1. Objectives Select project topics Review for exam Learn about DOAS systems

2. Final Project Group 1: Heather Smith Tommy Beales Matt Leos Group 2: Patrick Gorman Kenny Greaves Matt McCarthy Group 3: Sarah Johnson Jocelyn Citty Neil Woodson Group 4: Zaid Arzate Brian Burcham Justin Barrett Group 5: Nick Williams Stephen Mathai Kevin Carbonnier Group 6: Marcus Allen Josh Atkins Matt Larson Group 7: Stephen Fridley Shahrukh Gaziani Margaret Lawson Group 8: Marwa Zaatari Megan Gunther Elena Nirlo Group 9: Gregory Arcangeli Andrew Hoisington Tobias Nilsson Individual projects Wesley Cole Adam Keeling Sami Kolahdoozan Gautam Salhotra

3. Project topics 1) VAV system design Fresh air requirements and recirculation rate calculation Selection of zonal and central HVAC components based on cooling and heating load components For zones: VAV boxes, reheaters, reheater plumbing For whole system: AHU and components, chiller & cooling tower, boiler, and electric power requirement Control description – sequence of operation Heat recovery system and or economizers 2) DOAS system design Fresh air requirement and split between air and hydronic loads (sensible and latent cooling loads) Selection of zonal and central HVAC components based on cooling and heating load components For zones: fan coils and plumbing For whole system: AHU and components, chiller & cooling tower, boiler, and electric power requirement Control description – sequence of operation Heat recovery system and or economizers

4. Project topics 3) Cooling systems and distribution Air cooled condenser vs. water cooled condenser (energy performance analysis) Design of plumbing systems for campus and pumping stations Control of centralized system Saving with variable speed pumps 4) Duct Design (in Revit) - Diffuser selection, design of local and central duct system components - Spacing issues and difference between round and square ducts - Difference between manual calculation and calculation by Revit (for a section of the duct system) - Balancing and fan selection - Life cycle analysis and optimization (fan power consumption vs. system cost)

5. Course Exam This Thursday (April 21) 9:20 am Same classroom 1.5-hour exam Cheat sheets Questions: all problems (short but comprehensive)

6. Course Exam Next Thursday (April 15) 7 pm Same classroom (ECJ 7.208) 2.5-hour exam Open book open notes All problem types of questions (short but comprehensive)

7. Objectives Finish the pumps and plumbing systems Discuss the final project

8. Review for the Exam Should be able to do all calculations associated with lectures as well as HWs Problems may deal with context i.e. Explain how thermal conductivity influences fin efficiency? Holding all other parameters equal, how important is increasing the thermal conductivity

9. Psychrometrics and Processes (7 & 8) Know all parameters and their location/orientation on a psychrometric chart Be able to look up conversions of parameters on a psychrometric chart and with calculations Use protractor to calculate SHR and ΔW/Δh Plot processes on a chart for real buildings List what is held constant for different processes Describe processes in AHUs in psychrometric chat

10. Direct Contact (10) Purpose of cooling towers Psychrometrics Describe how a cooling tower works

11. Cycles (3), Refrigerants (4) Describe Carnot cycle and components Understand constant variables for each component List, describe, and calculate inefficiencies Use figures, refrigerant tables and equations for different substances List important parameters for refrigerant selection/differentiation

12. Heat Exchangers (11) Differentiate types Calculate ε, and UA, etc. Complete broad analysis Which m is larger, which Δt is larger? Within and between heat exchangers

13. Heat Exchangers (11) Calculate and compare different thermal resistances Describe influence of key factors Integrate different parameters/resistances Manipulate UA equation Describe differences for wet and dry heat exchangers

14. Diffusers, Duct Components (18) Select diffusers Define all terms on manufacturer data sheets Calculate pressure drop of: Straight duct Duct fittings Components (coils, VAV boxes, dampers, etc.) Differentiate fans and describe fan curves Use fan laws

15. Duct layout/design (18) Equal friction method Supply or return systems Balance the system Describe static regain method Compare them

16. Project Design problem For example: Given cooling and heating load design HVAC for the building Research problem Analysis based problem. For example: Find the optimum solution for…. Developed control strategy for… Life cycle cost analysis for … ……….

17. Pumps and Fans Power law Types and basic properties Selection process

18. DOAS System www.doas.psu.edu

19. DOAS with multi-split systems Fresh air?

20. DOAS fresh air configurations

22. Cooling and Heating Loads (For Project) » Zone orientation Commercial building

23. Cooling and Heating Loads (For Project) » Cooling and heating load for each zone and whole building: » Fresh air requirement based on number of occupants: » To provide acceptable IAQ in the building, ventilation » system supply minimal amount of » fresh air is in all spaces (except plenums) » that produce 0.2 ACH.

24. Cooling Load Calculation Mostly computer based Handouts for manual calculation http://www.ce.utexas.edu/prof/Novoselac/classes/ARE346N/Handouts/heatloss_table_2008.doc http://www.ce.utexas.edu/prof/Novoselac/classes/ARE346N/Handouts/ASHRAE_%20Gains_Calculation_Tables.doc

25. Heat Recovery Sensible and Enthalpy wheel

26. Economizer Economizer (fresh air volume flow rate control) » mixing » damper » fresh » air » T & RH sensors » recirc. » air » Controlled device is damper » - Damper for the air » - Valve for the liquids

27. Economizer – cooling regime How to control the fresh air volume flow rate? » % fresh air » Minimum for » ventilation » 100% » If TOA < Tset-point → Supply more fresh air than the minimum required » The question is how much? » Open the damper for the fresh air » and compare the Troom with the Tset-point. » Open till you get the Troom = Tset-point » If you have 100% fresh air and your » still need cooling use cooling coil. » What are the priorities: » - Control the dampers and then the cooling coils or » - Control the valves of cooling coil and then the dampers ? » Defend by SEQUENCE OF OERATION » the set of operation which HVAC designer provides to the automatic control engineer

28. Economizer – cooling regime » Example of SEQUENCE OF OERATIONS: » If TOA < Tset-point open the fresh air damper the maximum position » Then, if Tindoor air < Tset-point start closing the cooling coil valve » If cooling coil valve is closed and T indoor air < Tset-point start closing the damper » till you get T indoor air = T set-point » » Other variations are possible

29. Desiccant wheel » Figure 3 – A desiccant-based cooling system combined with regenerative heat exchanger, vapor compression cooling, and evaporative humidifier (hybrid system).