announcements 1) thursday 02/09 in class midterm exam - i will be in the classroom at 9:20 am -...

Announcements

1) Thursday 02/09 In class Midterm Exam

- I will be in the classroom at 9:20 AM

- Example and solution are posted on the course website

2) FIELD TRIP (HVAC systems) Tuesday 02/11 9:30AM

- Neural and Molecular Science (NMS)

- Meet in front of NMS building

Fieldtrip

• Neural and Molecular Science (NMS) building • building at the corner of Speedway and Dean

Keeton.  

• Tuesday 02/11 at 9:30 AM at

the door on Speedway side

• Do not arrive late !

Homework Assignment 4Table 1 Results of cooling load calculation and required amount of fresh air for ventilation

Zone 1Zone 2 Zone 3 Whole

building

Sensible cooling load for zone Time when the max cooling load appear

41000 Btu/hat 4 PM

45000 Btu/hat 6 PM

27000 Btu/hat 8 AM 92000 Btu/h

at 6 PMSensible cooling load for critical hour for whole building (6 PM)

37000 Btu/hat 6 PM

45000 Btu/hat 6 PM

9000 Btu/hat 6 PM

Latent cooling load (internal sources + infiltration)

5400 Btu/h 5200 Btu/h 5400 Btu/h 16000 Btu/h

Required amount of fresh air based on number of occupants

240 CFM(12 occupants)

520 CFM(26 occupants)

240 CFM(12 occupants)

1000 CFM(50 occupants)

Review

• What is purpose of psychrometric chart?

• What quantities are on axes?• Diagonal lines?• Curved lines?

• What is significant about the saturation curve?

• How do you find the dew point temperature?

• How to find the enthalpy?

Psychrometric Processes

• What does sensible heating or cooling look like on the chart?• What does sensible mean? What does latent mean?

• Why does some cooling cause dehumidification?• What does an evaporative cooling process look like

on the chart?• When two air streams mix, how do you find the

conditions for the new air stream?

Heat Transfer

• What defines a heat transfer though the wall?

• What are air films and when do you include them in calculations?• What parameters do you need to know for

determining the R-value of an airspace?

• When do you use R-values and when do you use U-values?

Heating and Cooling Loads

• What are the major components of a heating load?• What is the difference for a cooling load

calculation?

• How do you account for heating and cooling loads associated with windows?• With infiltration?

• Why are internal gains and solar gains most relevant for cooling loads?

Heating systems

• What is difference between furnace and boiler?

• What are advantages of water as a heat transfer fluid?

• What are the relevant equations for sizing steam and water pipes?• Where do you get the input data?

• Name four fuels that can be used in a boiler?• Which ones require venting?

Cooling Systems

• What are the differences between vapor compression and absorption cycles?

• What happens to water vapor in an evaporator?

• Does an evaporator have a sensible and a latent capacity?• Does a condenser?

• How the heat pumps work?

Ventilation Systems

• What are the components of AHU?• Which are the major ventilation systems? • Show Air-Conditioning in psychrometric chart. • When to use combination of air and water

systems.• Know the purpose and characteristics of duct

system and fans. • Know the purpose and characteristics of pipe

system and pumps.

Building HVAC - Delivery Systems

All air system(can use water or refrigerant

in cooling coil)

All water system(for heating you can use steam instead water)

Combined system

Single zone (a whole apartment can be the single zone)

Multi zone

CAV-VT VAV

VAV

Heating and cooling energy production

Cooling plant Heating plant Energy storage plant

Multi zone

Fan Coil

Baseboard heater

Radiant panels

ceiling floor

DOAS

water system

-Building sensible load

Transport - refrigerant - water - ….

air system

- Ventilation- Building latent load

Dual duct

VAVWith reheater

CAVWith Zonal terminal units

Project Assignment 1

• Cover the previous course material • Homeworks• Reading assignments

• Similar to a real-world project

• Preparation for ARE 465 project

Project Assignment 1

• Design the environmental system for large building• Project that you will have next year

• Simplification (one zone for calculation)

• Show the logic for zoning• Select the heating and cooling fuel• Select the heating and cooling source• Select and size the HVAC system• Size the Cooling Coil and analyze the process in AHU

Project Assignment 1

4 Groups (teams) – 4 Different assignments

• Type of buildings– hospital (group 1)– campus building (group 2)– bank (group 3) – hotel (group 4) – shopping mall (group 5)

• Location of the building– Boston MA (group 1) – Chicago IL (group 2) – Iowa City IA (group 3) – Newark NJ (group 4) – Pittsburg (group 5)

Project Assignment 1

EVALUATION• 90 points ~ 9% of your grade

• Second project assignment 60 points

• Each group project will be graded as integral work

• Group member effort and project grade will form your final grade on the project

Project Assignment 1

Project elements

1. Cooling and Heating load of building

2) Zoning

3) Heating and cooling source selection

4) HVAC system selection

5) Air handling Unit

Project Groups

• Total 5

• ????

Project Assignment 1

Suggestions

• Divide the groups into 2 subgroups and split the work • Subgroups should communicate • Have one person in charge for the final project form

• Divide the project into 3-4 sections and each student will work on a small portion• In the case that some student have a problem switch the tasks• Meet at least twice to discus the progress• One person will put together the whole project