the energy efficient management systems

Considerations about the energy efficient management systems

The energy management system comprises two aspects:

1. The first is related to the self-power management system included into modern devices placed in house, such as: microwave ovens, refrigerators, HVAC systems.
2. The second is related to the embedded controllers or PCs, which are used as supervisors of the house control.

An illustration of the main consumers in the house is given in figure 1

Figure 1 Cost of energy bill for different household products. ”Others” include: ovens, microwave ovens, stove and other small appliance in house (source: http://www.energystar.gov)

Building management systems (BMS) and energy management systems (EMS) can turn on or turn off systems or selected equipment, based on time-of-day schedules or on variable parameters such as temperature.

These systems may be connected to other building systems such as fire alarm, security/surveillance, or access control. They can also coordinate other critical systems such as the elevator control and other utility management systems, like gas or water.
EMS and BMS systems are versatile and sophisticated controllers for a small building, a

large office or college campuses. With current technology and sophisticated software, the temperature, pressure, humidity, voltage, current, switch or relay status of many points throughout a facility can be monitored. These BMS/EMS systems can be programmed either to provide room comfort in the most economical way or to perform some energy management strategies, such as thermal comfort settings.

Applications employing energy management strategies have produced significant electrical energy savings thus making possible the return-of-investment (ROI) in three to four years.
When the facility is served under an utility time-managed rate schedule, these systems can be set to turn off major equipment or motors during peak hours.

The BMS/EMS can be used not only as a saving energy tool but also to cut off peak demands, in order to save energy. These systems can also generate a variety of utilities and energy consumption reports or analyses.

Animation 1 Which are the elements of house management system ?

The list bellow presents some examples of measures that have been tacked in order to increase efficiency in energy consumption:
Concerning refrigerators and freezers:

1. Increasing the thermal isolation of refrigerators and freezers;
2. Introduction of special fans for implementing air movement into these goods;
3. Introduction of automatic defrosting systems into refrigerators and freezers, in order to increase the cooling process efficiency;
4. Better design of temperature control (regulator) inside the refrigerator or freezer.
5. Introduction of two compressors on the same system; this would provide better conditions for refrigeration and freeze processes. 

Concerning microwave ovens:

1. Better design of wave deflectors in order to obtain a better and uniform food exposure to microwave beams, thus increasing the heating efficiency.
2. Introduction of multiple beam power intensity levels in order to better meet the practical needs.

Concerning washing machines:

1. Modification of washing cycles and reduction of the water temperature.
2. Introduction of new washing methods, e.g. “bubble machines” system.
3. Adaptation of the washing cycle to tissue types and materials using “fuzzy logic circuits” for control. Fuzzy circuits allow choices between zero and one, and between true and false, using the whole scale of “grey levels” and not only the “black and white values”. These factors control the bubbles amount, the turbulence of the machine, and even the wobble of the machine.
4. Implementing the Active Balance Control, ABC, to reduce noise and disturbances during spinning. With the ABC system noise and vibrations are reduced up to 50%. The machine increases the speed by small steps and goes up to full spin speed only when the laundry is evenly distributed and the drum is in complete balance.

Concerning dishwasher machines:

1. Reduction of the water volume used in the washing process
2. Improving the water distribution in the washing space filled with dishes

Concerning air conditioning systems:

1. Introduction of mixed mode ventilation, which combines two different installations: one is the AC system that can supplement the cool /warm air in the house and another is a ventilation system that consumes only 20% of a classic AC system. At the same time, house comfort is increased. A mixed-mode building combines natural ventilation with mechanical ventilation and cooling and often incorporates sophisticated controls that allow the building to alternate between these two modes during different times of the day or season. This would maximize comfort while avoiding the significant energy use and the operating costs of year-round air conditioning.
2. Zoning HVAC system, which means to define different zones inside the house and to use numerous thermostats, a well designed pine network for control and temperature regulation. A special feature of a thermostat could be the “warm” or/and “cool” anticipation. This means to be able to evaluate in advance the temperature variation profile in order to prevent the over heating or extreme cooling.
3. Addition of a condensation cut-off to the radiant cooling systems that avoids the cases in which the radiant cooling surface temperature is so low that generates condensation.

Addition of new algorithms to the electric chillers so that to calculate heat recovery and to simulate a double bundled condenser.