1

New Kid on the Block: Passive House Comes into the Neighborhood

Lucyna de Barbaro & Ayres Freitas March 15, 2014

Content:

Passive House concept Transformational eco-movement developing

around Passive House -- in US, in Europe Our Squirrel Hill duplex, ½ of which (west

side unit) is available for sale

But first, few words about motivation…

2

3

Why Focus on Buildings?

Buildings account for 40% of total energy used and generate 45% of total US CO2 emissions

Hefty contribution to Global Warming and Climate Change

US adds ~6 billion tons of CO2 emissions a year, world’s total: ~34 billion CO2 emissions per capita in US: 17.3 tons, China 7.2 tons, EU average: 7.5,

average for the world: 4 (July 2011 data) Renewable energy growth too slow (25%) compared to fossil fuel use

increase in the last decade (41%) Effects of self-acceleration of global warming (“tipping points”) are very

serious With current trends we are not on a path to limit warming to 2o C by 2100

Passive House Standard could be part of the answer

The standard was developed in Germany in 1990-ties and is now widely tried and adopted

Was proven economically viable; ~10% increase in construction cost while achieving 80% reduction in energy use of the building (in Germany)

No additional energy generation like solar or geothermal Simply built to maintain a near constant indoor

temperature without adding much energy for heating and cooling

4

Passive Houses can be any shape / form

5

Retrofit, CA

Utah

IL

Boehm, Austria

Can have any function:

6

Religious center, VA

Community center, Austria

Office building

Innsbruck: Winter Olympics Village, now dorms

7

Passive House Standard Adoption in Europe

8

9

Annual New Construction #s in Austria

and in US

Belgium’s main province adopted the law that all new construction is to Passive House standard – 3 years later, PH hits mainstream

10

11

How does it compare? Different standards with respect to annual energy use

and cooling

12

Energy used in residential buildings

Median value: 70 kBtu/sf/y Passive House

Standard is defined by setting a limit on energy use

Over the life of the house, imbedded energy (in materials, construction, etc.) is ~10%, while operating energy is ~90%

1 kBtu=0.3 kWh

13

How does it work?

Building envelope: one of many possible wall solutions for Passive House:

R values for Passive House in Pittsburgh versus (code, new constr.):

Walls: R35-45 (20)

Slab: R35-45 (10)

Roof: R60-80 (38)

Windows R 5-10 (2.9)

A lot of building science, but well understood and modeled

R value: measure of thermal resistance; heat transfer per unit area per unit time

Squirrel Hill Passive House Duplex 15

Passive House windows Windows are the weakest part of insulation envelope Passive house certified windows:

excellent performance of glazing and frame

© YARO/Makrowin

Triple glazing

Wood, aluminum or PVC frame

Insulation core (uPVC , cork, etc.)

Aluminum cladding (some models)

Tilt/turn design for good seal

Thermal bridges are eliminated in PH due to smarter design and advances in energy modeling

16

17

Thermal envelope, before and after Passive House retrofit:

Important breakthrough: energy recovery ventilators

18

70-90% efficient in keeping the energy & humidity of the room/indoor air “inside”

Measurable performance of PH is “built in” into PH standard:

Criterion #1: total energy has to be less than 38 kBtu/sf/yr Note: this is primary (or source) energy, not site energy.

About 3 times more energy needs to be used at the source to generate energy we use on site due to generation inefficiency and transport losses. Source energy is the most relevant measure of carbon emission.

19

Criterion #2: heating and cooling energy limits: 4.75 kBtu/sf/yr, each

This is like heating the whole 2000 sf house with a hair dryer 9 hrs a day (and making it nicely warm!)

1 kBtu=0.3 kWh

20

Verifiable methodology is built into PH StandardCriterion #3: air tightness (0.6 air-changes per hour at 50 pascals)Measured through blower-door test to assure that standard is met

Passive House air leakage is about 10 times less than standard new construction

21

Passive HouseFocus on economic

feasibility: Shift money from

mechanical systems to the building envelope

Long lasting, high quality construction

Focus on comfort: Healthy interior

environments due to continuous ventilation

“Year-round barefoot indoor comfort on a dime” No drafts/uniform temp.

Focus on predictability: Computer modeling with

PHPP (Passive House Planning Package) and WUFI (Heat and Moisture Dynamics* modeling)

Optimization of performance w/ PHPP/WUFI

Certification from Passive House Institute US (PHIUS)

*Wärme und Feuchte Instationär

22

Our Passive House Duplex: 2883-2887 Fernwald Rd. Walkability Index: 45

Frick Park: ~0.6 Universities: ~3.5 miles

Distances/driving (20 lb of CO2 from each gallon of gas) are also a big part of sustainability

Squirrel Hill shops and amenities ~1.5 miles away

Fernwald Rd streetscape

23

2 Lots zoned for single family attached, 1RA , sizes: 35 x 100 ftSouthern slope ~10°

Squirrel Hill Passive House Duplex 24

Architect: Alan Dunn & Associates

25

Squirrel Hill Duplex, northern facade

26

Squirrel Hill Duplex from south-west

Permeable drivewayRain water cisternsPre-wired for PV arrayElectric car-charging …

27

Squirrel Hill Duplex, from north-east

28

First floor layout

29

Second floor layout

30

Life Cycle Analysis (LCA)Life cycle embodied energy plus operating energy of the building;

R. Jacobson, 2012 Passive House ConferenceDifferent type of superinsulated walls compared to standard frame

Over the life of the house, any superinsulated wall results in much smaller energy use

Squirrel Hill Passive House Duplex 31

Environmental impacts of building materials

Environmental Performance of Cladding, from CertainTeed FC_LCA_Report_FC057 (data from Building for Economic and Environmental Sustainability program, operated by NIST)

Significant differences – important to pay attention to LCA & Global Warming Potential

Squirrel Hill Passive House Duplex 32

Mechanical Systems for Squirrel Hill Duplex

• Fujitsu 12kBtu/hr ducted heat pump for both heating and cooling

• Zehnder Comfo 350 ERV for continuous ventilation with energy recovery

• Each system will have its own set of ducts to allow proper balancing of each function

Squirrel Hill Passive House Duplex 33

Mech. system design by John Semmelhack

34

Passive House movement in US

PH Institute (PHIUS) Committed to making high-performance Passive building the mainstream

market standard Trained more than 1,000 architects, engineers, energy consultants, and

builders

Passive House Standard is now a joint PHIUS and Department of Energy standard

PH Alliance – chapter structure for professionals and PH enthusiasts. Pittsburgh chapter founded in Oct 2013

8th Annual PH Conference just recently happened here; 400+ attendees

Pittsburgh area projects

35

• Former YMCA in McKeesport – retrofit to PH standard

• Heidelberg House• Walnut St. retrofit• Former VFW in

Hazelwood to house Carnegie Library

• Next planned:Uptown Lofts on FifthSquirrel Hill Duplex

36

Why engage in Passive House project?

To set an example Get the ball rolling To be part of the

movement dedicated to extreme efficiency

Because this is how much carbon it is safe to use*

So that the next generation(s) have Earth like the one we know…?*See Carbon Tracker or 350.org