REDUCE MONTHLY
NATURAL GAS
CONSUMPTION –
HVAC
Mohammad Shams,
Seyed Alireza Tabatabaei,
Roozbeh Hojatpanah,
Siavash Farahmand,
Shahriar Ahmadi Ghoohaki
Department of Mechanical Engineering, IUPUI
ME 414 Thermal-Fluid Systems Design
Fall 2010, Professor John Toksoy
Y Statement

Reduce monthly natural gas consumption by 20%
for the months of Dec thru Mar
 Set
back temperature
 Insulation improvements
The Funneling Effect
30+ Inputs
• Process Maps
All X’s
MEASURE
• C&E Matrix
ANALYZE
IMPROVE
CONTROL
• Failure Modes and Effects
Analysis
• Multi-Vari Studies
10 - 15
1st “Hit List”
8 - 10
Screened List
• Design of Experiments
(DOE)
4-8
Found Critical X’s
• Control Plans
3-6
Controlling Critical X’s
Critical Input Variables
Does the Setup Measure Energy
Consumption Accurately

For each of the 24 hr data set
 Calculate
the heater on time
 Calculate heating degree days
 Plot HDD vs. heater on time

Does it show a linear behavior
Analysis

Heater on Time vs HDD
Date
22-Jan
28-Jan
29-Jan
3-Feb
4-Feb
5-Feb
6-Feb
Total Heater On Time
Total Heater On
Calculated
Theoretical
Error percent
(hrs)
0.284
1.325
1.328
0.828
1.0465
1.185
1.057
Time (days)
0.011833333
0.055208333
0.055333333
0.0345
0.043604167
0.049375
0.044041667
HDD
30.05351743
49.58732704
50.30495225
36.87681015
33.9020865
32.6507873
42.25509352
HDD
30
48
50
37
35
32
41
0.178391443
3.306931342
0.609904497
0.332945553
3.136895702
2.033710322
3.061203695
Analysis
Heater on Time vs HDD
Calculated HDD vs. Total Heatre On Time
60
y = 382.75x + 23.306
50
R2 = 0.5049
Calculated HDD

40
30
Calculated HDD
Linear (Calculated HDD)
20
10
0
0
0.01
0.02
0.03
0.04
Total Heater on Time (days)
0.05
0.06
Analysis

Heater on Time vs HDD
Caculated HDD vs. Actual HDD
60
y = 1.0555x - 1.788
50
R2 = 0.9906
40
Calculated HDD
30
Linear (Calculated HDD)
20
10
0
0
10
20
30
40
50
60
Analysis

Error Percent of Heater on Time vs HDD
Error percent
3.5
3
2.5
2
Error percent
1.5
1
0.5
0
22-Jan
28-Jan
29-Jan
3-Feb
4-Feb
5-Feb
6-Feb
Therms Analysis
Total Heater On
Total Heater On
Calculated
Time (hrs)
0.284
1.325
1.328
0.828
1.0465
1.185
1.057
Time (days)
0.011833333
0.055208333
0.055333333
0.0345
0.043604167
0.049375
0.044041667
HDD
30.05351743
49.58732704
50.30495225
36.87681015
33.9020865
32.6507873
42.25509352
Theoretical HDD
Error
30
48
50
37
35
32
41
percent
0.178391
3.306931
0.609904
0.332946
3.136896
2.03371
3.061204
Energy Consumption (BTU)
Energy Consumption
18744
87450
87648
54648
69069
78210
69762
(Therms)
0.18744
0.8745
0.87648
0.54648
0.69069
0.7821
0.69762
Date
22-Jan
28-Jan
29-Jan
3-Feb
4-Feb
5-Feb
6-Feb
Total Heat loss for heating season (9 months) : (from the excel file)
BTU/hr
BTU
Therm
-8934.34
-58704867.84
-587.0486784
Total Heat loss for heating season (9 months) : (from the excel file)
BTU/hr
BTU
Therm
-8934.34
-58704867.84
-587.0486784
Total Heat loss for January : (from the excel file)
BTU/hr
BTU
Therm
-992.7044444
-6522763.093
-65.22763093
Total Heat loss for February : (from the excel file)
BTU/hr
BTU
Therm
-992.7044444
-6522763.093
-65.22763093
Average Daily Heat Loss for January: (form the excel file)
BTU/hr
BTU
Therm
-32.02272401
-210411.7127
-2.104117127
Average Daily Heat Loss for February: (form the excel file)
BTU/hr
BTU
Therm
-35.45373016
-232955.8248
-2.329558248
Measurement Error


Error due to long signal wires
Filter design
 Impact
on mean value
Initial Capability

Initial capability
 What
is the current energy usage as baseline where
savings will be calculated from


Degree day comparison
Past 5 to 10 years gas and electric bills (kWhr used not $$$)
 Calculate
heat loss from the house using the excel
analysis tool

Make the tool more general to include individual rooms
 Run
transient heat transfer analysis using the Matlab
tool and compare to measured data
Energy Cost Estimation
Date
Total Heater On Time (hrs)
Total Heater On Time (days)
22-Jan
28-Jan
29-Jan
3-Feb
4-Feb
5-Feb
6-Feb
0.284
1.325
1.328
0.828
1.0465
1.185
1.057
0.011833333
0.055208333
0.055333333
0.0345
0.043604167
0.049375
0.044041667
Calculated HDD
30.05351743
49.58732704
50.30495225
36.87681015
33.9020865
32.6507873
42.25509352
Theoretical HDD
Error percent
Energy Consumption (BTU)
Energy Consumption (Therms)
Energy Cost $
30
48
50
37
35
32
41
0.178391443
3.306931342
0.609904497
0.332945553
3.136895702
2.033710322
3.061203695
18744
87450
87648
54648
69069
78210
69762
0.18744
0.8745
0.87648
0.54648
0.69069
0.7821
0.69762
5745.036
26803.425
26864.112
16749.612
21169.6485
23971.365
21382.053
Results

Number of peaks =29
100
90

80
70
60
T_Out
50
T_Reg
T_Room
Humidity
40
30
20
10
0
0
1
2
3
4
5
6
7
8
9
10
11
Jan 22nd
12
13
14
15
16
17
18
19
20
21
22
23
24

The cost for one day at these
temperatures is: $0.33
The optimal day time
temperature is: 51 Degrees F
The total running time per day
is: 97 Minutes
Results

Number of peaks =51
100
90
80

70
60
T_Out
T_Reg
50
T_Room
Humidity
40
30
20
10
0
0
1
2
3
4
5
6
7
8
9
10
11
Jan 28th
12
13
14
15
16
17
18
19
20
21
22
23
24

The cost for one day at these
temperatures is: $0.13
The optimal day time
temperature is: 59 Degrees F
The total running time per day
is: 38 Minutes
Results
100
Number of peaks =59
90
80
Jan 29th
70
60
T_Out
50
T_Reg
T_Room
Humidity
40
30
20
10
0
0
1



2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
The cost for one day at these
temperatures is: $0.18
The optimal day time temperature is:
47 Degrees F
The total running time per day is: 53
Minutes
21
22
23
24
Results
100
Number of peaks =33
90
80
Feb 3rd
70
T_Out
60
T_Reg
T_Room
50
Humidity
40
30
20
10
0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
•The cost for one day at these temperatures
is: $0.24
•The optimal day time temperature is: 48
Degrees F
•The total running time per day is: 71
Minutes
22
23
24
Results
Number of peaks =48
100
90
80
Feb 4th
70
60
T_Out
T_Reg
50
T_Room
Humidity
40
30
20
10
0
0
5



10
15
20
The cost for one day at these
temperatures is: $0.28
The optimal day time
temperature is: 50 Degrees F
The total running time per day is:
83 Minutes
25
Results
Number of peaks=57
100
90
80
Feb 5th
70
60
T_Out
50
T_Reg
T_Room
40
Humidity
30
20
10
0
0



1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
The cost for one day at these
temperatures is: $0.27
The optimal day time temperature
is: 50 Degrees F
The total running time per day is:
79 Minutes
23
24
Results
Number of peaks=50
100
90
80
70
60
T_Out
50
T_Reg
T_Room
40
Humidity
30
20
10
0
0



1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
The cost for one day at these
temperatures is: $0.22
The optimal day time temperature
is: 49 Degrees F
The total running time per day is:
64 Minutes
20
21
22
23
24
Feb 6th
HEAT EXCHANGER
DESIGN
Department of Mechanical Engineering, IUPUI
ME 414 Thermal-Fluid Systems Design
Fall 2010, Professor John Toksoy
Mohammad Shams,
Seyed Alireza Tabatabaei,
Roozbeh Hojatpanah,
Siavash Farahmand,
Shahriar Ahmadi Ghoohaki
Design Parameters

Process Fluid
 Water
 Inlet
45ºC
 Outlet 25ºC

City Water
 Inlet

20ºC
Optimal Length Less Than 7 meters
Effective Variables
Effective Variables
Tube Thickness
Shell Thickness
Shell Material
M-dot Tube
M-dot Tube
Shell I/D
Shell I/D
Tube Length
Tube Length
Counter / Parallel
Tube O/D
Tube O/D
Tube Material
•Due to previous iterations these nine were the variables that
had the greatest effect on Weight, Length, Q, and ∆P’s
Generated Matlab File
Initial Inputs Generating
Plots of Main Effect
Pareto Charts for Optimization
•
Shell side pressure drop- Shell I/D had the greatest effect
•
Heat Exchanger overall weight- Shell I/D and Tube Length
•
Tube pressure drop- Mass flow rate through the tubes, Shell I/D and
Tube Length
Pareto Charts for Optimization
Optimization Plot
Optimization Results
Tube Side Heat Transfer Parameters
Number of Tubes, N
4169
Number of Passes
1
Tubes OD
0.0063 m
Tubes ID
0.0054 m
Tube Length, L
4.4000 m
Tube Pitch, PT
0.0079 m
Heat Transfer Coefficient, h
4158.44 W/m2.C
Overall Heat Transfer Coefficient
U (Tube outside Area)
1739.11 W/m2.C
Heat Transfer Rate
Desired Heat Transfer Rate
5106273.07 W
Calculated Heat Transfer Rate
5133356.91 W
Difference
-27083.84 W
Desired - To - Calculated Ratio
0.99
Shell Side Heat Transfer Parameters
Shell ID
0.5398 m
Shell Cross Sectional Area
0.2289 m2
Shell Flow Area
0.1059 m2
Shell Equivalent Diameter
0.0046 m
Mass Velocity, G
1028.84 kg/m2.s
Heat Transfer Coefficient, h
4419.42 W/m2.C
HE Pressure Drop
Shell Side ∆P
85606.84 Pa
Tube Side ∆P
8115.88 Pa
Heat Exchanger Weight
Total Weight
1362.78 kg
Adjusted Optimized Results
Tube Side Heat Transfer Parameters
Number of Tubes, N
3881
Shell Side Heat Transfer Parameters
Shell ID
0.5462 m
Number of Passes
Tubes OD
Tubes ID
1
0.0062 m
0.0053 m
Shell Cross Sectional Area
0.2343 m2
Shell Flow Area
Shell Equivalent Diameter
0.1084 m2
0.0045 m
Tube Length, L
4.2759 m
Mass Velocity, G
1006.65 kg/m2*s
Tube Pitch, PT
Heat Transfer Coefficient, h
0.0077 m
4087.62 W/m2*C
Overall Heat Transfer Coefficient
U (Tube outside Area)
1715.16 W/m2*C
Heat Transfer Rate
Desired Heat Transfer Rate
5106273.07 W
Calculated Heat Transfer Rate
5163877.58 W
Difference
-57604.51 W
Desired - To - Calculated Ratio
0.99
Heat Transfer Coefficient, h
4383.64 W/m2*C
HE Pressure Drop
Shell Side ∆P
85674.36 Pa
Tube Side ∆P
7956.80 Pa
Heat Exchanger Weight
Total Weight
1360.46 kg
Questions
?