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#14 Why is thermal balancing important in DHW systems?
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Thermal balancing in Domestic Hot Water systems. Why is it necessary? (hint: water moves into the path of least resistance) What's the difference between manual and automatic balancing valves? Where are the valves installed? How are these special valves maintained? (ahem.... water quality is key!)
Greg and Dan are back to answer these questions and discuss a real-time problem solver in this Episode of the Ask Caleffi podcast series.
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here we go
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[Music]
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welcome to ask Caleffi the podcast that
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dives into real life problems that
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plumbing and hvac technicians face in
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the field
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we're your hosts from the caleffi tech
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support team i'm greg tubbs
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and i'm dan firkus welcome we look
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forward to sharing some stories from our
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tech
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calls and using our background and
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expertise to make your days a little
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easier
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hey there welcome back here we are on
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episode 14.
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today we're going to talk thermal
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balancing in domestic hot water systems
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how are we doing dan we're doing good
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thanks for coming back everybody
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yeah thanks for tuning in so
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why would we use a thermal balancing
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valve in a domestic hot water system
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well you know that's exactly what
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they're designed for greg you know being
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thermostatic they're thermostatically
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adjusted so they provide
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automatic balancing of your research
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circuits
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absolutely kind of takes a little bit of
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the math out of it it certainly does
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uh takes a few things out of it
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less labor involved that really at the
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end of the day
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you're not hooking up a meter to it to
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test
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your pressure differential across it
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right it's it's there just to
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keep that loop off yeah absolutely so
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when you think about installing them
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you know typically you're going to stall
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them at the end or bottom of your riser
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so that it's controlling that riser
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temperature based on
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at the end points knowing that all of
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the water in that riser is going to be
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up to temperature before it starts to
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modulate down
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exactly it confirms 100 percent that
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that that
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particular riser has hit its temperature
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whatever it might be so if you set this
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valve at 120
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guess what that whole riser is hit 120
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degrees by the time it goes back to the
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end of the return to dump back into the
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main return
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right yeah and you know you talk about
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you know the whole
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preface of balancing is that water is
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lazy right so it's going to take the
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path of least resistance
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so with the thermostatic balancing you
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know the advantage here
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is that you know those risers that warm
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up quicker
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they're going to be allowed to warm up
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once they come up to their design
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temperature that valve is going to
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modulate down which is going to create
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restriction and force that water in
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other directions
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exactly and that's what you need to do
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is then far the
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there's more resistance to get there so
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as soon as those
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closer risers to the mechanical room
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heat up
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this guy will close them off and allow
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that water to push off
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right you know rob and peter to pay paul
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but in a good way in a good way
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right you know and they never close off
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completely no they're always going to
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allow a little bit of flow through them
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so it's always sampling the water
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temperature
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um so that that riser stays at temp and
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then we'll open up as it needs to
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absolutely you know another advantage
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too and what i like about these is
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you know think about a balancing valve
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so you install it and either
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you one you know the flow rate so you're
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ordering the
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flow you're ordering the balancing valve
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preset for that flow rate right
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or you're putting in a manual balancing
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valve which means you're coming back
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with a manometer or
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pressure differential tool checking it
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comparing it to your flow chart and
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balancing it
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you know or we have our quick setter
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which makes it a little easier
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with the thermal setter based on
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temperature you can preset your
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temperatures on the ground
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install it and walk away and it's set
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absolutely and
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it works great for trouble jobs existing
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jobs where maybe there isn't any
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balancing
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you know i don't know how many hotel
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calls i've taken or
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maybe you have two apartment buildings
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um there's a few for instance that come
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to mind
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but yeah you know what we don't get any
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flow to this end of the building
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it's always cold the legs are dead
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whatever the case may be this valve is a
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problem solver for that kind of
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sickness yeah it sure is you know and
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especially when you when you talk about
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those problem jobs you ask them well
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what are you doing for balancing
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and a lot of them they don't know or
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they're doing nothing you hear crickets
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yeah balancing what's that right or or
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they have balancing valves in
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but none of them are adjusted they don't
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know if they've been adjusted or
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balanced and
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odds are they probably aren't yeah and
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if they're the manual type with pt ports
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let's be honest i mean you and me as as
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techs in the field we didn't really have
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that kind of equipment with us
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no no we didn't and then when you look
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at as well
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you don't know what you need through
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that you don't know how long of a
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circuit it is
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you know how are you going to balance
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that based on a flow rate
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you don't know what's behind the drywall
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you don't you have no clue how many
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elbows are back there you know so that's
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where you're right thermal setter is a
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problem solver you're going to put it in
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and
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once the temperature of that loop comes
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up to your
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set temperature it's going to modulate
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down and the water is going to go to the
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next and
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you really don't need to to know a whole
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lot more about it
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right these things will help save energy
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you know
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you're looking at especially if you're
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running it on a variable speed pump
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as these things start to close off that
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pump can now
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drop down in speed and consume less
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electricity
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right you know you look at all the
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municipalities out there that they you
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know they talk about aqua stats in place
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because they want to control the pump
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you know based on the temperature of the
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loop so
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you know the aquasat is there to provide
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energy savings upgrading to a variable
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drive pump
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you know usually a delta p pump works
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the best
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putting in balancing valves and then you
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get that
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energy savings without without an
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aquastack because face it
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i mean you and i know when you start
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looking and talking in a whole different
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direction but
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you start looking at mixing valves a lot
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of the time you're using your
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research pump to make up minimum flow
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rates so you're not going to do that if
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you're shutting that pump off with an
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aquastate no you're certainly not and
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then
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you know they have to run more water out
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to get
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the heat there to get everything to work
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properly right it's kind of
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uh kind of brutal it is you know the one
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thing too is you know we talk a lot
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about thermal disinfection today
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you know and thermal disinfection you're
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elevating
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your temperature in your system to
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kill legionella uh if we're using
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thermal setters are we still gonna be
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able to do that
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we certainly can we have a couple other
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models available aside from the basic
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ones
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that you can either add the bypass
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cartridge the thermal
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bypass cartridge or you can
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use a 24 volt actuator
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that threads right on to drive that
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bypass right that bypass cartridge
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so and that can be tied into a building
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management system
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and and be completely monitored right so
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we can so so you're saying we can
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provide thermal disinfection by manual
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or by automatically opening the bypass
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cartridge with a thermoelectric
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actuator or with a thermal bypass
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cartridge exactly
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thermostatically yeah one one thing too
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is if you don't know if the building's
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going
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to do thermal disinfection or if they
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are going to come back later and
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possibly add it
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we sell it with the bypass port just
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capped
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so it's there you can add either the
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actuator
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or the thermal bypass cartridge later
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so you don't have to make a decision
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right away you can come back later and
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add that
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absolutely yeah that's our one one six
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one so that was
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that's like the basic model with the
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ability
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to add either a essentially
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a cartridge that's similar to what
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you'll find in our manifolds
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it's just a pin type cartridge that
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pushes up and down
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that opens and closes with the thermal
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actuator you know that would be in our
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1163 series right or
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you can get it get a cartridge a bypass
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cartridge that's
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similar to what's in our it is what's in
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our one one six two one one one six
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six series to where thermostatically
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it will go into bypass mode and allow
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that valve to work for thermal
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disinfection yeah once it sees that
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elevate
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elevated temperature it pops open and
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and bypasses
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right you know we have a couple of
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different temperatures available 140 or
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160 degrees for that bypass
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absolutely you know you can get them
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with check valves
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or without and you can also get them
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with or without a temperature gauge
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right you know but you guys you think of
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those jobs that are real price sensitive
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we do have a down and dirty option
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or one one six four which is going to be
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just the thermostatic bi or thermostatic
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balancing valve it's not going to have
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any bypass cartridge or the ability to
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add it later
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but boy when you're talking that
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price-sensitive project where you know
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thermal disinfection isn't going to be
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a key or isn't going to come back and
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play a role later that's a that's a nice
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solution yeah it's the down and dirty
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thermal setter
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it's very basic like you said
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how about maintenance of these things
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water
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quality always plays a role right
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absolutely we get that question all the
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time well how long it's going to last
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well when how often do i have to do
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maintenance yeah how hard is your water
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how often are they being used right you
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know hotter water i mean obviously
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you're going to experience
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if it's hard water and it's being kept
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really hot you're gonna
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probably see a shorter life on anything
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right yeah or more maintenance
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requirement because you're gonna get
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that
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get calcium to precipitate out of the
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water right
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and it'll build up on the walls of
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everything right but no they're easy i
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mean as far as maintenance goes you can
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jump in and you can pull the the
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thermal cartridge out and clean it out
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yeah put it back in or replace it we
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have replacement cartridges available so
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you know that's really nice because if
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you're out on a project and
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they've been in a long time and you know
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you want to pull them out and clean them
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or you find you need to replace them
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maybe something's not working right you
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don't have to cut the valve out and redo
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your piping and
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and and install an entirely new valve
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you can just replace that thermostatic
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cartridge
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yeah and same goes with the bypass
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cartridges
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they're there they're replaceable if you
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can't get them cleaned
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properly or you look at it and say you
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know it's just going to be easier
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to replace it we have the 140 and 160
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degree
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bypass cartridges available as
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replacement parts we sure do
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and we also offer insulation shells too
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yeah yeah we have an insulation shell
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makes insulating them very easy you know
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most of your domestic
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water research lines you're going to
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want to insulate them to prevent losses
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you know for energy efficiency so we
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have a nice insulation shell that'll
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snap around it'll still allow you to
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read the temperature gauge
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or make an adjustment yeah well what
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else can we cover with this
10:52
well you know i think we hit on a lot i
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think back to a call i received
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one time on a home yeah and um it was a
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large home it was out in california and
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the contractor was in there and
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the the home had you know kind of like
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two wings to it so it had a recirc line
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coming back from each direction and he
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had a variable speed pump and he had a
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mixing valve
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and he was having issues with one side
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of the home
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you know with with balancing and with
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mixing valve performing and
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i remember talking with him he did have
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a variable speed pump
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okay and but he had no balancing so he
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had that
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that recirc line came out in three
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quarter it teed to half
11:31
inch went to each section of the home
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but he had no way to know if it was
11:35
balanced so
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i know he went came back and he put the
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thermal setter in one on each one of
11:39
those half inch lines
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set them up worked perfectly took care
11:43
of his problems
11:44
that's awesome and i think memory serves
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correct a couple years back
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right when this product kind of came to
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market for us
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we had a job out in colorado
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yeah i remember hearing about that yeah
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that was a it was a large
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housing complex a rather tall building
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if memory serves correct
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and they were an apartment building
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wasn't it it was an apartment building
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and they had a lot of problems with dead
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legs in that building
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and i think legionella might have been
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part of an issue too
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somewhere along the way i think they had
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yeah issues with
12:20
yeah i mean i remember hearing stories
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about tenants there that would turn the
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water on
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make breakfast eat their breakfast and
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then finally get back to the shower and
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it still wasn't quite warm yet
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wow yeah that's that's pretty and they
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had research lines
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yeah they had research but they had a
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lot of it just wasn't balanced
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no it wasn't balanced so you're trying
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to push all that
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many feet of head to overcome that
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resistance to get up there
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and it just it's not happening and if
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people on the lower levels are taking
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showers they're getting everything right
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off the bat
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yeah if i remember right they came back
12:54
and they retrofitted the building with
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the thermal center thermal balancing
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valves and it corrected all the issues
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it certainly did it was kind of a win
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for us early on
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yeah a win for us win for the contractor
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win for the building owner because
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i remember hearing at one point the
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department of health was called in yeah
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because they weren't getting
13:14
hot water to where they needed it right
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right so
13:17
a huge win for that building owner
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absolutely
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well i think we covered this pretty well
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so
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next week i think we're going to talk on
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the legio mix
13:27
yeah that makes sense you know we get a
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ton of questions about that product and
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it works really well with
13:33
the thermal setter yeah it sure does as
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far as the balancing aspect the thermal
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setter is a great match with the legio
13:38
mix
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all right well tune in next week thank
13:42
you for tuning in
13:43
if you ever need help please feel free
13:45
to contact our tech support team
13:47
anytime at techsupport.us
13:51
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at 7 30 a.m to 4 30 p.m
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