# What to use to find drafts? Smoke pencil, dry ice?



## Alumifab (Jul 23, 2009)

Hello:

I am debating getting a thorough energy audit which will be about $350.

Before I do that are there any efficient ways in finding drafty leaks in a home?

Should I buy/rent a smoke pencil or get some dry ice and see if I can find drafts?

Never done this before so any ideas are appreciated.

Thanks.


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## WhatRnsdownhill (Jan 13, 2016)

in my opinion, a house that breaths is a healthier house, all these air tight houses might be a little more energy efficient and they keep all the contaminants inside for you to breath and cause health issues..the old" this old house series" when ever they did a new renovation and sealed up the house, they put in a fresh air ex changer to let the house breath..so a few drafts here and there keep the air moving...even in the winter its healthy to keep a window or 2 cracked for fresh air...so you save a few pennies ,but pay with your health....


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## Bud9051 (Nov 11, 2015)

The saying is to seal it tight and ventilate it right and that does sound confusing. But, you are addressing two different issues, energy efficiency and air quality. 

From an efficiency point of view, air leakage not only transports your expensive energy to the outside, it reduces the efficiency of the insulation it often passes through. Old homes certainly provided enough fresh air, but they were far from energy efficient.

However, once we tighten up the house beyond a certain point we can encounter air quality issues, thus they recommend mechanical ventilation or at the least cracking open a window (not very reliable).

So, what is the benefit of air sealing if we have to turn around and add ventilation? It boils down to the path the air takes. Much of the air one breathes in an old leaky house comes from the basement or a crawlspace, not the best source of air to breathe. It also filters through old insulation that has become contaminated with dust, pollen, and other pollutants from outside and maybe some rodent droppings from inside.

If you want the benefits of fresh air, seal the undesirable leaks and provide nice clean serviceable air paths for incoming air. In reality, houses don't need to breathe, it is the people inside that need the good air.

Bud


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## Bud9051 (Nov 11, 2015)

Since I failed to answer your question, I'll try again. Smoke or dry ice will only find the active leaks which is better than nothing. An energy auditor can help with a blower door assisted air sealing effort. The problem is, they don't like to spend the time.

Since this is a DIY forum, here's what you can do. Rent an infrared camera for a day. Turn on all exhaust fans in the house and possibly set up a good window fan. All of that exhaust air will be replaced by infiltration, thus all leaks (assuming it is cold outside) will give you a cold signature. Smoke, dry ice, and even an IR camera will only see some of the leaks without the depressurization.

There are images from an IR camera that can be difficult to interrupt, but most are very obvious.

As for the energy audit, you need to ask yourself, what is s/he going to tell me. If you can locate the majority of the leaks and determine how much insulation is in the house there are several programs that will give you those audit numbers. The one missing is the actual blower door number if that is needed to qualify for some incentive program.

Bud


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## Windows on Wash (Aug 30, 2011)

+1

IR camera with a blower door running is a much better tool for diagnosing and cataloging the leak locations.


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## Alumifab (Jul 23, 2009)

Well these are the types of things I am looking for.
I obviously don't need a smoke pencil for this as I could feel the cold air blowing through the foil insulation, cooling my attic.
2 big ol slashes.
Foil tape and Mastic coming their way.......


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## Bud9051 (Nov 11, 2015)

Hi Af,
Attics are supposed to be cold, so how is yours being ventilated if cold air is a problem?

I can't tell where that foil faced insulation is installed, but in an attic you need to identify where you want the air barrier and insulation and have only one location. You shouldn't have insulation in the rafters as well as insulation in the ceiling below.

Tell us more.

Bud


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## Alumifab (Jul 23, 2009)

Here are some better pics of my unit.


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## Bud9051 (Nov 11, 2015)

I don't see the slashed foil from your picture?
Mechanicals in an attic is not good, but I recognize it isn't going to change. To make the best of it, all supply and return ducts need to be completely air sealed and then neatly insulated. Air leaks into or from an unconditioned space will result is the same amount of air being drawn in or pushed out elsewhere in the house.

House style? I see the short wall.
Approximate climate location, heating or cooling, or both?

Bud


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## Alumifab (Jul 23, 2009)

Dallas, TX, built 2006, 1800 sq ft.
The first picture with the whole unit, it's the first line. I could feel the air coming out. None of these foil insulated sleeves are sealed, just sitting back a few inches from the start......


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## Bud9051 (Nov 11, 2015)

I was afraid of that. The foil and insulation isn't in the walls, but is being used to cover the ducts, correct?

If so, that tells me they never air sealed all of the seals and junctions on those ducts. Basically, you won't be able to seal the ducts by sealing the foil/insulation on the outside. You should peel back all of the insulation, seal with foil tape or duct mastic, and then cover again with the insulation.

Just an FYI, here is an Energy Star web page on all sorts of air sealing.
https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/TBC_Guide_062507.pdf

Bud


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## Alumifab (Jul 23, 2009)

Yeah it seems that the lines going to/from the unit have mastic on the inner part (black) but the outer foil insulation was never sealed over that or it just came off over time??? I just can't tell.

Now the lines going to all of the rooms, I have no way of knowing as there is a lot of blown insulation covering this and I do not feel comfortable as of now, tracking through this and trying to see if any of that is sealed.

I'm just trying to make my home a little more efficient as the summer is sooooo HOT down here.

Not sure if what I am doing is going to make a difference......


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## Windows on Wash (Aug 30, 2011)

Google Wizard Pen. You can use that for up in the attic.


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## ZZZZZ (Oct 1, 2014)

A stick of incense generates a nice stream of smoke. 

A pack of 10 for $1.00.:vs_cool:


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## Alumifab (Jul 23, 2009)

Incense, yes, forgot about that..... I'll get some of that


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## Windows on Wash (Aug 30, 2011)

While it works, I always prefer a non-combustible option.


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## Nestor_Kelebay (Jun 17, 2008)

Alumifab:

Get a cotton shoe lace and cut the plastic ferrule off the end. Light the end so that it's burning on it's own. Now, blow out that flame and it'll smolder releasing a steady stream of smoke. You can use that as a poor man's smoke pencil to find air currents.

Incense will work, but you'll end up filling your house with the smell that incense makes.


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## beenthere (Oct 11, 2008)

Alumifab said:


> Yeah it seems that the lines going to/from the unit have mastic on the inner part (black) but the outer foil insulation was never sealed over that or it just came off over time??? I just can't tell.
> 
> Now the lines going to all of the rooms, I have no way of knowing as there is a lot of blown insulation covering this and I do not feel comfortable as of now, tracking through this and trying to see if any of that is sealed.
> 
> ...


Sealing all leaking supplies and returns will help your A/C cool the house better. As it reduces the amount of unconditioned air entering your house.


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