METI / ECCJ / ACE Training Program MTPEC06 (2007.01)

Counter measures for buildings
which ECCJ is disseminating.

EE&C Tuning for Buildings

Importance of EE&C Tuning for Buildings

Examples of EE&C Tuning items for Buildings

Example1:	Save energy by modifying room temperatures
Example2:	Save energy by stopping the dehumidification-reheat control in summer
Example3:	Save energy by reducing the outside air intake during air- conditioning
Example4:	Save energy by changing the operating mode of parking lot ventilation fans
Example5:	Save energy by optimizing the operation of the number of secondary chilled water pumps

ECCJ proposes 44 Tuning items for building owners and energy managers.

Example 3:

Energy-saving effect by reducing the outside air intake
during air-conditioning
~Outline~

Throughput heat energy of the outside air taken in during air-conditioning is unexpectedly large.
About 20 kJ of heat energy is required to cool down and dehumidify 1 kg of outside air of 32^oC dry-bulb and 60%RH to standard room climate conditions (28^oC dry-bulb and 50%RH).
In an office building, about 6 kg of outside air is usually introduced hourly per square meter of floor area, meaning that 120 kJ/h of treating heat energy is loaded on the air-conditioner, which is equivalent to 29% of the total load of air-conditioner (about 420 kJ/m2).
Reviewing the number of persons working in the room, reduction of outside air intake should be made so that the CO_² concentration range should be within the one allowed by the Law for Maintenance of Sanitation in Buildings and you can make large saving of consumed energy by heat source equipment

Example 3:

Saving energy by reducing the outside air intake
during air-conditioning (1)

Building: High-rise office building in Tokyo, 40,000 m².
(Regional heat supply = Chilled water, 25 air-conditioners)
Reduction of outside air intake during air conditioning within the range (CO² concentration: 1,000 ppm or less) allowed by the Law for Maintenance of Sanitation in Buildings

Designed outside air intake 3600m³/H
(600m² × 0.2 person/m² × 30m³/person)
Before tuning 2700m³/H
(600m²; × 0.15 person/ × 30 m³/person) After tuning 1900m³/H
(600m² × 0.1 person/ × 30m³/person)

[Air volume per air conditioner]

	Before tuning (m³/h)	After tuning (m³/h)
Outside air intake	2,700	1,900
Circulated air	11,900	11,900
Ventilated air	13,100	13,100
Exhaust air	1,500	700

Source: ECCJ Survey

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