Radon in Alexandria VA

[bachissimo]

I work in DC but sick of condos and NOISE want to move to a house. We really like the living between Alexandria and DC (officially Alexandria). Very quiet street.

Contract ratified. Currently being Radon inspected. Sellers agreed to be out of the house for 48 hrs. I wanted to ask few questions about Radon and would be REALLY GRATEFUL for your thoughts.

Note that due to my history/family I am at much higher risk of lung cancer than average. I am also VERY sensitive to noise.

Problem is that the best place of the house is the lower level, not really much of a basement, since it is mostly above grade and counted in Sqft. Has a really nice office and appealing features.

My first question is, how loud is the most quiet mitigation system? Most likely the work will be in the laundry area which is adjacent to the office, so will I hear anything in the office?

My second question is , based on my history should I just avoid the basement for any measurement above 2pc/L? Since mitigation systems apparently can't guarantee a lower level post-mitigation...

I think my agent will kill me if I walk out yet again on another house. Also my options are limited since Radon is apparently everywhere in North Virginia. I'd rather stay in Condo over increasing significantly my lung cancer risk.

I am really very confused and distressed....

[Scottpat]

Mitigation systems are quiet on the inside of the home. The fan will be outside and they are quiet.

I would not worry about radon if the home has a mitigation system. Yes, 2.0pCi/L is the normal level that all mitigation contractors will guarantee.

Why even worry at this point? You don't even know if the home has high radon levels.

[Jim Katen]

If you need to install a radon mitigation system, the fan is typically installed high. You want negative pressure in most of the pipe in case it leaks. When you install the fan high, in the attic or, if it's outdoors, under the roof overhang, then the noise will be less noticeable, particularly at the lower levels of the house. Also, these fans are pretty quite to begin with. As an added precaution, you can ask the installer to place flexible sleeves at the inlet and outlet connections.

A 48-hour screening is good for telling whether or not you have very high levels, but it's nearly meaningless at telling you whether or not you levels are consistently low. After the 48 hour test is done, whether you install a mitigation system or not, do a year-long test as well.

If you're really interested in lowering the radon levels as much as possible, in addition to an active radon mitigation system, you can do a few other things that will tend to drive down radon levels:

• Install an energy recovery ventilator and set it to slightly pressurize the house. This will tend to bring in fresh outdoor air and exhaust indoor air, which is a good thing all around. Setting it to slightly pressurize the house will enhance the action of the radon mitigation system. It could cause problems with condensation in walls, depending on when your house was built - when was the house built?
• If you have a forced-air furnace, set it's blower to run 24/7 and install a 4-inch thick high quality pleated filter or an electronic air cleaner. Radon molecules tend to attach themselves to dust particles in the air and good filtration can lower radon levels. Also, constant air movement causes particles in the air to "plate out" or stick to surfaces in the home. If they're stuck to surfaces, you're not as likely to breathe them into your lungs. For this same reason, if you don't mind them, install paddle fans in several rooms and set them to run as often as possible.
• Any house in Alexandria is bound to have granite countertops. You might want to test them specifically or just get rid of them.

[kurt]

The fans are so quiet, they approach being noiseless. On occasion, I'll have to touch them or place my ear against the exhaust to see if they're running.

Standard filters, event the pleated ones, don't do much to improve indoor air quality. If you're hyper sensitive, you may want a HEPA bypass filter system.

[bachissimo]

Thanks all for your replies. The reason why I am asking ahead of the results is because I have 1 day to decide after test and wanted to study it.

The place is a split level and the basement is not really a basement, it is mostly above ground: does that make it less prone to radon?

I hear mixed reviews about the noise level, but I am guessing if I want to make it very silent I can... (??). I was assuming the pipe will be in the laundry room which is adjacent to my would-be office.

Finally, ANY THOUGHTS about how much you can drop radon concentration by just keeping windows open or having window fans on the lower level. Say it is 4 windows closed, can I assume it would drop below 2 with more aeration?

Thanks !!

[Jim Katen]

Thanks all for your replies. The reason why I am asking ahead of the results is because I have 1 day to decide after test and wanted to study it.

The place is a split level and the basement is not really a basement, it is mostly above ground: does that make it less prone to radon?

Makes no difference.

I hear mixed reviews about the noise level, but I am guessing if I want to make it very silent I can... (??). I was assuming the pipe will be in the laundry room which is adjacent to my would-be office.

Even if the pipe is there, the fan motor will have to be high. You don't want positive pressure in the vertical portion of the pipe, you want negative pressure.

Finally, ANY THOUGHTS about how much you can drop radon concentration by just keeping windows open or having window fans on the lower level. Say it is 4 windows closed, can I assume it would drop below 2 with more aeration?

Impossible to say. Opening windows sometimes increases radon levels. It's more about pressure than it is about "aeration" (whatever that is).

[tim5055]

For several years I lived a little west of you out by Wolf Trap. We had a mitigation system installed and as the guys here have pointed out the fan will be mounted high. In our case it was in the in a space over the garage like an attic. We heard nothing.

Do a little more research on Radon. Yes, I wanted the mitigation system, but the more I read the more I truly believe the levels for mitigation are more based on what the industry can deliver than on medical science and what levels are truly healthy/unhealthy.

I think what you are describing is a daylight basement, one or more walls have windows and doors. So to answer your question, yes - windows and doors open with fans will exchange air and reduce the level.

[Erby]

Of course, how likely is it that you'll open the windows and doors when snow is on the ground?

[bachissimo]

Erby, you mean of course opening windows will reduce the concentration?

I definitely open the windows during the winter. DC is not that cold most of the winter, and I like a bit of cold inside the home (good for health, losing weight,..).

[bachissimo]

And sorry a couple more questions:

does or does not opening window bring the radon levels down?

Can the mitigation be safely turned off for few hours a week, if I have people over and we're sitting on the patio? I guess some people who work long hours at work might consider turning it off when they get back home since it takes 12 hours for radon to creep back.

If you install a mitigation system and reduce radon level below EPA, do you have to have it in your DISCLOSURE?

[kurt]

......... the more I read the more I truly believe the levels for mitigation are more based on what the industry can deliver than on medical science and what levels are truly healthy/unhealthy.

Yes. Absolutely. If you're making rational considerations about radon, factor this in.

Don't turn off the fan. Leave it on. Read Jim's post again. It's about pressure differentials, not windows being opened or closed. Depending on broad ranges of variables, it's possible to increase radon with windows open, or not. Pressure gradients drive radon into and out of houses, not drafts.

Install a system and run it continuously to maintain a negative pressure under and around the house. It's as close as you can get.

The noise part.... If it's a Panasonic or similar quality inline fan, they're silent. Really. I suppose if you stayed up late on a dead still winter night and laid awake trying really hard to hear it, you possibly could imagine a slight hum....but I doubt it. They're really quiet.

Disclosure? I have no idea. Any marginally competent inspector is going to note the presence of a radon mitigation system, so any buyer would be notified during an inspection.

Personally, I'd tell them. It's a feature, not a negative imho.

[bachissimo]

sorry for butting again. But it seems like there is something I got confused about. If the mitigation system is trying to create a different pressure between under the house and the house, then does that mean that opening the windows will be self-defeating and might reduce the efficacy of the system???

Maybe I misunderstood, and the system only affects the pressure of the space right below the basement...

[Jim Katen]

sorry for butting again. But it seems like there is something I got confused about. If the mitigation system is trying to create a different pressure between under the house and the house, then does that mean that opening the windows will be self-defeating and might reduce the efficacy of the system???

Maybe I misunderstood, and the system only affects the pressure of the space right below the basement...

Opening windows won't have any direct effect on the operation of the radon reduction system. It'll create negative pressure under the concrete no matter what the windows are doing.

Opening windows *will* effect the relative pressure between the inside of the house and the outdoor air and it might very slightly increase or decrease the total pressure differential between the basement air and the slab below. It's unlikely to have much effect on radon, but if it does, it could tip it one way or the other.

I can't begin to imagine why you'd want to turn off the radon fan when you have people over and they're sitting on the patio. No one is going to hear a thing when a group of people is there making noise.

From your questions, I think that you imagine that the radon fan is some kind of really noisy blower. It's really very quite.

[bachissimo]

So the inspector report gave an average of 2.1. Apparently she used two detectors in the basement, one gave a reading of 1.9 the other 2.3

I guess I will do the 3 months test and see, but for now I shan't worry about this. Do you agree? I am thinking even though I am at high risk for lung cancer, I already quit smoking, I am 36, I will not live in the house for more than 5-6 years and next time I will make sure to chose an area or building with near zero radon...

thanks all for your comments. If you have any thoughts please let me know

[kurt]

Only that radon is a single issue, easily remediated; there are dozens of others not so simple. Be careful out there.