1. Lecture Objectives: Answer questions related to HW 4
Solar Systems
Discus Final Projects
Continue with HVAC system

2. Final Project You need to email me till Monday 3 pm:
Project group members
1 Page proposal for your project
The proposal need to provide basic information about the modeling building or system (you can add a schematic) and the project objectives
Project report guideline is listed in HW sections of the course website
You will have to visit me next week

3. Final Project Topics Solar Systems Geothermal systems
Expand HW3 (PV and hot water)
Geothermal systems
Incorporated into the eQUEST
Building Envelope Optimization
Campus buildings, AEI competition, ….
HVAC systems
Lighting Systems
Specific building in eQUEST or other software
Modeling in matlab
Weep holes, attic temperature, façade systems,….

4. Solar hot water system

5. HVAC Systems Ventilation, Heat Recovery, Economizers,… AEI Student Competition Building or some other
Commercial buildings
Residential buildings
Saving % - depends on how much ventilation we have in the building

6. Geothermal Energy Systems (in combination with a cooling machine / heat pump)
Summer
Winter
In the summer, the earth acts as a cooling tower. The Cooling Machine loads the loop with heat, sending warmed water to be cooled by the earth
In the winter, the earth acts as the boiler. The Heat Pump extracts heat from the loop, sending cooled water to be warmed by the earth.

7. Envelope optimization
AEI Student Competition
A mixed use boiling in New York
Some other building, too

8. Project Fixing Problematic Building at UT
Example of ECJ building

9. eQUEST HVAC Models Predefined configuration (no change)
Divided according to the cooling and heating sources
Details in e-quest help file:
For example:
DX CoilsNo Heating
Packaged Single Zone DX (no heating)
Packaged single zone air conditioner with no heating capacity, typically with ductwork.
Split System Single Zone DX (no heating)
Central single zone air conditioner with no heating, typically with ductwork. System has indoor fan and cooling coil and remote compressor/condensing unit.
Packaged Terminal AC (no heating)
Packaged terminal air conditioning unit with no heating and no ductwork. Unit may be window or through-wall mounted.
Packaged VAV (no heating)
DX CoilsFurnace
Packaged direct expansion cooling system with no heating capacity. System includes a variable volume, single duct fan/distribution system serving multiple zones each with it's own thermostatic control.
Packaged Single Zone DX with Furnace
Central packaged single zone air conditioner with combustion furnace, typically with ductwork.
Split System Single Zone DX with Furnace
Central single zone air conditioner with combustion furnace, typically with ductwork. System has indoor fan and cooling coil and remote compressor/condensing unit.
Packaged Multizone with Furnace
Packaged direct expansion cooling system with combustion furnace. System includes a constant volume fan/distribution system serving multiple zones, each with its own thermostat. Warm and cold air are mixed for each zone to meet thermostat control requirements.

10. Examples of HVAC System
Multizone Dual Duct System
Multi zone VAV with Re-heaters
55°F
90°F
55°F P C P C
Perimeter (P)
Core (C)

11. Dual Duct vs. VAV with Re-heaters for Different Weather Conditions
What happens
if outdoor air is
A, B, C A B C

12. Example of a Plant System (Chilled Water System)
Air cooled chiller
Chiller with a cooling tower
COP ~ 3
COP ~ 5
COP = Cooling Energy / Electric Energy ( same units)

13. Two Basic Approaches for Modeling of HVAC and Building Envelope
Load System Plant model
Building
Qbuiolding
Heating/Cooling
System Q
including
Ventilation
and
Dehumidification
Plant
Integrated models
Building
Heating/Cooling
System
Plant

14. Example of a HVAC Model Schematic of simple air handling unit (AHU)
Mixing box
m - mass flow rate [kg/s], T – temperature [C], w [kgmoist/kgdry air],
r - recirculation rate [-], Q energy/time [W]

15. Example of a Plant Models (Chiller)
P electric () = COP () x Q cooling coil ()
TOA
What is COP for this
air cooled chiller ?
T Condensation = TOA+ ΔT
Evaporation at 1oC
TCWS=5oC
TCWR=11oC
water
Building users (cooling coil in AHU)
COP is changing with the change of TOA

16. Plant model Refrigeration Cycle
Released energy
(condenser)
T outdoor air
T cooled water
- What is COP?
- How the outdoor air temperature
affects chiller performance?
Cooling energy (evaporator)

17. Chiller model: COP= f(TOA , Qcooling , chiller properties)
Chiller data: QNOMINAL nominal cooling power,
PNOMINAL electric consumption for QNOMINAL
The consumed electric power [KW] under any condition
Available capacity as function of evaporator and condenser temperature
Cooling water supply
Outdoor air
Full load efficiency as function of condenser and evaporator temperature
Efficiency as function of percentage of load
Percentage of load:
The coefficient of performance under any condition: