Backdraft detection

Originally Posted By: Douglas Williamson
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What method of backdraft detection do you use (assuming the draft is not obvious)?


There are various items available on the market that I would rate between "money-hole" and "useless", and others that make me want to cry from the stupidity of it.

I'm curious what range of items the pro's here employ.


Originally Posted By: lkage
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Hold a mirror at an angle by the hood. If it fogs it is backdrafting.



“I have never met a man so ignorant that I couldn’t learn something from him.”


Galileo Galilei

Originally Posted By: bkelly2
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What Larry said.



“I used to be disgusted, Now I try to Be amused”-Elvis Costello

Originally Posted By: Gary Reecher
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I use a Dwyer 460. The little flow meter ball is sensitive and changes are readily visible.



Gary Reecher, CM


HVAC Service Technician


MechAcc's Carbon Monoxide Site Links

Originally Posted By: dvalley
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Mirror trick works great. I use it daily.



David Valley


MAB Member


Massachusetts Certified Home Inspections
http://www.masscertified.com

"Some cause happiness wherever they go; others, whenever they go."

Originally Posted By: kshepard
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A lighter will work too.


Originally Posted By: Gary Reecher
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kshepard wrote:
A lighter will work too.


Heat rises a better test would be with a neutral bouyancy smoke puffer. The type of puffer where the smoke neither rises or falls but hangs in the air and is moved by room air patterns. If this smoke is dispensed near a draft hood and there is a draft it will pull into the draft hood. Since there is more smoke generated than with an extinguished match draft patterns are highly visible.


--
Gary Reecher, CM
HVAC Service Technician

MechAcc's Carbon Monoxide Site Links

Originally Posted By: abishop
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Could you guys go into more detail of what this is all about?


Is this to detect that the draft is working correctly?


Where do you put the mirror and such?


Appreciate.



Andy Bishop


Bishop Home Inspection, LLC.


bishophomeinspection@charter.net


269-686-6485

Originally Posted By: Caoimh?n P. Connell
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Douglas:


For qualitative assesments, I use the same method as Gary Reecher. For quantitative assesments, I measure ultrafine particles.

Cheers,
Caoimh?n P. Connell
Forensic Industrial Hygienist

www.forensic-applications.com

<SMALL> (The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG </SMALL


Originally Posted By: kshepard
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Backdraft testing to determine whether the products of combustion are entering the living space either as reverse flow (backdraft) from the vent or directly from the burn chamber.


Re: lighter vs smoke. I watch to see which way the flame leans, toward or away from the vent, but the puffers sound good. What do they cost and how long do they last?


Originally Posted By: dvalley
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Quote:
Could you guys go into more detail of what this is all about?
Is this to detect that the draft is working correctly?
Where do you put the mirror and such?



You get a mirror and you face the glass towards the open gap under the draft hood. If your mirror sweats, the water heater is not venting properly. It's backdrafting. Call it out for Plumber evaluation.
![](upload://jrIlo3bFuzIaW4vK96ewgJCtpUP.jpeg)


--
David Valley
MAB Member

Massachusetts Certified Home Inspections
http://www.masscertified.com

"Some cause happiness wherever they go; others, whenever they go."

Originally Posted By: kshepard
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Re: mirror


I wonder if the same method would work using a pair of glasses.


Originally Posted By: dvalley
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Kenton,


Sure, but not every Inspector has glasses.

They all should carry a small mirror.


--
David Valley
MAB Member

Massachusetts Certified Home Inspections
http://www.masscertified.com

"Some cause happiness wherever they go; others, whenever they go."

Originally Posted By: kshepard
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Yes, but I wasn’t thinking of every Inspector, I was only thinking of myself. eusa_silenced.gif Hey, my ex-wife was right!


Originally Posted By: bkelly2
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glass mirrrors break, I prefer stainless steel.



http://www.professionalequipment.com/xq/ASP/ProductID.129/id.9/subID.105/qx/default.htm


--
"I used to be disgusted, Now I try to Be amused"-Elvis Costello

Originally Posted By: rcooke
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I find 12 inches of toilet paper works well .


It is also a simple way to know if the bath fan has much suction.


Does it hold the paper up there or not .



Roy Cooke Sr.


http://Royshomeinspection.com

Originally Posted By: Douglas Williamson
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Thanks for all of the replies!


I've seen the "powder puff" bottles for sale and figured that was the safest way to go but am concerned about the mess.

The mirror method seems to be most frequently used method, based on the information I've found from various online sources.

The lighter method worries me. I remember (vaguely, the details are sketchy) when I was young my father used a lighter to test a water heater for backdraft - no backdraft detected, but some unknown chemical which was previously spilled atop the water heater definitely took exception to the new source of flame! Quite a hair raising experience - blew us away you might say!

Then of course in high school there was the "no other light source available" lighter we used to change the fuel filter on my friends car late one summer night - I tell you, one littler lighter can produce A LOT of flame.. and the desired light of course. Again, the results blew us away! Man teenagers are dumb when a liberal amount of beer is applied.

Anyway - a few past experiences have me concerned about using a lighter! Thanks again for the replies, sounds like a mirror is the way to go.


Originally Posted By: abishop
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Thanks Dave and others.


The water heater does have to be running to do this correct? What if it isn’t running? Do i turn the hot water faucets on for awhile?


How close do i put the mirror? This is fun stuff as i learn and then go try it!


Thanks



Andy Bishop


Bishop Home Inspection, LLC.


bishophomeinspection@charter.net


269-686-6485

Originally Posted By: dvalley
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Andy,


If the w/h fuel supply is not on, I turn up the temperature control at the base of the w/h. I know, I know...I'm not suppose to mess with gauges. But to me, it's the same as turning up the thermostat for the home heating appliance.

I then place the mirror right against the draft hood, glass is facing the opening.

Try it.


--
David Valley
MAB Member

Massachusetts Certified Home Inspections
http://www.masscertified.com

"Some cause happiness wherever they go; others, whenever they go."

Originally Posted By: kshepard
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David, if the fuel supply is turned off, and there’s just a water heater full of cold water sitting there, how does turning up the temperature control help you to check vent backdraft with no burners lit?


Kent