high rise condo experience?

[airhandler]

Does anyone have any high rise apartment experience? I am designing an 11 story building with approximately 90 condo units. I have two questions. First is regarding makeup air to each apartment and is it necessary or common practice. Second is regarding common clothes dryer exhaust ducting.

The condos are two bedroom units with two baths, gas range, clothes dryer. I have designed plenty of hotels where the air balance is simple: 35 -50 cfm exhaust (continuous with central fan) for the bathroom and 60 -70 cfm outdoor air through a PTAC or ducted to a register above the doorway from a central 100% OA ventilation unit. However in this application, the bathroom exhaust is not required to be continuous per International Mech Code. The clothes dryer operation is intermittent and exhausts 150-200 cfm. The hallway cannot be used as a supply plenum to deliver makeup air to each apartment. What are your thoughts? Keep in mind the exterior wall cannot have any louvers on it. We will be using a water source heat pump system.

Secondly, the clothes dryers are stacked each floor. I cannot run the exhaust throught a side wall. I will be putiing a utility set fan on the roof that runs continuously. A barometric damper and cleanout will be installed at the bottom of the shaft. The problem is that the base of the riser will enter an underground parking garage. Can the garage air be used for makeup to the constant volume exhaust riser?

Thanks

 

[SlipMatWax]

Commonly, here in Canada, gas fired or electric heat make-up-air is delivered down a shaft to each floor normally discharged in the elevator lobby. Fire and Fire/smoke dampers may be a requirement behing the mua grille, depending on your local code.

We frequently use "slab duct" to exhaust bathrooms and dryers

http://www.eccomfg.com/links/ProductListing/ECCODUCT.htm

You are best to check with the local inspection department to see if you can use the parkade air to make-up-air for you dryer exhaust duct.

We have done this here before. It is important to ensure the dryers are not always subject to negative pressure - so an open ended duct in the parkade without barametric relief was used. We used a series of inexpensive prop fans on top of the shaft for exhaust.

This way we were sure that the fan would not be capable of generating excess static pressure in the exhaust duct. A static pressure controller may also used as a back-up safety measure.