Announcement

Course Exam

October 6th (Thursday)

In class: 90 minutes long

Examples are posted on the course website

Lecture Objectives:

• Answer questions related the Project 1 and the Final Project

• Continue with Photo Voltaic (PV) and hot water systems

• Discuss HW3

• Learn about the impact of HVAC system on energy consumption

- overview HVAC systems

Requirement for the projectUndergrad students: Team project (2 or 3 members)

Grad students: Individual effort

Email me (till next Friday):• Final project group members • Project title• One paragraph (200-300 words) including

- Project objective - Methodology- Expected results

Any schematic drawing is welcome

HW3 Design of zero energy house

• Install a PV system on your house from your project 1-a

http://www.nrel.gov/gis/images/eere_pv/national_photovoltaic_2012-01.jpghttp://rredc.nrel.gov/solar/old_data/nsrdb/1961-1990/redbook/atlas/

PV system Silicon crystal base

Tin film

Hot Water Solar

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.

Building HVAC Systems (Primary and Secondary Building Systems)

AHU

Buildingenvelope

Cooling(chiller)

(or Gas)

Electricity

Gas

Heating(boilers)

Fresh air For ventilation

Distribution systems

Air transport

Secondary systems

Primarysystems

AHU – Air Handling Unit

HVAC systems affect the energy efficiency of the building as much as the building envelope

Integration of HVAC and building physics models

BuildingHeating/Cooling

SystemPlant

BuildingHeating/Cooling

SystemPlant

Load System Plant model

Integrated models

Qbuiolding Q

including

Ventilation

and

Dehumidification

Example of System Models:Schematic of simple air handling unit (AHU)

rmSfans

cooler heater

mS

QC QH

wO wS

TR

room TR

Qroom_sensibel

(1-r)mS mS

wM

wR

Qroom_latent

TSTO

wR

TM

Tf,inTf,out

m - mass flow rate [kg/s], T – temperature [C], w [kgmoist/kgdry air], r - recirculation rate [-], Q energy/time [W]

Mixing box