Radon Reduction thread

[Daox]

I mean why didn't you just add drain tile in the first place instead of all the sumps.

[Xringer]

The basement wasn't suitable for drain tile.

The guy across the street had a 'French Drain' installed and it works okay.
He still has a sump and sump pump..
His basement is totally unfinished, no walls, flooring or anything else down there.
Just the oil tank, heating system and washer & drier.
He won't tell me how much it cost.. I assume it wasn't real cheap..

[Xringer]

Because there are tons of decaying radioactive rocks under my house,
Radon gas is forced up into my basement via one of my new sump holes.
It's heavy, so it accumulates in low areas (like sump holes).

Radon sticks to things like dust & mist, due to it's electrical charge.
It floats around in the basement air for abt 4 days and then turns into radioactive lead.

Lead 210 stays radioactive for a long time. It's half life is over 22 years.
Lead 210 emits alpha and beta particles. After 22+ years, it will turn into plain old lead at some point.
22.3 years+143 days (or +12.3 min). It's random.




You don't want get any Lead 210 in your lungs, since those Beta particles penetrate and can cause damage, maybe even cancer.
When you work in a uranium (or Thorium) mine with poor ventilation, you need to wear a "high-efficiency particulate air filter mask"..

So, after the earth quake last week, I heard my radon alarms beeping.
One had an error, and the other one was reading 4.5 pCi/L.
I reset both and after a couple days, they are both up to 4.0 pCi/L
which seems to be the 'normal' level these days. (We have had some rain too).


I'm not sure if my Radon detectors are picking Radon, or Lead 210..?.
Since Radon seeping out of the ground into my basement doesn't last very long,
it seems like the long-life Lead 210 is likely the most dangerous stuff.

So, I had this idea of using an air filter unit to clean up the contaminated air.
It would suck in the basement air with it's Lead 210 (hanging onto micro dust bunnies),
which would lodge in the 'high-efficiency particulate' filter..

When the filter got loaded up, it would be replaced with a clean filter.
Maybe bury it for 23 years.?.

Anyways, the sensors won't pick up much when there is air flowing in the area,
(per the manual), so the air cleaner is on a one hour on-off cycle.
The sensors will get 12 hours of still air each day to record the levels.

If those sensors can pick up Beta particles, and the filter accumulates
a lot of Lead 210, there might be a change in the 'normal' 4.0 pCi/L number.

To find out if my Radon sensors are actually picking up emissions from Lead 210,
I'll let the filter load up for a few weeks, then move it to a low Radon area,
and place a Radon detector right next to the filter for a few days.
If the count is higher than 3 pCi/L then it's seeing the Lead 210..

~~~~
The amount of Fresh air in the basement has been reduced lately.
We used to run the oil burner for 1/2 hour each morning.(for hot water).
Nowadays, the only stale air dump is up to the laundry dryer. Once a week.

Edit 6/18/13:
After posting the above, I ran an air filter for about a week and saw no change in the radon levels.
I then moved the filter away from the 'hot' area and placed a monitor on it.
It only showed the normal levels. A geiger counter only showed back-ground radioactivity.
Filter experiment was a flop. Maybe the activated charcoal in the filter is acting as a shield or absorber of the emissions.?.

[Xringer]

This month, I installed some ventilation in the basement.


(not really 20 CFM) http://www.suncourt.com/Images/Radon-airflow-chart.jpg


(My wife loves it when I drill 3.5" holes in the house)..

The blower is set up to run between the hours of 10AM & 8PM.
Radon Fan Instructions
The air intake is about 6" from the basement floor.
The output is outdoors, on a wall in front of the house.

My goal was to increase fresh air flow in the basement.
Now it smells nicer, not musky like it has been.
Also, I want to warm up the basement using warmer outside air.
During the last few days, I've noticed the temperature has gone up a few degrees.
(That might be the normal heat gain, since it's been up in the 80s outdoors).

Since I didn't install this unit as a radon abatement setup (sucking air from below the floor slab),
and well away from our only large source of radon (from a sealed sump hole),
I didn't expect much (if any) drop in the radon readings at the sealed sump.
I wondered of the lowered pressure in the basement would pull up even more radon gas..


This week, we've been having a lot of rainy weather, which has raised the water table.
The pumps started running, and I had to un-seal the Radon hole!
After placing a pump in that hole, I re-set the Radon monitors. (ave was 4.2)
I know from experience, that we always get a jump in radon during flooding.
Even a small upward change in the water table always causes more radon.

Now that the hole was un-sealed, I was expecting to see higher readings.
But, they are now lower than we've ever seen. (Water blocking the gas now?)

I had hoped the fresh air setup might help the radon problem.
Never figured they would be this low with the sump unsealed.

After the rainy season is over, I plan to remove that pump and re-seal the sump.
It will be interesting to see if the level drops even lower.

~~~~

The main air-input to the basement is coming down the basement stairs,
from the attic pull-down stairs, which is open about 6". (isolated by a door from the main house).

I was hoping this will help keep the attic a bit cooler this summer.
(while warming up the basement a bit).
But, I'm not sure the blower can fight the chimney effect in the attic.
The slight air flow I can feel coming down the stairs, doesn't feel warm at all.
This is on days when it's 120F or more in the peak of the attic..
Perhaps the air nearer the attic floor isn't so hot..
I'll have get up there when the sun comes back and measure the attic floor heat.

[Xringer]

The sumps are starting to dry up again. Meaning the water table has gone down,
and the radon gas flow is going to decrease.
1.7 pCi/L with an unsealed sump, is excellent, considering what it was before.

The location of the blower in another room, means there is no real breeze blowing past the detectors.
So, there is no error introduced by air flow.

But it seems obvious there has to be a general slow air flow from the cold
floor slab, towards the equipment room and the suction of the blower.

I've read that radon is normally not a problem in a ventilated basement.
I wonder if radon reduction is really a lot easier than it looks.?.
Maybe drilling holes in the slab, and trying to suck radon gas out of the soil
isn't really needed in a lot of cases??


It's been warm outdoors, but the basement temperature isn't increasing as much as I expected..

~~~
I just realized that a sump pump can move radon, thus lowering the average.
(This old sump is located within 3 feet of the airpump input).


That dump pipe on the lower right, dumps the water from the 'hot' sump.
When the pump cycles, the last 15-20 seconds are dry. Meaning it's pumping air. Radioactive air..
Now dry weather means the pumps are not running.. We'll see if the radon level goes back up some..

[Xringer]

I've been running this 80W blower from 8AM to 8PM ($4.94/month) and the basement temperature is slowly climbing.

I don't want it to get too warm in the basement, so I'll have to add controls soon.
Monitor the inside temperature and try to limit blower operation to under 72F.
At the same time, stop the blower, if the outdoor humidity is too high.

Winter Operations:
In the winter, when the basement normally gets down to around 55F to 45F,
Maybe I can run the blower in cooling mode.?.

I would set Cooling Mode, only when the outdoor air is colder than Basement air.

Set the blower to come on and run, until the basement air temp is <=44F. *
After the blower stopped, the slab/geo heat and leakage from the rooms above,
would slowly heat the basement back up to above 44F, restarting the blower.

*Note: 44F is just an example. I would use the average basement air temp overnight as the setpoint,
and use that setpoint -2 deg F as the low limit.

[Xringer]

We are now running the fresh air fan just 7 hours a day between 8AM & 8PM.
The timer runs one-hour-on and one-hour-off with the last two hours on.
Using the 7 hour mode, and after detector reset #3, the readings are at 1.6 pCi/L

The radon sump hole has been dry for a few days now, and it seems
that I was wrong about the sump pump's dry running lowering the radon.
The readings are very low now and the pump has not been running at all.

My next test will be to turn off the fresh air blower and watch the radon level.
I'm planing to wait until a few days of rainy weather roll in..
Don't like to suck in fresh air with 100% humidity.