We have plenty of elevated radon in Southwest Florida. Home Inspectors should recommend a radon test on every home purchase. Why else would the EPA give the Florida Department of Health a special grant to study the causes?
http://www.doh.state.fl.us/environment/community/radon/
“The Florida Department of Health is conducting a study, funded by a United States Environmental Protection Agency (EPA) grant, to investigate the causes of elevated radon levels in mid and high-rise multi-family residences in Lee and Collier Counties.”
“In some areas of Florida, one out of two homes has excessive amounts of radon” “RADON IS THE MAIN CAUSE OF LUNG CANCER AMONG NON-SMOKERS”
Florida Law:
“The Department currently requires the certification of individuals and businesses offering radon testing or mitigation.”
interesting link Doug, I can’t help but wonder why the State and EPA are interested in mid and high rise buildings, I would expect that any elevated radon levels in uildings of that type to be within the stairwell areas which are mostly well vented.
No not really, by the time the aggregate has been mined, processed, trucked and mixed into the concrete any radon gas would have been long gone as Ra has a very short 1/2 life.
The concrete is the problem in parts of SW Florida. Friend of mine needed mitigation. She lived on the 6th floor. Building envelopes are the issue. Most condo owners never open the windows. No way for the gas to escape.
Keep in mind that the Radium-226, which produces the Radon-222 gas has a half-life of 1600 years. The element that produces the Ra-226 is Thorium-230, which has a half-live of ~ 80,000 years. As you work backward even farther, you start at Uranium-238, which has a really crazy half-life of ~4,510,000,000 years. Based on these numbers, I think radon is going to be around for a while.
Regarding the SW FL problem, it isn’t isolated to Lee and Collier Counties! We’ve seen the same thing in GA, NC and TN. Yes, it appears to be the radon emanating from the concrete into the living quarters, but with help. The high readings are almost always associated with very low fresh air exchanges too. By making the buildings super-tight for energy efficiency reasons, another problem is introduced. We’re not talking about concrete with enough radiation to make the walls glow, we’re talking about a small, but steady amount of radon coming from the massive amounts of concrete surface area in these buildings, getting into a condo or apartment and not getting diluted by fresh air.
I heard that ASHRAE made some changes in 2003 to require a certain amount of fresh air, but there could be a huge number of concrete buildings constructed between the 1970s and now that were designed with maximum energy efficiency in mind. I bet they’re not all in the SE US.
I do agree they could use some system of air change but to think a HRV is required is in my openion more then needed .
These are small aptarments and do have the space or need for this .
This is Florida and I do not think Radon Needs as much air exchange as is done by an HRV.
…Cookie
Jay, thanks I stand corrected I used to do alot of Ra testing in New England but never had encountered Ra associated with building aggregates. The problem in most areas is that the Ra is comming up through the natural rock.
What strikes me here is, where is the aggregate comming from that is producing those results, there must be some very high natural levels within local rock and gravel quarries.
Maybe yes/ maybe no! It would depend on the cost of cooling and how much ventilation will be needed to meet the recommended radon levels.
A large part of the cost of cooling in this part of the country is the latent moisture load…just to condense the water out of the air before you can substantially lower the sensible temperatures takes a lot of power.
The heat wheel dessicant passively removes a portion of the moisture from incoming fresh air and transfers it to the exhaust air, lowering the cost of cooling cheaply. A good economic analysis from someone working HVAC in that area would be interesting.
Yes I see this all the time ("removes a portion ") But never many facts ,is it 1% or 60% .
I seldom see and moisture in the traps coming from an HRV unit.
Advertising is great at using it might or it can or it does .
I would like Facts from these companies stop the Bull SXXX .
I am of the opinion that HRVs should not be run at certain times of the year as they can add moisture to the home and other times cause the home to be lacking in moisture . ("Thoughts? ")
Just lost another fairly long post back to you, Roy!! GD board!! Why can’t they fix this fatal flaw??? I may call you tonight to answer your questions/concerns!! Don’t have the time to type it again.
These are small aptarments and do have the space or need for this .
This is Florida and I do not think Radon Needs as much air exchange as is done by an HRV.
Points:
thousands of condos between 3,000 to 10,000 sq ft in Naples alone.(ten high rises on gulfshore blvd alone with more than a 100 units)
Most high rises are mitigated with ERV if possible, sometimes 2 or 3 ERV’s.
Smaller condos 1300 to 2000 sq ft (2story or low rise) are generally mitigated with a mechanical ventilation system (just brings air in, a few hours a day).
We find elevated radon on all floors even up to the 25th or 27th, I don’t really pay much attention, we perform hundreds of radon tests.
Bill Levy, Associated Radon /east coast, Gene Yacobacci, at RMS, Radon Mitigation Services / statewide (www.radonfix.com), and Shawn Price at Air Chek, inc. (www.radon.com ) are experts. After going to over 15,000 homes, I don’t really pay much attention to anyone but these guys, they’ve proved they know what they’re talking about. Lots of opinions out there about radon, too many people underestimate the business. Not trying to slam anyone but you want facts about radon, mitigation etc. not someones guess.
I have to get back to work, it’s almost 5:30 and I did want to go home before dark, we might get a frost tonight, need to cover my tomato plant (1).
HRV’s do not have to be run all the time in either season. Some manufacturer’s offer timed “off/wait state” or “re-circulation” periods interspersed with timed “air exchange” periods or air exchange “on demand”. At least one manufacturer offers a programmable timer.
To run them all summer is senseless unless family members have severe pollen allergies or the house is closed up for air conditioning purposes. We put windows in houses for air exchange also!
In 1987 or so, saw an HRV cause a mould bloom in a basement during the summer!!! This was 7 houses down the street from the former owner/founder of the HRV manufacturer (now owned by Fantech; he’s rich and retired now). This was a small new retirement home for a couple. She liked to sit in the basement knitting/watching the soaps, etc and wanted lots of air down there. A period of very high exterior rh occurred (like Florida, Miss.) and mold showed up. The installer came and installed a much larger volume unit (275 cfm vs 135 cfm) to “dry the place up” and the mould got worse!!! I eventually got called because of my R2000 connections. Put a small Van Ee 1000 (100 cfm) in but specially wired it so that when the summer outdoor air got above 55-60%, the unit shut down and wouldn’t bring the humid air into the cool basement
Standby for radon emanating fom Granite counter tops…
As to radon exprtise, call Anreas George. He consults and teaches for RTCA in Elmford, NY. Andy ws the physicist who worked or the Atomic Energy Commission, who ventured into the mines and did much of the investigative work with regard to radon gas. He is responsible for many of the meauremnt protocols and development of testng equipmet, valdation, and criteria. Andy developed manyof the algorythms in usetoday in the radon field.
Except for the one that analyzes charcoal kits. Modesty prevents me from telling you who wrote that algorithm :roll: .
Anyway, the problem with commercial buildings isn’t typically solved by increasing air exchange. You could double the air exchange rate and only cut the radon level in half by dilution. The problem stems from commercial buildings operating under negative presssure due to, mostly, stack effect.
But if the radon source is not the geology beneath the structure, the chimney/stack effect will not be introducing much, if any, radon into interior spaces. One of the radon consultants mentioned above claims sometimes only a few hours of air exchange per day are enough to lower radon concentrations to or below recommended maximum limits.
What does he mean by “a few hours of air exchange”? Makes no sense. That isn’t a rate of exchange.
The question isn’t does the air exchange, all buildings exchange air. What matters is change in current rate. Increase the rate from its current rate and the radon levels lowers. Increase it some more and the radon level lowers some more.
Now if it is a tight building, lowering radon by increasing exchange rate becomes easy because the rate can be increased dramatically, but if the exchange rate is already high, lowering radon by increasing exchange rate becomes difficult because the change in rate will be less dramatic.
The last part is true but these buildings seem not to need a lot of extra exchange since it was implied many were built since the 1970’s and may be fairly tight…Hasn’t this, in fact, been part of the problem with raised radon levels- too little “natural” ( I hate that term; we now know better- it’s not dependable) ventilation coupled with radioactive concrete.