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HVACR216 - HydronicsHVACR216 - Hydronics

Hydronic HeatingHydronic Heating

2Hydronic Heating SystemsHydronic Heating Systems

• Hydronic heating systems rely on circulating water or steam to deliver heat to the remote locations where warming of a space is desired.

• Hydronic heating systems rely on circulating water or steam to deliver heat to the remote locations where warming of a space is desired.

3Hydronic Heating Systems Hydronic Heating Systems

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Hydronic Heating SystemsHydronic Heating Systems

5The Heat SourceThe Heat Source

• Heat energy is transferred from the heat source (burners) to the water in the boiler.

– There are two different types of boilers on the market today.

• High mass• Low mass

• Heat energy is transferred from the heat source (burners) to the water in the boiler.

– There are two different types of boilers on the market today.

• High mass• Low mass

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The Heat SourceThe Heat Source

• Cast iron (high mass) boilers are most commonly boiler found in residential applications.

– Residential cast iron boilers typically hold

between 10 - 15 gallons of water.

• Cast iron (high mass) boilers are most commonly boiler found in residential applications.

– Residential cast iron boilers typically hold

between 10 - 15 gallons of water.

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Cast iron (high mass) boilerCast iron (high mass) boiler

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Cast iron (high mass) boilerCast iron (high mass) boiler

• The boiler manufacturer supplies us with a booklet that is sent with the boiler.

• It is important that these instructions are followed when the boiler is installed.

• This booklet also contains information about proper boiler maintenance or troubleshooting.

• The boiler manufacturer supplies us with a booklet that is sent with the boiler.

• It is important that these instructions are followed when the boiler is installed.

• This booklet also contains information about proper boiler maintenance or troubleshooting.

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The Heat SourceThe Heat Source

• Stainless steel (low mass) boilers are gaining popularity due to the higher efficiencies being obtained today by many different manufacturers.

– Low mass boilers hold between 4 - 7 gallons of water.

• Stainless steel (low mass) boilers are gaining popularity due to the higher efficiencies being obtained today by many different manufacturers.

– Low mass boilers hold between 4 - 7 gallons of water.

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Low mass boilerLow mass boiler

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Hydronic controlsHydronic controls

• Thermostat

– The heating thermostat, whether it is a modern digital, snap action or mercury bulb type, is a close on temperature drop device.

• Thermostat

– The heating thermostat, whether it is a modern digital, snap action or mercury bulb type, is a close on temperature drop device.

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Thermostat typesThermostat types

• Digital Snap action Mercury bulb

• Digital Snap action Mercury bulb

13Hydronic controlsHydronic controls

• Aquastat

– The Aquastat is a temperature-sensing switch that is responsible for cycling the boiler on and off to keep the water in the boiler close to the desired temperature.

– It may be strapped onto a pipe or immersed in the water via a well.

• Aquastat

– The Aquastat is a temperature-sensing switch that is responsible for cycling the boiler on and off to keep the water in the boiler close to the desired temperature.

– It may be strapped onto a pipe or immersed in the water via a well.

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Aquastat typesAquastat types

• Immersion Strap-on Triple • Immersion Strap-on Triple

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Low Water CutoffLow Water Cutoff

• The Low Water Cutoff is responsible for de-energizing the combustion operation in the event the water level in the system falls below the desired level established by the manufacturer.

• The Low Water Cutoff is a safety device that code officials require to be installed on all hydronic systems.

• The Low Water Cutoff can be a stand alone device or a built in part to the Aquastat.

• The Low Water Cutoff is responsible for de-energizing the combustion operation in the event the water level in the system falls below the desired level established by the manufacturer.

• The Low Water Cutoff is a safety device that code officials require to be installed on all hydronic systems.

• The Low Water Cutoff can be a stand alone device or a built in part to the Aquastat.

16Low Water CutoffLow Water Cutoff

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High limit switchHigh limit switch

• Manual reset high limit switches are required in light commercial applications.

• Manual reset high limit switches are required in light commercial applications.

18Circulator PumpsCirculator Pumps

• The circulator pump is used to move water throughout the hydronic system.

• The circulator pump is also called a centrifugal pump.

• The centrifugal pump is made up of a motor, a linkage and an impeller.

• The circulator pump is used to move water throughout the hydronic system.

• The circulator pump is also called a centrifugal pump.

• The centrifugal pump is made up of a motor, a linkage and an impeller.

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Circulator pump styles and brandsCirculator pump styles and brands

• Taco 007 Taco 110 Grundfoss • Taco 007 Taco 110 Grundfoss

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Circulator locationCirculator location

• Early circulators were large and heavy. The easiest place to mount them was on the return piping close to the boiler.

• Modern locations for a circulator is on the supply piping just beyond the air eliminator and the expansion tank.

• Early circulators were large and heavy. The easiest place to mount them was on the return piping close to the boiler.

• Modern locations for a circulator is on the supply piping just beyond the air eliminator and the expansion tank.

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Pump control panelsPump control panels

• Circulator pump panels (switching relays) control the operation of multiple pumps (zones) at one time.

– A thermostat located in the space to be heated calls for heat and the zone panel turns on the correct circulator for that space.

• Circulator pump panels (switching relays) control the operation of multiple pumps (zones) at one time.

– A thermostat located in the space to be heated calls for heat and the zone panel turns on the correct circulator for that space.

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Taco zoning controlsTaco zoning controls

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Zone valvesZone valves

• Zone valves are sometimes used to allow or dis-allow water from flowing through a system.

• Zone valves are either directly controlled by a thermostat or a zone panel

• Zone valves are sometimes used to allow or dis-allow water from flowing through a system.

• Zone valves are either directly controlled by a thermostat or a zone panel

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Zone valve brandsZone valve brands

• Taco Honeywell B & G• Taco Honeywell B & G

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Cut-away picture of a zone valveCut-away picture of a zone valve

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Zone valve panelsZone valve panels

• Zone valves can also be controlled by a panel much like the circulator pumps.

• Zone valves can also be controlled by a panel much like the circulator pumps.

27Non-electrical componentsNon-electrical components

• Expansion Tanks

– There are two types of expansion tanks• Standard expansion tank

– Nothing more than a large tank located somewhere above the boiler.

• Diaphragm expansion tank–Divided into two sections separated by a

rubber, semi-permeable membrane.–One side of the tank contains air and the

other side is open to the water circuit.

• Expansion Tanks

– There are two types of expansion tanks• Standard expansion tank

– Nothing more than a large tank located somewhere above the boiler.

• Diaphragm expansion tank–Divided into two sections separated by a

rubber, semi-permeable membrane.–One side of the tank contains air and the

other side is open to the water circuit.

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Modern diaphragm expansion tank with air scoop

and vent.Modern diaphragm expansion tank with air scoop

and vent.

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Automatic water feedAutomatic water feed

• Automatically maintains the preset water pressure in the system.

• Usually 12-14 psi

• Automatically maintains the preset water pressure in the system.

• Usually 12-14 psi

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Combination Auto Feed and Backflow PreventerCombination Auto Feed and Backflow Preventer

The backflow preventer allows water flow only in one direction similar to a check valve.

Its very common to see the backflow preventer and the water feeder together like this.

The backflow preventer allows water flow only in one direction similar to a check valve.

Its very common to see the backflow preventer and the water feeder together like this.

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Pressure-reducing ValvePressure-reducing Valve

• Another name for the water feeder is the pressure reducing valve.

• The pressure-reducing valve automatically lowers the pressure of the supply water to the pressure at which the boiler is designed to maintain.

• Another name for the water feeder is the pressure reducing valve.

• The pressure-reducing valve automatically lowers the pressure of the supply water to the pressure at which the boiler is designed to maintain.

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Pressure reducing valvePressure reducing valve

33Pressure Relief ValvePressure Relief Valve

• The pressure relief valve is designed to open if the pressure in the system reaches the set point on the valve.

– The is the most important safety device installed on a hydronic system.

• The pressure relief valve is designed to open if the pressure in the system reaches the set point on the valve.

– The is the most important safety device installed on a hydronic system.

34Pressure Relief ValvePressure Relief Valve

35Flow-Control ValveFlow-Control Valve

• The flow-control valve controls flow in a hydronic system.

• The flow control valve is also called a check valve or flow check.

• The flow-control valve controls flow in a hydronic system.

• The flow control valve is also called a check valve or flow check.

36Flow-Control Valve typesFlow-Control Valve types

37Balancing ValveBalancing Valve

• Balancing valves are used to even the water flow through each branch of the circuit.

• Balancing valves are installed in each branch of the circuit and are manually adjusted.

• Balancing valves are used to even the water flow through each branch of the circuit.

• Balancing valves are installed in each branch of the circuit and are manually adjusted.

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Balancing ValveBalancing Valve