journey from student to nist researcher
TRANSCRIPT
Journey from
Student to
NIST Researcher
Lisa Ng, Ph.D.
ASHRAE Member
Don’t Repeat My Mistakes –
Make Your Own
Undergrad NISTGrad
Undergrad
Department of Civil & Architectural
Engineering
Co-op #1: Construction Management
Almost transferred out of CAE
Co-op #2: More Civil than Architectural
Love/Hate AutoCAD
Marvin Waxman Consulting
Co-op #3: HVAC system design
Ok, I could do this for a living…
Mistake #1I never took the PE exam.
Undergrad
Undergrad
Mistakes #2, #3I wasn’t active.
I couldn’t apply for their scholarships.
Undergrad
It’s not about networking,
it’s about building your network.
Undergrad NISTGrad No idea & then…
Undergrad NISTGrad Why grad school?
Cleanroom facility
(http://www.terrauniversal.com/)
Grad
Yep, back there again!- New faculty
- Research interests aligned with mine
- Staying close to my family
Dr. Jin WenOptimizing sensor placement
Indoor Air Quality
• GAANN Fellow
• Kling-Lindquist Scholarship (ASHRAE)
• Otto Gresner Scholarship (ASHRAE)
• NSF Graduate Research Fellow
• Koerner Family Fellowship
Framework for the Utilization of Forward and Inverse Airflow
Models in Systematic Sensor System Design for Indoor Air
Mistakes #…
Grad
My favorite chapters (having not read it)
2. Ignore the market
3. Stay at the same university
9. Expect the money to take care of itself
16. Expect people to hold your hand
17. Concentrate only on your thesis
20. Do not teach, or teach a ton of courses
30. Write only your PhD thesis
31. Postpone publishing
42. Say whatever pops into your head on social media
57. Consider a non-academic career a form of failure
Piled Higher and Deeper
Grad
http://www.phdcomics.com/
Framework for the Utilization of Forward and Inverse Airflow Models in Systematic Sensor
System Design for Indoor AirNailed it!
Undergrad NIST
IAQ & Ventilation Group
Indoor air quality
Airflow modeling
Energy modeling
Other
Undergrad NIST
40% of U.S. Primary Energy Consumption
Total U.S. Energy Consumption
Source: 2007 Buildings Energy Data Book. Tables 1.1.3, 1.2.3, 1.3.3
Source: 2008 EIA Annual Energy Outlook
Undergrad NIST
IAQ & Ventilation Group
Indoor air quality
Airflow modeling
Energy modeling
Other
Undergrad NIST
IAQ & Ventilation Group
Indoor air quality
Airflow modeling
Energy modeling
Other
-36 -18 0 18 36 54 72
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-20 -10 0 10 20 30 40
Indoor-outdoor temperature difference (oF)
Air
ch
an
ge
ra
te (
h-1
)
Indoor-outdoor temperature difference (oC)
System on, CONTAM
System off, CONTAM
-36 -18 0 18 36 54 72
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-20 -10 0 10 20 30 40
Indoor-outdoor temperature difference (oF)
Air
ch
an
ge r
ate
(h
-1)
Indoor-outdoor temperature difference (oC)
System on, E+ (tight)
System off, E+ (tight)
System on, E+ (CONTAM-equiv.)
System off, E+ (CONTAM-equiv.)
Undergrad NIST
CONTAM model
Perform multizone airflow
simulation w/ weather
Infiltration = Idesign [A + B|ΔT| + D•Ws2]
• Ng, Persily and Emmerich (2015). Improving infiltration modeling
in commercial building energy models. Energy and Buildings vol. 88
• Presented at ASHRAE/IBPSA Simbuild 2014 +
ASHRAE Energy Modeling Conference 2015
Building characteristicsH: height
SV: surface-to-volume ratio
Fn: net system flow
normalized by SA
Method determines
A-D for any
building using only
height, surface
area, volume, and
system flow
Undergrad NIST
-36 -18 0 18 36 54 72
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-20 -10 0 10 20 30 40
Indoor-outdoor temperature difference (oF)
Air
ch
an
ge
ra
te (
h-1
)
Indoor-outdoor temperature difference (oC)
System on, CONTAM
System off, CONTAM
-36 -18 0 18 36 54 72
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-20 -10 0 10 20 30 40
Indoor-outdoor temperature difference (oF)
Air
ch
an
ge r
ate
(h
-1)
Indoor-outdoor temperature difference (oC)
System on, E+ (tight)
System off, E+ (tight)
System on, E+ (CONTAM-equiv.)
System off, E+ (CONTAM-equiv.)
Undergrad NIST
Net-Zero Energy Residential Test Facility
• “Net-zero”: Building that produces as much energy as it consumes annually
• Features
• Tight building envelope
(0.6 h-1 at 50 Pa)
• R-values
• Roof: 72
• Walls: 45
• Windows: 5.3
• CFLs, LED, EnergyStar, LEED Platinum
Undergrad NIST
Net-Zero Energy Residential Test Facility
• Mechanical ventilation provided by heat recovery ventilator (sized to meet ASHRAE
62.2)
• Heating/Cooling provided by air-to-air heat pump with dedicated dehumidification
capability
• For future use: ground source heat exchangers (geothermal), mini-split, small
duct high velocity
• Domestic hot water provided by solar thermal system with heat pump water heater as
backup
• Family of 2 adults & 2 children simulated
• Heaters generating heat
• Humidifiers generating moisture
• Electrical and hot water usage taken from Building America (DOE)
Undergrad NIST
Net-Zero Energy Residential Test Facility
• Completed construction in 2011
• Completed instrumentation in 2012
• Demonstrated (better than!) net-zero from July 2013-June 2014
• 38 days of snow coverage
• Starting in Oct 2014, began 2nd
round of testing after making
improvements to heat pump system
• http://www.nist.gov/el/nzertf/
1440 miles
IAQ results at houseUndergrad NIST
Air-vapor barrier
Poppendieck, Ng, Persily and Hodgson (2015).
Long Term Air Quality Monitoring in a Net-Zero
Energy Residence Designed with Low Emitting
Interior Products. Building and Environment vol 94
IAQ results at houseUndergrad NIST
Ventilation system off + very tight house =
8-10x higher concentrations!
(when temperatures +7 C, 2-3x higher only)
MistakesOpportunities to learn
Undergrad NIST
Student opportunities
• Summer High School Intern Program (SHIP)http://www.nist.gov/ohrm/staffing/ship.cfm
• Summer Undergraduate Research Fellowship (SURF) http://www.nist.gov/surfgaithersburg/
• General student employment information http://www.nist.gov/ohrm/staffing/students.cfm
• Postdoctoral associates
• Guest researchers
Undergrad NIST
MistakeNot taking an opportunity to co-op
Undergrad NIST
