing winds• In snowy climates, elevated above snow lineimage courtesy of R

• Provide adequate space for air flow• Minimize air flow interaction b/w adjacent HPsMultiple (staged) AWHPverticalrackmounting in alcove

Multiple (staged) AWHPStaged AWHP heat pumps for 20,000 square foot house.image courtesy of Foley Mechanical

Heat emitters for AWHP systems• They should operate at low supply water temperatures to enhance the thermal efficiency of the heat pump.Max suggested

Slab-on-grade floor heating02040600 10 20 30 40 50 60 70 80 90 100upward heat flux!(Btu/hr/ft2)Driving ∆T (Tw-Tr) (ºF)!Average water temp. - room air t

Is radiant floor heating always the answer?“Barefoot friendly” floors...

Consider a 2,000 square foot well insulated home with a design heat loss of 18,000 Btu/hr. Assume that 90 percent of the floor area in this house is h

A comparison of THERMAL MASS for several heat emitters:All heat emitters sized to provide 1000 Btu/hr at 110 ºF average water temperature, and 70 ºF r

space heating zoneslow flow resistance cast-iron boilerspace heating zoneshigh flow resistance mod/con boilerModern compact boilers have much higher flow

Low thermal mass allows the heat emitters to quickly respond to changing internal loadsNotice where the tubing is in this 6” heated concrete slab

Low temperature hydronic heat emitter options

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

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

What about standard fin-tube baseboard?Most fin-tube baseboard has been sized around boiler temperatures of 160 to 200 ºF. Much too high for good therm

Some low- temperature baseboard is now availableHydronic heat emitters options for low energy use housesStandard residential fin-tube baseboardMestek S

One of the fastest responding hydronic heat emittersFrom setback to almost steady state in 4 minutes…Panel RadiatorsHydronic heat emitters options

• Adjust heat output for operation at lower water temperatures.Panel RadiatorsHydronic heat emitters options for low energy use housesRECOMMENDATION:

Site built radiant CEILINGS…Thermal image of radiant ceiling in operationWhere:Q = heat output of ceiling (Btu/hr/ft2)Twater = average water temperatu

Site built radiant CEILINGS…

circuit 2 circulator 2common!piping circulator 1circuit 1common!piping circulator 1circuit 1circuit 2 circulator 2common!piping Divide & Conquer:H

Thermal image of radiant ceiling in operationSite built radiant CEILINGS…

Site built radiant WALLS…

Example Systems usingair-to-waterheat pumps

AWHP provides zoned heating + DHWmake up waterbuffer tankOUTSIDEINSIDEair to water heat pumpflow switchpressure regulated!variable speed circulatormani

(S1)RCsensors(S2)L1 N120 VACmain!switch(MS)HX - tank!circulatorL1 L2(R1)240 VACelectric!tankless!water!heaterHP - HX!circulator(R3-1)(P1)(P2)(P4)(R2-1

buffer tankOUTSIDEINSIDEair to water heat pumpflow switchoutdoor!temperature!sensoroutdoor!reset controllerpressure regulated!variable speed circulator

buffer tankOUTSIDEINSIDEair to water heat pumpflow switchoutdoor!temperature!sensoroutdoor!reset controllerpressure regulated!variable speed circulator

heat!exchangersensors in well(P3)(P4)(S2)zoned radiant ceiling panelsmanifold valve actuatorszone!thermostatsthermal trap(P2)outdoor!reset controller(

OUTSIDEINSIDE2-stage!air to water heat pumpantifreeze!protected!circuitheat!exchangerDHWexpansion !tankmake up watersensors in wellthermostatically !c

AWHP provides excellent matching to solar PV system in net zero houses.• Future trends are toward “all electric” houses.• Heating loads are so small i

• Simplifying system analysis• Preventing flow interferenceDivide & Conquer:

Chilled Beams:• All chilled beams must operate above dewpoint temperature of room!ceiling!warm air rising!cool air decending!dry, ventilation air inta

• reduces air flow requirements to those required for ventilation and latent cooling• reduces duct sizes• reduces blower size and reduced operation co

Radiant Ceiling Panels for heating & cooling1/2" drywall3/4" foil-faced polyisocyanurate foam stripsaluminum heat transfer platetube7/16

1/2" drywall3/4" foil-faced polyisocyanurate foam stripsaluminum heat transfer platetube7/16" oriented strand boardtop side insulationc

• low thermal mass• fast response• connect with “stab” fittingsSuspended ceiling panels (for heating & cooling)images courtesy of Zehnder

Suspended ceiling panels (for heating & cooling)installed in T-bar ceilingimages courtesy of Zehnderinstalled as self-supporting, suspended panels

Water temperature through radiant panel circuits must be maintained above dewpoint to avoid condensation.Chilled Water Cooling with Radiant Ceiling Pa

• Mixing valve operated by dewpoint controller maintain radiant panel supply temperature about 2-3 ºF above current room dewpoint temperature.• Latent

Same mixing valve and radiant panel can be used for heating, but with outdoor reset control logic (rather than dewpoint control logic).COOLING MODEHEA

• geothermal pre-conditioning of ventilation air• chilled water coil provide latent cooling (moisture removal)• Radiant panel(s) provide sensible cool

Primary / Secondary piping - where it all began... Dcloselyspacedteesmaximum 4xDflowprimary loopsecondary circuitsecondarycirculatorprimarycirculator

1. Air to water heat pumps are available for hydronic heating, chilled water cooling, and domestic water heating.2. Both “self-contained” and “split s

Parting thoughts...1. Plan ahead...

Parting thoughts...2. Keep it neat...

Parting thoughts...3. Keep it simple...

Parting thoughts...4. Recognize opportunity...

http://www.spacepak.com/Thanks for attending today’s sessionwww.hydronicpros.com Please visit our website for more information Coming in October 201

primary!circuitcirculator with integral flow-check (on supply)18"!min.swing-check !on returnswing check (or flow-check) valve (on return)underslung

load!#1load!#2load!#3closely!spaced!tees!(typical)primary!circulatorsecondary!circuitsecondary!circuitsecondary!circuitsecondary circuitprimary!circui

Both series and parallel primary/secondary systems require a primary circulator.This adds to the installed cost of the system AND adds hundreds, even

An example of primary loop circulator operating cost:Consider a system that supplies 500,000 Btu/hr at design load. Flow in the primary loop is 50 gpm

Assuming electrical cost escalates at 4% per year the total operating cost over a 20-year design life is:This, combined with eliminating the multi-hun

Understanding Hydronic SystemsToday’s topics...• Hydraulic separation, what is it? & Why itʼs important• Distribution efficiency & low power pu

Question: What is the “ideal” header in a hydronic system?Answer: One that splits up the flow without creating head loss Think about a “copper basket

So why donʼt we build headers like this???very low head loss!inside headerShort / fat headers are GOOD!Instead, we approximate the ideal header by mak

So whatʼs EXACTLY is a short / fat header???shortfatmax (design) flow rateselect pipe size that yields a flow velocity no higher than 2 feet per second

very low flow resistance!common piping!size headers for max flow velocity of 2 ft/seclow flow resistance heat!sourceThe “short / fat” headers hydraulical

The “short / fat” headers hydraulically separate the distribution circulators from each other.closely spaced teesvery low flow resistance!common piping

multiple!boiler!controllerouside!sensorclosely!space!teeszone circulators!(w/ check valves)air!ventdrain!valvepurge!valves"short/fat" header

The “short / fat” headers hydraulically separate the distribution circulators from each other.buffer!tankvery low flow resistance!common piping!size he

Hydraulic Separation in “Micro-load” systems:The small insulated tank provides:• Thermal buffering• Hydraulic separation• Air separation and collectio

hydraulic separatorvery low flow resistance!common piping!high flow ! resistance boilersize headers for max flow velocity of 2 ft/secThe “short / fat” he

diameter = 1"flow velocity = 4 ft/secdiameter = 3"flow rate = 6.5 gpmflow velocity = 0.44 ft/secflow rate = 6.5 gpmarea = Aarea = 9Aalmost zero

Hydraulic SeparationWhat it is.Why itʼs important.How to achieve it.

drain valveair vent"STANDARD"!hydraulic !separatorWhat does the “coalescing media” do inside a hydraulic separator?The coalescing media crea

drain valveair venthigh performance!(low velocity zone)!dirt separatorhigh performance!(microbubble)!air separatordrain valveair ventWELDWELDdrain val

heating!load(s)boiler circuitdistribution systemair!separatorsediment!strainerclosely!spaced!teesheating!load(s)boiler circuitdistribution systemHydra

1. Flow in the distribution system is equal to the flow in the boiler circuit.2. Flow in the distribution system is greater than flow in the boiler circ

T4T3T2T1f1f2f3f4NOTE:=f1f3 (always!)f2f4=NOTE: (always!)In this case only:!T1T2T3T4==Case #1: Distribution flow equals boiler flow:Very little mixing oc

T4T3T2T1f1f2f3f4NOTE:=f1f3 (always!)f2f4=NOTE: (always!)Case #2: Distribution flow is greater than boiler flow:Mixing occurs within the hydraulic separa

Case #3: Distribution flow is less than boiler flow:T2=f4− f1( )T4+ f1( )T1f4⎛⎝⎜⎞⎠⎟The temperature returning to the boiler (T3) can be calculated with:W

Sizing of Hydraulic Separators:Hydraulic separators must be properly sized to provide proper hydraulic, air, and dirt separation. Excessively high flo

Typical European concepts for multiple mod/con installation:

Typical European concepts for multiple mod/con installation:

Hydraulic Separation:When 2 or more circulators are operating simultaneously in the same piping assembly, they try to “interfere” with each other.This

hydraulic!separatormultiple!boiler!controllersupply!temp.!sensoroutdoor!temperature!sensorto / from!loadsWhat did you notice in common on those last t

Example of Hydro Separator Installation in New System:Magna Steel Corporation - ConnecticutPhotos courtesy of Peter Gasperini - Northeast Radiant

Example of Hydro Separator Installation in Old System:Because hydraulic separators remove sediment fromsystems they’re ideal for applications where ne

Example of Hydro Separator Installation in Old System:Because hydraulic separators remove sediment from systems theyʼre ideal for applications where n

existing cast-iron radiators (converted from steam)existing pipingmod/con boiler!w/ compact heat exchangersupply!temperature!sensorECM!pressure!regula

fluid feederearth loop circuitspurging!valvespurgevariable-speed!pressure-regulated!circulatorgeothermal manifoldshydro!separatorto / from!other heat p

Whatʼs wrong with these installations?Answer: There is nothing to drive flow through the circuit on the left side of separator. The closely spaced tee

Distribution Efficiency& Low Power Pumping...00.050.10.150.20.250 2 4 6 8 10 12 14 16 180481216wire-to-water efficiency (decimal %)flow rate (gpm)hea

The North American Hydronics market has many “high efficiency” boilersIn the right applications these boilers have efficiencies in the 95+ range:It may

The present situation:What draws your attention in the photo below?If all these circulators operate simultaneously (at design load) the electrical dem

What is “COMMON PIPING?”The degree to which two or more operating circulators interact with each other depends on the head loss of the common piping.T

Here’s another example…Great “craftsmanship” - Wrong “concept”

Here’s another (award winning) example…

If you run out of wall space consider this installation technique…Notice the installer left provisions for additional circulators.

So what can you conclude from these photos?Perhaps that it’s GOOD to be in the circulator business these days!

You might also conclude that…The North American hydronics industry tends to “overpump” its systems!

Just to be fair to the pump guys – there is such a thing as overzoning with zone valves…

Although as an industry we pride ourselves on ultra high efficiency and “eco-friendly” heat sources, we…Must look beyond the efficiency of only the heat

Defining DISTRIBUTION EFFICIENCYEfficiency = desired OUTPUT quantitynecessary INPUT quantityDistribution efficiency for a space heating system.Consider

So is a distribution efficiency of 353 Btu/hr/watt good or bad?To answer this you need something to compare it to.Suppose a furnace blower operates at

Room for Improvement…A few years ago I inspected a malfunctioning hydronic heating system in a 10,000 square foot house that contained 40 circulators.

Very little head loss occurs!in this portion of the circuits.common piping circulator 1circuit 1circuit 2 circulator 2When the head loss of the common

Water Watts… It’s hard to say if the wattage of past or current generation circulators is “where it needs to be” without knowing the mechanical power

Example: How much mechanical power is necessary to sustain a flow of 180 ºF water flows at 5 gpm through a circuit of 3/4” copper tubing having an equi

The ratio of the mechanical wattage the impeller imparts to the water divided by the electrical input wattage to operate the motor is called wire-to-w

00.050.10.150.20.250 2 4 6 8 10 12 14 16 180481216wire-to-water efficiency (decimal %)flow rate (gpm)head added (feet)pump curvewire-to-water efficiencym

The electrical wattage needed by the circulator is:we=0.4344 × f × ∆ Pnw/wA current-generation wet-rotor circulator has a maximum wire-to-water efficie

Consider that a flow of 5 gpm in a circuit with a 20 ºF temperature drop is moving about 50,000 Btu/hr, and the electrical power to “run the conveyor b

This graph shows the relationship between system flow rate vs. operating hours for a typical Northern climate.Recognizing that partial flow is common, c

What happens when a zone valve closes?

Applying ∆P CirculatorsFlat pump curves produce less of the undesirable increase in ∆P as zone valves close.

What would be the ideal pump curve for a hydronic system using valve based zoning?zone valvesDHWCWAnswer: a perfectly flat pump curveA perfectly flat p

Very little head loss occurs!in this portion of the circuits.common piping circulator 1circuit 1circuit 2 circulator 2Assume that circulator 1 is oper

Approximating a flat pump curve with ∆P bypass valveA ∆P bypass valve helps limit changes in differential pressure, but does so “parasitically” by thro

Approximating a flat pump curve with ∆P bypass valveBy varying the speed of the circulator it is possible to produce the same “net” effect as would be

PROPORTIONAL DIFFERENTIAL PRESSURE CONTROLThis method is best for systems where the heat source and/or “mains” piping leading to the load circuits dis

How does a ECM Circulator work?

Single or multi-speed wet-rotor circulators like those commonly used in North America would be rated “D” or “E” on this scale.All these circulators ra

Small ECM circulators now available in North AmericaGrundfos Alpha: Provides constant and proportional differential pressure and three fixed speed set

Grundfos MAGNAWilo STRATOS circulatorsLarger ECM circulators now available in USTaco ViridianHeads to 45 feet, flows to 345 gpmpower inputs to 1600 wat

Savings in electrical energy are 60 to 80 percent relative to a fixed speed circulator of equal peak performance in the same application.Computer model

TRVTRVTRVTRVTRVTRVthermal storage tankthermostatic radiator valves!on each panel radiatorpressure-regulated!variable speed circulator1/2" PEX or

Homerun systems allow several methods of zoning.Another approach is to install a thermostatic radiator valve (TRV) on each heat emitter.One approach i

Very little head loss occurs!in this portion of the circuits.common piping circulator 1circuit 1circuit 2 circulator 2Imagine a hypothetical situation

NON-ELECTRIC THERMOSTATIC RADIATOR VALVE: operatorvalve body

thermostatic radiator valves are easy to use...manual setback dog reset controldogs are “thermally discriminating.”

The modern way to install fin-tube baseboard:• Thermostatic radiator valve on each baseboard• ECM-based pressure-regulated circulator.

Air-to-Water Heat Pumps:OUTSIDEINSIDEair to water heat pump

Why Water rather than air

14" x 8" ductthis cut would destroy the load-carrying ability of the floor joists2 x 12 joist3/4" tube Water is vastly superior to air f

compressorthermal expansion valve!(TXV)condenserevaporatorSOURCE!mediaLOAD!media1234refrigerant flowhigh temperature!high pressure!VAPORmedium temperat

Basic heat pump operationcompressorthermal expansion valve!(TXV)condenserevaporatorlow !temperature!heat!absorbed!from source!(Q1)higher !temperature!

compressorthermal expansion valve!(TXV)condenserevaporatorreversing!valvelow !temperature!heat!absorbedhigher !temperature!heat!dissipatedHEATING!MODE

Refrigeration cycle in AWHPevaporatorTXVRVcomp.air-to-water!heat pump(in cooling mode)circulatorcondenserfanoutside!airoutside!airheat!from!buildingco

The higher the flow resistance of the common piping, the more each circulator will “influence” flow in the other circuit (e.g. the lower the hydraulic se

Self-contained air-to-water heat pumpswarmer climate application(water in outside unit)colder climate application(antifreeze in outside unit)image cou

One comparison with Geothermal w/w heat pump:Example house: 36,000 BTU/hr design load at 70ºF inside & 0 ºF outsideLocation: Syracuse, NY (6720 h

20000300004000050000600007000080000-10 0 10 20 30 40 50 60 70Heating capacity (Btu/hr) Outdoor air temperature (ºF) leaving load water temp = 86 ºF

Heating performance:Anything that reduces the “temperature lift” increases both the heating capacity and COP of the heat pump.outside airload watertem

Cooling capacityIncreases with:a. lower outdoor temperatureb. Higher chilled water temperatureEERIncreases with:a. lower outdoor temperatureb. higher

Anything that decreases the temperature liftʼ increases both the cooling capacity and EER of the heat pump.outside airtemperature!"lift"!(le

AWHP + auxiliary heating050001000015000200002500030000350004000070 60 50 40 30 20 10 0Load or heat pump output (Btu/hr) outdoor temperature (ºF) heat

Flow switches protect the heat pumpflow switchesAn internal or external flow switch turns off the refrigeration cycle if water flow through the heat pump

Heat exchangers between heat pump and distribution systemIF a heat exchanger is required between heat pump and storage (due to requirement to keep hea

Low voltage interfacing with AWHPRYOC24 VACcompressorreversing valvecommonRYOC24 VACcompressorreversing valvecommon(RA)heat!demand(RA-1)cool!demandrel