Geothermal heat pump filter slot

[Brandon Whitmore]

I just got done inspecting a geothermal heat pump installed in a high rise condo. http://www.climatemaster.com/index/res_tranquility27_page (http://www.climatemaster.com/index/res_tranquility27_page)

The heat pump is the tranquility 20.

The heat pump is located in the laundry room while the return air is located in the hallway outside this room.

Question: does it matter that the filter slot is wide open, and that some of the return air is being pulled from the laundry room? The way they installed these systems, there is about a 1" gap between the filter and return air duct. Picture a return air duct run to a furnace, but being partially open on 2 of the 4 sides.

[Jerry Peck]

Yes, they need to seal those two other sides.

One allows access to the filter, so they would need to make a cover for it which would be readily removable, yet seal tight when installed over the filter opening.

[Jerry Peck]

Forgot the code.

From the 2006 IRC. (underlining is mine) (note: "exceptions" to a "Prohibited source" means it is allowed under those conditions)
- M1602.2 Prohibited sources. Outdoor and return air for a forced-air heating or cooling system shall not be taken from the following locations:
- - 1. Closer than 10 feet (3048 mm) to an appliance vent outlet, a vent opening from a plumbing drainage system or the discharge outlet of an exhaust fan, unless the outlet is 3 feet (914 mm) above the outside air inlet.
- - 2. Where flammable vapors are present; or where located less than 10 feet (3048 mm) above the surface of any abutting public way or driveway; or where located at grade level by a sidewalk, street, alley or driveway.
- - 3. A room or space, the volume of which is less than 25 percent of the entire volume served by such system. Where connected by a permanent opening having an area sized in accordance with ACCA Manual D, adjoining rooms or spaces shall be considered as a single room or space
for the purpose of determining the volume of such rooms or spaces.
- - - Exception: The minimum volume requirement shall not apply where the amount of return air taken from a room or space is less than or equal to the amount of supply air delivered to such room or space.
- - 4. A closet, bathroom, toilet room, kitchen, garage, mechanical room, furnace room or other dwelling unit.
- - 5. A room or space containing a fuel-burning appliance where such room or space serves as the sole source of return air.
- - Exceptions:
- - - 1. The fuel-burning appliance is a direct-vent appliance or an appliance not requiring a vent in accordance with Section M1801.1 or Chapter 24.
- - - 2. The room or space complies with the following requirements:
- - - - 2.1. The return air shall be taken from a room or space having a volume exceeding 1 cubic foot for each 10 Btu/h (9.6 L/W) of combined input rating of all fuel-burning appliances therein.
- - - - 2.2. The volume of supply air discharged back into the same space shall be approximately equal to the volume of return air taken from the space.
- - - - 2.3. Return-air inlets shall not be located within 10 feet (3048 mm) of any appliance firebox or draft hood in the same room or space.
- - - - 3. Rooms or spaces containing solid-fuel burning appliances, provided that return-air inlets are located not less than 10 feet (3048 mm) from the firebox of such appliances.

[Brandon Whitmore]

Jerry,

Thank You once again.

[Brandon Whitmore]

This is on a 30 floor high rise. The Realtor told me that they are all done this way, but was not arguing with me-- he is curious too.

I now need to go to the Oregon Structural Specialty Code to see whether this applies...............

[Billy Stephens]

Most I see have a Slid-In piece of Rigid Duct Material about 2 inches wide( I usually remove to get at the filter) or a hinged flap door.
.

[Brandon Whitmore]

Yeah, this one just wasn't designed to accept a slide on cover, and it looks like they just decided to keep both sides open

Anyways, thanks guy's.........off to vacation I go