HVAC Clearance

[John Allingham]

Question #1
When a builder finishes the basement in a new home, is there a minimum space to be left between the furnace and an adjacent wall for future removal of the A/C A-coil?

Question #2
The basement has been finished off by the owner and he has left no space for removal of the A-coil. How does the HVAC tech handle the situation if the A-coil needs work or replacement.

[Ted Menelly]

Question #1
When a builder finishes the basement in a new home, is there a minimum space to be left between the furnace and an adjacent wall for future removal of the A/C A-coil?

Question #2
The basement has been finished off by the owner and he has left no space for removal of the A-coil. How does the HVAC tech handle the situation if the A-coil needs work or replacement.

The obvious is that there should be sufficient work space. But seeing how there is not then the entire nit will have to be disconnected and slid out to do the work. I find this a lot in Town Homes. They never leave enough room to service the units properly.

[Jerry Peck]

The required work space is not sufficient to allow for removal of the coil, only to allow for joining and sealing the unit to the duct.

That said, the above applies to 3 sides, the other side much meet working space/service space requirements.

If gas only, *no* electric, then the service space is required to be a minimum of 30" in front of the service side of the unit.

If *any* electric to unit, then it also become "electrical equipment" and now requires the 30" wide by 36" deep in front of the service access panel as required for all electrical equipment.

Typically, with that fourth side being left open, which is required to be the service panel side, the coil is removed from that side.

If the service side of the unit does not have 36" in front of it, then the unit needs to be rotated so the service panel side faces the open fourth side.

[John Allingham]

The required work space is not sufficient to allow for removal of the coil, only to allow for joining and sealing the unit to the duct.

That said, the above applies to 3 sides, the other side much meet working space/service space requirements.

If gas only, *no* electric, then the service space is required to be a minimum of 30" in front of the service side of the unit.

If *any* electric to unit, then it also become "electrical equipment" and now requires the 30" wide by 36" deep in front of the service access panel as required for all electrical equipment.

Typically, with that fourth side being left open, which is required to be the service panel side, the coil is removed from that side.

If the service side of the unit does not have 36" in front of it, then the unit needs to be rotated so the service panel side faces the open fourth side.

Let's see if I follow.
At my house the A-coil was inserted into the furnace ducting through an opening cut in the rear of the ducting i.e. the side opposite the furnace service panels.
Even so, there is no space requirement for the rear of the furnace.
To do any servicing of the A-coil, the technician would have to cut a new opening in the front of the ducting.
Have I got it?

[Jerry Peck]

Let's see if I follow.
At my house the A-coil was inserted into the furnace ducting through an opening cut in the rear of the ducting i.e. the side opposite the furnace service panels.
Even so, there is no space requirement for the rear of the furnace.
To do any servicing of the A-coil, the technician would have to cut a new opening in the front of the ducting.
Have I got it?


If your local code allows for that, the IRC does not.


SECTION M1305
- APPLIANCE ACCESS
- - M1305.1 Appliance access for inspection service, repair and replacement.Appliances shall be accessible for inspection, service, repair and replacement without removing permanent construction, other appliances, or any other piping or ducts not connected to the appliance being inspected, serviced, repaired or replaced. A level working space at least 30 inches deep and 30 inches wide (762 mm by 762 mm) shall be provided in front of the control side to service an appliance. Installation of room heaters shall be permitted with at least an 18-inch (457 mm) working space. A platform shall not be required for room heaters.

If that is now in the attic, then:

- M1305.1.3 Appliances in attics. Attics containing appliances requiring access shall have with an opening and a clear and unobstructed passageway large enough to allow removal of the largest appliance, but not less than 30 inches (762 mm) high and 22 inches (559 mm) wide and not more than 20 feet (6096 mm) long when measured along the centerline of the passageway from the opening to the appliance. The passageway shall have continuous solid flooring in accordance with Chapter 5 not less than 24 inches (610 mm) wide. A level service space at least 30 inches (762 mm) deep and 30 inches (762 mm) wide shall be present along all sides of the appliance where access is required. The clear access opening dimensions shall be a minimum of 20 inches by 30 inches (508 mm) by 762 mm), where such dimensions are large enough to allow removal of the largest appliance.


- - Exceptions:
- - - 1. The passageway and level service space are not required where the appliance can be serviced and removed through the required opening.
- - - 2. Where the passageway is unobstructed and not less than 6 feet (1829 mm) high and 22 inches (559 mm) wide for its entire length, the passageway shall be not more than 50 feet (15 250 mm) long.
- - M1305.1.3.1 Electrical requirements. A luminaire controlled by a switch located at the required passageway opening and a receptacle outlet shall be installed at or near the appliance location in accordance with Chapter 38.

[John Allingham]

Thanks Jerry.