RN 4EC ECM Radon Fan

These fans do not come with a plug. They are typically installed outdoors and in most states that would require them to be hard-wired. If the electrical code in your area allows for the use of a plug on permanently installed outdoor fixtures you could put a plug on this fan. To know if that is the case in your area you would want to speak to a qualified local licensed electrician or the electrical inspector in your town.

Resistance created by friction between air or water and the pipe and fittings is referred to as Pressure Drop. It is annumerated or measured in inches of water column. You can certainly measure the footage of pipe, as well as count the different fittings. Then using a table determine the pressure drop for both 3” and 4” to put a number to the difference. However, I have not done that since plumbing school decades ago. More importantly I think there is an easier and more effective way to think about this that may help you get to where I think you are going. When you put your thumb over the end of a hose you are not increasing or decreasing the pressure. The pressure is constant. Because the pressure is constant the same amount of water needs to come out of the hose. Therefore, the water must speed up. What you have created is velocity, not pressure. The pressure drop you have created with your thumb is insignificant relative to the velocity change. Now back to your question. If you increase the pipe size the same amount of air will move through the pipe but because of the increased pipe capacity the air will not need to move as fast. So, there will be less speed and less noise. I run into this with sump pumps quite a bit. When homeowners install a sump pump, they often bush down the outlet size and run a small discharge pipe. They find they get a lot more sound and often pipe hammer when the pump shuts off. This is all due to the velocity created by under sizing lines.

Your resistance is largely determined by the 3" suction piping you already have. Changing the outlet to 4" probably wouldn't change much unless you have a very long run between the outlet of the fan and the end of your outlet pipe.

Yes you can install this fan either inside or outside as it is rate for both. If you are trying to meet code, then you may need to check your locality but assuming you are just swapping with existing fan you should have no issue.

I am sorry but I can’t give you a definitive answer as I do not know the building codes in your state. To know for sure, I would speak to a local qualitied licensed contractor or the local building inspector. I have installed Fan tech brand fans in my own attic without issue. But again, I am unfamiliar with your home or state.

The fan is variable speed and can be used in a high suction (low CFM but high vacuum or High CFM and lower vacuum). This depends on your soil conditions. But this fan specifically can be used in either mode as it is adjustable.

The volume of air moved will always be dependent on the resistance. This is why fans and pumps are always rated on graphs. On one axis you have resistance and on the other a flow rate. The graph displays performance across the unit’s entire range. From no resistance to so much resistance that air flow drops to zero. If you scroll down the Home Depot product listing page you will come to a section entitled Product Details. If you expand that section, you will find PDFs of the product documents. The performance graph can be found on the third page of the specification sheet. Most manufacturers refer to their fans by the performance with no resistance. That is a little disingenuous because there will always be resistance so you really need to know how the fan will perform under load, thus its torque. With no resistance to this fan will move over 200 CFM. Your radon system should have a manometer that shows the CFM your fan produces under load; on a constant basis. If you do not know what a manometer looks like look at Fantech model 95905 which is Home Depot SKU 330557851

If you scroll down the Home Depot product listing page you will come to a section entitled Product Details. If you expand that section, you will find PDFs of the product documents. If you open the specification sheet it states “Rn4EC-3 can create 4.75” of suction while moving 20 cfm or moving from 125 to 200 cfm when operating at only 0.5” of suction.”

Fran Tech does not publish a decibel rating for radon fans for the simple reason radon fans are typically installed in locations where sound is not a factor such as outdoors. Please keep in mind that any decibel rating you find will be of the fan running without any static pressure drop. Meaning with no duct work or pipe attached to it. In that situation that vast majority of fans make very little sound. The sound comes from the movement of air through the duct. The larger the duct the lower the static pressure drop the lower the sound level. It’s the restriction of air flow that you hear, not typically the fan. These centrifugal fans are typically extremely quit. You typically only hear sound if they are oversized or if the duct is undersized. I do have this model installed on my homes radon system and I can’t hear it at all. The only way I know if its running is if I put my hand on it and feel the slight vibration.

This particular fan comes in two variants, a 4" and 3". The fan is the same it just contains a rubber/fernco adapter.. I think this is the 3" version listed but you can get adapters as needed.

If you scroll down the Home Depot product listing page you will come to a section entitled Product Details. Expand that section you will find PDF’s of the product documents. The specification sheet calls out that it is meant to work with 3” PVC.