Joshua Rogers Final Project

download Joshua Rogers Final Project

of 9

  • date post

    05-Apr-2018
  • Category

    Documents

  • view

    218
  • download

    0

Embed Size (px)

Transcript of Joshua Rogers Final Project

  • 8/2/2019 Joshua Rogers Final Project

    1/9

    Mechanical Cooling Design

    for The New Orleans Home

    B

    Joshua Roge

    Building Systems ARCH 5

    Spring 20

  • 8/2/2019 Joshua Rogers Final Project

    2/9

  • 8/2/2019 Joshua Rogers Final Project

    3/9

    Table of Contents

    HVAC Design and Theory

    Project Overview

    Designing the HVAC System

    HVAC System Layout

    2

    3

    4-5

    6-7

    ! " # $ $ % & " ' & & ( ) ) " 0 ! 1 2 3 1 4 0 2 2 " 5 & 2

  • 8/2/2019 Joshua Rogers Final Project

    4/9

    HVAC Design and Theory

    An HVAC system provides cool air to a buildings occupant during even the hottest

    summer days. An HVAC system is often overlooked when it is working, but when it fails

    everyone realizes it. After all other steps of passive cooling have been exhausted onlythen should an HVAC system be applied to any building.

    There are several key design issues which must be accounted for during the design

    process of an HVAC system. First, the system needs to distribute air eciently, quietly,

    and gently across a room. It should distribute air around the room, the walls, and

    ceilings so it provides an environment of cold air throughout the building. It is

    important to recognize that a system cannot deliver air across a distance of greater than

    twenty feet, so the supplys for cold air need to be placed accordingly. Duct work can

    cause great ineciencies in the system, so it should always be designed to deliver airwith as little friction and interruption as possible. The system should be quiet and the air

    quality high. Finally, the system needs to be easy to install and maintain for long periods

    of time.

    6 7 8 9 @ 8 A B C D E F G H E I P Q R S T U V W X Y 7 ` ` 7 a D G A B b Q X c G R S b A 8 R b 9 d e e 9 8 A B X f W g h i g p f h h X q b B G p

  • 8/2/2019 Joshua Rogers Final Project

    5/9

    Project Overview

    The New Orleans Home is a small, two-bedroom residence located in New Orleans,

    Louisiana. The home is located in an area devastated by ooding during Hurricane

    Katrina, and therefore has all the living spaces seven feet above the ground. NewOrleans is a very hot and humid climate located along the Gulf of Mexico, so having a

    cool home during the summer is priority for residents of New Orleans.

    The home is 866 square feet, and is designed to be LEED Platinum. The walls and ceiling

    have a R-Value of 30, and the house has very few windows facing East and West which

    are not shaded. The building is designed to have a very high indoor air quality, so the air

    leakage from inside to outside is minimal.

    Even with the high levels of insulation and care in designing the building envelope, thebuilding will still require an HVAC unit. The average temperatures in New Orleans in July,

    is 95 degrees with 68% relative humidity. Living in New Orleans without air conditioning

    during the summer months is a very uncomfortable experience.

    r s t u v t w x y s s w x w t u u t w x j k x

  • 8/2/2019 Joshua Rogers Final Project

    6/9

    Designing the HVAC System

    1. Estimate Heat Gain Using Table F3 from Mechanical and Electrical Equipment for Buildings

    A. People and Equipment

    Heat gain from people: 230 BTU/H per person = 230*3 = 690 BTU/H

    Heat gain from appliances: 1200 BTU/H per residence

    B. Electrical Lighting

    Heat gain from interior lighting: 2.7 BTU/H

    C. Heat Gain through Building Envelope

    Heat gain through windows: Total window area/total oor area = 99 SF/866 SF = 2.4 BTU/SF

    Heat gain through walls: (Total Wall area/total oor area)*U-value of wall*25=

    (1871 SF/866 SF)*.065*.25 = 3.5 BTU/SF

    Heat gain through roof: (Total roof area/total oor area)*U-value of Roof*45=

    (1290 SF/866 SF)*0.34*45 = 2.2 BTU/SF

    D. Inltration

    Heat gain from inltration in windows and walls:

    {(Total window area + Total wall area)/Total oor area}*1.9 =

    {(99 SF+1871 SF)/866 SF)*1.9 = 4.32 BTU/SF

    E. Ventilation

    Heat Gain from air ventilation:

    (Total CFM of outdoor air/Total oor area)*27 =

    (45 CFM/866 SF)*27 = 1.4 BTU/SF

    Add B, C, D, E together = 2.7+2.4+3.5+2.2+4.32+1.4 = 16.52 Total Heat Gain per SF

    Total Transmission = 16.52 BTU/SF * 866 SF = 14,306 BTU/H

    Room Sensible Heat = People + Equipment + Total Transmission

    = 690 BTU/H+1200 BTU/H+14,306 BTU/H = 16,196 BTU/H

    2. Calculate quantity of air required to cool the room

    A. Calculate Cubic feet per minute: Room sensible heat/1.1*Change in temperature =

    16,196 BTU/H/1.1*(75-20) = 736 CFM

    B. Calculate portion which is outdoor air: 3 People * 45 CFM = 135 CFM

    135 CFM/736 CFM = 18% Outdoor Air

    l m n o n z { | } ~ m m { | } n | o o n

  • 8/2/2019 Joshua Rogers Final Project

    7/9

    B A 18%

    OUTD

    OOR

    AIR

    82%

    INDOOR

    AIRC

    D

    3. Calculate Grand Total Heat

    A. GTH = 4.5 * cfm * (Hc-Hb) = 4.5 * 736 * (34-23) = 36,432 BTU

    The size of required refrigeration unit is specied in tons where 1 ton = 12,000 BTU/H

    The refrigeration required: 36,432 BTU/H/12,000 BTU/H ton = 3.036 Tons

    A 3 Ton unit will be sucient

    4. Calculate Duct Size

    B. Table 9.4 in MEEB: 3 ton system will supply 1600 CFM

    (1600CFM * 144(in/ft))/1700 CFM = 135 in so choose a 10*14 duct

    Point A - Bulls eye Temperature @ 75 degrees & 50% RH

    Point B - Desired condition of the chilled air @ 55 degrees,

    Enthalpy is 23 BTU/H

    Point C - Mixture of indoor and outdoor air,

    Enthalpy is 34 BTU/H

    Point D -Temperature outside @ 95 degrees and 68% RH

    - -

    2

  • 8/2/2019 Joshua Rogers Final Project

    8/9

    HVAC System Layout

  • 8/2/2019 Joshua Rogers Final Project

    9/9

    ! " # $

    % & ' & ( ) & ( 0 1 ' ( 1 ) 1 2 1 3 4 5 6 7 ' 8 ( ( 9 @ 1 ' 8 8 A 6 3 ) 3 8 A 8 ' 1 9 @ 6 3 B C D 6 7 ' 8 ( ( 9 @ 1 ' 8 8 A E

    % & ' & ( ) & ( 0 1 ' ( 1 ) 6 4 8 3 F 9 @ 1 7 1 & 4 & 3 F ( 9 8 1 2 1 3 4 5 ) & ( 9 ' & G H 9 1 9 @ 1 6 & ' E I @ 1 7 8 8 4 6 & ' P 6 4 4 ( 9 8 9 @ 1 F ' 8 H 3 ) Q @ & 4 1

    9 @ 1 Q 6 ' A ' & ( 1 ( 6 3 ) & ( 1 R 0 1 4 4 1 ) 2 & 6 9 @ 1 S & 9 7 @ 1 3 6 3 ) G 6 9 @ ' 8 8 A P 6 3 ( E

    % & ' & ( 9 @ ' 8 Q 3 P ' 8 A 9 @ 1 6 & ' ( H 0 0 4 & 1 ( 6 4 8 3 F 9 @ 1 7 1 & 4 & 3 F ( 6 3 ) 9 8 Q 6 ' ) ( Q 6 4 4 ( E I @ 1 6 & ' 9 @ 1 3 P 6 4 4 ( 7 8 A P 8 ' 9 6 G 4 5

    6 3 ) 1 2 1 3 4 5 ) 8 Q 3 9 8 9 @ 1 ' 1 ( & ) 1 3 9 ( T 0 ' 8 2 & ) & 3 F 6 3 1 2 1 3 T 7 8 A P 8 ' 9 6 G 4 1 1 3 2 & ' 8 3 A 1 3 9 & 3 9 @ 1 @ 8 A 1 E