How to read the radon vacumm monitor?


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Old 07-11-13, 07:08 PM
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How to read the radon vacumm monitor?

Please tell me what information we can draw from the radon vacuum monitor. I understand that the two levels in the tube need to be separate. In my case, one is way below 0 and one is about 1.5. I wonder why it is not 2, 3, or higher?

Thanks in advance for the explanation.
 
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Old 07-11-13, 08:15 PM
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Welcome to the forums.

This is not my area of expertise but I know that the actual readings aren't as important as the fact that they are different. If the reading were the same it would mean that there was no vacuum inside the pipe. The further apart the two fluid levels are......the better the vacuum within the system.

Normally when a system is installed the high and low points are marked.
 
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Old 07-11-13, 08:57 PM
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Thanks for your explanation, PJmax. I thought of the same thing. When the difference between the two levels are higher, the more suction the system has which is probably a good thing??

Then, a question came up when I play with my two sump pumps. I notice that if I stop one pump, the water level in that sump pit raises to level about 5 in. lower than the basement. At this level, the drain pipe is completely submerged under the water. I believe that the drain pipe is connected to the radon mitigation system because the covers of the two sump pits are completely sealed. Then, it came an interesting observation: the suction of the radon system increases a bit, from 1.5 to 2. I don't know if this is a good thing there seems to be one good and one bad thing. My thinking was:

Bad thing: Radon can not be drawn from part of underground under the basement related to the drain pipe to the not running pump because the water already filled the pipe.

Good thing: The suction of the system is increased.

In terms of drawing radon out of the basement, is this setting (one pump stops, one pump runs) good or bad?

By the way, I also have the secondary question about sump pump. Why do the sump pit is deep as it is (seems to be 22in. deep?)?
 
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Old 07-12-13, 08:04 AM
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Just an opinion here, but IMO it would be more important to be depressurizing more area of the basement than to have a greater pressure. As long as you are getting a negative pressure, any radon gas below the slab will be venting out through the system.

With that much water below the slab you will be limiting the path for air flow. As for the deep sump pits, the deeper the better (within reason). The pumps will run longer but less often, however, the max height for the water should prevent the drainage system from becoming blocked.

As a side note, do what you can from the outside to direct surface water away from the house to lessen the load the sump pumps have to carry. Also, if you have a lot of water a lot of the time, consider a a back-up power option for those occasions when the lights go out.

Oh, there should be a guide right next to that manometer, but it is probably calibrated in inches of water column and "1" is a lot. The real number you need is the resulting radon level and if that is too high, then you need more depressurization.

Bud
 
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Old 07-12-13, 12:48 PM
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Thanks, Bud.

So, I should not let the water level go too high to submerge the drain pipes, right?
 
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Old 07-12-13, 02:12 PM
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I'm not a pro on this, but IMO, you want to keep the air space (within the gravel) as open as possible so the vacuum can draw air from the farthest leaks. Since the drain pipes are part of that space, you would not want them full of water.

Let's see if one of the radon pros jumps in.

Bud
 
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Old 07-12-13, 05:11 PM
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The U-tube manometer is read from the top of one side of the fluid to the top of the other side of the fluid. If one side is one inch below the zero (or other index) and the other side is one above the zero you have a differential pressure of two inches. Most common units are inches of water pressure.


If the water level in the sump is above the point where the drain piping enters the entire area being drained will be additional reservoir for the water. Best results will require the pump control to start the pump when the water level just approaches the bottom of the drain tile.
 
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Old 07-12-13, 09:46 PM
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Many thanks to both Bud and Furd for the inputs. I will keep the water level always right belows the drain pipes.

Back to the radon thing, do you have experience with this radon detector. It seems to be the best one available?
 
 

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