Can I close my crawl space vents if the furnace & boiler is in the basement?

emaydeoh

My unfinished, uninsulated cellar has a bedroom-sized open part that holds the gas boiler for steam heat (vented out the chimney, not currently working), and also holds the gas water heater.

Then a 3ft tall dirt crawl space goes through a cutout in the cellar wall all the way from the back to the front of the house. This is where the water main pipe comes through into the cellar, along with other electrical stuff.

I see a lot of conflicting info on closing the dirt crawl space vents. There is 1 vent on each side of the crawl space completely open to the elements with just a grate over it. There is also a vent in the cellar part. I read the furnace needs the fresh air to work properly so I should not close them. Other sources say to close them when it is cold. My main concern is pipes freezing now that the boiler isn't working and used to be the main source of heat in the basement. No moisture/humidity here (Colorado). I have also thought about adding an oil filled space heater down there on really cold nights.

Most of the copper pipes to the kitchen and bathroom are in the cellar part, not the crawl space part. Just the water main comes through the crawl space.

Jamie Hall

You really don't want that water main freezing... on the other hand, how tight is the main basement? In older construction, you may be able to close the vents and still have enough air.

emaydeoh

@Jamie Hall thank you! The main cellar/basement is about 6ft wide and 11ft long. I was thinking of closing the 2 vents in the crawl space next to the water main, and maybe leaving the vent in the bigger cellar open? The whole thing is very drafty and even kind of open to the house upstairs (no barrier between the floor, just floor boards and light leaking through from upstairs)

STEVEusaPA

Ideally you would leave the vents open and completely encapsulate/seal the crawl space.
You should also consider testing the basement/house for radon. It’s a very inexpensive easy test.

emaydeoh

@STEVEusaPA I just rent so, unfortunately, can't do any encapsulation! It's a family member's home and they are letting me stay here for a few years. I definitely think there is radon but again can't do anything as a renter but hoping only living here for 6 or 7 years won't have major health effects. I've heard radon actually isn't as big of an issue as people make it seem unless it's decades of exposure + smoking? Could be wrong but unfortunately again as a renter, there is not too much I can do! Do the vents help with radon?

ethicalpaul

With that much draftiness you won't have to worry about radon I wouldn't think. And there's no way you will be able to seal that space up enough to choke the boiler if your description about all the leaks is accurate

emaydeoh

@ethicalpaul this is good to hear! Yes there are literal holes to the outside from the falling apart addition that leads to the cellar so definitely lots of drafts...and holes...

Jamie Hall

STEVEusaPA said:

Ideally you would leave the vents open and completely encapsulate/seal the crawl space.
You should also consider testing the basement/house for radon. It’s a very inexpensive easy test.

May or may not be a good idea. Radon shouldn't be a problem, but without ventilation to somewhere moisture most surely would be.

STEVEusaPA

ethicalpaul said:

With that much draftiness you won't have to worry about radon I wouldn't think. And there's no way you will be able to seal that space up enough to choke the boiler if your description about all the leaks is accurate

Is that your professional opinion as a radon specialist? Or just more incorrect advice as a non professional?

https://www.maine.gov/dhhs/mecdc/environmental-health/rad/radon/radonfaq.htm

Mad Dog_2

You go Steve...ha ha. Mad 🐕 Dog...Happy Friday everyone!!!!!!!@!

ethicalpaul

I stand by what I said. There is wind blowing through this basement/crawlspace.

hot_rod

Sounds like the OP is staying come h—- or high water😏
Sounds like high water is the only issue they have not experienced. So far.

STEVEusaPA

ethicalpaul said:

I stand by what I said. There is wind blowing through this basement/crawlspace.

Of course you do. Why let facts get in the way?

Maybe you should read the article from people who study this as opposed to your non-professional bad advice.
It's very simple and cheap to do a radon inspection, don't know why you would recommend the opposite.

ethicalpaul

OK I rescind my comment. Definitely check for radon in this drafty basement/crawlspace.

hot_rod

Cheap and easy, why not. 16 bucks on Amazon.
Kinda like a Covid test

emaydeoh

Thanks guys! Great news, the boiler is back up and running (for now, as long as the patched pipe holds). If there was hypothetically radon, is there anything I could cheaply do as a tenant to minimize it? There is already a vent thing going out a window maybe I could attach a fan to?

Solid_Fuel_Man

Test for radon first. 

It is a bit controversial actually. I live in Maine, just like the link posted by Steve. 

There are many radon systems which have gone in here in the last 10 years since radon "has been a thing". There are many people who live well into their 90s here (all 4 of my grandparents did) when their homes were sold (mandatory radon rest for home sale) levels were very high. 2 of my grandparents smoked as well. Last one to pass away was 97. 

Read some about radon and its half life etc. 

I'm not saying radon isn't a health concern, just that you should follow the money, and think rationally. 

hot_rod

Radon, like lead concerns isn’t a simple black or white. Water in Flint Michigan was fine until a new source and treatment stripped the bio film from the lead pipes. As well with the issue of switching to Flint river water and the legionella outbreak that came along with it.

Radon levels can vary depending on conditions. If a breeze always crosses the crawl space, levels may be low, safe. If you do start sealing the crawl better, eliminate cross drafts, the levels could increase.

A couple tests would give you some data. Could be no level is detected.

In Utah 1 out of 3 homes test some level. You could go with the EPA numbers or decide for yourself if levels are a concern.

If you plan on being there 6 years it might be worth the $$ to explore. It could be a simple as covering the crawl dirt and a small “muffin” fan exhausting some air if levels test high.

Kickstand55

Heat tape and insulate the pipes if you're worried of freezing. The electric bill will reflect usage, but, can be shut off when temps rise.