No one is arguing that Ron.
Of course it will.
The point is is that it part of the normal operation of the home 24/7 and represents the conditions in the home when tested.
You don’t turn off any operating Radon mitigation fans do you? Same thing
Sometimes an HRV is used part of a radon mitigation system, in which case it **should **be running during a radon test. I was looking at it from the standpoint of a home which is currently not being mitigated.
Again, why would that matter? If the HRV is part of the everyday function of the living conditions, then shutting it off would create a different scenario. So would turning off the hvac system, so would seasonal changes, etc.
I bet Larson will dig till he get the right answer though.
What’s the difference?
Look at it this way.
If the HRV is removing some Radon, and it is, you may be recommending a mitigation system unnecessarily.
If the Radon test comes back above the limit when the HRV is turned off but would not have if ere running, what is the value of your test?
HRVs are sometimes all that is needed to reduce radon levels below the mitigation limit.
What’s the difference?
Look at it this way.
If the HRV is removing some Radon, and it is, you may be recommending a mitigation system unnecessarily.
If the Radon test comes back above the limit when the HRV is turned off but would not have if the HRV running normally, what is the value of your test?
HRVs are sometimes all that is needed to reduce radon levels below the mitigation limit.
If the HRV is not balanced properly it could cause a negative pressure in the home resulting in a high radon reading.
I tested my home and got an excessively high reading (692 Bq/m3). I then tested the HRV as per manufacturers recommendations and got a negative pressure result.
The HRV was adjusted and another (long term) radon test is being done presently.
Hopefully balancing the HRV to a slight positive pressure and leaving it on 24/7 will bring the radon reading down to a safe level…
I am going to continue to research this because it needs a definitive answer. Recently took the class for licensing and was pretty sure HRV’s were mentioned. Unable to find anything I can quote though. I’m OK with learning that I was wrong, but as of yet I don’t think so.
Hopefully somebody will chime in with the correct answer.
FYI
Indoor action level in the United States is 4 pCi/L or 150 Bq/m3
Indoor action level in Canada is 5 pCi/L or 200 Bq/m3
I agree.
Let us know what you find.
From the EPA
A Citizens Guide to Radon
If you are doing a [FONT=Palatino Linotype,Palatino Linotype][size=3]short-term test, close your windows and outside doors and keep them [/size][/FONT]closed as much as possible during the test. Heating and air conditioning [FONT=Palatino Linotype,Palatino Linotype][size=3]system fans that re-circulate air may be operated.** Do not operate fans **[/size][/FONT]or other machines which bring in air from outside. Fans that are part of [FONT=Palatino Linotype,Palatino Linotype][size=3]a radon-reduction system or small exhaust fans operating only for short periods of time may run during the test. [/size][/FONT]
[FONT=Palatino Linotype,Palatino Linotype][size=3]According to Ohio protocol, radon reduction system must be labeled as such.[/size][/FONT]
[FONT=Palatino Linotype,Palatino Linotype][size=3]Will post more as I find it.
[/size][/FONT]
Ron, that information is not what the protocol states.
You are reading a consumer guide.
I’d like to hear your thoughts on this:
Mike
If the HRV is removing some radon (maybe it’s not, see post 26), then is it part of a radon mitigation system? If it is not, then how do I know if someone will not come along later and disable the HRV for some reason. So I would have to do the test for the worst case scenario. Then if the result was above 4 pCi/L, I would have to recommend mitigation. Then they could have a mitigation contractor come in and maybe they can get him to certify the HRV as a mitigation system.
Ideally I would like to do 2 tests, one with the HRV in operation and another with it off.
If it were my house, I would want to know how critical that piece of equipment was to my family’s health. Wouldn’t you?
Gotta go. Stuff to do. My anniversary today.
BTW it’s Ron with a b
Can’t disagree with that.
ROB
That’s my sons name.
External ventilation systems such as HRV’s or ERV’s should not be on during the test if they are left on high. Normal ventilation is fine as many houses that have HRV are much more tighter and mimic the more naturally ventilated older house.
Not according to my brother in law who both installs HRVs and mitigation systems and who is AARST certified and who I spoke to today at a family function.
If you have information from an authoritative source, please post it.
And you have not defined “high” as in cu ft or cu M per minute.
So what is he saying Michael because all my teaching says it is OK on low. Most but not all are about 50 cfm to 80 on low. When has it changed to shut it off if that is what you are referring too.
Personally think a person should not be in a tight building without ventilation of some kind.
Post your source or stop blabbering.
Could you get the info on this Michael! I think it is very important as I have never considered a HRV on low having any affect on the radon measurement but it could I guess.
I have posted the recognized protocol.
I think it could have been written a bit cleaner as it does not adequately define high and low volume air exchange devices.
I think the effect is minimal as the HRVs are not high cfm devices and I have shared my opinion as to why HRVs that run 24/7 are part of the houses system of normal operation.
Inspecting always involves some judgment and opinions will differ.
But when you have published protocols I think it is wise to follow them.
Just completed a second radon test on a home with a HRV.
1st test HRV off: 11.3 pCi/L
2nd test HRV on: 8.1 pCi/L
Not sure what to make of it, but with the HRV operating results were lower. The HRV was not part of any radon mitigation unit. I believe I will start testing with them all operating.