Combustion Aplliance Safety Test

[retire09]

Energy raters in our area have started to conduct "Combustion Appliance Safety Tests" as part of the energy rating programs.

When conducting this test they close all exterior openings in the house and open all interior doors including the door to the attached garage and turn on all exhaust fans including the range hood, bath exhaust fans and the cloths dryer.

With the house in this condition they test for carbon monoxide.

They insist that they are conducting the test properly by propping the door open to the garage where the only gravity gas vent in the building is located.

All houses tested in this manner have failed.

I see no possible way that any house could pass this test when with the entire house is in a negative pressure with all the exhaust fans running and the only remaining opening to the exterior is the gas vent in the garage. Exhaust gasses are drawn back down the B vent and into the house setting off the CO detector. To remedy this situation they require direct vent appliances in the garage in order to pass.

I have been battling with the energy raters over this for quit a while and getting no where.

The problem appears to be that they consider the door to the garage an interior door when reading the test procedure...

Can someone tell me if they are misinterpreting the procedure for this test?

 

[cda]

they following any written guidelines??? offical written guidelines, recognized written guidelines, approved written gudelines?????????

Tight seal between the house and garage, including a self-closing, self-latching fire door.:::

http://cbpca-hpp.org/wp-content/uploads/2012/04/CBPCA_CASTestingGuidelines_2012-0405.pdf

ask them to show you the procedures they are follwing

 

[Builder Bob]

I believe it may be an interpretative issue as to what is considered the envelop of the house for the energy code to follow.

 

[retire09]

There is a written procedure and it is being misinterpreted.

It requires the house to be tested with all exterior openings closed and all interior doors open.

My opinion is that the door to the garage is not an interior door and should be closed with the exterior openings.

They disagree and so all houses fail the test.

This test is being conducted on both new and resale homes. Builders and sellers are having to provide unnecesary combustion air openings or direct vent appliances that are not otherwise required by code in order to sell homes.

 

[Builder Bob]

I guess the question that should be asked... is what does the policy define as an exterior door..... If they are using that interpretation, i am sure that my house would fail since I have screen porches on the front and back of my house. So I guess my exterior doors are screen doors????

 

[Builder Bob]

This test is based on combustion air requirements for the appliances...... so if the garage is not used to obtain combustion air, it should not be a part of the Combustion Appliance Safety Tests.

If it does have the furnace and water heater, then the garage door should be closed.........

Combustion Appliance Zone (CAZ)

A combustion appliance zone (CAZ) is the room in which any natural or induced draft or direct vented space heating system, gas log fireplace or water heater resides. The room must have a door that closes,

such as a garage, closet or laundry room. Buildings that are detached from the living space do not need to be tested for Worst Case Depressurization. Back up heating units do not need to be tested.

Key Word RESIDES -

The test is used to ensure two things:

1.) That adequate combustion air intake and venting operations for a single appliance is adequate and

2.) that multiple devices when used do not overload the intake for fresh air and still allows efficient venting of the appliances while being used simultaneously. The CO production that is monitored is to ensure adequate venting exists under these circumstances.

Seems like a contractor is finding away to make money at "unknowing" builder and code enforcement knowledge...