Your House as a Healthy System

Bruce Stahlberg

Improvements / Remodeling

• When one has finished building one's house, one suddenly realizes that in the process one has learned something that one really needed to know in the worst way - before one began. -Friedrich Nietzsche

Remodeling

• Who in the room has had a remodeling project done in the past?

• Who is planning to have one done?

Common types of remodels?

• Bathroom• Kitchen• Addition• Basement• Entire House

Common changes included• Increased mechanical ventilation• New heating and air conditioning system• New windows, doors• More insulation• Air sealing / Reduction in Infiltration • New roof and siding• Other…

The House as a System:

One improvement on your home may affect the operation of another part of

your home...and not always positively.

Questions to ask before remodeling!

PRE-Remodel: Questions

Is the house safe?Are there carbon monoxide sources?

Does it have any pre-existing conditions (that may get worse)?

How tight is the house?

PRE-Remodel: Questions

Are there comfort problems? Are there moisture problems?

Ice dams?Water damage?

What is being proposed? Does it include the entire home?

The House as a SystemExample

• Install new kitchen exhaust hood

• What may be some unintended consequences?

Bath fan

dryer

Kitchen Exhaust

Water heater(natural draft)

Heating / Fireplace

Air is pulled from the house and has to come from some place

Bath fan

dryer

Kitchen Exhaust

Water heater(natural draft)

Heating / Fireplace

Air is pulled from the house and has to come from some place

Negative ( - ) Pressure

House Depressurization

PRE vs. POSTWill appliances still vent properly?

How leaky (or tight) is the home?

• Blower door test • PRE and POST = what impact?

Negative pressure can create backdrafting

Signs of combustion gases entering the home

Carbon Monoxide?

One way to determine if

you have carbon monoxide

Other Sources of Carbon Monoxide

Check for carbon monoxide in unlikely locations

The House as a SystemExample

• Replace old atmospheric draft, inefficient furnace with an Energy Star, sealed combustion system?

• What may be some unintended consequences?

The House as a System:Example

• Possibly moisture on the windows the next winter

• And / or Orphaning of the water heater and potentially back drafting of the system

Atmospheric draft vs. power vented

• New furnace was elimination of a small but continuous exhaust system

• Possibly “orphaning” the water heater

Two pipe system on right does not take any air from inside the house: closed combustion

Moisture On Windows

• Moisture levels can go up in home• Excessive moisture on windows can ruin

windows and create mold

Moisture Problems

• Excessive moisture can also show up in the attic• Important to control the relative humidity of a

home

Signs of moisture at attic hatch

Atmospheric draft vs. Power vented

Available in Water Heaters too

Much less chance of back drafting

AIR BARRIER* WITH INSULATION

*Think rain coat over sweater

Sealing air leaks the easiest and most cost effective yet often missed in remodeling project

We agree insulation is important

Need to make it work right

Continuous Air Barrrier

• ContinuousContinuous• Full contact withFull contact with

interior air barrier interior air barrier (e.g., sheet rock)(e.g., sheet rock)

• Fully enclose Fully enclose conditionedconditionedspacespace

Courtesy of Southface Courtesy of Southface InstituteInstitute

Penetrations through the air barrier

• Chimney and open wall.

Penetrations through the air barrier

• Need to be air SEALED !

22ndnd FloorFloor

First First Floor Floor

Thermal Thermal BypassBypass

Thermal Thermal BypassBypass

SolutionSolution::•align insulationalign insulation•add air barriersadd air barriers

Open Floor Joist air leak

Longfellow Bungalow Air Leak

• Major air leak often overlooked and missed• Holes sealed with foam, caulk, air tight materials

Penetrations through air barrier

• Open floors represent large leaks

Is insulation effective?

• How does yellow or pink fiberglass turn so dark? Answer: Air moving through it (filter)

Insulation

• “We already have insulation”

Insulation

• Needs to be installed correctly to be effective

Avoid Problems

• Ice dams, moisture issues

Avoid Problems

• Safety, carbon monoxide

• Interior moisture

Project / Remodeling Process

• Plan! Part of planning process includes testing• Home Performance Test to determine pre-existing

conditions• Gain information, make decisions, set priorities• Communication (i.e. ask questions) with all parties

(contractor, owner, etc.)• Site visit or questions along the way (while still in process

and dusty)• Test out and Verify when project is complete

Safety concerns

• Do not tighten a home with a safety or serious indoor air quality problem!

• Correct the situation before proceeding with air tightening measures

Solutions Include

• Air sealing and insulation

• Energy Efficient mechanical equipment

• Designed ventilation

• Safe operation

• Increased comfort

• More durability

Solutions!

• Mechanically Controlled Ventilation• High Efficiency equipment

Solutions!

• Effective and documented air sealing

Solutions!

• Properly installed insulation products

Solutions!

• Verify with thermal imaging

Why the need to test?

Examples of real life remodeling projects $400,000 remodel, utility audit post-

inspection only, payments wanted Ice dams, owner wanted roof torn off

(just needed air sealing) Lower efficiency equipment installed, not

given option or choice

Why the need to test?

Test before starting Incorporate ideas into plans Check during remodel (still dusty and

messy) Best not to ask for advice after-the-fact

Home Performance Testingfor Existing Homes

On-site evaluation of your home Safety testing Inspection of mechanical systems; Heating, Cooling,

Water heating, and Ventilation systems Inspection of insulation types, levels and values for

walls, attics, crawlspaces, windows, etc. Diagnostic Pressure testing: Blower door test Thermal Imaging Camera Measuring exhaust fan flow rates Documentation of recommendations for improvement

Bruce Stahlberg612.558.5959