services

1. AIR CONDITIONING
CASE STUDY

2. Ano 2005
Electric energy 803 MWh
233 tep
Specific consumption 197
kgep/m2
CICA - Informatics Center
The building CICA has three floors and the ground floor is the centre of
informatics resources. The function of this building is mainly to ensure and
make available all the informatics services for the FEUP community and to
uphold its innovation and use. The cooling power installed in these spaces is
not enough to remove the total load that occurs inside the building, which
causes a high indoor air temperature leading to harmful situations, causing
damages and reducing the performance of the informatics hardware.
The main goal of this audit is to evaluate the correct cooling power, as function
of the demand of the four zones showed on Figure 1. It is, also, necessary to
verify the efficiency of air flow distribution inside the different spaces and the
assessment of ventilation as it was proposed in earlier. The indoor air set point
temperature will be object of concern in this studied case.
If this value can be increased (i.e. increase
set point temperature) lower energy
consumption will be achieved without
reducing the total performance of all
systems.
This building employs electric energy as a
source of final energy. The following
picture shows values for the energy
consumption in the year of 2005, as well
as for the specific consumption.

3. Design Details
The HVAC system installed in below grade floor of
CICA building is an all refrigerant system, where,
all units work with R22 refrigerant. In D-102 and D-
104 rooms, there are ceiling splits with 5 kW of
cooling power, connected to the condenser units
installed in the building’s rooftop, Error! Reference
source not found.. The rooms, D-101, D103 and D-
104 are equipped with close control units; one unit
in the first two places and two units in the last one,
Error! Reference source not found., an individual
condensing outdoor unit is also located in the
building rooftop. The Close control units allow
humidity control inside the spaces.
Schematic of the ventilation
systems distribution
illustrates the functionality of
the close
control units installed in the
different zones where reheated
/re-cooling air is supply by grids
under the floor.
Schematic of the condensers existing in the building rooftopSchematic of the close control
Control Strategy
The HVAC system works in continuous throughout the year where the indoor air
set point temperature is 25ºC and the relative humidity is 50%. Each close control
unit performs the specified set-point of the air conditioning space.

4. Problems
• Actual HVAC system is not adjusted to the demand
• The internal loads are higher than the installed HVAC system, causing the
damage and reducing of the performance of the informatics hardware.
• In summer the indoor comfort is more challenging
Solutions –
Major Modifications The solution proposed is, in energetic and environmental
field, the most adjusted since it is a centralized system and has a higher
efficiency. This solution also allows the power increase without major costs.
The considered HVAC system can be defined as an air/water system. It will be
composed by a cold-water central producer (chiller), located in the building
covering, and by a cold water distribution net with two pipes, for supply and
return. This circuit will supply the existing cooling coils in the independent
Close Control units. These units are located inside the acclimatized spaces or,
guarantee the indoor air quality. This system will also include the possibility of
free-cool the spaces, given the adequate exterior air conditions.
The following equipments form the proposed system:
- Chiller with scroll compressor with 100 kW of cooling capacity;
- Four Close Control units supplied with cold water which integrates system of
humidification and electric resistance for heating;
- Ventilation, piping and control system…
As it was already referred, the treated air is supplied through the
floor, and there aren’t any ducts to promote the air distribution.
figure 6 shows an air outlet, which allows the treated air supply in
to the zone. As shown, there are cables in the floor that difficult the
air flow and do not allow a uniform air distribution. Thus, it was
verified that the indoor air temperature in the different spaces are
not homogeneous.
it is possible to conclude that the equipment placed in the opposite
side of the Close Control units, can easily reach temperatures about 34/36 ºC.

5. ‘Upside Down Townhouse’ Designer Demands
Sustainability, Space-Saving features in Heat Pump
System
The Challenge:
Jayna Cooper wanted to maximize her
living space but the heating and
cooling equipment would require
setting aside scarce space to
accommodate bulky HVAC ductwork.
Daikin’s Solution:
With Daikin’s 4-Port Multi-Split ductless
system, Cooper regained use of valuable
space and kept her
commitment to sustainability with a system
rated SEER 17.2 and HSPF 9.3.
The 1,600-sq.-ft. home in Los Angeles designed and built by
architect Jayna Cooper is a model of sustainability. It includes
an energy-efficient, duct-free Daikin AC® 4-port Multi-Split
system for heating and cooling.
Application:
Residential
Location:
Los Angeles, CA
Cooper’s home has an open-loft design on the
third floor, which includes the living, dining,
kitchen and office areas. Two wall mounted
units service the space, including one in the
kitchen area, operated by individual wireless
remote controllers.
1,600-sq.-ft. “upside down urban
townhouse” is a model of efficiency, where
the use of space is optimized and the living
areas comfortable.
If a conventional unitary ducted system were
chosen, Architect would have to design a
space with space for ductwork throughout
the stacked house, winding through the
kitchen cabinets and closet space.
Solution to the problem. A duct free Daikin
4-port Multi-Split system that eliminated
the need
for ductwork, noisy outdoor compressors, or
bulky window units was specified.
Cooper’s home was recently featured in the
prestigious magazine Architectural Record,
recognized for its innovative design, which
includes a third floor open loft with living,
dining,
kitchen, and office; a second floor for two
bedrooms; a first floor dedicated to the
driveway and carport; and fourth floor roof
deck.

6. The Daikin system that serves the residence
includes two unobtrusive CTXS12 wall-
mounted indoor units located on opposite walls
of the loft area and one CTXS09 indoor unit in
each of the bedrooms. The compact 4MXS32
outdoor unit sits in the corner of the roof deck.
The 32,000-Btu/h system has a SEER rating of
17.2, one of the highest in the industry, and an
HSPF rating of 9.3.
The compact 32,000-
Btu/h outdoor unit
sits in
the corner of the
home’s top-floor roof
deck. It
has a SEER rating of
17.2, one of the
highest in
the industry. The
system features
inverter
technology, which
delivers exactly the
amount of
heating or cooling
needed to each zone
of the
home.
The Daikin system based on its inverter
variable speed compressor technology,
which operates at required capacity,
delivering exactly the cooling or heating
needed to maintain the desired comfort
condition while reducing energy
consumption to one-third compared to
normal on/ off units. The system avoids
short start/stop cycling operation of the
compressor, reducing costly current peaks,
and minimizes temperature fluctuations.

7. 1) High efficiency VRV
Sensible heat and latent heat are controlled separately with the combination
of High efficiency VRV and DESICA. This enhances interior thermal
comfort by individually controlling temperature and humidity. Drastic
energy saving is realized by reducing wasteful energy use such as
excessive cooling or heating.
2) Natural energy
Water cooled VRV which is an under developing prototype is utilized for the
entrance hall of TIC. This equipment achieves big energy saving thanks
to the use of natural energy;
- Utilization of geothermal heat for cooling / heating water
- Collection / release of heat via solar heat collection / release panel
Aims for a Net
Zero Energy
Building (ZEB),
and 70% energy
saving was
achieved in
2015 by using
various Daikin
technologies.
100% energy
saving is to be
achieved by
2020.
Air conditioning system study

8. 3) Solar power
Solar panel with solar tracking system is adopted to TIC. It can chase
sunlight and generate 1.3 times electricity greater than a general fixed
type solar panel.
In TIC total 300kW of electricity is generated by fixed type and tracking
type.
4) Water mist spray
Water mist spray system for outdoor units is installed to make the heat
exchange efficiency higher.
By spraying pulverized water droplets, moisturizing of heat exchanger is
largely curtailed while the effect of water sprinkling is maintained.* This
system is available in Japan only
5) Data analysis
Demonstration experiment system adopted for further energy saving
activities to achieve ZEB. Comfort and energy saving performance are
evaluated by many sensors attached to the building. The analysis data is
used for optimum control of not only air conditioning but also lighting,
blind, and shades.

9. Comfort assessment
Finely placed sensors monitor temp.,
humidity, CO2, human feeling &
illuminance
Energy saving
assessment
Individual monitoring of air
conditioning, ventilation, lighting
and office equipment.
Total control of facility
Following facilities are
controlled comprehensively.
- Air-conditioning and
ventilation
- Lighting : ON/OFF,
Illuminance
- Shades : Height, Angle
Optimum air conditioning products for office and laboratory
At TIC, 2 types of applications (Office
and laboratory) are integrated in one
building. For this reason, optimum A/C
products and control for each application
are needed.
In the office area, the number of people
differs substantially in accordance with
the situation. Additionally the heat load
varies greatly due to many glass
windows. That’s why VRV, which can
cope with different heat load of the
space, are adopted.
There are large space and many rooms
in the laboratory area. Module type heat
pump chiller and centrifugal chiller are
adopted for the laboratory area. They are
utilized for the air conditioning system
and also providing cool water for
experiment use. VRV is also adopted for
the laboratory area and supports air
conditioning. Chiller and VRV are
managed and controlled all together by a
central monitoring system.