Dryer fire hazard?

One of my houses has washer/dryer hookups in the garage. There is a hole in the wall where the dryer tube, etc. is supposed to vent to the outside. Unfortunately, the way the house was built, the AC condensor is right in front of that hole, so the dryer vents right into the AC condensor when the tenant is drying clothes.

I was told by a couple people that I can't leave it this way because it will damage the condensor over time. They told me to divert the air flow.

I bought another dryer vent tube and one of those door flap devices (don't know what they are called) and connected it to the vent hole outside the house, so that it blows the exhaust three feet further from the AC condensor. The tube is propped up on cinder blocks. So it travels from a tube inside the garage (connected to dryer) and then another tube once it's outside the house.

However, now I'm wondering if this could be a fire hazard (having too long a tube, and it gets backed up with lint? ). Do I need to put it back to the way it was?

I know that dryer fires are extremely dangerous and I don't want to create a hazardous situation. I don't know if having such a long tube through which the exhaust needs to travel creates a hazard or not. Thanks.

Mitch Kronowit

SFR Investor · Orange County, California

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Jul 09 '11, 02:11 PM

Can you provide a photo? The only harm I see in having dryer exhaust that close to the A/C condenser is the build up of lint on the coils. Left unchecked, it could plug up the fine air passages around the coil. And with tenants, you know it'll go unchecked.

If you can reroute the duct using smooth-walled fittings, I would move the exhaust port along the wall several feet, either horizontally or vertically and secure the ductwork to the wall using metal straps.

I wouldn't have the duct running away from the house and supported on blocks. Sounds too fragile and just an invitation for damage. Unless you have lots of bends and elbows, I wouldn't worry too much about the length. Our condo has a dryer in the middle of the unit and the duct work runs at least 10-15 feet to the outside wall. Hasn't been a problem in nearly 20 years, but it should be cleaned out occasionally.

Mike Tooley

Wholesaler · Orange County, California

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Jul 09 '11, 02:56 PM

I have to agree with what Mitch says. The extended distance shouldn't be a problem. I've been on several dryer fires in my career and the cause of them is due to lint build up inside the dryer frame (not the actual drum). The lint ignites since it is so close to the heating element of the dryer. Basically it's from not cleaning the lint trap on a regular basis. Extending the vent line is not going to increase the fire danger at all. Hope this helps!

Mitch Kronowit

SFR Investor · Orange County, California

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Jul 09 '11, 03:07 PM

Originally posted by Mike Tooley

Basically it's from not cleaning the lint trap on a regular basis.

Thanks for that Mike! I'm going to print it out in a very large bold font and tape it to my wife's forehead. :wink:

Dave Barnard

HVAC Contractor · Santa Clarita, California

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Jul 09 '11, 03:42 PM

I actually lived in a home where the dryer vent ran vertically through a wall, up through the attic and out of the roof through a "t-top" type flashing that had a wire mesh to keep animals out. I had to go up there regularly and clean the lint off of that mesh. This was a single story home, however the length was close to 15 feet long. With regular cleaning and inspection, I don't see a problem with this either.
As Mitch stated, it is very important to keep lint (or any other type of build-up) off the condenser.

Bienes Raices

· Orlando, Florida

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Jul 09 '11, 04:06 PM

Dave Barnard

HVAC Contractor · Santa Clarita, California

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Jul 09 '11, 04:15 PM

Personally, I would have used all hard pipe there on the exterior using a 90* elbow right at the wall penetration. As well as strapping it to the wall. That flexible ducting has many bends in it which can decrease air flow and create more areas for lint to build up. Also the hood where the air exits is blowing right on top of that cinder block. If the assembly is strapped to the wall as I described the blocks will not be needed.

Bienes Raices

· Orlando, Florida

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Jul 09 '11, 05:57 PM

Originally posted by Dave Barnard

Personally, I would have used all hard pipe there on the exterior using a 90* elbow right at the wall penetration. As well as strapping it to the wall. That flexible ducting has many bends in it which can decrease air flow and create more areas for lint to build up. Also the hood where the air exits is blowing right on top of that cinder block. If the assembly is strapped to the wall as I described the blocks will not be needed.

Thanks Dave--will it still be possible to put the hood on at the end, though, if the elbow is flush against the wall?
I don't want to just leave an exposed hole at the end because lizards, insects, etc. will enter the tube.

Mark H.

Residential Real Estate Agent · Phoenix, Arizona

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Jul 09 '11, 06:56 PM

You're "allowed" to have a complete & total length of 35 feet.
Every 90 degree turn gives you a 5-foot "penalty" - so if you have four 90-degree turns, that's the equivalent to twenty-feet of straight pipe, and there's only 15 feet of straight pipe left on a code-compliant install (and shorter is going to work much better & clog less).
I wouldn't worry about the "hood" at the end - although there is a version of that "hood" that has a lightweight "flapper" inside that will keep pests out.

Take a peek at these low-restriction elbows...

http://www.dryer-ell.com/dryer_vent_duct_elbow_comparison.htm

Dave Barnard

HVAC Contractor · Santa Clarita, California

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Jul 09 '11, 07:08 PM

--will it still be possible to put the hood on at the end, though, if the elbow is flush against the wall?
I don't want to just leave an exposed hole at the end because lizards, insects, etc. will enter the tube.

Just assemble everything together first (before strapping) leaving the elbow out away from the wall a little including the hood first, and then strap to the wall.
Dave

Joel Owens

Commercial Real Estate Broker · Canton, Georgia

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Jul 09 '11, 07:24 PM

Why can't you just drill a new hole in the next cinder block over and cover up the other hole to mount the vent??

Then where the dryer is they now have lint clean outs at the wall to prevent build up for the exhaust pipe.

Mike Holmes puts them in on his show on all the properties.Do not know how much they clean outs cost though.

Mitch Kronowit

SFR Investor · Orange County, California

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Jul 09 '11, 09:43 PM

Sorry Bienes, but that photo reminds me of these beauties:
http://thechive.com/2010/02/18/honey-i-took-care-of-it-21-photos/

No, I'm not being mean or anything, but that dryer vent extension does say "jerry-rigged" all over it. :wink:

Of course, not being one to criticize without offering a solution, I do not see the A/C condenser in this photo, so it must be more than a few inches away. If it's off to the left (I see what looks like electrical conduit on the wall heading that way), I would restore the exhaust port the way it's supposed to be and construct a small little wall, a barrier if you will, between it and the A/C to keep the air flow and lint away.

Rusty Thompson

Real Estate Investor · Salem, Oregon

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Jul 09 '11, 11:45 PM

Or move.the ac condenser

Bienes Raices

· Orlando, Florida

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Jul 10 '11, 03:31 AM

Originally posted by Mitch Kronowit

Sorry Bienes, but that photo reminds me of these beauties:
http://thechive.com/2010/02/18/honey-i-took-care-of-it-21-photos/

No, I'm not being mean or anything, but that dryer vent extension does say "jerry-rigged" all over it. :wink:

Of course, not being one to criticize without offering a solution, I do not see the A/C condenser in this photo, so it must be more than a few inches away. If it's off to the left (I see what looks like electrical conduit on the wall heading that way), I would restore the exhaust port the way it's supposed to be and construct a small little wall, a barrier if you will, between it and the A/C to keep the air flow and lint away.

Yes, I did it in a hurry because they were moving in last week, and then realized after the fact that it was harebrained...

I think the "wall" idea may actually be the easiest thing to do in this case, since the AC unit is off to the the left. Thanks.

Bienes Raices

· Orlando, Florida

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Jul 10 '11, 03:32 AM

Originally posted by Rusty Thompson

Or move.the ac condenser

It's on a concrete pad.

Mark Troutt

· White Lake, Michigan

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Jul 10 '11, 04:32 AM

Bienes,
As mentioned earlier it's not a fire hazard to have the dryer cap near the condensor. However, kids will be playing with your metal flex before the week is out and it will end up crushed.
I would recommend that you put the dryer cap back where it belongs and take a look in two months at the condensor coils near the vent. If there is no lint, you are fine. If it is clogged with lint then you can either separate the two or use the garden hose and spray off the coils twice a year or as needed.

Joel Owens

Commercial Real Estate Broker · Canton, Georgia

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Jul 10 '11, 09:46 AM

Trust me I am no expert at all with this.Watching the Mike Holmes show though there are many times when it has to be so many inches away and if it's not there is a violation of code.

You need to know the building codes for your area.It seems to be a frequent occurrence for this to happen on many of his shows.

Joel Owens

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Jul 10 '11, 09:48 AM

If you rent the right tool it really isn't that hard to make another hole in the cinder block over.

Mitch Kronowit

SFR Investor · Orange County, California

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Jul 10 '11, 09:59 AM

Originally posted by Rusty Thompson

Or move.the ac condenser

I thought of that as well, but moving an A/C unit can't be cheap, especially if it's an older R-12 system. I thought about moving our antique temporarily for some concrete work, but the cost of removing and replacing the freon (4 to 6 pounds at $30 per plus labor) was out of the question. R-22 is much cheaper or reusing the freon, but I'm not sure if that's a good idea. HVAC guys?

Dave Barnard

HVAC Contractor · Santa Clarita, California

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Jul 10 '11, 01:39 PM

Moving the condenser seems overkill to me given the situation. It was stated it sits on a concrete pad. If moved you need concrete, copper, refrigerant, drier and electrical work plus labor. The cost will be very high to do this.

I like the idea of drilling a new hole, however we do not know where the interior walls are to know if that is even possible.

As to
"I would recommend that you put the dryer cap back where it belongs and take a look in two months at the condensor coils near the vent. If there is no lint, you are fine. If it is clogged with lint then you can either separate the two or use the garden hose and spray off the coils twice a year or as needed."

There are two things wrong with this. Number one is that there will be lint (not "if") and it will need to be cleaned regularly. The problem is that dirt and lint will eventually build up in the fins that a simple hose down will just not get it. The second thing is why would you want all that heat on a condenser coil thats trying to remove heat. Every time that dryer is running while the a/c is on you affect efficiency and performance. It may not be by a huge amount but over time it adds up. Plus the extra strain it puts on the compressor which is the most expensive component to replace.
Dave

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