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View Full Version : Dryer Vent Next To Condensing Coil



imported_John Smith
04-27-2007, 05:31 PM
Why do they put these things so close to the condensing coil? The outside of the coil (hidden by the outer casing) was almost fully covered with lint on the side exposed to the dryer vent. I asked the owner when was the last time he had the unit serviced. He kind of stumbled for an answer so I figure it had been a while. In my final report I suggested having a licensed HVAC contractor clean and service the unit, and have someone clean the dryer duct. It would be difficult to move either the duct or the outside HVAC unit. What could they do different to keep lint from collecting on the unit. I have a couple of ideas, but wanted to hear what the experts thought.

Jerry Peck
04-27-2007, 07:53 PM
Why? Because it's the cheapest and most direct route.

There is a relatively (relative to not costing as much as moving the dryer or a/c condenser unit) inexpensive solution (I've recommended it before and I've seen it done).

Remove the dryer exhaust vent cap, install a 90 degree elbow, run a piece of rigid galvanized dryer duct 5 feet to one side, box the dryer duct in, stucco, brick, whatever-the-choice-is it up and over (to make it weather resistant like the house and to match the house), then install a new dryer exhaust cap on the end of the extension such that it faces away from the a/c condenser unit.

Now, it is 5 feet away, and blowing even further away.

Rick Hurst
04-27-2007, 08:05 PM
One of my clients just had the condensing unit moved over several feet from the dryer vent.

The move cost them like 300. bucks by the HVAC contractor. Looks much better plus the electrical disconnect is now not directly behind the unit.

Bruce Breedlove
04-27-2007, 08:09 PM
Jerry's solution should work but one possible repercussion is the additional 10' it adds to the effective length of the dryer duct (5' of additional duct and 5' for the 90° elbow).

Phillip Stojanik
04-27-2007, 08:37 PM
What gets me is that it’s the HVAC contractor that typically does the both the A/C condenser unit and the dryer vent installations. I would think that any competent HVAC guy would not shoot himself in the foot by putting his dryer vent termination right beside his outside condenser unit.

Makes me wonder if there is not some other contractor picking the spot for the dryer vent after the HVAC guy has staked out his location for the condenser unit?

Jerry Peck
04-27-2007, 08:45 PM
Jerry's solution should work but one possible repercussion is the additional 10' it adds to the effective length of the dryer duct (5' of additional duct and 5' for the 90° elbow).

Depends, I have not even seen cheapy ones which will only push 25 feet. Most will push 35 feet to 50 feet, and the better dryers will even push to 90 feet.

Thom Walker
04-27-2007, 10:17 PM
Because they can. I think it's a kind of teenage rebellion. You can't show them the code because there isn't one. So, na-nee-na-na-na-na!

I used a modified version of JP's solution. I was going to move the condensing unit until I realized it already is only about 12 feet from the pool chlorinator, and down wind.

I live in a flood and hurricane area. Any thoughts out there about maybe building a platform and raising the new condensing unit (later this year) above it all?

imported_John Smith
04-28-2007, 03:55 AM
The owner suggested that maybe he run it through the interior wall and dump it into his attic like the bathroom exhaust fan vent :^)

Thom, I see houses all along the coast in Galveston that have the condensing units mounted about 10' or > above grade. Im sure it makes the a real pain to service, but they are hopefully above the flood zone.

Eric Shuman
04-28-2007, 07:14 AM
I ran into this same issue yesterday (and have before- I always write as repair) on a one year old home during an end of builder's warranty inspection. Cooling fins completly covered in lint on two sides of the unit. The client asked how to remedy the situatuon. I told him to be prepared for an argument with the builder.

I do not of know of a code that prohibits this but what about manufacturer's install guidelines. Does anyone have any condensing unit install guides that state that this is a no-no? Seems like that would be justification as manu. specs often trump code?

Any input would be helpful. As I certainly do not think my client should have to constantly clean the condensing unit, or worse have to pay someone to do it.

Thanks,
Eric

Thom Walker
04-28-2007, 08:28 AM
Thanks, John.

Sorry, but sometimes I speak shorthand. What I meant was, any ideas about best materials and best methods for construction so that the platform will serve the purpose it is intended to serve without moving the dryer vent? I see the elevated platforms all the time, too. The 10' ones crack me up. The rest of the house will be gone, but, by God, they saved the condensing unit. I was thinking more of the 2 feet high range. I can't decide if there is an advantage either way between a a ledger on the house and two vertical posts, or just four vertical posts. I am space limited.

I didn't mean for this to drift from the topic. A part of this plan is to build the deck so that the dryer vent could be under the deck for the condensing unit; or wolud the lint still get sucked onto the fins?

Ron Tate
04-28-2007, 05:31 PM
I'm going to have to agree with Bruce. The IFGC states in [M]614.6.1 Maximum length. The maximum length of a clothes dryer exhaust duct shall not exceed 25 feet (7620 mm) from the dryer location to the outlet terminal. the maximum length of the duct shall be reduced 2 1/2 feet (762 mm) for each 45-degree (0.79 rad) bend and 5 feet (1524 mm) for each 90-degree (1.57 rad) bend. The maximum length of the exhaust duct does not include the transition duct.

There is an exception and it states: Where the make and model of the clothes dryer to be installed is known and the manufacturer's installation instructions for such dryer are provided to the code official, the maximum length of the exhaust duct, including any transitioin duct, shall be permitted to be in accordance with the dryer manufacturer's installation instructions.

I doubt that the contractor ever knows what kind or type of dryer is going to be installed. Therefore nothing to give to the code inspector.

I have yet to do an inspection where the dryer was installed and the manufacturer's installation instructions available.

Some dryer may blow upto 90 feet. The person moving out may have had a dryer that would. However, the person moving in may not. Have to stick to the code, Jerry, that's why you say it's there.

Jerry Peck
04-28-2007, 07:39 PM
"There is an exception and it states: Where the make and model of the clothes dryer to be installed is known and the manufacturer's installation instructions for such dryer are provided to the code official, the maximum length of the exhaust duct, including any transitioin duct, shall be permitted to be in accordance with the dryer manufacturer's installation instructions."

Correct.

"I doubt that the contractor ever knows what kind or type of dryer is going to be installed. Therefore nothing to give to the code inspector."

"I have yet to do an inspection where the dryer was installed and the manufacturer's installation instructions available."

Not where I've inspected. They know the model long before hand. If the dryer vent is long, they show the installation instructions to the inspector, and the inspector confirms that dryer was installed before final mechanical inspection.

"Some dryer may blow upto 90 feet. The person moving out may have had a dryer that would. However, the person moving in may not. Have to stick to the code, Jerry, that's why you say it's there."

AND, allowing for the exception (which IS sticking to the code), those long runs ARE allowed - BY CODE. I also say you cannot pick and choose which sections you want to write up.

Yes, when the owner moves out and takes one of those dryers with them, and the next person moves in with a cheap one which does not push that far, that then becomes a problem and no longer complies with the code.

That is just another one of my pet peeves.

The first owner is not allowed to burn the house down with their dryer, but the second owner is?

Ron Tate
04-29-2007, 02:52 PM
If only we could all live in utopia, Jerry. I'm just joking. Not trying to be a smart ass. I think it's great that the code inspectors are that concerned in your area. Here in central Arkansas I'm not sure the inspectors even look to see if a dryer vent is installed let along where it goes or how long it is. I say that because I inspected two houses this month, one was new construction and the other a resale about 4 years old and both had dryer vents exiting into the attic. I think the city of Little Rock only has two or three code enforcement inspectors. To much work to do the kind of job that needs to be done.

Just wanted you to know that I think you are very knowledgeable and I enjoy reading your replies.