Two wrongs still don’t make it right.

Two wrongs still don’t make it right.

As you can see in the picture, the cut truss (wrong #1) is pointing right at the whole house fan (wrong #2).

While whole house fans may have been a good idea, once upon a time in some climates, they have virtually no place in modern energy efficient construction. In northern climates they are of particular concern as they are typically NOT adequately insulated and sealed against heat loss in the winter. When they are not insulated and sealed, the natural stack-effect of the home will pull warm air into the attic more or less around the clock.

The idea of these units is to flush the warm daytime air from the home at night, and then pull in the cool night air to cool the home off. Not a bad idea really. While this principle works in older poorly insulated homes, in modern well insulated homes they should not be necessary. Merely opening a few windows on opposite sides’ f the home should achieve the same result.

If the home is overheating during the day, one should look to the causes of that overheating and fixing the overheating as opposed to installing a system that should not be necessary. If one’s home is overheating and one considers it “well insulated,” I would argue that one should perhaps re-think one’s definition of “well insulated” or that perhaps there are other factors contributing to the overheating.  A good question to ask might be, “what are the air sealing abilities of the insulation?”  Not all insulation is created equal.

As a side note, I can pretty easily argue that even newly constructed homes in areas of the country with high cooling needs are NOT adequately insulated to appreciably reduce energy costs. Code requirements for energy conservation are “minimum” standards, and make no distinction between the air sealing characteristics of the various kinds of insulation.

If installed properly, and if used properly, and if maintained properly in the off season, these fans can help reduce air conditioning costs, improve comfort and improve air quality. Please note that this statement includes a lot of “ifs” and their installation can more often result in increased heating costs in the off season.

Another issue that arises from these fans is that if they are not sized properly (and they rarely are) they are capable of drawing more air into the attic than the attic space can get rid of. This can result in pressurizing the attic and minimizing the effectiveness of the fan—oversized or not. Regardless, even if additional venting is installed to compensate, there will then be compromised and possibly inadequate venting of the roof structure for that part of the year when the fan is merely wasting energy. It might be possible to balance these differences, but the reality is that often the different requirements for the different functions are simply not taken into account—or, worse yet, not even possible to take into account. More often than not, when I see them installed in the Northwest, they seem to be installed on the insistence of someone that has moved here from a climate where they worked or were possibly even necessary.

For the installation above, someone is now going to have to incur the cost of removing the fan and repairing the damaged truss. These costs will now need to be added to the increased energy costs created by the installation in the first place

By Charles Buell, Real Estate Inspections in Seattle

If you enjoyed this post, and would like to get notices of new posts to my blog, please subscribe via email in the little box to the right. I promise NO spamming of your email! 🙂

So glad the smoke alarm never went off!

This past vacation, down the Oregon coast, led to an interesting experience at a motel.

Now I know what you are probably thinking, but this is not your typical racy story about fun activities in a “notell-motel,” it is about how a home inspector never really leaves his work behind.
This motel was a very modern, new construction unit, built in 2007 (according to the water heater and refrigerator date codes–you know I had to look).

There was a little kitchenette in our unit and the unit actually looked newer than 2007, it was so well cared for.

In the morning, my sweetie decided to try out the toaster and immediately proceeded to make charcoal. To avoid setting off the smoke alarm, she turned on the kitchen range hood but nothing happened. The smoke just sat there.

I decided to open the kitchen window to see if that would help.

As soon as I opened the window the kitchen range hood actually started to do its job and air poured into the room through the open window.

This was a great example of how all modern, tightly constructed homes function.

When we turn on the exhaust fans in our homes, there has to be a way for the air that is being displaced by the fans to come into the home from somewhere else. If it cannot, a negative pressure is created on the home and the fan will not function. It will just sit there and whine. The fan will spin and spin doing nothing but spin. As soon as the window was opened the spinning fan could start to do some work and move the smoke from the room. The fact that the fan was actually “working” could be detected in the sound difference as soon as the window was opened. The fan got noticeably louder and the smoke started leaving the room.

The best thing of all—the smoke alarm never went off.

By Charles Buell, Real Estate Inspections in Seattle

If you enjoyed this post, and would like to get notices of new posts to my blog, please subscribe via email in the little box to the right. I promise NO spamming of your email!

Hope will not help—unless that is the workers name!

Hope is almost always like “frosting on a turd.”

frostingonaturd1People often ask me if it is OK for bathroom exhaust vents to terminate in the attic.  There was a period of time when lots of builders considered the attic “outdoors.”  Well of course, it did not take too long to figure out that the attic environment is anything but “outdoors.”  If the attic was outdoors, the temperature and humidity  would be the same as out doors.  We of course now know that temperature and humidity can vary widely in the attic and this is why proper ventilation of attic spaces is so important.  We do not want to trap moisture in the attic but instead provide a pathway for it to escape.  If we terminate bathroom, kitchen and dryer vents into the attic we obviously risk introducing more moisture into the attic than even the best ventilation system can remove.

Over and over I find attics that cannot handle the moisture that is being added to the attic space.  A vent fan that is not properly terminated to the exterior at a cap with a back draft damper, or one that has become disconnected, can add a lot of moisture into the attic—especially in the winter.  This can contribute to mold and rot in wood structures as well as contribute to ice dams.

I still find lots of homes from the late 70’s and early 80’s with vent ducts that merely aim at a roof vent. This method I consider the “Hope” method of venting.  The installer is “hoping” that the air will simply find its way out through the waiting roof vent and then to the exterior.  This next picture is perhaps one of the best improper vent terminations I have come across.  It is pretty obvious that the screen in the roof vent is completely caked with lint.

Lint clogged roof vent screen

Lint clogged roof vent screen

There are two problems with this approach.  First of all, over time, the vent screen will become clogged with lint.  This will be the end of the hoping and now all that moisture is going to stay in the attic—guaranteed—creating the anticipated turd of a result—mold and decay/rot in the roof structure.  The second part of the equation is that now the roof vent will no longer function to do its job and is being burdened with even more moisture than it should have to deal with to begin with.

It is important that your inspector verify that all of the vent fans in the home properly terminate to the exterior whenever possible.

If you look back at the picture of the vent you will notice that all of the plywood has been painted white as part of a recent mold remediation.

Why was this vent not fixed as part of that remediation?

Dang—there goes hope again!

By Charles Buell, Real Estate Inspections in Seattle

If you enjoyed this post, and would like to get notices of new posts to my blog, please subscribe via email in the little box to the right. I promise NO spamming of your email!