1. Intelligent HVAC Control
Pete Wituszynski Advisor: Professor Drake

2. Motivation
Commercial buildings

3. Motivation Residential Systems
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4. The Problem
Each thermostat knows what it wants, but the system as a whole only knows “on” or “off”
Energy wasted “waiting” for heat calls
Space is still heated when it is unoccupied
Expensive commercial solutions

5. Project Residential Heating Installation
Zones being added by homeowner
Each bedroom independent
Hot water through heat exchanger
Easily programmable temperatures
Affordable

6. Software Control
PC Based

7. Software Control Python Code for Control Script
Will run every few minutes
Re-load configuration data each time
This makes it easy to change settings

8. Easily Programmable Crucial piece of the project
User must have control over all aspects
Each zone on a time/day schedule
Modified in real-time by smartphone

9. Web Interface Provides user access for programming
All data stored in MySQL database
This is the same data used by Control Script
Possible Internet connectivity
Used from smartphone

10. Simple Hardware Maxim Integrated 1-Wire devices USB Interface
Master talks over network
Unique addresses
Output to commercial relay board

11. Control Web Interface  MySQL MySQL  Python Zone Concept
Zones require a pump and heat
Controlled by sensor or thermostat
Relay output to valves, pumps, boiler
Setpoint on a schedule

12. Control “Voting” Voting schedule Ignore non-voting zones
Still heat them when voting zones call
Analog thermostats as a user interface
Temperature in other zones track together

13. Software Flowchart Website and MySQL Database
Apply configured rules and schedule to determine setpoints
Initialize Variables from Database
Activate Zones where temperature is below setpoint
Map devices to Variables
Poll Temperature Sensors
If any zone is active, turn on boiler
Turn off inactive zones or boiler
Poll Input Triggers

14. Hardware Details 1-Wire Temperature Sensors 1-Wire 8x I/O chip
5v Relay Board
24VAC Inputs
USB Master

15. Hardware Details DS18B20 Temperature Sensors
DS channel One- Wire I/O
Thermostats
24VAC to 5VDC Input Module
DS channel One- Wire I/O
Valves and Pumps
8-Channel Relay Board
DS9490R USB One-Wire Master
Raspberry Pi Miniature PC

16. Implementation Prototyping right away Begin writing software
Still waiting for Raspberry Pi computer
Final hardware design by winter break
Installed with homeowner end of winter

17. Testing Collect at least 2 weeks of system use
Make necessary improvements
Run time per cycle
Track actual vs. desired temperature
Determine “response time” of each zone
Frequency of user interaction

18. Timeline to Completion

19. Budget Item Quantity Price per piece (Dollars) Raspberry Pi 1 40.00
Output Module
20.00
DS18B20 8
4.56
DS2408 2
7.22
DS9490R
30.00
LTV-844H 3
1.12
Misc. Components -
Total
$164.28