The real danger here is to be complacent in our actions and our thinking. As most of you know ( at least around here ) when you do see primary and secondary air vents they are usually 6 inch or 8 inch vents with the age old thought from the HVAC contracting world that one sizes fits all in regards to furnace systems ( BTU sizes of, number of furnaces etc. ). I have always prided myself in being extremely anal in regards to construction matters and radon systems in general. So with that said I would have to say that ( without thinking or realizing it ) took the one size fits all thought and ran with it also. Leo of course is correct in regards to ( maybe not in exact wording but surely intent ) of the guidelines stating we have to follow all mechanical codes in regards to the installation of a radon system. I do not know if the code says anything in regards to running anything through a fresh air vent but I know that there is ( in the code ) a guideline for X amount of free breathable vent area in a fresh air return. As a side note I have had for a long time had a pet peeve about radon contractors not sealing up a liner in a crawlspace around girder piers and against the foundation itself. We believe that the liner should be sealed, taped around all areas and that adds time and money to a crawlspace system but it is the right thing to do. But at the same time I run a subslab vent up through a primary air vent with no thought to the mechanical code on HVAC vent systems….. We must always challenge ourselves to do the right thing and not get complacent. Again …thanks for the input and like always…..just thinking….. Jim Medley Radon Systems 4U LLC From: International Web Resource for Radon Professionals [mailto:RADONPROFESSIONALS@LIST.UIOWA.EDU] On Behalf Of jackwaj75@aol.comSent: Friday, March 25, 2011 10:48 AMTo: RADONPROFESSIONALS@LIST.UIOWA.EDUSubject: Re: [RNPROF] Radon Systems Liability Good advice Leo. This sounds like trouble. The use of open pipe between mechanical room and attic for combustion air + the tall return is a lot of potential for air to leave the house through the attic. The unlined return may violate fire code, but also represents a depressurization source. The potential for the mechanical system operation to play with Radon entry rate is high. Could be an interesting home check delta P and develop some CRM data.Does this home qualify for those HUD funds? Might be the best application for the new owners to a safer home.Jack BartholomewSent from my HTC on the Now Network from Sprint!----- Reply message -----From: "Leo Moorman" Date: Thu, Mar 24, 2011 5:17 pmSubject: [RNPROF] Radon Systems LiabilityTo: Jim, you are in dangerous territory here. Because you saw someone else make a mistake that does not mean you have the right to do that. I love inventions, but you have to be able to know the full consequence of what you are doing as a contractor.First study your local mechanical codes on all of this, as should everyone who considers doing this.Then you know exactly how far you are sticking your neck out on this type of modifiction.After all of that my opinion is a No on (1) and a No on (2) since the EPA document says you are supposed to follow the local Mechanical Code. Finally it has never been the only way to go into the attic and has been proposed by loads of home owners around here. There is something good about being a professional and able to properly recommend solutions to home owners. There are also homeowners that you will not be able to deal with because they will find an unprofessional to do what and how they want it done. The best thing to do is to gently part ways with such a homeowner and find another job that fits you as a professional.Leo MoormanIn a message dated 3/24/2011 12:56:47 PM Mountain Daylight Time, jim@RADONSYSTEMS4U.COM writes:To All : Ran across a situation today….some advice or comments would be appreciated. I went and looked at a sub slab system install today ( to work up a bid on a sub slab system ). In our area we try to do the out of site / out of mind type set up so I usually look for a furnace room or a storage area ( on a basement home ) to install the system in. With this being the case the first thing the owner said to me was….this house has been for sale for 2 years how cheap can you install the system for? Well that was my clue right there as to what I was getting myself into. In this area it is normal to have what we call primary and secondary air vents for 80% efficiency furnaces installed in the basement. These vents will of course go up through the mechanical chase and into the attic where they will provide fresh air to the furnace systems and the gas water heater. On the install of these system fresh air vents one is installed high close to the ceiling and one is installed low to the ground which of course provides fresh air flow for the systems in question. All of this is standard HVAC type venting. All of the vents go up through a 36 x 36 inch chase area that is framed in and is covered by sheetrock as it goes up through the house. Normally you will see the cold air return go up through this area also with the cold air return being solid galvanized ductwork all the way to the attic with flex duct at the top in the attic going to the different bedroom cold air locations etc. What got me thinking about all this ( the problem with the system install ) is the fact that when I got up into the attic to look down inside the chase there was no galvanized return air ductwork present inside the chase itself. What the HVAC contractor had done was to run a galvanized boot from the furnace up to the subflooring and then when he got to the attic ( 12 feet up ) he installed another boot on top of the ceiling joist and then ran the flex duct from there to the bedrooms etc. Which in turn made the whole chase the cold air return. Personally I do not like this and I think it is just away to save some money and some time but I have seen this before. So question number 1. Is….We have on occasion ran our radon system pipe up through the primary air vent to get it into the attic. The primary vents is usually 2 - 6 to 8 inch galvanized ducts that are completely to the attic and when we run our system pipe through these it takes x amount of space up inside the vent itself…..so the question is does this go against any guidelines that anybody knows about ( EPA guidelines etc ) in regards to the system install. I cannot find any issue’s with it but the question is still there. Now if there is any past HVAC contractors out there they may have a fit with the system requiring X amount of fresh air flow to the furnace and the system pipe blocks that air flow……that is a ……????...thought…. It is easy to get used to doing something one particular way and not really give it much thought …But again if we do not ask we do not know. As a side note we do not always do this….I prefer to cut a 4.5 inch hole through the floor and then go up through the chase but again this is not always the case……It is not always a option….that is where the air vent comes into play…. Question # 2. Which is what got me really thinking about this. When I got up into the attic area I only saw one of the two vents sticking up into the attic and the second one was not present. Someone had stuffed batt insulation down around the chase at the top as it enter the attic area. When I pulled back the insulation and looked down into the chase area that is being used as a return I saw the secondary vent down inside the chase itself ( about 6 feet down inside the vent ) which of course made the primary air vent mix with the return air vent inside the vent itself. So if the furnace was running and it needed fresh air and it tried to pull fresh air from the attic it would instead be pulling air from the return air of the furnace itself. Basically just recycling the air in the return vent. Which cuts down on the fresh air available to the system and with my system pipe going up through the second pipe then that creates a issue….yes….??....no…??? I am not there to do anything with the HVAC system but again if I know about this and the only way to get the system pipe to the attic is through the vent then where does that leave me…….?......should it be noted in the estimate and then left at that or something else…..Any thoughts are appreciated. I do not need the job so bad that I am going to do something wrong but at the same time it is not good to rock the boat when the owner is standing on the edge of the boat…….just thinking ……..like always….Thanks ……… Jim Medley Radon Systems 4U LLC_http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1_ (http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1) ***********edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ********************* RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ********************* RN PROF (Subscription changes - archives) - http://list.uiowa.edu/scripts/wa.exe?SUBED1=RADONPROFESSIONALS&A=1 ***********