Ask The HvacMan
Air Grilles
Air Diffusers
Air Quailty
All Air Systems
All Water Systems
Building .Managament Systems ..BMS
Cooling Towers
Cooling Load Calculation
Energy Saving
Duct ,Smacna
Dampers ,Air
Dust Collection
Fire Dampers
Glass Selection
Heat Exchangers,water
Heat Recovery
Heat Tracing Systems
Hepa Filters
Hvac Applications
Humidifiers / Dehumidifiers
Insulation , Duct
Insulation , Pipe
Insulation , Sound
Nano Tech.,In Building
Occupancy Sensors
Pneumatic Conveying
Pool Ventilation
Process Piping
Radiant Heating
Refrigerant Systems
Solar Collectors
Steam Generation
Tables & Charts Gnr.
VAV Sytems
VRV Systems
Solar Collectors
Flat Plate Collectors
Evacuated Tube Collectors
Concentrating Collectors
Transpired Collectors
Solar Control Systems
Standalone Systems
Grid Connected Systems
Hybrid Systems
Back-up Systems
Solar Cells
Solar Arrays
Change Controller
Hybrid Systems
Grid Systems
Water Pumping
Using Wind Energy
Enviromental Aspects
Buyer's Guide
Fire Exit Systems
Save Energy
Solar Water Heating
Solar Electric Systems
Wind Turbines
Passive Solar Heating
Passive Solar Cooling
Building Material
Water Conservation
Ground Source Heat-Pumps
Green Hotels

Glass &Windows Selection

Water Source Heat Pump Systems Operation Modes

A typical building has a perimeter with outside exposure that is directly affected by variable outdoor weather conditions and a core without outside exposure that is almost unaffected
by the weather. In order to understand the energy sharing benefits of a water-source heat pump system, the interaction of the loads in the core and perimeter zones must be analyzed for occupied periods (internal gains present) and unoccupied periods (temperature setback/setup and little or no internal gains) throughout the year. For illustration, the following are the main energy consuming operating modes

Summer Occupied

During hot weather with most or all units cooling, heat removed from the air is transferred to the water loop. An evaporative water cooler rejects the excess heat outdoors to maintain a maximum water temperature of approximately 90°F (32°C).

Winter Warm-Up

During recovery from night setback, most zones will require heating and will be extracting heat from the water loop.The boiler maintains the minimum water loop temperature according to a predetermined setpoint. The heat rejector is off. The warm-up period is typically one hour or less per day

Or only in very cold weather with most or all units heating is it necessary to add heat to the water with a water heater. This is done when the temperature of the water loop falls to 64°F (18°C). The amount of this heat is reduced any time one or more units are operating on cooling. The central water heater is never larger than two-thirds the size required in other systems but is usually less because of diversity.

Winter Occupied

Most core zones will require cooling because of the internal heat gains discussed previously. Most perimeter zones will require heating. Because heat is being simultaneously rejected into and extracted from the water loop, both theboiler and the heat rejector remain off much of the time. The inherent sharing of energy within the water loop minimizes boiler and heat rejector operation and provides maximum system efficiency.

At Partial loads

Water-Source Heat Pumps provide zone heating and cooling at the highest rated levels of efficiency.

The water loop inherently recovers much of the energy needed for heating the building, minimizing boiler use.

Water-loop heat pump systems operate efficiently under partial occupancy and at part-load conditions.

They also eliminate the double energy waste of zone reheat (cooling with subsequent reheating), which is common in many HVAC systems.

This all translates into reduced energy consumption and lower operating costs.

Back to HvacApplications Main Page
Back to Hvac Expert Main Page




Legionnare Disease
Energy Saving
Control Software
Hotel Design Books

Hotel Design