Be the MVP in the CAZ:Combustion Testing

for Beginners

ESSN 1Wednesday, April 21, 2010 10:30 am to Noon

2010 National ACI Conference, Austin TXA. Tamasin Sterner and Steve Dyba, Pure Energy

Objectives of This SessionBe the Most Valued Professional (MVP) in

the Combustion Appliance Zone (CAZ)

►Learn why it is important to be sure the combustion appliances are safe to use: before and after weatherization

►Learn how to take each test, efficiently and safely

On The Job Mentoring

Featured in Home Energy Magazine

Givens►We will be referring to BPI Standards,

procedures and action levels, for testing

►We’ve made mistakes and want to save you from doing the same

►We’ve learned much about old and new systems and want to share this knowledge to save you time

Learning Curve►You will be a MVP, but not a Pro after this session – or

even after testing several systems and CAZ’s.

Testing Sessions

Learning Curve

Sometimes It Is Easy To Diagnose Problems

Ultimate Goal►The best scenario is to eliminate all older,

inefficient atmospherically drafted combustion appliances

►And replace them with high efficiency, direct vent appliances so we are in control of the house and its systems instead of being controlled by the systems

►But, until this can happen, we must ensure safe operation when weatherizing

Most Older Systems Don’t Have Safety Mechanisms

►Most newer systems won’t fire if there is a problem with the flue

►Older systems will fire – if they are making CO, the CO in the flue gasses can leak into the living area

►We are mostly concerned with systems that are not 90+, direct vent

►There are always exceptions!

Some Tests are Always Performed, Regardless of Appliance Age or Type

►Gas Leak Testing

►Ambient CO Monitoring

►Flame Roll Out Observation

►CO in Exhaust – sometimes higher than BPI Action Levels – but manufacturers may allow higher CO levels due to being power vented

Why Is This Important Now?►Some programs are requiring Energy Auditors

and Field Technicians to be BPI Building Analyst Certified.

►More families are using combustion appliances as supplemental heat.

►Some electric programs are beginning to air seal homes with combustion appliances to reduce cooling load.

So…..►The purpose of air sealing and some insulation

is to reduce the air exchange across the thermal boundary.

►If the home has a fossil fuel heating or water heating system, the reduced air leakage may change the way the combustion appliances work.

►Any planned reduction in air flow (CFM -50Pa) means the combustion appliances must be checked BEFORE air sealing to be sure they are operating safely…. And they need to be checked AFTER air sealing to be sure they still operate safely.

The Big PictureWhy Perform Combustion Safety Tests?

►When fuels don’t burn fully, Carbon Monoxide (CO) can be formed. This is our main concern.

►Carbon monoxide can get into the house if it can’t get out by the chimney/flue.

►It might not be able to get out due to chimney problems and/or because exhaust fans in the house are pulling air down the chimney.

Beside COOther Issues

►Flame rollout has caused house fires

►Gas leaks can cause explosions – even small gas leaks can become big gas leaks

The Tests Determine:► Is there CO in the ambient air; the combustion appliance zone

(CAZ); the flues; the gas oven, and if so, how much? Is it too much?

► Are there any gas leaks in the gas lines or valves or joints?

► Do the fumes go out the chimney/flue quickly? Do any fumes come back into the room?

► When the water heater or furnace or boiler fires up, do any of the flames come out of the unit?

► When the CAZ is depressurized the most by exhaust fans in the house, do the appliances still draft?

► Is the pressure in the flue with reference to the CAZ strong enough to be sure the appliance drafts?

Combustion Safety TestingAll Combustion Safety Tests must be

performed if:

►Atmospherically vented combustion appliances exist and

►Air sealing or insulation is done – to reduce cooling load or to reduce heating load

►During the worst case CAZ depressurization set-up is when these appliances are most likely to fail to draft properly

►When bathroom fans, vented kitchen range hoods, vented dryers are on, they are pumping air out of the house.

►New air has to come from somewhere to replace what is being pumped out.

►A likely place for that new air to enter the house is the chimney and flues.

►If the water heater or furnace comes on when air is coming down the flue, the flue gasses will enter the house.

►THIS IS BAD

“Worst Case” Test

Action Levels

What is Carbon Monoxide ?

►CO is a product of incomplete combustion of a fuel

►It is very dangerous for human and animals, because it prevents the absorbstion of oxygen in the blood stream

►CO is expressed in parts per million (ppm)

Sometimes Things Go Backwards

►Back-Draft

►Flame Roll-Out

►Spillage

Graphic © Readers Digest

2001

Courtesy of Bill Spohn, Trutech Tools

Sources of CO►Fuel burning furnaces, boilers, and water

heaters

►Fuel burning space heaters

►Fireplaces

►Gas ranges & ovens

►Vehicles

►Tobacco smoke

Characteristics of CO

►Odorless►Colorless►Tasteless►Mixes well in air

Does not stratify

Follows air flow in a structure

►Poisonous

Courtesy of Bill Spohn, Trutech Tools

CO Health Effects► 35 ppm NIOSH Permissible Exposure Limit – 8 hours► 200 ppm NIOSH Ceiling– 15 minutes► 200 ppm Slight headache with 2-3 hours► 400 ppm Headache within 1-2 hours► 800 ppm Sickness & twitching of limbs within 1-

2 hours; unconsciousness in 2 hours► 1,600 ppm Headache within 20 minutes; death

within 2 hours► 3,200 ppm Death in 30 minutes► 6,400 ppm Death in 10-15 minutes► 12,800 ppm Death in 1-3 minutes

Courtesy of Bill Spohn, Trutech Tools

Types of Furnaces ►Atmospheric – Natural Draft

Buoyancy Creates NEGATIVE Pressure in Flue

►Induced Draft Fan Creates NEGATIVE Pressure in Flue

►Power Draft –Power Vent Fan Creates POSITIVE Pressure in Flue

►Condensing “Sealed combustion”, Direct vent, POSITVE

Pressure in Flue

Combustible Gas Leak Detection

Big Problems

►Flame Rollout►Spillage, Backdrafting

More Big Problems

Testing for CO in the Appliance

►Test for CO in undiluted gasses

Testing Draft Pressure►Some combustion analyzers test draft pressure as well

as CO

Oven CO Testing

Sealing Test Holes►For double wall (B-vent) flue pipes, letters from vent

manufacturers say “If you must drill, use high temperature, non-hardening sealant to plug the hole on the inner sleeve. Do the same for the outer sleeve, but cover with a patch of aluminum tape over the sealant”.

►For single wall flue pipes, use the same, or metal hole plugs.

►High Temperature Metal Flue Tape is available. Good up to 600 degrees F. www.3M.com

What If A Test Fails?

►If a test fails before air sealing and/or insulating: follow procedure – no air sealing until the problem is fixed

►If a test fails after air sealing and/or insulating: follow procedure – fix the problem

These Tests Take Time►Hear from a seasoned Energy Auditor who has

experienced it all…

►Proper testing is essential – these tests can be a matter of life and death

►A little knowledge can be dangerous

►We want to share skills we’ve learned – to help you multi-task successfully

Time Spent Preparing is Time Well Spent

Organize Your Tools, Office, Equipment, Vehicle, and Yourself

In the office

►Have your data collection forms prepped

►Make sure you have combustion analyzer printer paper

►Is the equipment charged? Need batteries?

►Does the customer know how to prepare for your visit?

Could You Find What You Need in This Office?

You Could in This Office!

Before Your Appointment►Order tools and parts if necessary

►If the oxygen sensor on your combustion analyzer has expired, your tests aren’t valid

►Not having one tool will shut you down

►Check to be sure you have all the tools, equipment, supplies you will need

In Your Vehicle►Do you have all the supplies you need,

such as chemical smoke, high temperature flue tape or plugs?

►Is your vehicle organized enough so you can find your tools and supplies?

►Is everything accessible and secure?

Organization Pays Off

So Many Things… So Little Time

Equipment You Will Need in The CAZ

At the Customer’s Home►Can you get to the CAZ and all other areas?

►Can you get to the water heater and furnace?

►Take the tools and equipment to the CAZ as you are unloading

►Turn the water heater down and the furnace off if conditions allow – mark settings

►Remember to return the water heater and furnace to prior settings

It Takes Time to Clear Out the CAZ – Have the Customer Do It Before You Arrive

The House, and Everything In It, IS a System

►The water heater and furnace or boiler may never have been tested for adequate draft pressure or CO.

►It is very likely the systems have never been tested with the CAZ under the most negative pressure (worst case).

►You may be the first to fully test.

Resources

►Building Analyst Field Training Video, www.buildingsciencetech.com

►www.trutechtools.com videos

►YouTube.com