Astria MM39VF Manual de Instruções de Instalação e Operação - Página 12

Procurar online ou descarregar pdf Manual de Instruções de Instalação e Operação para Lareira de interior Astria MM39VF. Astria MM39VF 20 páginas. Grand meridian vent free universal masonry firebox

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Unconfined Space

An unconfined space has a minimum total air volume of

50 cu.ft. (cubic feet) for each 1,000 Btu/Hr input rating of all

appliances in the total space (cu.ft. = length x width x height

of space). Include adjoining rooms only if there are doorless

passageways or ventilation grills between the rooms. If the Btu

per 50 cu.ft. is less than 1,000 Btu/Hr, then fresh air will be

provided by the natural air flow into the house.

Confined Space

A confined space has an air volume of less than 50 cu.ft. for

each 1,000 Btu/Hr input rating of all appliances in the space (cu.

ft. = length x width x height of space). Include adjoining rooms

only if there are door less passageways or ventilation grills

between the rooms.

Determining Total Air Volume

Use this work sheet to determine if you have a confined

or unconfined space. The space to be considered includes not

only the room in which you will install the fireplace but also any

adjoining rooms with ventilation grills between them or door

less passageways.

1. Determine the total volume of your space

L x W x H = _______ cu.ft.

Example: Space size = 20 ft. long x 20 ft. wide x 8 ft. high

(ceiling height) = 3,200 cu.ft.

If adjoining ventilation to adjoining room is supplied with

grills or openings, add the volume of these rooms to the total

volume of the space.

2. Divide the space volume by 50 cu.ft. to determine the

maximum Btu/Hr the space can support.

_______ cu.ft. (volume of space)

50 cu ft. = (Maximum Btu/Hr the space can support)

Example: 3200 cu ft. (Volume of space) / 50 cu. Ft. = 64.0 or

64,000 (maximum Btu/Hr the space can support.)

3. Add the Btu/Hr of all fuel burning appliances in the space.

Vent-free fireplace

Gas water heater*

Gas furnace

Vented gas heater

Gas fireplace logs

Other gas appliances*

Total =

Example:

Gas water heater 40,000 Btu/hr

Vent-free fireplace +36,000 Btu/hr

* Do not include direct-vented gas appliances. Direct vent draws

combustion air from the outdoors and vents to the outdoors.

_______ Btu/hr

Total = 76,000 Btu/hr

4. Compare the maximum Btu/Hr the space can support with

the actual amount of Btu/Hr used.

_________ Btu/Hr (maximum the space can support)

_________ Btu/Hr (actual amount of Btu/Hr used)

Example:

64,000 Btu/Hr (maximum the space can support)

76,000 Btu/Hr (actual amount of Btu/Hr used)

The space in the previous example was a confined space

because the actual Btu/Hr used was more than the maximum

Btu/Hr the space could support. If you find you have a Confined

Space, you must provide additional fresh air. Your options are

as follows:

a) Re-work worksheet, adding the space of an adjoining room

that may not have qualified for the extra volume. If the extra

space provides enough volume to convert the area to an

unconfined space, remove door to adjoining room or add

ventilation grills between rooms.

b) Vent room directly to the outdoors.

c) Install a lower Btu/Hr gas log (if lower Btu/Hr size makes

room unconfined).

If the actual Btu/Hr used is less than the maximum Btu/Hr the

space can support, the space is an unconfined space. You will

need no additional fresh air ventilation.

WARNING: If the area in which the heater may be operated

is smaller than that defined as an unconfined space, provide

adequate combustion and ventilation air by one of the methods

described in the National Fuel Gas Code, ANSI Z223.1 Section

5.3 or applicable local codes.

Local codes may have stricter definitions for confined space

and/or for unusually tight construction. Installing our optional

outside air kit may allow the space to be classified as not being

unusually tight or being an unconfined space. Check you local

codes.

IMPORTANT: Do not provide openings for inlet or outlet air

into an attic if the attic has a thermostat-controlled power vent.

Heated air entering the attic will activate the power vent.