Heat Pumps

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Heat Pumps
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Agenda

• How does a heat pump work
• Why use heat pumps
• Types of heat pumps
• AAON heat pump offerings
• AAON Advantages
• E-CAT

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Heat Pumps

• How does a heat pump work?
• In cool mode, the heat pump utilizes the same
  refrigeration cycle as any typical HVAC
  equipment.
• In heat mode, the heat pump uses the same circuit
  used for cooling, but reverses the refrigerant
  flow. Reversing the flow of the units
  refrigeration circuit allows the indoor coil to
  be used for heating.

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Heat Pumps
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Heat Pumps
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Why Heat Pumps?

• Energy Savings specifically Heating Efficiency
• Efficiency is shown in two forms EER or COP
• Energy Efficiency Ratio- EER used for cooling
• Coefficient of Performance - COP used for heating
• Efficient Gas-fired Heaters typically yield a 82
  to 92 range in heating efficiency (COP 0.82
  to 0.92) COP Capacity Out / Power In
• Electric-resistance Heaters typically yield even
  more100 heating efficiency (COP 1.00)
• Heat Pumps typically yield 200 to 400 heating
  efficiency (COP 2.00 to 4.00 and even higher!)
• HOW CAN THAT BE?...

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Heat Pumps

• With traditional Gas or Electric air heating,
  heat is generated by the given energy source.
• However, with Heat Pumps, very little of the heat
  is
• generated by electricity, but the majority of the
  heat is
• moved (or pumped) in from an outside source,
  taking
• heat out of a medium (water/air), and
  transferring (or
• pumping) it into the indoor space. A small amount
  of
• electrical energy used results in a large amount
  of
• heat output, resulting in COPs always greater
  than
• 1.00!

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Heat Pumps
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Heat Pumps

• EER verses COP
• EER Net Cooling Capacity / Power Input
• COPc Net Cooling Capacity / Power Input
• COPh Net Heating Capacity / Power Input
• EER (Net Cooling in Btu/h) / Watts
• Convert EER to COPc
• COPc EER / 3.413
• Convert COPc to EER
• EER COPc x 3.413

Cooling EER 11.1 gt 11.1 / 3.413 3.25
COPc Heating COPh 4.38
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Heat Pumps

• What is the minimum
• Supply Airflow ?
• Outside Air Temperature ?
• Mixed Air Temperature ?
• Leaving water temperature ?
• It Depends
• The design must stay within the compressor
  operating envelope

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Heat Pumps
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Heat Pumps

• How to stay within operating conditions
• Condensing Temp too low in Heating Mode
• Raise the minimum design outside air temperature
• Will raise the Mixed Air Temperature Entering the
  Coil
• (raises the condensing temperature)
• Reduce supply (condenser) airflow
• Raises the condensing temperature
• Heat Wheel
• Will raise the Mixed Air Temperature Entering the
  Coil
• (raises the condensing temperature)

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Heat Pumps

• Heat Pumps in Cold Climates
• The outdoor section on some units may "frost up"
  when outdoor temperatures are between 32F and
  41F and there is sufficient moisture in the air
  which causes restriction of air flow across the
  outdoor
• To avoid freezing over, or to remove the ice, the
  heat pump will switch to "defrost" mode. This
  setting will turn on the cooling portion of the
  heat pump in order to warm the coils.
• During defrost the supplemental heater turns on
  (resistance electric, gas, etc.) in the indoor
  section to temper the cold air being distributed.

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WattMaster Defrost

• A user-adjustable Suction Temperature Setpoint
  determines when the unit will go into Defrost
  Mode during Heat Pump Heating. The unit will
  operate in Defrost Mode for 10 minutes or until
  the Head Pressure reaches 450 PSIG.
• An Adaptive Defrost Adjustment configuration is
  available that will automatically adjust the
  length of the Defrost Timer (interval between
  Defrost Modes) depending on if the unit stays in
  Defrost Mode for the full 10 minutes or leaves
  the Defrost Mode early because of reaching a Head
  Pressure of 450 PSIG.

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Types of Heat Pump Systems
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Heat Pumps

• Air to Air
• Utilizes the typical refrigeration system with
  two fan coils
• Air to Water
• Utilizes a fan coil for the supply air and a
  water coil for rejecting heat in the cool mode
  and obtaining heat in the heat mode
• Water to Water
• Utilizes two water coils as the condenser and the
  evaporator

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Types of Heat Pumps
Air to Air
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Types of Heat Pumps
Air to Water
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Types of Heat Pumps
Water to Water
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Water Source Heat Pumps

• Types Water Source Systems
• Water Loop Systems A closed-loop piping system
  normally located within a building.
• Geothermal Systems These systems take advantage
  of the earths relatively constant temperature
  and use the ground or surface water to reject or
  absorb heat. These systems offer better energy
  efficiency than either air-source or water loop
  systems and can do so at extreme ambient
  conditions.

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Water Source Heat Pumps

• Water-loop heat pump system (cooling mode)

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Water Source Heat Pumps

• Freeze Protection
• We must recognize the freeze potential of units
  with water coils and the need for protection when
  the compressors arent running. Glycol is the
  safest way to be sure your unit is protected from
  low ambient conditions.
• Thermostatic control of the water control valve
  is another, yet less effective way. This is
  simply a thermal override of the valve to ensure
  it stays open, allowing continuous water flow
  when the compressors are off, thus providing
  freeze protection. This is available only by a
  SPA.

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Water Source Heat Pumps

• Geothermal heat pump systems

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Water Source Heat Pumps

• The ground is a heat source in the winter and
  heat sink in the summer

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Water Source Heat Pumps

• An air source heat pump heats on a moderate
  winter day using a heat source of 40 deg and a
  sink of 70 deg (30 deg difference)
• A geothermal heat pump on the same day uses a
  source of 55 deg and a sink of 70 deg (15 deg
  difference)
• Halving the difference in temperature greatly
  increases the efficiency

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AAONs Heat Pump Offerings
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AAON Units

• Packaged Units
• RQ Series, 2-5 tons
• RN Series, 6-70 tons
• RL Series, 45-230 tons

Double Wall Rigid Polyurethane Foam Panel
RN Series Geothermal or Water-Source Heat Pump
Variable Capacity Compressor
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AAON Units

• Self Contained Units
• SA Series, 23-70 tons
• SB Series, 2-30 tons
• M2 Series, 5-70 tons

SA Series Geothermal or Water-Source Heat Pump
SB Series Geothermal or Water-Source Heat Pump
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AAON Units

• Condensing units
• CC Series units matched with M3, M2, SA, H3/V3,
  F1, RL, RN and RQ Series Air Handling Units, 2-63
  tons
• CB Series Units matched with H3/V3, F1 and RQ
  Series Air Handling Units, 2-5 tons

From Geothermal Heat Exchanger
To Geothermal Heat Exchanger
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AAON Advantages

• Industry leading efficiencies
• Cabinet construction
• Corrosion resistant paint (outdoor units)
• Direct drive fans
• Digital Scroll Compressor option
• Heat Wheel Option
• Supplemental (dual fuel) heat options
• electric, gas, hot water, or steam
• 100 Outside Air units
• Spec Stoppers

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AAON Advantages
Heat pump with a VC Compressor reduces cycling
losses!
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E-CAT32 Heat Pumps
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E-CAT Heat Pumps
Select Heat Pump - Unit Configuration
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E-CAT Heat Pumps
Select Half VC or ALL VC Compressors
Why ALL VC Compressors ?
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E-CAT Heat Pumps
Selecting Supplemental Heating Types (Dual
Heating Available!) Spec Stoppers!...VC
Compressor Dual Heat !!
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E-CAT Heat Pumps
Electric Heating Staging Options
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E-CAT Heat Pumps
Select a Heat Wheel for Even Higher HEATING COPs
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E-CAT Heat Pumps
Low Ambient Option 8 is not available in Heat
Pumps Due to refrigerant component complexities.
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E-CAT Heat Pumps
Controller types available VAV, CV or MUA
Select a Control Option
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E-CAT Heat Pumps
Select from the water-cooled options
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E-CAT Heat Pumps
Auxiliary Heating Heating is sized to provide
only the additional heat needed to raise the
indoor coil leaving air temperature to the
desired unit leaving air temperature.
Auxiliary gt Compressors ON ! Emergency gt
Compressors OFF!
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E-CAT Heat Pumps
Emergency Heating is sized to meet the full
heating load.
Using this selection with Electric Heat will
cause an increase in a units electrical service
requirements.
Auxiliary gt Compressors ON ! Emergency gt
Compressors OFF!
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E-CAT Heat Pumps
MCA Limited Auxiliary heating additional
heating kW will be installed equal to the
compressor amp draw thats available when
compressors are off or the capacity needed to
raise the indoor coil leaving air temperature to
the desired unit leaving air temperature
Auxiliary gt Compressors ON ! Emergency gt
Compressors OFF!
Does not increase electrical MCA, BUT may not
meet unit heating design capacity.
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E-CAT Heat Pumps
Specifying Unit Conditions
The cooling conditions screen for a WSHP will
also allow selection of fluid type (water or
glycol) plus input of the fluid temperature and
GPM. Standard defaults are shown.
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E-CAT Heat Pumps
Specifying Unit Conditions
This heating tab will only be shown if a
Heating Type has been selected for Model Option
B. It will apply to any type of heat selected. It
allows a Leaving Air Temperature to be input.
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E-CAT Heat Pumps
The heating conditions screen for a WSHP allows
input of the heating CFM, the fluid temperature
and the GPM. Standard defaults are indicated
here.
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E-CAT Heat Pumps
Rating Sheet Format
ARI Testing in progress
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E-CAT Heat Pumps
Rating Sheet Format
No Heat occurs when an Auxiliary Heat is not
selected or even when it is selected but it is
not required to meet the specified unit leaving
air temperature.
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E-CAT Heat Pumps
Rating Sheet Format
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E-CAT Heat Pumps
Rating Sheet Format
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Literature

• Geothermal Heat Pump Solutions

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Questions?