Ask Caleffi
Ask Caleffi
#24 How do I measure energy consumption?
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Energy metering. Is that EASILY accomplished? Are there well suited applications for metering AND can a building owner be confident about energy consumption? (YES!) Greg and Dan, our Ask Caleffi gurus, talk about energy metering during this episode of the podcast. They talk Modbus-to-BACnet (say what??) and what applications are perfect for calculating BTUs in a specific space. Interested in a real-life example? No problem! Dan digs into an actual case study of successful tracking of energy usage with the 7504 Series CONTECA heat energy meter in action.
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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 we're your hosts from the
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caleffi tech support team i'm greg tubbs
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and i'm dan ferkus welcome we look
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forward to sharing some stories from our
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tech 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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[Music]
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hey there welcome back to the ask luffy
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podcast
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here we are coming at you again with
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another episode how we doing dan yeah
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we're doing good thanks for coming back
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so we get a question or a request every
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so often for
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energy metering do you guys offer
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something that i can use to
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read consumption yeah measure energy
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consumption yeah a lot of you may not
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even be familiar with it or aware that
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we offer it i mean it's a product we've
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had now for a while um
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last year or more has really taken hold
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we're starting to see a lot of these
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going in but that's our can take a heat
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meter or energy meter the energy meter
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the 7504 series yeah
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so we offer it in
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a variety of sizes and
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configurations yeah a lot a lot of
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options out there with it gives the
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building owner
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of the ability to measure the energy
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being used you know you can measure
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energy for hot water you can measure
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energy for heating
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space heating you know basically it's
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going to be a btu meter
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right it'll measure and record it
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all that information
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you can tap into it remotely if you have
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the data logger yeah we have a data
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logger or user interface that allows you
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to tie into it a user interface will
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convert it from modbus to bacnet so you
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can tie it into a building automation
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system and and watch the usage and be
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able to read and harvest the the
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information off of it exactly nice thing
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about them is
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you know you can tie up to 250 of these
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meters together that's a lot it is it is
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for a large apartment building that
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this is a great option yeah it's perfect
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you know apartment building commercial
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space
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any application where you're going to
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have a common
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utility service
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gas and electric service
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this is going to give you the ability to
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measure
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the amount of btus used in a space so
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you know when you look at calculating
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btus is simple you calculate your delta
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t between supply and return
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times your gallons per minute flow rate
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times 500 for straight water gives you
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the amount of btus used and this
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device will
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come with a supply temperature sensor
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and return temperature sensor and a well
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to install those in
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um and that's how it's going to measure
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that delta t so that's going to give you
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your temperature difference it also
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comes with a flow meter right and we
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have varying sizes here
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being able to
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measure different flow rates essentially
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different cvs so
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a single jet flow meter
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half three quarter in one inch and then
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the multi-jet
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um
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from
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what is it one inch all the way up to
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inch and a half yeah
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yeah and we'll we actually have the unit
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available up to eight inch flanged
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so for large commercial applications we
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have the ability to the sensors are
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going to come factory wired into the
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control
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and that's important
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this control is calibrated and to meet
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the standards it has to have it has to
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be
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tamper proof essentially so it has to
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have those the sensor leads are i
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believe they're 20 foot leads on each
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and they're pre-wired into the control
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and
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they're
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secured in a way that they can't be
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tampered with right and we'll get that
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question on occasion hey can i extend
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the wires you're changing the resistance
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values then which is going to throw that
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off right yeah calibration is going to
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be different right you don't really have
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a way of calibrating it unfortunately no
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that's all done at the factory that's
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all
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and rightfully so right because again
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trying to keep it from being tampered
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with right
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so we had a local project that we had
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these installed in and it was a great
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opportunity it was fun to go out on that
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project yeah you got to go out and see
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it in action and actually help the
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contractor set them up didn't you yeah
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yeah it was fun so it was
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a multi-family project
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it was an existing buildings and there
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were two eight family apartment
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buildings okay that were heated off of
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two boilers the boilers were located in
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the basement of one eight family supply
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and return piping went underground into
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the basement of the second wow
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and then was piped throughout that
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building and they were you know small
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apartments um
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hydronic uh fin tube baseboard for
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heating okay
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but previous to that
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the building owner was paying all
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utilities so he heat was included
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so what that owner had done is he had
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upgraded to high efficient boilers
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he had put an individual electric water
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heater in the basement of each one of
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the apartments so you know now that the
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the electric was separated but the gas
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wasn't okay so
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then in each one of the apartment units
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they installed it can take a heat meter
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okay and it was relatively easy because
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you know being common piping
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and you know
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each
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basement of the
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apartment complex had basements so in
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the basement you know it was common pipe
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throughout the unit and there was a zone
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valve tied to a thermostat for each of
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the apartments sure so after the zone
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valve he installed his supply
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temperature sensor
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on the leaving
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return loop from the apartment going
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back to the main he installed his return
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temperature sensor so that gave him the
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ability to calculate his delta t
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and then on the return side he installed
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the water meter and the water meter
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calculated his flow rates how many
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gallons per minute was flowing through
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that through that loop when it was
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heating and it was interesting because
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you know we were there and
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we were running it and it was
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calculating the delta t it was
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calculating the flow rate you know it
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was anywhere
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you had variable speed pumps on on the
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boilers so it was anywhere from you know
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maybe three quarters to
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one
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and a quarter gallon per minute of flow
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okay through the unit and it was
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measuring the temperature difference and
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it was telling us how many btus that
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unit was using in heating
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very nice
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and then
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they had tied a communication wire from
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each one of they can take us back to the
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boiler room um to one of the data
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loggers okay so
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we were able to go in there you know we
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had to assign each one an address okay
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and again you can put up to 250 cantekas
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on
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a single system sure you only had 16
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there yeah we had 16 other right
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and then at the data logger we were able
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to
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search and found each one of the
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addresses okay and then it was able to
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tell us you know how many btus it was
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using and it's going to record that and
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at the you know end of the month the
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building owner can tie into that he can
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tie a laptop computer into it he didn't
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have a building automation system sure
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but he could go down and plug in with
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his laptop and read all that info right
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pull that information off and and record
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it and and log it well yeah and then it
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gave him the ability to
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look at how many btus they used and
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separate and say okay unit one used you
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know x amount of btus and unit two used
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x amount and then he was able to take
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his gas bill and break that out and bill
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each tenant for the amount of btus they
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use that month sure well that's pretty
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handy to be able to do that yeah it was
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pretty interesting i mean you look at
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going from
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you know having from paying the gas bill
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which
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you know how rentals are you pay the gas
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bill and you drive by and the
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apartment's 80 degrees and the windows
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are open oh yeah i i'm familiar with
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plenty of those situations so now
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when the tenant's paying the utility
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bill
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you're going to see the thermostat set
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lower you're going to see the windows
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close because that you know that's
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affecting them directly it certainly is
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they got to pay for it so
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they're going to
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have a little more care in it yeah and
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the other option he would have had
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would have been to have the municipality
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come out and install a gas meter for
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each unit which is going to be a big
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investment
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and then put a
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boiler in the basement of each of the
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units yeah separating separate boilers
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so that's
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16 boilers 15 boilers that's 16 times
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the maintenance yep
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um yeah it's 16 gas meters gas piping
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throughout the entire building it's a
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huge lake venting would have been next
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to impossible yeah you know because
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either you're going high efficient which
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there you know the
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side-by-side apartments didn't give a
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lot of venting location you know if
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you're mid efficient they didn't have
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chimneys or class b vents to vent them
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so that wouldn't have been a great
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option as well um but this allowed him
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to
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complete his task you know he he
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made the investment in two new boilers
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and he's able to
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allow the tenants now to pay their
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utility bills so
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you know he's recovering recovering that
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as a
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return on investment so to speak yeah
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it's a great option to be able to do
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that
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those jobs are always fun to go to
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weren't they
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the apartments you know to try and
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troubleshoot
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yeah they are because
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you know zone valve is either up in the
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apartment someplace buried under the
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zone
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the baseboard right in the cabinet yeah
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or
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they're in the divided up basement
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somewhere and you don't always have
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access to it right yeah this one was
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really easy this was a like a perfect
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setup for the candeca
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but you could do this in a commercial
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application i mean you you know had they
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had um you know common water heaters and
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they had you know
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supply lines going out to
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you know each of the apartment they
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could have done metering on domestic hot
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water there's four additional inputs
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where they could tie in
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you know for gas usage to help measure
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gas usage or any anything
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you know a
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pulse signal will indicate great
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well i think that pretty well covers it
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doesn't it
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it's uh it's an overview i mean yeah
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it's a general overview of the product
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and as we start getting more questions
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and seeing things we'll be sure to share
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them with you 100 we sure will
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well
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till next time
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thank you for tuning in if you ever need
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help please feel free to contact our
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tech support team anytime at
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techsupport.us
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caleffi.com
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or call us during our business hours at
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7 30 a.m to 4 30 p.m
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central time
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at 414-238-2360
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