Are Natural Gas Detectors Necessary?

[pete_c]

you're going to create too high a static and essentially starve the furnace/blower.

 
My very first power attic fan installed in the attic did the do of a negative pressure in the two story zoned HVAC system in the 1980's. 
 
It was just a phone call asking for the biggest and best power attic vent that was available at the time.  Problem was that there were not enough vents in the attic to the outside air.
 
After turning it on the first time I called the gas company as I thought I was smelling gas and to my amazement I was smelling gas coming out of the HVAC in the basement and on the second floor HVAC unit.  I shut off the power vent and contracted a roofer to install more vents and that was it.
 
The newer home today is very tight with more insulation than the older home built in the 1970's.  I do utilize an electronic filter with charcoal on one side and a regular filter on the other side of the electronics.  I change these filters every month and keep the HVAC fan on 24/7 (low speed).  I do also open windows on the two floors when the outside temperatures are OK.
 
The guru builder knowing about the high radon levels in the early 2000's did properly(?) / passively vent out the two wells in the basement.  Some neighbors did go to that active radon venting thing with electric fans and other do whats that cost some more than $2000 or more. These huge PVC stacks today stick out of the side of their basements and go up attached to the side of the ir homes; looks a bit too ugly for my tastes; but I guess it fixes that radon gas stuff.  Their original builder didn't do anything relating to radon levels in their homes and probably assumed they would never ask?   Not really sure that makes it better or just a more costly solution?

 

[NeverDie]

 I do utilize an electronic filter with charcoal on one side and a regular filter on the other side of the electronics.  

If it's effective against radon, I'd probably most prefer to do it like that, because it would filter more than just the radon.
 
Do you have a radon detector?  It would be interesting to compare your average levels when your filter is running like it is to your average levels when the filtering is off (e.g. perhaps when you're away on vacation).  The Corentium detector ano mentioned is allegedly accurate to 5%.  It uses a photo diode (I presume together with a scintillation material) to detect alpha particles instead of a geiger counter and allegedly doesn't require callibration for the life of the product (claimed to be more than 10 years).  The SafetySiren 3 supposedly needs annual callibration, so lifetime cost is a lot higher even if initial purchase cost is lower. On the other hand, maybe you wouldn't really need it beyond a year anyway.
 
I'd still prefer if it could give telemetry, almost like a weather instrument, but that's just me I guess.  Maybe someday there will be a wireless or IoT version that I wouldn't have to hack together myself.

 

[ano]

I've had the previous version running in my bedroom 24 hours a day. http://www.iqair.com...iers/gcmultigas It has nothing to do radon, but my wife has allergies, and this is the best air cleaner made. I see no change in radon levels with it, and bedroom radon levels are similar to the rest of the house.
 
So nope, no difference from my testing, but I haven't explored it extensively.

 

[pete_c]

Just did the do here and continue the monthly maintainance. 

 

[lleo]

Radon cannot be filtered with typical household filterring methods, and activated carbon will also not do much as it is a noble gas that will not bind chemically to much anything. This is akin you would say that you can filter CO or CO2 which have a larger molecular diameter than the single atom Rn.
The 4 piCu/L radioactivity amount to 8-9 atoms decaying every minute in each liter of air.
If you compare the number of N, O2 and CO2 molecules in a liter of air, even at this concentration, it is like needle in the haystack.
Anything that can be penetrated by air and water moisture will also be penetrated by radon.

 

[pete_c]

Yup; here the purpose of the electronic filter installed over 10 years ago with charcoal is to filter the air.

 

[pete_c]

The Radon paranoia in my little neighborhood worked well as vendors made thousands selling PVC and little fans per installation...kind of funny in a way...
 
I was though concerned with the water here when I first moved to this location as I was used to Chicago water and never really paid attention to water in general well until I moved here. (boil order water pressure and so much iron that my toilet water turned blood red).

 

[NeverDie]

Radon cannot be filtered with typical household filterring methods, and activated carbon will also not do much as it is a noble gas that will not bind chemically to much anything. This is akin you would say that you can filter CO or CO2 which have a larger molecular diameter than the single atom Rn. The 4 piCu/L radioactivity amount to 8-9 atoms decaying every minute in each liter of air. If you compare the number of N, O2 and CO2 molecules in a liter of air, even at this concentration, it is like needle in the haystack. Anything that can be penetrated by air and water moisture will also be penetrated by radon.

I'm pretty sure you correctly nailed the issue.  My radon test kit used activated carbon to collect the radon sample, and so I assumed radon had a strong affinity for it. However, as you point out, being a noble gas that simply can't be right. 

 

[lleo]

For a complete picture, the canister of activated charcoal, which initially has no radon in it, when exposed, will be diffused to the same concentration as the space is placed in. Radon, as an inert noble gas, adsorbs onto activated charcoal surfaces by means of physical non-chemical interaction - physical adsorption, or "physisorption", as a long-range but weak interaction of a molecule with a surface.
A physically adsorbed molecule will eventually desorb from the surface. Due to thermal agitation, the adsorbed molecule "vibrates" within the adsorption site, and with every vibration there is a chance that the weakly bound molecule will leave the site. The probability that desorption will occur within a certain time period greatly increases as temperature rises.
After the measurement is completed (i.e. short term exposure, typically 48 hours) one simply seals the canister trapping the diffused and weakly 'absorbed radon, and in the laboratory simply an alpha counter is placed next to it to measure the activity based on which an average concentration of radon is reported, factoring in exposure, humidity and other factors.
Canisters are not good for picking up variation of radon concentration, say you got a rain that pushes more radon into the basement, followed by wind which mechanically dilutes the concentration due to increased infiltration. you will still get one number representing some average.