The statistics I have seen for lung cancer incidence have shown African American men as significantly higher risk than other groups for reasons that aren't clear to me. This group as well as all service men and women living at military bases in hot climate regions typically have living quarters that have very low air exchange rates that exasperate the radon exposure potential. In the past Dave Wilson has seen radon levels as a whole increase when buildings on the bases are renovated with tighter windows and doors and outdoor air is not included.

I understand the reluctance to have homeowners obsessing over small changes in their radon levels. In a survey of my own results I found about 85 percent were reduced to 2 or less. That means 15 percent wound be running around 3 pci/l. And often those systems are very difficult to get lower. Mostly this means a discussion with owners about how radon fluctuates.

Yes it is true a 10 minute or one hour measurement is not valid but it can be really helpful if it is a comparison measurement with 2 -3 - 4 or more detectors at the same time. One caution with doing this. The monitor must be very close to an entry source because radon diffuses back to area average within a foot or so.

Karen. I have been using and testing the Radoneye's for several years. They have a higher sensitivity than the other home radon monitors that allows them to give the 1st reading in 13 minutes and a revised reading every 10 minutes. The 1st reading is typically about 75% of actual result. After an hour they are close to the actual level. Because of their cost and fast response they can be used by radon mitigators to get a quick idea of the approximate radon levels in 30 minutes. We often place 6 of them in the basement of a problem house to try and figure out where radon may be entering the basement. The down side is they must however be plugged in or you have to purchase small 12 volt battery packs to use them as diagnostic tools. They are also sensitive to thoron so you have to be aware of this. There is also no clock or date stamp for the basic model. Their Pro version is fully certified to use for Real Estate testing and has all the typical features. If left in place the hourly data can be downloaded with a cell phone as a text file and converted to spreadsheet. You have to record the time stamp separately.

Unfortunately up until recently there has not been any studies done in the US that measure the effect of rim joist exhaust versus roof line since the mid 90's. This year we may get the final report from Bob Lewis and Brad Turk that did an extensive test in several homes. I myself have been amazed how quickly radon diffuses from a source in a basement when I'm trying to locate it.
I just submitted a paper to try and measure radon diffusion from a rim joist exhaust. So maybe in Nashville we will have some actual data to reconsider this long held position. I think a good comment at this point is maybe we can all learn from the example of our brothers to the North that we would all be better off making decisions based on science rather than our own opinions.

George You are very perceptive. The existing guidance requires the radon fan and all piping above it to be in unconditioned space (which also should be ventilated space) . New homes are now being built with conditioned attics and insulation in the rafters. Just as no one would put a radon fan inside a cathedral ceiling home the guidance does not allow the radon fan to be installed in your conditioned attic. Maybe other members on this forum could give an answer of how to deal with this and be within code.
One solution as you mentioned is to create an unconditioned space in the attic for the fan and piping. I would recommend it also be ventilated space. It would need an access door to be able to install and repair the fan. And it would need to be have an electrical power source and large enough to house the fan. Good luck with your new home. Sounds like you are considering every detail.

Hi Jim

The Modus is basically the DM1 unit. I would recommend that unit other than it does not self-zero. At the last symposium I presented a session on pre and post diagnostics that included a comparison of digital micro-monometers and their cost. Unfortunately my favorite, the Energy Conservatory unit, has been upgraded to a much more expensive unit but there are other choices that self zero. The ability to measure to 0.1 pascals or 0.001" is a minimum requirement. I posted the talk I gave to a page on my web-site and the 2nd slide compares the different units I found that were available. Check them out at this link.

https://www.wpb-radon.com/PFE_Communication_Test.html

Jessica - Compare the Counts per pCi/L for each unit. Because real estate testing revolves around 4 pCi/l the higher count units have much less variation hour to hour. CRM's only have to be within 25% of the average so all of the certified units can do that but when you compare hour by hour is when you see the large difference in variation. You can easily see the difference between the sun-nuclear base model versus their higher sensitivity model.

Things have changed with new low voltage fans and cheaper solar panels since we discounted solar. I just did some quick calculations which are likely to be way off but here is what I figured. Using RadonAway's new LV175 24 volt radon fan as an example. It uses 30 to 71 watts at 120 volts via the 24 volt converter. That is about a maximum of 0.6 amps at 120 volts. At 24 volts it would be using about 15 watts. You can buy a Renogy 5'5"X3'3" 24 volt 270 watt panel for $300. You can also buy two deep cycle 25 pound 12 volt 300 AH batteries for about $150 and wire them for 24 volt. You would also need some voltage regulator to keep the batteries from over charging. The solar panel would easily run the radon fan. Two batteries should keep the fan running for 2 days when no sun. And the solar panels at full capacity are putting out 11 amps at 24 volts so theoretically they could re-charge the batteries in 6 hours of bright sun. Besides the fan that makes the basic solar materials about $500. Maybe others can correct my conversions

Donald & Bob
Excellent points that we need to do a much better job teaching and motivating worker safety, especially in the states. The intro mitigation course only spends less than an hour on safety over our 3 days. It needs an update. I will put in a plug that we include a safety course at the next conference. I did a quick search and only found one CE course on PPE by spruce so there is a big void there.

I agree that outside venting is a good idea however the reality is most crews sent out to do two jobs a day or one big job are too time crunched and not willing or in many cases not capable of doing any system diagnostics. So the concept of OSD was to make it super simple and very quick to do with no math, no extra vacuum airflow or pressure measurements or even needing an app. Obviously you can raise the radon levels way up by venting into the basement. At the same time if you are trying to measure a tenth of a pascal or thousand of an inch vacuum an open window and a bit of wind will make that difficult to see. The solution is to minimize test run time by having a super simple set up that allows multiple test variations at the same time test hole vacuum is being measured.
In about 2 minutes you could test the performance of an RP140, RP145, RN3 and RN4-4 fan with equivalent 3" or 4" piping used. And the installers only need to refer to a chart that is small enough to tape to the body of the fan. As for radon exposure people always forget that risk is based on Dose. Dose requires two components - an exposure and time being exposed. 2 pci/l in your house is 2X12X365 = 8760 pCi/l/hrs. which most of us would not consider a serious risk. If you raised the basement to 20 pCi/l for one hour or 40 for 30 minutes that is 20 pCi/l/hrs.

Two days and they are gone!! Not a good idea to fly through the blades of a 10 year old used Fury. Of course quality mitigation also includes sealing. Next step is getting the foam gun out of the truck and closing up the holes.

The paper I presented at the 2003 AARST conference that includes remediating high CO2 levels with ASD system is the following.

http://www.wpb-radon.com/pdf/Vapor%20Intrusion%20Mitigation%20VOC.pdf

Angela
I have worked on a half dozen homes with elevated co2 in Pennsylvania. These homes had co2 levels so high they displaced the oxygen and often caused the pilot light to go out on the water heater in the basement. There may have been one death from co2 that i think was misdiagnosed. In all the cases we think the co2 was produced by rotting wood in the ground. In one case it may have been the builder who buried trees. In most of the cases I worked on it was due to rogue coal mining shafts done years before that had rotting timbers.

We were able to fix these houses using standard ASD systems. Be careful in these homes. If oxygen levels go below 15 percent you can pass out. The fire department was called in to one of the houses when the daughter passed out and one of them passed out.

I did publish an aarst paper about the work.

Bill

I won't make a comment about fan placement but I can make some statements about fans used for radon mitigation. Leakage of the fan housing is one issue but there are many other considerations. A big one for our company was noise. If you are installing a fan inside the dwelling it must be an even bigger consideration for you. I tested the Suncourt fans 10 years ago and the vibration hence noise was significantly louder than the common radon fans. Maybe it has improved in that regard, maybe not. You can see the performance graph for this fan on my website.
There are new fans from all the manufacturers as well as new fan suppliers that I have been trying to keep up on my website so you might check them out if you haven't recently. If you know of any fans not listed let me know.
http://www.wpb-radon.com/radon_fan_performance.html#aTF104
Bill

Ryan. I have visited homes I sealed center floor cracks 20 years ago with urethane caulk and it is still there in great shape. Silicone often has poor adhesion to concrete and can be scuffed off with any traffic. In a basement UV light degradation should not be an issue. I have seen degradation of urethane caulk in Guam for outside sealing from the intense sunlight outside. There are many grades of silicone and I'm sure there are grades that have better adhesion to concrete but most of us will grab the lowest priced tube. Urethane is also paintable while silicone is not. Our general recommendation is use silicone for sump pit covers because you are making a seal that will latter need to be removed. Use Urethane to create a permanent seal. There maybe other products that adhere to concrete but may not have the elasticity of urethane. There are also issue with the fumes from urethane are very toxic. Maybe other more knowledgeable mitigators can better address the products that are available.

Brian. The monazite in the bed was inserted to produce negative ions which Koreans generally believe to be a health benefit. The mattress company thought they could sell more mattresses if they claimed it also produced negative ions. A purchaser using a radon eye placed it on the mattress and got a high reading thinking it was radon. Actually it was thoron because the radon sensor is on the bottom of the radon eye and is sensitive to thoron. The government initial said the mattresses were safe because they measured low radon levels. Later they retested it for thoron and it was 9 times above guideline exposure.

Because thoron is short lived, 55 seconds, it actually is not a great idea to sleep on a thoron source. All the mattress were re-called.

We have very few wood foundations in PA but lots of superior walls. Both manufacturers and installers worry about water pressure and water entry because they typically have no footers. If the lot is sloped it will surely have drains to grade. If it has window wells they will be a direct leakage. Leakage can be a bigger problem than lack of permeability. Design your system to minimize the impact of leaks you can't seal rather than just use the sump. good luck

This is a sad day for me learning about Paul's passing. At every meeting with Paul I would be greeted with a big smile and a discussion about his recent work and interest in what I might be doing. The radon industry and AARST in particular has lost a piece of it's soul. I will miss him greatly.