airdistribution in cinemas

M.Sc. In Engineering Design http://in3.dem.ist.utl.pt/mscdesign/

Air Conditioning Active Distribution System PT 103232, 04/02/2005 IST/ISEL/José Gaspar

March 2005

1 IN+ Centre for Innovation, Technology and Policy Research, Instituto Superior Técnico, Universidade Técnica de Lisboa

The main purpose of the Air Conditioning Active Distribution System is the acclimatization of large entertainment spaces like cinema theatre.

Prior Art (medium and large spaces): System designed to operate at total occupancy level; Big reaction time to thermal load changes - occupancy; Low performance and efficiency for part occupancy; Temperature shock when people arrive or leave the room; Thermal comfort at standard conditions (ASHRAE); Homogeneous thermal ambient - thermal neutral world; Thermal steady state across time; Thermal equilibrium across space; Big waste of effort and energy to maintain a uniform and unnatural environment; • Poor environment sustainability; • Long thermal transient discomfort to adapt to new occupancy levels; • • • • • • • • •

ACADS Art (medium and large spaces): • System designed to operate well at different occupancy • • • • • • • • • •

levels; Low reaction time to occupancy changes; Excellent performance and efficiency for all occupancy levels; Temperature progressive change when people arrive or leave the room; Thermal comfort at standard conditions (ASHRAE), given when the user rests in his seat; Richer space thermal experience - thermal delight and affection; Heterogeneous thermal ambient when the spectator moves between zones or groups of seats; Thermal environment with symbolic and cultural role; High environment sustainability; Adaptation to changes on occupancy levels and spectator distribution with short thermal transient; Neutralization of the transient discomfort using predictive information.

2

Part Occupancy Total Occupancy

ACADS Design

Industrial Design Approach: • The ACADS integrate ergonomic and aesthetics concerns; • The product aspects related to interactions and functional interface with the users (ergonomics),

are: ease of use; ease of maintenance; quantity of user interactions, novelty of user interactions, comfort and safety; • The aesthetical appeal principles that will produce the product differentiation, pride of ownership, fashion, image and designers motivation, are given by the pyramid of thermal needs: Necessity, Delight, Affection and Sacredness. This four qualities enrich the cinema and theatre rooms, with new space experiences, that creates affection between space and users. These qualities and value to the ACADS product, complemented by the low energy consumption.

Sacredness ACADS Affection (room affection) Delight (room experience) Prior Art

Necessity (Thermal neutral room) Pyramid of Thermal Needs

EcoDesign Approach: • The key element for a sustainable air conditioning product is the efficient use of energy

resources (ASHRAE recognizes the effect of its on environment and natural resources to protect the welfare of posterity, 1990); • To accomplish the resource conservation several design principles were used on the ACADS project: thermal load reduction; efficient component design; energy smart design practices and adoption of intelligent control; These approaches were the fundamental support for the development of the ACADS project. The overall system can be seen on the next page.

3

For big entertainment spaces like cinema or theatre it is difficult to give appropriate comfort conditions individually, because it requires large mass of air to handle. Due to the large mass inertia, difficulties arise in the air conditioning reaction time to changes in quantity (thermal load) and distribution of the occupancy. When people arrive or leave the room, the thermal perturbation is detected very late, because of the air mass inertia and the distance it must travel. The transient adaptation of the air conditioning system to the load changes realizes with large reaction time and when it begins it last for long time, and people feel discomfort. Frequently users protest that felt cold/warm when they got in to a place with few people. To resolve these problems, a predictive system will be develop, linking the ticket management system to the air conditioning control system. The load vs. time characteristic of the cinema is scheduled before the real time events, given capacity to the ACADS to adapt sooner to the new load conditions. This approach reduces the system inertia to the thermal load changes between film sessions. This solution can be applied with good results to the air conditioning systems with one single temperature sensor. But the better choice to eliminate the remain problems, is the adoption of a multi-temperature measurement system. The thermal perturbations are detected sooner and the system have a better reaction time. If the underfloor air distribution system is active and can be configurable from the spectator distribution information supplied from the ticket management system, then optimal results can be obtained. The air conditioning will operate only were the spectators are seated, and with the zone temperature feedback the comfort conditions are guaranteed. If the cinema owner feels that this ACADS configuration is not sufficient, because of the movement of user to other seats that are different from the predictive system, then a detection system must be implemented. 4

The cinema room is divided on several zones controlled individually by temperature sensors (two in zones with 30 seats, and one for zones with 18 seats), with predictive information and spectator localization in real time. Even with no predictive or real time spectator distribution information, the system works well with only the multi-temperature measurement system, but with poor efficiency, mainly on part occupancies. The temperature sensors are encapsulated on boxes (right figure) for protection. The sensor is visible from the top (transparent material) given to the spectator the functional characteristic of the box. The box isolate the sensor from the ascent air movement, given the capability to measure the still or ambient air temperature. The box design integrate ergonomic and eco-efficient principles, allied to functional requirements. The aesthetical appeal and functional expression of the box contributes to the spectator affection to the cinema room. 5

The spectator detection is made by reflective materials (light responsive materials) placed on each seat. This elements will have a geometrical shape (can be a symbol or the cinema brand) than can be easily recognized by the software. Therefore each seat has a luminous sign that is interrupted by the spectator when he seats down. This interrupted sign capture by the CCD camera, means a seat taken. The light emitting materials can be fluorescent, phosphorescent, photoluminiscent. Other materials also can be used like the retroreflective technology (3M Scotchlite reflective material) that reflects light directly back to the light source. The vision can detect many signs with one single image avoiding high costs using other alternatives, like installing switch mechanical sensors on each seat, whit a lot of wiring and PCI cards to transmit and receive digital 308 signals. 6

Another solution to increase the efficiency of the air conditioning system is to reduce the heat gains from the cinema illumination. The detection system can also be used to control the room illumination, given more intense lighting to occupied seats than the rest of the room, reducing the heat gains. Aesthetic qualities to the space can be acquired using appropriate lights that focus only on the seats that will and be occupied. Using different colors and localized light, the spectator feels a “warming” reception and a good orientation to find is seat. This is one of the features of the ACADS project to customize the spectator seat, given the “warming reception” to the user. One example of this can be seen on next photo.

7

The cinema virtual prototype was obtained from the entertainment room anthropometrics requirements and represents the standard type for commercial cinemas. There are 308 seats distributed on 15 zones, acclimatized individually. There are 4 zones with 30 seats each, 8 zones x 18 seat 1 zone x 20 seat and 2 zone x 12 seat. Each zone have temperature and air flow sensors, one electric actuator and a PID control. The mechanism used to move the air diffusers on each zone is presented on next pages. This type of room also is included on the polyvalent rooms that contribute about 42% of the room activity/total rooms ratio in the 1T/O4. The rest of the activity can be seen on the next table. Room activity / total rooms ratio in the 1T/04 (INE) Type

Dimension

Cinema Auditorium

Medium

Cinema on shopping center

175 seat per session

Polyvalent room

313 seat per session

The cinema virtual prototype was made on SolidWorks and the thermofluid flow will be simulated on the CosmosFlows, to test and obtain results. If the ergonomic requirements will be satisfied by the prototype, then the next step is the study of the control and management system of the ACADS. The tests protocol will include the different percentage and distribution of the spectator occupancy, remembering the seat preferences, conditioned by the screen position (next photo and statistics).

Mean & Standard Deviation Left

Center

Right

1.3 ; 1.5

4.0 ; 2.0

1.7 ; 1.8

1.1 ; 1.5

4.8 ; 0.9

1.8 ; 1.6

0.6 ; 0.9

2.3 ; 2.4

0.8 ; 1.2

0.6 ; 0.8

1.0 ; 0.7

0.8 ; 0.9

Very Bad (1); Bad (2); Sufficient (3) Good (4); Very Good (5); Excellent

8

The virtual test will be made without seats and the air diffusers movement mechanism. On the real prototype (1/20 scale) a 30 seat zone with movement mechanism will be included to test the control and management system, including vision control. The test results will contribute to improve the ACADS project, and again tested to refine the project. A benchmarking study also can be made by studying the cinema prototype for the prior art and the ACADS air conditioning art. Also different types of air flow supply can be studied. The goal is to refine the project and to establish the final specifications (including benchmarking study). The instrumentation equipment to make the test is: • • • • • •

Keitlhey datalogger; PCI card Keitlhey; CCD camera; PC computer with LabView Software; Termopar and differential sensors; Light responsive materials;

•

The air conditioning air flow will be supplied by a laboratorial air handling unit;

The forward photos show the virtual mechanism that control the air flow of a 30 seat zone. This mechanism will be included on the real cinema prototype.

9

10

11

12

13

14

15

Control and Management System for ACADS Function

Component

Active Floor + Predictive Inf. + Artificial Intelligence Analog multiplexer with temperature sensor (DAQ) Multifunction PCI Card (DAQ)

NI Amux-64T NI 6024E

Analog Output PCI Card (DAQ)

NI 6703

Electric actuator (24 Nm)

DM1.1

Electric actuator (32 Nm)

DMG1.1

Desktop PC

Target PC

LabView Real-Time Module (RTX) for Windows

Intelligent Vision Color or Monochrome Image Acquisition (PCI) + NI IMAQ Color Camera (NTSC)

NI 1405 LTC0435/20 LTC 3341/21

Illumination Control

16