-GoBengals- Posted November 9, 2011 Report Share Posted November 9, 2011 so as many know i bought a house almost two years ago now, but i am finishing my basement finally, making a materials list, and was measure some board for walls etc.. and notice something ODD... i was measuring around the air return, you know, big silver box that should come from your return registers in the house, down to the base of the furnace, etc... sooo im looking and there is a pipe coming out of the return... going across the floor(ceiling)... i thought" maybe thats a return from.......(there is nothing on that side of the house for a return its my kitchen, bedroom, etc on that wall.. so i look closer.. then i pop the basement screen out and look out... and there is a vent there... the MF'er goes outside... so my mind is confused... am i heating the outside? no, its the return.. so im...sucking in..freezing cold air to HEAT? WTF! so i go turn on my furnace fan.. go outside.. its sucking like a prom date.... straight cold air from outside.. i turn it off... not sucking at all.. so i let it churn in my head for a while.... nothing.. i converse with my dad.. he seems bewildered... so i called the home warranty dude... he stumbles over words and essentially says its normal and "since the houses are so tight the furnace needs that little extra to breath" which if it needs more air intake.. it needs to be coming from INSIDE the house... so he is sending the HVAC guy out to double check and make sure we are talking about the same thing, he first thought i meant the one thats the fresh air for the hot water heater and assumed i was retarded... So i called my sister, same builder... WAY bigger house... they dont have one.... my dad went home, same builder same size house... he doesnt have one... sister went by her rental properties (they are next door to eachother) and one doesnt have it, the other has renters at the moment so outside it only has the one vent, so air return, is assumed and it NOT having it is assumed... so 1 of 5 houses...all same builder many different sizes...bigger and smaller, mines the only one with it.. here are pics...vent at wall and going into air return... [attachment=912:IMAG0236.jpg] [attachment=913:IMAG0235.jpg] this is crazy right? sounds like they fucked up on air returns and did this to compensate... any logical reasons for this? thanks for any input! Link to comment Share on other sites More sharing options...
esjbh2 Posted November 9, 2011 Report Share Posted November 9, 2011 Perfectly normal. My house is older and before they were so "airtight" and even it has a fresh air intake. You want a percentage of recirculating air intake and fresh air intake from outside. I would expect with newer houses that are more airtight, and the fact that the new HVAC systems vent less exhaust (small PVC exhaust instead of huge duct thru roof), I would expect that this fresh air intake is all the more important. Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 9, 2011 Author Report Share Posted November 9, 2011 i have the fresh air intake that just dumps into the room there you can see it in the one pic, one goes into the air return(one on left) and one dumps into the room, but one that goes right into the air return? that would cause the furnace to be terribly less efficient, right? Link to comment Share on other sites More sharing options...
|Montana Bengal| Posted November 9, 2011 Report Share Posted November 9, 2011 [quote]Yes, the furnace does need outside combustion air. Some houses supply that combustion air through leaks but modern homes are sealed very tightly and a seperate pipe to the outside is necessary. [/quote] [url="http://www.houserepairtalk.com/f8/outside-air-really-needed-furnace-3465/"]http://www.houserepa...d-furnace-3465/[/url] I don't know shit, but it sounds like your furnace is using outside air for combustion, and you aren't necessarily heating it. If you don't get a very good answer, I can check with my brother-in-law this weekend. He is an HVAC tech. Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 10, 2011 Author Report Share Posted November 10, 2011 this is tough conversation to have, as so many different things are going on, even in my pics... the link from montana is there, but not the one im talking about... that one is more for my hot water heater honestly, but i have that... THEN, on the other side of the house, another identical tube comes in.. and connects right into the air return, the exact same place thats attached to my return vents in my upper floors.. SO.. if i were 8 inches tall.. i could hop into my air return vents in my master bedroom.. shimmy down the tube to the big silver air return box that normally, in a closed furnace system, goes into the bottom of the furnace, however, i could then, once i get to that box, walk right out the side in this tube,, and out the side of my house into the cold freezing winter air.. this isnt logical to me... if it needed more air.. it would ideally get it from within the house, thus heating up remotely warm air VS potentially 20 below zero air from outside... which is what is happening... am i wrong or missing something? heating freezing cold air doesnt add up in my brain.. and only 1 of the 5 houses from this builder, and one from a different one have this... NONE of the others have anything even close... Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 10, 2011 Author Report Share Posted November 10, 2011 better described photos... the "not this" one is the one described in montanas link, thats not the one im concerned with.. i know what it does and what its for, and you can see the white PVC's going into and out of the furnace for combustion, etc, being a closed furnace system and all... and here are the better described pics... [attachment=914:IMAG0235x.jpg] [attachment=915:IMAG0236x.jpg] Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 10, 2011 Author Report Share Posted November 10, 2011 if a furnace needs air, the last place ever, that it would logically get said air, would be from the bitter cold outside... Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 10, 2011 Author Report Share Posted November 10, 2011 this makes sense: [img]http://www.blueflame.org/images/combustair2.gif[/img] i have this... and THEN nother one of the A-B things, instead of dumping at point B, its connected to that middle tube feeding the furnace... which is "crazy".. in my head... Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 10, 2011 Author Report Share Posted November 10, 2011 actually i have THIS... [img]http://www.blueflame.org/images/combustair3.gif[/img] which is labelled as such: [size="3"][color="#0569BF"][b]Duct Supplying Outside Air into the Cold Air Return[/b][/color][/size] [url="http://www.blueflame.org/datasheets/combustair.html#top"][size="1"]Return to top[/size][/url] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] This method is permitted by code. However, experience indicates potential problems such as [u][b]shorter equipment life[/b][/u], [b][u]poorer performance[/u][/b] in unusually cold temperatures and possibly [u][b]voided warranties.[/b][/u][/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] [/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] what a bunch of lazy jerks....[/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] [/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] looking to see if this voids my warranty... if so.. theyll be fixing this for sure...[/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] [/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] guess i maybe answered this question now...[/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] [/size][/font][/color] [color=#000000][font=Arial, Helvetica, sans-serif][size=3] never seen this before..[/size][/font][/color] Link to comment Share on other sites More sharing options...
esjbh2 Posted November 10, 2011 Report Share Posted November 10, 2011 [quote name='GoBengals' timestamp='1320894293' post='1059713'] this makes sense: [img]http://www.blueflame.org/images/combustair2.gif[/img] i have this... and THEN nother one of the A-B things, instead of dumping at point B, its connected to that middle tube feeding the furnace... which is "crazy".. in my head... [/quote] This is what I have, and what I was referring to in my post above, and I agree that it makes sense. I have seen many houses with this design. It is not that "active" of a system quite honesty as I've tried to feel air flow and see air flow with a piece of paper, etc. and it's very minimal, almost a redundancy really. The other one you showed where it's tied into the return is stupid in my opinion, and I've never seen that setup myself, so I agree with you there as well. In that mode it is "very active" as it's pulling outside air with much more "suckage" (pun intended). I can't imagine any house would need that much "fresh/outside" air to support the furnace system. Good luck. Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 10, 2011 Author Report Share Posted November 10, 2011 [quote name='esjbh2' timestamp='1320896698' post='1059729'] This is what I have, and what I was referring to in my post above, and I agree that it makes sense. I have seen many houses with this design. It is not that "active" of a system quite honesty as I've tried to feel air flow and see air flow with a piece of paper, etc. and it's very minimal, almost a redundancy really. The other one you showed where it's tied into the return is stupid in my opinion, and I've never seen that setup myself, so I agree with you there as well. In that mode it is "very active" as it's pulling outside air with much more "suckage" (pun intended). I can't imagine any house would need that much "fresh/outside" air to support the furnace system. Good luck. [/quote] exactly, its nuts... about to make my calls to these folks now.. Link to comment Share on other sites More sharing options...
|Montana Bengal| Posted November 11, 2011 Report Share Posted November 11, 2011 [quote name='GoBengals' timestamp='1320894702' post='1059715'] actually i have THIS... [img]http://www.blueflame.org/images/combustair3.gif[/img] [/quote] My Brother-N-Law said this is typical for commercial buildings and it does meet code. It is less efficient and means that your furnace will run a little bit harder. It shouldn't affect your warranty. Link to comment Share on other sites More sharing options...
|Montana Bengal| Posted November 11, 2011 Report Share Posted November 11, 2011 [quote name='esjbh2' timestamp='1320896698' post='1059729'] [quote name='GoBengals' timestamp='1320894293' post='1059713'] this makes sense: [img]http://www.blueflame.org/images/combustair2.gif[/img] [/quote] [/quote] See the post before this one as well.... He said it isn't that hard to modify it to this. A lot of people add a couple of 90 degree joints at the bottoms (so it kind of makes a U). Then the cold air sits in the bottom instead of pouring in. The reason you want outside air is to air in combustion. Houses are too tight and you need the extra Oxygen. Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 11, 2011 Author Report Share Posted November 11, 2011 [quote name='Montana Bengal' timestamp='1320977249' post='1060174'] See the post before this one as well.... He said it isn't that hard to modify it to this. A lot of people add a couple of 90 degree joints at the bottoms (so it kind of makes a U). Then the cold air sits in the bottom instead of pouring in. The reason you want outside air is to air in combustion. Houses are too tight and you need the extra Oxygen. [/quote] yea, im going to change it, first option is to chop it off at the air return main box, leaving a hole there, then take the duct 90 degree it to the floor, leaving it open like the other one, just at the floor.. in 2 months that whole hvac setup will be boxed in and closed off, so it can get any fresh air it needs, but its not SUCKED in DIRECTLY from the freezing outdoors. I thought the white PVC pipes were for the combustion, as theyare direct lines to the outside, one incoming, one outgoing..could be wrong, but i am going to fix that here in a few weeks as we start finishing things. another option is to shop it off at the end by the wall, and duct it to the floor as another return, with the other fresh air return still in place i'd think enough fresh air is in place either way... the thing i keep getting back to in my head, is that 1 of 5 houses by the same builder has this setup... all are brand new and "tightly sealed"... they just half assed this one..... atleast i know where i stand.. thanks for all of the input everyone... Link to comment Share on other sites More sharing options...
|Bunghole| Posted November 11, 2011 Report Share Posted November 11, 2011 How cold does it get during the coldest months where you are? And do new home's furnaces really need outside air for [u]oxygen[/u]? Surely they can't be so "tight" that air doesn't get in through all manner of creases, crevices, etc? Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 11, 2011 Author Report Share Posted November 11, 2011 [quote name='Bunghole' timestamp='1321008345' post='1060317'] How cold does it get during the coldest months where you are? And do new home's furnaces really need outside air for [u]oxygen[/u]? Surely they can't be so "tight" that air doesn't get in through all manner of creases, crevices, etc? [/quote] we had some record lows at night last year and it was 20 below. but that was a 1-2 day span.... the average lowest point is 16 degrees. http://www.weather.com/weather/wxclimatology/monthly/graph/USCO0105 and yea, its not that tight, and there IS another fresh air duct right there in the pic.. a 6 inch duct.. that can rock in a LOT of fresh air... Link to comment Share on other sites More sharing options...
|Bunghole| Posted November 11, 2011 Report Share Posted November 11, 2011 So unless the air is [i]really[/i] cold, having the furnace draw air in from the outside instead of essentially recycling inside air shouldn't be too big a hit on efficiency, right? The benefit I can think of is that its helping bring fresh air into the home and "airing it out" without having to open windows when its really cold outside. I don't know if I'd change that if I were you, although you do mention that you have a smaller vent bringing outside air in too, so maybe that's enough. Link to comment Share on other sites More sharing options...
|Montana Bengal| Posted November 12, 2011 Report Share Posted November 12, 2011 From what I understand, I don't think it makes a huge difference. Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 13, 2011 Author Report Share Posted November 13, 2011 its about 15% of the airflow based on duct dimensions, HOWEVER, the "sucking power" from that duct is quite a bit more than any other, probably due to it being closest to the furnace itself. so the exact efficiency loss is nearly impossible to figure, but my fathers engineer mind figured it around 25% of the air coming in, so 25% of the air being brought in is 40-70 degrees cooler than the other air being brought into the furnace. hell at once point last winter it got 10-20 below, which would be almost 80-90 degrees colder... the furnace almost never stopped running for those few days.. its not going to be a huge difference...but it should be a difference indeed... Link to comment Share on other sites More sharing options...
|Bunghole| Posted November 13, 2011 Report Share Posted November 13, 2011 Well, to be fair, when its [i]that[/i] cold outside your furnace is going to be running all the time anyway. Link to comment Share on other sites More sharing options...
STRAYCAT Posted November 13, 2011 Report Share Posted November 13, 2011 email Mike Holmes if anybody would know it would be him Link to comment Share on other sites More sharing options...
-GoBengals- Posted November 14, 2011 Author Report Share Posted November 14, 2011 [quote name='STRAYCAT' timestamp='1321198311' post='1060957'] email Mike Holmes if anybody would know it would be him [/quote] that guy is the best....i was addicted to that show when we first moved.... it made me assume every house ever was built like ass and was going to kill the people living in it.. Link to comment Share on other sites More sharing options...
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