Transcript UA Delta T - HVAC Excellence
Energy Auditing & Building Science
South Point Hotel, Las Vegas, NV 2013
Presenters
• Richard Benkowski, United Association • Frank Spevak, Energy Conservatory • Erik Rasmussen, ESCO Group
Session Time Line Tuesday 13:30 to 16:45
• Introductions • What is Building Science • Exercise & Handouts • Exercise Discussion • UA Delta T 13:45 to 16:20 • The Building Shell • Heat Transfer • BREAK 15:00 to 15:20 • NEAT Software 16:40 to 16:45
Wednesday 08:00 to 16:00
• Blower Door & Infiltration Duct Blaster & Leakage 08:00 to 11:20 • Neat Software 09:35 to 09:40 • Break 09:40 to 10:00 • Neat Software 11:25 to 11:30 • Lunch 11:30 to 12:30 • Health and Safety CO • Heating systems • Neat Software 13:20 to 13:25 • Combustion • Break 14:00 to 14:20 • Finalize audit and Discuss
Building Science / Energy Audit
• Building science is the study of a building’s interactions between the structure and its components.
• A structure’s occupants, mechanical systems, and the surrounding outdoor environment all play a role in the performance of a building.
Energy Audit • The process of identifying energy conservation opportunities.
Building Science Design & Development
• Climate • Thermal dynamics • Insulation • Thermal boundary • Air leakage • Ventilation • Heating and cooling • Humidity and moisture sources • Stack effect and fans
WHAT IS ENERGY?
THE MEASURABLE QUANTITY OF
•
HEAT
•
WORK
•
LIGHT
HEAT ENERGY – BTU/HR
WORK ENERGY
LIGHT ENERGY
Industry Guidelines
Industry Scorecards
• LEED • GBCI • ASHRAE • RESCheck
Industry Scorecards
• NEAT / e+ • COMCheck • Joe Biden’s Home Energy Score • DOE
Industry Scorecards
• EPA • GreenCHILL • Portfolio Manager
ASHRAE COMPARISON
ASHRAE 90.1 – WHAT’S NEXT?
New Change
“2010” Min Efficiency Standards
up to 63 tons
IEER
part load metric replaces IPLV
Exhaust air energy recovery
scope mandated
Manual dampers
not allowed
Low leakage economizer dampers 2 Speed Fan
zone systems > 10 tons Multiple requirement for single
VAV control changes
: Re-Heat, DDC, Dehumidification Effective Date Jan 2010 Federal Jan 2010 Federal Jan 2010 State Jan 2010 State Jan 2012 State Jan 2012 State Jan 2012 State Reference Section Section 6 Section 6.2.2 Addendum y, au Section 6.5.6.1 Addendum e Section 6.4.3.4 Addendum b Section 6.4.3.4
Section 6, Addendum n Section 6, Addendum b,c,h, bh, bx
HIGHER TIER STANDARDS AND GUIDES
• –
LEED (just revised and will be revised again in 2012)
– New Building Institute Core Performance Guide – Commercial EnergyStar (being revised) – FEMP (being revised) – CEE - Consortium for Energy Efficiency (being revised) – ASHRAE 189.1 and ASHRAE 189.2
(new)
– ASHRAE Building Rating System
(new)
– ASHRAE Advanced Energy Design Guides
(new)
– California Green Building Standards Code (CALGREEN)
(new)
– GBI - Green Building Assessment Protocol for Commercial Buildings
(new)
– IECC - International Green Construction Code (IGCC)
(new)
Go to Carrier.com for up to the minute updates
Climate Zones – 2009 IECC
FUTURE EFFICIENCY Single Phase Requirements < 5 tons
< < Effective dates: May 1, 2013 for non-weatherized furnaces
Jan 1, 2015 for air conditioners & heat pumps, including weatherized furnaces (gas packs)
Effective dates of subsequent standards: 2019 for non-weatherized furnaces and 2022 for air conditioners/heat pumps and weatherized furnaces
NEW
ENERGY STAR / CEE / ASHRAE 189
• Multiple higher efficiency standards are being developed and revised –
Not
mandatory at the state levels – EnergyStar is now
required
on Federal buildings (Jan 2007), may be required on state buildings Size – Often tied to Category
rebates
ASHRAE 90.1 CEE Tier 1 E-Star 5/10 ASHRAE 189 CEE Tier 2 2010 <65k, 3 phase >=65K &<135K >=135K & <240K >=240K & <760K >=760K Electric Gas Heat Electric Gas Heat Electric Gas Heat Electric Gas Heat Electric Gas Heat Split System Single Package Split System Single Package All All All All All All All All 13 SEER 11.2 EER 11.0 EER 11.0 EER 10.8 EER 10.0 EER 9.8 EER 9.7 EER 9.5 EER 14 SEER 11.7 EER 11.5 EER 11.7 EER 11.5 EER 10.7 EER 10.5 EER 9.9 EER 9.7 EER 14 SEER 11.7 EER 11.5 EER 11.7 EER 11.5 EER
FUTURE FUTURE FUTURE FUTURE
14 SEER 11.5 EER 11.3 EER 11.5 EER 11.3 EER 10.0 EER 9.8 EER 9.7 EER 9.5 EER 15 SEER 12.2 EER 12.0 EER 12.2 EER 12.0 EER 11.0 EER 10.8 EER 10.4 EER 10.2 EER
HUMAN COMFORT • • • • • • •
TEMPERATURE HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT
HUMAN COMFORT • • • • • • •
TEMPERATURE 70 - 75F HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT
HUMAN COMFORT • • • • • • •
TEMPERATURE 70 - 75F HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT 30 – 60%RH
HUMAN COMFORT • • • • • • •
TEMPERATURE 70 - 75F HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT 30 – 60%RH 10 -20 FPM
HUMAN COMFORT • • • • • • •
TEMPERATURE 70 - 75F HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT 30 – 60%RH 10 -20 FPM 7.5CFM/PERSON
HUMAN COMFORT • • • • • • •
TEMPERATURE 70 - 75F HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT 30 – 60%RH 10 -20 FPM 7.5CFM/PERSON MERV 13
HUMAN COMFORT • • • • • • •
TEMPERATURE 70 - 75F HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT 30 – 60%RH 10 -20 FPM 7.5CFM/PERSON MERV 13 25 -40 dBA
HUMAN COMFORT • • • • • • •
TEMPERATURE 70 - 75F HUMIDITY AIR CIRCULATION AIR VENTILATION AIR FILTRATION SOUND LIGHT 30 – 60%RH 10 -20 FPM 7.5CFM/PERSON MERV 13 25 -40 dBA 50-300 LUX
Mechanical Science
Heat Transfer
• Conduction • Radiation • Convection
WHICH WAY DOES “HEAT” FLOW?
RESIDENTIAL HEAT LOSS
AIR INFILTRATION • AIR LEAKING OUT OF A 70F HOME • WILL BE REPLACED BY 20F AIR INFILTRATION
AIR MOVES BY PRESSURE DIFFERENTIAL
AIR MOVES BY PRESSURE DIFFERENTIAL
• FROM HIGH • TO LOW
WHAT IS “R” VALUE?
Compared to the “U” Factor?
What is the ‘U’ Factor ?
• Overall coefficient of heat transfer, given in BTUH per square foot of heat transfer surface area, per degree F temperature difference
Heat Flow Thru a Wall
Conductivity = k
• Amount of heat in BTUH flowing through a
one inch thickness
of a material of uniform consistency when the area of the material is one square foot and when the difference in temperature between the faces of the material is one degree F.
Conductivity = k
One square foot, one inch thick, one deg F
BTU MOVEMENT
•
71F 1 SQ. FT.
ONE HOUR 1 BTU 70F
Conductance = C
Amount of heat in BTUH flowing through an area of one square foot of a material, having a certain specified thickness , when the difference in temperature between the two faces of the material is one degree F.
Conductance = C
Thermal Resistance = R
Defined as the reciprocal of the heat transfer coefficient. The higher the number of the heat transfer coefficient, the more readily will the material transfer heat and the more rapid the heat flow will be. Resistance is just the opposite of the coefficient of heat transfer.
Thermal Resistance = R
Which material will have a higher R value?
Face brick or common brick?
Thermal Resistance = R
Which material will have a higher R value?
Asphalt shingles or 3/8” plywood?
ADDING “R” VALUES
• YOU HAVE A CEILING AREA OF 1,000 FT. SQ. - R-38, WITH A PULL- DOWN ATTIC STAIRS WITH A PLYWOOD BOARD ACCESS 10 FT. SQ. - R-0.5. HOW WILL THIS EFFECT MY OVERALL R VALUE?
ADDING “R” VALUES 1,000 FT.SQ. TOTAL 990 FT.SQ. R-38 10 FT.SQ.
R-0.5
(990 x .0263)+(10 x 2) 1,000 (26.037)+(20) 1,000 46.037
1,000 U-.046037
U = 0.0263 U = 2.0
= = =U-.046037
= R-21.7
What is the ‘U’ Factor ?
• Overall coefficient of heat transfer , given in BTUH per square foot of heat transfer surface area, per degree F temperature difference
Calculate the ‘U’ Factor ?
ADD the R values: R = Total Resistance
R
T =
R
1 +
R
2 +
R
3 +
R
4 , etc.
Calculate the ‘U’ Factor ?
INVERT the Total Resistance:
U
=
1 / R
T
Calculate the ‘U’ Factor ?
A wall has the following characteristics: Outside surface coefficient – 0.17
Brick, 4” thick – 0.40
Air space filled with insulation – 5.30
Gypsum wallboard – 0.45
Inside surface coefficient – 0.68
U = ?
Calculate the Heat Flow
What is the heat flow for the wall (previous slide) that is 10’ high 150’ long, when the outdoor temperature is 95F and the indoor temperature is 72F?
BTUH
T =
Area
x
U
x
(T
1 –
T
2
)
Three HVAC Fluids
• Air • Water • Refrigerant
Three HVAC Devices
• Fans • Pumps • Compressors
THE TASK OF TRANSFERING HEAT
H6
FOUR BASIC SYSTEMS USED 1 - ALL-AIR 2 - ALL-WATER 3 - AIR/WATER 4 - DX HEAT
H6
Change of State
THE TASK OF TRANSFERING HEAT Which process transfers the most heat?
1. 50 gallons of water @ 32 degF changing to 416.5# of ice @32 degF 2. 20 gallons or water @ 212 degF to steam at 212 degF 3. 30# of steam @ 212 degF condenses to 3.6 gallons of water at 80 degF
P D P D’ P C’ P S’ Liquid Subcooling A’ A CONDENSER INLET PRESSURE & CORRESPONDING SAT. TEMP.
+ P BETWEEN COND. & EVAP.
E Compressor Discharge D DISCH. LINE PRESS. DROP D’ B’ B EVAPORATOR OUTLET PRESSURE & CORRESPONDING SAT. TEMP.
C S C’ SUCTION LINE PRESS. DROP FLASH GAS REFRIG. EFFECT HEAT OF COMPRESSION H F H A’ = H B’ H C H S’ = H C’
ENTHALPY - BTU/LB
A OR A’ CONDENSER OUTLET B OB B’ EVAPORATOR INLET C OR C’ EVAPORATOR OUTLET S’ COMPRESSOR INLET D COMPRESSOR DISCHARGE D’ CONDENSER INLET
H8
Refrigerant Properties
R – 12 Boiling -22 120 Cond 158# 40 Evap Sp Vol LH Vapor BTU/# 37# 1.5
68 CFC 22 -44 260# 69# 1.2
93 410 -61 418# 119# 1.25
98 HFC 134 -15 171# 35# 1.9
90
H7
Psychrometric Chart
Air and Water Analysis
Evaporative Cooling Humidification Heat and Humidify Sensible Cooling Heating Cooling and Dehumidification Dehumidification Heating and Dehumidification
66
Exercise: Heat Transfer
You have two sheets 1. Diagram of a commercial HVAC system 2. Mechanical systems recording sheet Objective: Identify and record all heat transfers that occur using this system during the year.
H9
Heat Transfer Exercise