Vapor-Compression Refrigeration condenser D C expansion device compressor A B evaporator
Types of Heat Pumps water-source heat pumps water-to-water heat pump air-source heat pumps
Cooling
Heating
Water Source Heat pumps
Heat Pump in Cooling Mode expansion device water loop refrigerant-to-air heat exchanger compressor reversing valve refrigerant-to-water heat exchanger
Heat Pump in Heating Mode expansion device water loop refrigerant-to-air heat exchanger compressor reversing valve refrigerant-to-water heat exchanger
Water-Source Heat Pump refrigerant-to-air heat exchanger fan expansion device compressor refrigerant-to-water heat exchanger reversing valve
Compressor rotary (rolling piston) scroll reciprocating
Refrigerant-to-Air Heat Exchanger refrigerant-to-air heat exchanger
Refrigerant-to-Water Heat Exchanger coaxial refrigerant-to-water heat exchanger
Expansion Device thermal expansion valve (TXV)
Reversing Valve refrigerant-to-air heat exchanger reversing valve
Unit-Level Controls Space temperature control Night setback Random start Anti-short-cycle timer heat pump thermostat
Water-Source Heat Pump Systems period two What Is a Water-Source Heat Pump System?
Water-Source Heat Pump System cooling tower air separator expansion tank pumps plate-and-frame heat exchanger boiler water distribution loop heat pumps
Summer Operation cooling tower on boiler off 90ºF [32ºC] heat pumps in cooling mode
Winter Operation cooling tower off boiler on 60ºF [16ºC] heat pumps in heating mode
Spring and Fall Operation cooling tower off boiler off heat pumps in cooling mode heat pumps in heating mode
Benefits of a WSHP System Heat recovery offers energy savings Individual space control Performs both cooling and heating Flexibility Individual tenant metering Small amount of floor space required Unit failure does not affect the rest of the system
Issues of a WSHP System Ventilation Acoustics Accessibility requires coordination
Water-Source Heat Pump Systems period three Components of a WSHP System
WSHP Configurations unit ventilator horizontal vertical stack vertical rooftop console
WSHP System Serving a Hotel vertical-stack WSHPs vertical WSHPs horizontal WSHPs rooftop WSHPs
Water Distribution Loop cooling tower pumps boiler heat pumps
Direct- Versus Reverse-Return direct-return reverse-return
Accessories air separator expansion tank strainer shutoff valves drain valve
Heat Rejecters Open cooling tower with heat exchanger Closed-circuit cooling tower Natural heat sink (ground, lake)
Open Tower with a Heat Exchanger fill propeller fan outdoor air sump pump plate-and-frame heat exchanger water distribution loop
Closed-Circuit Cooling Tower outdoor air water distribution loop fan tubes sump pump
Heat Adders Boiler (electric, gas-fired) Heat exchanger Natural heat source (ground)
Optional Storage Tank cooling tower pumps boiler hot water storage tank heat pumps
Electric Heat water loop fan compressor electric strip heater
Air Distribution System return duct horizontal heat pump return air grille diffuser supply duct
Dedicated Ventilation System air handler ventilation duct system horizontal heat pump
Dedicated Ventilation System air handler OA ducted directly to space OA ducted to heat pumps OA ducted to plenum near heat pumps
Exhaust-Air Heat Recovery Coil loops Fixed-plate heat exchangers Heat pipes Sensible- or totalenergy wheels exhaust air total-energy wheel outdoor air
System-Level Control heat pump system-level controller thermostat
Water-Loop Temperature Control cooling tower pumps boiler system-level controller heat pumps
Advanced System-Level Control Centralized scheduling Schedule override Morning warm-up and cool-down Alarms Trend logging Integration with other building systems
Water-Source Heat Pump Systems period four System Configurations
Cooling-Tower-and-Boiler System cooling tower heat pumps boiler water pumps
Ground-Source Heat Pump Systems ground heat exchanger
Ground-Coupled System heat pumps vertical-loop ground heat exchanger water pumps
Vertical Loop Advantages Requires least amount of land Least amount of total piping Can require least amount of pumping energy Disadvantages Drilling costs may be higher than trenching costs Backfilling requires special material and practices Potential for heat buildup
Horizontal Loop Advantages Trenching costs are lower than drilling costs May not build up as much heat over time Disadvantages Requires more land than vertical loops Greater ground-temperature variations More total piping than vertical loops Risk of pipe damage during backfilling of trenches
Spiral Loop Advantages Requires less land area and trenching than horizontal loops Lower installation cost compared to horizontal loops Disadvantages Requires more total piping than vertical and horizontal loops Still requires a large area of land
Surface-Water System heat pumps ground heat exchanger lake water pumps
Ground-Water System heat pumps water pumps well
Hybrid WSHP Systems cooling tower pumps boiler water chiller heat pumps air handler
Hybrid WSHP Systems cooling tower pumps boiler to interior spaces heat pumps self-contained VAV air conditioner
Water-Source Heat Pump Systems period five Maintenance Considerations
Water-Source Heat Pumps Inspect and replace filter Inspect and clean... Drain pan Refrigerant-to-air heat exchanger Internal surfaces in wet section Fan drain pan
Water Distribution Loop Recommended maintenance Clean strainers in open systems Check cleanliness of refrigerant-to-water heat exchangers Use a qualified water-treatment specialist for cooling tower maintenance Check loop water for proper amount of antifreeze, when necessary
Freeze Protection Closed-circuit cooling tower Locate indoors Use antifreeze solution Winterize the tower Open cooling tower Locate intermediate heat exchanger indoors Winterize the tower Ground-coupled systems Use antifreeze solution closed-circuit cooling tower
Water-Source Heat Pump Systems period six Application Considerations
Acoustic Considerations supply return horizontal WSHP space hallway console WSHP
Acoustic Considerations return duct horizontal heat pump return air grille diffuser supply duct
Acoustic Considerations supply air vertical WSHP closet return air duct return air
Space Humidity Control ASHRAE-recommended discomfort & health problems microbial growth 0 10 20 30 40 50 60 70 80 90 100 relative humidity (%) source: Section 5.10 of ASHRAE Standard 62 1999
Space Humidity Control expansion device reheat coil water loop compressor refrigerant-to-air heat exchanger reversing valve refrigerant-to-water heat exchanger reheat valve
Condensate Management refrigerant-to-air heat exchanger fan condensate drain pan
Condensate Management draw-through heat pump vent return air fan supply duct condensate drain line trap
Airside Economizer return air supply air vertical WSHP outdoor air
Waterside Economizer waterside economizer coil refrigerant-to-water heat exchanger horizontal heat pump three-way valve
Building Pressurization infiltration
Building Pressurization air handler central relief fan ventilation duct system horizontal heat pump
Equipment Rating Standards Purpose Establish definitions, testing, and rating requirements Scope Water-source heat pumps Cooling only, heating only, or both functions Water-source and groundsource system applications
Water-Source Heat Pump Systems period seven Review
Review Period One expansion device water loop refrigerant-to-air heat exchanger compressor reversing valve refrigerant-to-water heat exchanger
Review Period Two cooling tower off boiler off heat pumps in cooling mode heat pumps in heating mode
Review Period Three cooling tower air separator expansion tank pumps plate-and-frame heat exchanger boiler water distribution loop heat pumps
Review Period Four heat pumps ground heat exchanger water pumps
Review Period Five Maintenance considerations Heat pump components Water distribution loop and heat transfer surfaces Freeze protection
Review Period Six Application considerations Acoustics Space humidity control Condensate management Airside and waterside economizers Building pressurization Equipment rating standards