Pittsburgh Theological Seminary Anderson Apartment
Retrofit Study Phillip Kuehne Xinxin Hu
Methodology Stage 1: Upgrading Envelope Stage 2: Upgrading Mechanical Equipment Stage 3: Upgrading Appliances Stage 4: Rooftop Solar PV Stage 5: Exceeding Code Envelope Upgrade Metrics: • Annual Energy Reduction • Annual Energy Cost Reduction • HERS Score.
Software: REM/Rate
Code Compliant with 2015 IECC
Site Energy Use Intensity(EUI) Comparison • Zero Energy Single Family Site EUI: 5 - 20 KBtu/ft2 (ZEH Lec 3, 2018) • Average Multi-family Site EUI: 59.6 KBtu/ft2 (Fannie Mae Industry Survey, 2012) Site EUI (KBtu/ft2)
No-Change
Retrofit
Retrofit + PV
Existing Best Unit
78.3
22.6
10.2
Existing Worst Unit
92.7
24.3
12.2
Average US MultiFamily
59.6
Zero Energy Single Family
5-20
Code Compliant Retrofit Strategies - Overall Performance • * Envelope only is compared to baseline performance • Each subsequent row compares performance to the previous row BestCase CodeCompliant Retrofit
Energy Cost Savings ($)
Percent Energy Savings (%)
HERS Score
75
31%
98
Env+ME
130
52%
69
Env+ME+App
40
39%
42
Env+ME+App+PV
1676
65%
12
WorstCase CodeCompliant Retrofit
Energy Cost Savings ($)
Percent Energy Savings (%)
HERS Score
Envelope
111
32%
110
Env+ME
123
50%
63
Env+ME+App
22
23%
45
Env+ME+App+PV
1438
42%
19
Envelope
*
1. Envelope Retrofit • Reduces Heating and Cooling Load • Reduces ME Capacity 2. Mechanical Equipment Upgrade and adding PV system saves more Energy, Energy Cost and achieves lower HERS score.
Notes: • Env: Envelope • ME: Mechanical Equipment • App: Appliances
Best Unit Location & Properties
View Looking Northeast
Energy Performance
Site EUI (KBtu/ft2)
Best Unit
78.3
HERS Score
134
Annual Total Consumption (MMBtu/yr)
Annual Energy Cost ($/yr)
72.7
2934
First Floor Middle Unit Floor Plan
Best Unit Code Compliant Retrofit Strategies Energy Performance 1.
Seal the Envelope •
2.
15 → 3 (unit: ACH@50Pa)
Exterior Wall Insulation • R13 Rockwool and Fiber Reinf Conc Panel
3. 4.
65%
60%
MechEquip
• Dbl Pane LoE, U=0.3, SHGC=0.52
50%
Water Heater EF
40%
(2) AO Smith - HPTU-50N, Voltex Hybrid HP, 50 gal Drain Water Heat Recovery 0.74 EF to 3.53 EF
Clothes Washer Efficiency • Whirlpool - WED9290FW, 7.4 cu. ft., CEF=4.5, Hybrid HP
6.
70%
Window U value
• • •
5.
Percent Energy Savings (%)
Rooftop Solar PV •
Envelope
Appliances
32%
30% 23% 18%
20% 10%
10% 6%
6% 0%
2%
1%
1%
0% -10%
-5%
(70) Canadian Solar - CS6U, 300W, Hi Eff Polycrystaline Dishwasher is a default input in REM/Rate simulation, it is upgraded to 270kWh/yr with 8 place setting capacity.
Worst Unit Location & Properties Energy Performance Site EUI (Kbtu/ft2)
Worst Unit
View Looking Northeast
92.7
HERS Score
Annual Total Consumption (MMBtu/yr)
Annual Energy Cost ($/yr)
161
104.8
3049
Third Floor End Unit Floor Plan
Worst Unit Code Compliance Retrofit Strategies Energy Performance 1.
Seal the Envelope •
2.
Roof Insulation •
3.
4. 5.
6. 7.
Peerless - 52 PBC, NG, AFUE=95.3%, MBH=114 70 AFUE → 95 AFUE
Window A/C unit Eff • •
8.
(2) AO Smith - HPTU-50N, Voltex Hybrid HP, 50 gal Drain Water Heat Recovery 0.74 EF → 3.53 EF
Heating Boiler AFUE • •
8.5 EER → 12 EER high performance Env → Demand decreased
Rooftop Solar PV •
42% 40%
Dbl Pane LoE, U=0.3, SHGC=0.52
Water Heater EF • • •
51% 50%
R13 Rockwool and Fiber Reinf Conc Panel
Window U value •
60%
R36 Rockwool and WP on Existing
Exterior Wall Insulation •
Percent Energy Savings (%) MechEquip
15 → 3 (unit: ACH@50Pa)
(70) Canadian Solar - CS6U, 300W, Hi Eff Polycrystaline
Appliances
30%
Envelope
24% 19%
20% 14%
13% 10%
22%
12%
10% 5%
3% 0%
0%
2%
Code Exceeding Retrofit Strategies performed not well Compared to Code Compliant Envelope Case Best Case Dwelling Unit
Upgrade Description
Cost Savings Percent Energy HERS ($) Savings (%) Score
Exterior Wall
R21 Rockwool and Fiber Reinf Conc Panel
1
2%
96
Window
Fenestral Dbl Pane LoE, U=0.28, SHGC=0.45
0
0%
96
Compared to Code Compliant Envelope Case Worst Case Dwelling Unit
Upgrade Description
Cost Savings ($)
Percent Energy Savings (%)
HERS Score
Roof
R45 Rockwool and Water Proof on Existing
-89
-37%
137
Exterior Wall
R21 Rockwool and Fiber Reinf Conc Panel
-102
-42%
140
Window
Fenestral Dbl Pane LoE, U=0.28, SHGC=0.45
-132
-55%
150
Proposed Exterior Wall Assembly • Exterior building envelope approach allows for major improvements with minor impact to tenants
Exterior
• Continuous exterior insulation is typically Interior superior to interior • Interior insulation in a cold climate masonry retrofit can cause freeze/thaw issues (cracking & spalling)
Proposed Exterior Wall Assembly
Proposed Windows • New windows are proposed in-plane with the new exterior insulation layers for thermal continuity • High performance windows with thermally-broken frames are required to meet energy code Exterior
Interior
Proposed Window Assembly
Proposed Roof • Proposed Rockwool Multiflex accommodates direct waterproofing adherence (no additional cover board) • Compatible with a wide range of waterproofing membranes Exterior
Interior
Proposed Rooftop Solar PV Arrays • Pennsylvania net metering is allowed for up to 110% of electrical consumption • 50 kW residential/ 1 MW commercial max. capacities
• Adding battery storage will help reduce peak electrical demand and utility demand surcharges
View Looking Northeast
Takeaways – Retrofit Strategies 1. Seal your envelope: 3 ACH @ 50Pa according to IECC 2015 2. Insulate Roof • R-49
3. Insulate Exterior Wall • R-13
4. Increase U-value of Window • U-0.32
5. Increase Water Heater Energy Efficiency (EF) 6. Increase Boiler Efficiency (AFUE) 7. Rooftop Solar PV
Thank you
Any Questions?