Carbon Monoxide, and Naps

It may not be the Turkey that makes you sleepy.

Carbon monoxide from an electric oven

Cooking the turkey for hours can introduce considerable amounts of carbon monoxide to the home during the cooking process.  Turkey has a component that has been attributed to that nap after dinner.  Others hypothesize it is just eating too much that leads to sleepiness.  It is also possible that exposure to Carbon Monoxide is a contributor.

If carbon monoxide is a culprit, it is not only related to gas ovens. 

I am not sure how much CO is given off in an electric oven during the cooking of a turkey, but certainly some amount is likely. I will have to wait until Thanksgiving to get more information on that.

Considerable is created when using the self-clean function of the oven. 

My own oven gives off between 28 and 3 PPM for the first 1-1/2 hours of the 3 hour cycle.  After that time, whatever was creating the CO was successfully incinerated and CO levels dropped to normal. 

These amounts are perhaps not enough to kill you, but certainly enough to affect a person–especially infants that might be around.

In the first 15 minutes of operation, my own oven gave off about 28 PPM, after about half an hour it settled down to 12 PPM and after about an hour it was down to 5 PPM.  At the one-hour mark, ambient CO levels in the kitchen 10 feet away from the oven hovered around 3 PPM—with the exhaust fan on and a window open.

I suspect the amount of CO will depend on what the oven is burning off in the cleaning mode, and levels likely could be considerably higher, and for longer periods of time, if the oven is not cleaned very often.  I clean min probably twice a year.  I may start doing it more often now.

Of course your ordinary CO alarm is “not allowed” to alarm, per its listing, at these low levels, so most of the time you will have no idea why you need a nap.

I think the lesson here is to clean your ovens regularly–don’t wait until you can see the bottom of the oven.  You should also run the kitchen exhaust hood the whole cleaning cycle and keep a window open.

Perhaps I will go take a nap, while I wait for the oven to finish.

Charles Buell, real estate inspections in Seattle

Simply EXHAUSTED!

Most bathrooms have exhaust fans in them—or should.

Bathroom Exhaust fan cap

Bathroom Exhaust Fan Cap

Most modern codes (Washington State) require exhaust fans even if there is a window that can be opened. If we do not control moisture levels in our bathrooms, it can not only have a detrimental effect on the bathroom itself, it can also create moisture issues for the rest of the home.  We all know how useful it can be to change the air in the bathroom even if water is not involved.

Who is going to open their window every time they take a shower when it is cold outdoors? Not me.  If you were to do this, you might be surprised at how well it works to lower the humidity in the bathroom, even if it is cold and rainy outside.

Now that I have convinced you of the necessity for bathroom exhaust fans, we need to make sure they are working when we turn them on. Just because the thing shakes, rattles and rolls, does not mean that it pulling any air from the room. Simply turning the fan on is no test of its function.

There are many ways to determine if the fan is pulling any air; and many ways the function can be compromised.

1. The biggest way the function of these fans is compromised is that the user does not use them!

I know this is in the “DUH” category—but it is painfully true.

People need to be taught to turn these fans on, and to leave them on for a set amount of time. Typically I recommend that they be installed on a timer that can be set for various amounts of time and that after showering they be run for 60 minutes. This amount of time can be cut drastically if one raises the temperature in the bathroom itself before taking a shower. Air that is 75 to 80 degree F can contain a LOT of moisture—considerably more than 65 degree air. To the point, even without the fan running, the bathroom mirror may barely fog up if it is hot enough. If you raise the bathroom temperature to 80 degrees F, take your shower, then turn the exhaust fan on for 20 minutes, everything will likely be hunky-dorie in terms of adverse moisture conditions in the bathroom.

We have all taken hot steamy showers in cold bathrooms without fans and then have seen the condensation on the mirror and walls. This can be very damaging to the home (especially modern tight houses), promoting mold/fungal growth on the wetted surfaces. Most bathrooms do not have a “localized” means of heating the bathroom previous to taking a shower, making this not an option. In that case it is best to run the fan the entire time you are showering and for an hour afterwards—assuming the fan is functioning properly.

2. The fans are so noisy they do not get used.

Yes, if every time you take a shower you have to listen to the roar of a jet engine, or feel the house being shaken apart, or make the neighbors complain, there is a good chance the fan will not be used at all.

3. There is no space under the bathroom door.

Many times I see bathroom doors so tight against carpeting that no air can be pulled in under the door to replace the air that the fan is attempting to exhaust. Again, with this installation, no/not enough moist air is removed from the room, making the fan non-functional.

4. There is something restricting the flow of air from the fan to where it terminates at the exterior.

This can be caused by many things—things your home inspector will be looking for. Perhaps the fan motor is running but the squirrel cage has lost its squirrels. Perhaps the damper in the fan unit is stuck closed. Perhaps the vent pipe is crushed, or the end of the vent pipe or outlet of the unit itself is covered with insulation. Perhaps the vent cap damper at the exterior is stuck–maybe blocked with wasp’s nests, paint, debris or other restrictions. Maybe the missing squirrels are living in the vent pipe.

So how does a homeowner test to see if the fan is functional?

Well of course there is sophisticated testing equipment that can be used, but there are less scientific means of determining some degree of function.

1. The paper test.

The paper test can be done on the unit itself—all openings of the fan unit should be fully covered however. Covering only a portion of the opening may not tell you that the air is moving into the unit and then right back out the uncovered part of the cover. If the fan is too high to get to, or the cover is too complicated to cover, you can place the tissue paper right along the bottom edge of the bathroom door on the floor. If the tissue scoots across the floor when you turn the fan on, all that air is going somewhere—and shows that the fan is moving air. (As a side note, if the fan is running and forcefully holding the tissue paper in place, this is a good time to close the bathroom door if it is open.  All of these tests should be done with the bathroom door closed and because if the tissue paper falls off or starts to fall off you will know you have inadequate clearances under the door.)

2. The wet finger test.

If you don’t have any tissue paper you can use the wet finger test. This is kind of like testing to see which way the wind is blowing. You will feel your finger get colder as air is pulled under the door and attempts to dry your finger.  If you feel a good draft with a dry finger, that is an even a more confirming test.

3. The business card test.

If you don’t have a wet finger (it is surprising how resistant people can be to putting their fingers in their mouth) or tissue paper, you can stand up a business card on the floor up against door. It should tip over when you turn the fan on.

While not very scientific, these methods of testing will give you some general information as to function of the fan—at least enough to tell you whether it might be a good idea to have the vent evaluated further. For the best results with this “testing,” make sure that windows are closed during testing and throw a towel or rug over the forced air heat register. These openings can affect how much air is moved from the room—especially the window (The ductwork typically has so much friction losses that it is not often a factor).

Now go back and look at the picture at the top of the post. Can you predict, based on the picture, whether the bathroom exhaust fan moved any air from the room?

Perhaps not so obvious, the screen is keeping the damper closed.

By Charles Buell, Real Estate Inspections in Seattle

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Testing for Asbestos

While I always have to chuckle to myself whenever anyone buying a 1967 house wants to know if the house has asbestos in it, or whether I do testing for asbestos, I always do my best to take their questions seriously.  I realize that in all walks of life people don’t know what they do not know, and what good does it do to poke fun at them?

The fact that any house from 1967 is going to have asbestos in it, seems to not be common knowledge.

I know for a fact that there is endless stuff I do not know.  It is “normal.”  I think we can all appreciate what a pain in the butt it is dealing with someone that knows it all.

At a recent inspection of a 1967 house, the inevitable question came up when we went into the laundry and saw the floor covered with 1967 vintage vinyl tiles.  Now typically, I don’t have any problem telling my client that the tiles from this time period are “considered to contain asbestos,” but that only testing can tell you for sure.

This is a useless exercise as near as I can tell, but from a liability standpoint it is what home inspectors will say.

In this case however I was able to categorically state:  “yes—the tiles contain asbestos,” as there was a box of the same tiles, unused and stored, in the closet in the laundry room.

asbestos tiles

No testing necessary.

By Charles Buell, Real Estate Inspections in Seattle

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