Cold draft in the house.

[DavidV]

Standing in front of the sink last night, I felt a cool breeze on my feet. I got down on the floor and started hunting for the source. I pulled the stove out and sealed a hole in the floor when the electrical runs thru. That wasn't it. Then I pulled the grate on the heat vent. Yup. Shoddy job. they just cut thru the subfloor and oak floor, wedged thething up screwed it to the wood and that was it. SO, I got a can of latex foam and sealed it up. Then I went around to other vents in the house ands sealed some of them. Afterwards I n oticed that I still had some draft coming thru the duct work itself. What can I do about this? It's a gas furnace and I have cold air coming from it. I find it hard to believe that the wood stove is pulling that air thru. The house is anything but tight . I have been going aro[und sealing and insulating things as much as I can but it still has a very long way to go. once I get everything done, am I likely have an increased problem of air being pulled thru ?? I figure it's coming in from my garage since that's where the furnace is located.

 

[begreen]

If your stove has an outside air inlet, that will help. Our furnace is in a cool basement and this is the primary source of cool air intrusion in the house as well. I've thought about sealing and insulating the ductwork. But I don't think thsi would totally fix the problem. I've lived with it because we've had other priorities and I am mulling over removing the warm air furnace and switching to a hot water system for greater efficiency.

 

[Corey]

That is interesting. A few thoughts...your furnace and duct system should be sealed completely within the house. Even if the envelope of the house was perfectly air tight, the stove still shouldn't pull air through the furnace vents (unless you have some type of vent out in the garage, or a broken duct somewhere.)

The only things I can think of is the "natural" draft of the stove...hot air rising and flowing across the ceiling while cool air flows across the floor. (I get a pretty good dose of that draft when I come home and the house is at 65F and the stove comes up to full fire) Or the possibility that hot air is somehow forcing its way into the return air ducts (which are generally up high anyway) then cooling and displacing the air out of the floor vents.

As for what to do...may double check that all ducts are hooked up and nothing has broken loose (especially if you have ducts in an attic or unfinished crawl space) Close the registers and see if that helps. I have seen magnetic sheets that go over the top of the register to help seal even more. My grandma always used a shoebox or a towel which seemed to work just as good...and cheap, too!

Good Luck
Corey

 

[begreen]

In most installations, metal ductwork has many small crevice leaks at joints and along the seams of elbows. Our basement is an extension of the crawlspace (old farmhouse here) and is not part of the heated interior envelope. In David's case, the furnace is in the garage. In this circumstance, ductwork can be a point for outside air to enter into the house when there is negative pressure in the heated space.

 

[saichele]

Glad you posted this. My (unused) ductwork seems to be a source of drafts. Basement is uninsulated, and ductwork is older, so I'm not terribly surprised.

Steve

 

[drizler]

Go buy some incense sticks and hold one in front of the suspect places....................

 

[begreen]

Yes, that's why I said I don't think this will totally fix the problem. IMHO it's also why central, forced-air systems are rare in homes outside of North America.

 

[Roospike]

BeGreen wrote . . .
"Yes, that’s why I said I don’t think this will totally fix the problem."
Good thing you clarified that - otherwise, nobody would have known that you came to the same conclusion as me.

"IMHO it’s also why central, forced-air systems are rare in homes outside of North America."

I think this is incorrect. The reason why central forced-air systems are rare in homes outside of North America, by which I guess you mean the U.S., is because we're so much richer than most of the world.


The main reason that many new homes come with central forced air is so that A/C can be easily included in the system. I have lived in many houses. The best system value, no doubt about it, is a baseboard boiler system. In surface systems are nice, but expensive to install and maintain.

Hot air systems, by design, are garbage. Blowing air is a bad way to heat. Period. For the folks who live in the southern states or who have never had baseboard heat, you really don't know what you're missing.

Another bad thing about air systems is that you have to heat a room hotter to feel as warm, because there is contantly moving air pulling heat off of your body. They're also dirty.

BUT, the reason they are so common is because you can slap an A/C unit in and use the air system to cool the house.

Go to Russia. You think people can afford A/C?

How about Portugal?

Throw in that many parts of Europe would not benefit greatly from A/C, and you've got your reason.

Frank wrote "Blowing air is a bad way to heat." So how do you get the heat around your house with out moving air with your stove frank ??? The question just had to be asked after the statment you made.

 

[Rob From Wisconsin]

Finally, this year we have been able to almost entirely heat w/ wood!!
Big deal?? Yes!!
Our living room, near where our theromstat is, was always chilly & somewhat drafty.
Finally tracked the source to our Gas Fireplace, and more specifically the top seam
where the fireplace meets the brick face. I caucked the joint, and now we can get
our entire first floor area up to 70 Deg., even in windy, single-digit temps!!

As for forced-air heating system being "sealed", we discovered the hard way that they
are not! In an attempt to distribute heat around our house from our stove, we turned-on
our furnace fan, and were surprised to see that our thermostat was dropping temp.
quite rapidly! After tracking our ductwork, I discovered that our furnace brought in fresh
outside air to be heated & blown through our house. (Note: our house is only five (5) years old).

Rob

 

[begreen]

BeGreen wrote . . .
"Yes, that’s why I said I don’t think this will totally fix the problem."
Good thing you clarified that - otherwise, nobody would have known that you came to the same conclusion as me.

"IMHO it’s also why central, forced-air systems are rare in homes outside of North America."


Another bad thing about air systems is that you have to heat a room hotter to feel as warm, because there is contantly moving air pulling heat off of your body. They're also dirty.

BUT, the reason they are so common is because you can slap an A/C unit in and use the air system to cool the house.
.

Wrong. Forced is not used in much of the world because it's inefficient, not because of a/c or no a/c. There are parts of this country that have forced air systems when a/c isn't really necessary. Our house came with forced air and yet there is no way we need a/c. The main reason forced air systems became popular is because they are less expensive to install than a hot-water system. In addition, some people put in forced air because they like the quick heat up. Some put it in because they don't like the look of radiators. A correctly designed system is draft free unless you are standing on top of a register, and some people like the comfort better with forced air. I'm not defending forced air, but the main issue is economic.

But you are correct, they are used the most in North America, (remember Canada?) because fuel has been cheap here and until recently, inefficiency wasn't a big deal.

 

[begreen]

As for forced-air heating system being "sealed", we discovered the hard way that they
are not! In an attempt to distribute heat around our house from our stove, we turned-on
our furnace fan, and were surprised to see that our thermostat was dropping temp.
quite rapidly! After tracking our ductwork, I discovered that our furnace brought in fresh
outside air to be heated & blown through our house. (Note: our house is only five (5) years old).

Rob

Fresh make-up air and required by code in a modern air-tight house for both safety and health reasons. There are alternatives, but this type of installation is common because it is easy and out of sight.

 

[Willhound]

So BeGreen, you write . . . "Wrong. Forced is not used in much of the world because it’s inefficient, not because of a/c or no a/c. "


There are very few houses in the Northeast that are forced hot air, unless they also have A/C. Most new construction in CT that I've seen comes standard with forced air heat and central air.

The reason I'd guess that your system is ducted, as well as many that are below the Northeast, is that they use a heat pump, which requires the ducting.

Well Frank, just to throw in a different perspective, the vast majority of residential heating systems around here are natural gas forced air. Natural gas hot water with baseboard type radiators would be second. And we're a heck of a lot colder than the Northeast U.S., to the point of usually several weeks in a row of -40 every winter.

However, I beleive that we get better "efficiency" or at least less heat loss in our air systems because it is virtually unheard of to build a house here without a full basement, so all of the ducting runs in an enclosed, warm, insulated space. Basements are a pre-requisite when you get 6 to 8 feet of frost every year, otherwise your house gets moved around a lot from frost heave.

And, most do not have central A/C, although I would definately agree that for the majority of new builds A/C is included. But for the majority of systems installed back into the 1950's, A/C wasn't even a consideration.

I also agree that considering installation cost and the ability to easily control zones or room temperatures seperately, electric is the way to go. But ever since they ran the first natural gas line through the area in 1951 there hasn't been a time when gas wasn't cheaper than electricity.

We all know that this is likely about to change Big time, hence the move back towards wood. Reminds me a lot of the last big wood craze back in the 70's, except the stoves now are a heck of a lot more efficient, and safer too I would imagine.


Willhound

 

[elkimmeg]

In MA 1998, the sixth edditionof building codes were adopted. Requiring R. 5.0 insulation of ducts and heat pipes located in un-conditioned spaces. On dual heat and AC, the R value is 6.8 for the rest of the country its R4.2. Also includes is mastic sealing all joints of the duct system. Language is there to require leak testing and balancing the system. With all these measure, will ducts still leak? Yes, but not as much as before. More inspections for me adding more check items. I have to look for dampers for balancing. I peal back the duct insulation to see if the joint have been properly sealed. I have to check the r value of duct insulation and check the furnaces for air leakage. With the New monoxide laws I plug the pvc exhaust with a ballon or tennis ball to cause automatic shut down. and that's only part of the inspection process.

 

[Willhound]

There are only a handful of days here that go above 80 in the summer. And although the cost of central A/C has dropped significantly in the last decade or so, it was still considered a relatively expensive "extravagance" up until about 10 years ago here. Employmnet has always been pretty stable, but no high tech or large manufacturing jobs, so wage levels are not particularly high. Also, most of the early houses had 60 amp electrical services, so a costly service upgrade was also needed if you wanted central A/C.
Around here you had to have heat, but you didn't "need" to have A/C.
So people just didn't do it.

 

[DavidV]

In my attic the duct work is insulated. how well is a good question, but it's got an insulated sleeve on all the ductwork. I assume the below is the same, but I will defer the questiion till warmer weather. I do not cherish the idea of climbin into my crawlspace this time of year. Little by little I am making progress toward properly insulating and sealing my house. I will try the insense thing. Thanks.

 

[begreen]

And BeGreen, instead of going back and forth with "Is too - Is not," here is some evidence for you . . .

I went to Realtor.com and typed in Simsbury CT and then I went to the advanced options and checked "forced air"
heat.

The first 20 properties in CT also had central air conditioning.

How do you explain that?

Based on experience. I've installed a couple dozen home hot air systems before a career change. 90% were warm air only. How many have you installed Frank?

 

[Sundeep Arole]

On this one I'd have to agree with Frank. Air is just a bad medium to heat with. It has low heat capacity, the ducts get logged with allergens, and, if you have a combined heating/cooling system, the registers are in the wrong place for half of the year. But, it is cheaper to put in a furnace than a boiler, and the added advantage of easily adding air conditioning just makes it great for builders. Just my opinion.

 

[DavidV]

I did the incense stick test and was astounded at the air movement in the house. I did find at least one vent that is taking in air on the second level. so it seems likely that I have a circular movement of air thru the heat/ac ducts....with the air cooling as it moves around. Also I was pretty surprised at the speed of air movement in and out of rooms. hot air moving away from the stove room and cold air rushing back toward it. That's why I love this board. The depth of experience really helps solve these problems. probly would have wondered about that for years before I ran into someone who could tell me what the deal was. Still gonna crawl under the house this spring and fill all findable gaps, but I feel less manic about it now.