Old basement install in older house

[stevemartin]

Hi all,

I have an old cape cod home built in 1940. We have a finished basement which we spend most of our time in. Our 1995 Enviro fire EF-3 was installed in the basement by the previous owners.

Our home can be quite drafty in the winter as you can actually feel the cold air rushing down the basement steps while you sit on the couch. We also have an oil furnace in the home but I simply prefer and enjoy heating with the pellet stove.

I am learning about pressurization in the home and understand that I am in for quite a battle since the basement is the lowest pressurized point in the home and on top of that we have a pellet stove, an oil furnace AND a radon mitigation system all located in the basement.

Since the house is old and does have cracks in the basement floor (I can see some in the unfinished furnace room, so I assume there are more) I am wondering if the radon pump could be a culprit for the cold drafts as well (pulling air from the house down through the cracks and up and out the radon pump).

So I guess I am wondering if it's worth the effort to go through a concrete block basement wall to install an OAK or am I just ice skating uphill at this point?


Thanks for any feedback!

You guys are awesome and I'm glad I found a place where my pellet stove obsession is not "weird". Lol

 

[Lake Girl]

No pellet stove obsessions here. If you can run all three without problems, you definitely have air infiltration problems. Have you ever had an energy audit (blower test)? When you start to button up your exterior envelope on the house, it may cause problems if you don't have an OAK. Besides, you're wasting heat by using interior heated air for combustion on your pellet stove. Should be able to rent a core drill but may be possible to go out through rim joist.

 

[stevemartin]

Yes, I had an energy audit last year and the technician said that he had never seen as much negative pressure in a house before as I have in mine. The upstairs of the home is terrible and leaks massively.

 

[bogieb]

I think an OAK would be beneficial as you will be drawing air from outside and forcing it inside. That would help push air up and out (meaning warm air is moving, instead of cold air coming in because of negative pressurization). It was noticeable on the main floor when I installed an OAK for the P61a (before I had a main floor stove). Before OAK I had massive drafts coming in thru windows, walls and everywhere else. Although the drafts weren't eliminated by the OAK install, they were reduced greatly. then last summer I replaced windows and tore out walls to install insulation and vapor barrier. It still isn't what would be considered "tight" by today's (or even year 2000) standards, but it does retain the heat better and reduced the drafts even more.

I know nothing about radon systems, so can't comment on that.

 

[Lake Girl]

negative pressure

This usually occurs when the home is too airtight. Appliances like pellet stove, furnace, clothes dryer, bath/kitchen fans and some radon systems are drawing air from inside and expelling it outside creating the same problem.

Is a heat recovery ventilator part of your radon remediation system? Does your furnace have dedicated outside air for combustion?

 

[stevemartin]

Oops you have to forgive me, I am still learning about this stuff. The tech that did the test said that it was the lowest "base line" he had seen when he initially turned the machine on to get a reading before starting the big fan. I took that to mean negative pressure. I am not sure what a heat recovery ventilator is. I looked at my furnace and it only has one pipe that goes out and ties into the house chimney, so I'm guessing it draws from inside the house for combustion.

So in light of that, would the OAK still be worth doing?

 

[Lake Girl]

Definitely! Surprised your not having troubles with the pellet stove burning properly.

What kind of hot water heater? If not electric, it would require combustion air too.

 

[stevemartin]

The hot water heater is electric. So no problems there.

I will definitely be installing an OAK within the next week or so.

Since I'm going to be running the intake up and out right below where the exhaust terminates, the intake will be in full view when we are in the basement.

That said, I see a lot of OAK "kits" being sold that are just dryer vent style flex tube.

The OAK terminal on the back of my stove is only 1 & 5/8" in diameter. So could I run an aluminum or steel pipe of the same size up and out to keep it looking decent? Looks like the kits use bigger diameter flex tube, but if the inlet on the stove is only so big, would that matter?