Dryer duct in a condo building-11 floors-using chase duct 4

[local19]

Job conditions are as follows:

City of Philadelphia, PA

11 story bldg. 6-8 condos per floor.
commercial/ retail space on first floor-drug store and restuarant.

basement-parking garage.

Owner wants the dryer ductwork to exhaust via fire rated chase ductwork up to the roof. Ductwork will be sized using a diveristy factor. It is a push-pull system

Is there any variance for NOT using a fire/smoke damper or smoke damper in this application?
Code offical insists on using some type of the above noted dampers.

Thanks for you time and imput. It is appreciated.....

John

 

[atlas06]

Consider ventless dryers, that's the hot ticket nowadays for condos, no need for exhaust ducts and shafts altogether.

 

[DrRTU]

I believe Philadelphia is IMC 2003. An application of 22” subduct should meet the code and NFPA. The FD and SD will be lint traps. Watch your distance to combustibles.

 

[AbbyNormal]

Are those heat pump dryers atlas?

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[atlas06]

Abbynormal,
These are condensing type dryers, they condense the flues and drain it out.
There are other types which are a combined Washer AND dryer all in one. You throw in your clothes and they come out clean and dry.
They offer the flexibility of being installed anywhere in the house.

I rented a house in Europe last year that had combied washer and dryer unit, it worked great. They install them in the kitchen over there, just like a dishwasher. Great space savers, no need for a washer and dryer room, no need for a shaft, subduct, fan, code compliance, etc.

Local19.
On another topic, in Europe (and Japan), they install tankless domestic water heaters as part of the kitchen cabinets, right over the kitchen sink flue through the wall), no need for a water heater room, heating of stored water, etc. Check out

http://www.takagi.com

(Japanese) or Bosch (German). Something you may want to consider for your condos.

See some web sites on ventless dryers such as

http://wwww.splendide.com

 

[darkvibe]

http://www.exhausto.com/

they make a prefab 22" subduct.

http://us.exhausto.com/files/pdf/ProductInformation/3932003.pdf

 

[AbbyNormal]

they are pushing the instantaneous propane water heaters here right now, just no one here has a combustion analyzer, so I am lobbying against them unless they can get some training.

Your exterior wall space is precious with condos, hard enough to get bathroom exhausts, dryer vents,fresh air intakes, etc the proper code clearances, not many condo kitchens on the exterior walls of the interior units. Entrance on one wall, solid glass and a balcony facing the sea on the other wall.

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[AbbyNormal]

atlas, perhaps you could give me an idea how the hell these ventless 'condensing' dryers work

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[atlas06]

AbbyNormal,
See below a description from wikipedia, better than I would've described it.
I guess, a better description should be "condensing and evapoprating", condensation being only the first step prior to evaporation.

Ventless dryers

Spin dryers
These machines simply spin their drums faster than a typical washer could in order to extract additional water from the load. They may remove more water in two minutes than a heated tumbler dryer can in twenty, thus saving significant amounts of time and energy. Although spinning alone will not completely dry clothing, this additional step saves a worthwhile amount of time and energy for large laundry operations such as those of hospitals or hotels.


Condensation dryers
Just as in a normal dryer, condensation dryers pass heated air through the load. However, instead of exhausting this air, the dryer uses a heat exchanger to cool the air and condense the water vapor into either a drain pipe or a collection tank. Afterwards, this air is run through the loop again. The heat exchanger uses ambient air as its coolant, therefore the heat produced by the dryer will go into the immediate surroundings instead of the outside.

Because the heat exchange process simply cools the internal air using ambient air, it will not dry the air in the internal loop to as low a level of humidity as the fresh, ambient air. As a consequence of the increased humidity of the air used to dry the load as well as the increased complexity of the design, this type of dryer requires more time and energy than a traditional dryer. However, it is a valid option where long, intricate ducting would be required to vent a traditional dryer.


Heat pump dryers
Whereas condensation dryers use a passive heat exchanger cooled by ambient air, these dryers use a heat pump. The hot, humid air from the tumbler is passed through a heat pump where the cold side condenses the water vapor into either a drain pipe or a collection tank and the hot side reheats the air. In this way not only does the dryer avoid the need for ducting, but it also conserves much of its heat within the dryer instead of exhausting it into the surroundings. Heat pump dryers can therefore use less than half the energy required by either condensation or traditional dryers.

As with condensation dryers, the heat exchanger will not dry the internal air to as low a level of humidity as the ambient air. With respect to ambient air, the higher humidity of the air used to dry the clothes has the effect of increasing drying times; however, because heat pump dryers conserve much of the heat of the air they use, the already-hot air can be cycled more quickly, possibly leading to shorter drying times than traditional dryers, depending on the model.

 

[AbbyNormal]

thanks

Take the "V" out of HVAC and you are left with a HAC(k) job.