B. Negative Pressure

WARNING

Asphyxiation Risk

•Negative pressure can cause spillage of combustion fumes and soot.

•Fire needs to draft properly for safe operation.

Draft is the pressure difference needed to vent fireplaces successfully. Considerations for successful draft include:

•Preventing negative pressure.

•Location of fireplace and chimney.

Negative Pressure

Negative pressure results from the imbalance of air avail- able for the fireplace to operate properly. Causes for this imbalance include:

•Exhaust fans (kitchen, bath, etc.).

•Range hoods.

•Combustion air requirements for furnaces, water heaters and other combustion appliances.

•Clothes dryers.

•Location of return-air vents to furnace or air conditioning.

•Imbalances of the HVAC air handling system.

•Upper level air leaks (recessed lighting, attic hatch opening, duct leaks).

To minimize the effects of negative air pressure, the follow- ing must be considered:

•Install the outside air kit. Install the intake on the side of the house towards prevailing winds during the heating season.

•Ensure adequate outdoor air is supplied for combustion appliances and exhaust equipment.

•Ensure furnace and air conditioning return vents are not located in the immediate vicinity of the fireplace.

•Avoid installing the fireplace near doors, walkways or small isolated spaces.

•Recessed lighting should be a “sealed can” design; attic hatches weather stripped or sealed; attic mounted duct work and air handler joints and seams taped or sealed.

•Basement installations should be avoided due to stack effect. Stack effect creates negative pressure in lower levels. Hearth & Home Technologies recommends the use of direct vent fireplaces in basements.

Location of the fireplace and chimney will affect performance. As shown in Figure 2.1 the chimney should:

•Be installed through the warm airspace enclosed by the building envelope. This helps to produce more draft, especially during lighting and die-down of the fire.

•Penetrate the highest part of the roof. This minimizes the effects of wind turbulence.

•Be located away from trees, adjacent structures, uneven roof lines and other obstructions.

Offsets can restrict draft so their use should be minimized. Consider the fireplace location relative to floor and ceiling and attic joists.

 

 

Recommended

Recommended

 

 

Location

 

 

 

Location

 

Location

Marginal

 

 

Location

 

 

Not

 

 

 

 

 

Recommended

 

 

 

 

 

Location

 

 

 

Not

 

 

 

Recommended

 

Windward

 

 

 

Outside Air Intake

Leeward

 

 

Multi-level Roofs

 

 

Figure 2.1 Recommended Chimney Locations

 

6

 

Heatilator • Novus BV-Mesh • 4031-553 Rev F • 11/07

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Heatiator NB4236MI, NB4842MI, NB3933MI, NB3630MI owner manual Negative Pressure, Asphyxiation Risk
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NB3933M, NB3630M, NB3630MI, NB3933MI, NB4236M specifications

The Heatiator series of gas fireplaces, including the models NB4236MI, NB4842MI, NB3933M, NB4236M, and NB3933MI, epitomizes modern heating technology with a focus on efficiency, design, and user comfort. These models are engineered to provide warmth while enhancing the aesthetic appeal of any living space.

One of the standout features of the Heatiator series is its advanced combustion technology. The fireplaces are designed to maximize heat output while minimizing emissions. This is achieved through high-quality burners that ensure a clean and efficient flame, allowing users to enjoy the ambient glow without compromise. The models boast impressive thermal efficiencies, meaning they convert a high percentage of the fuel consumed into usable heat, which is an essential factor for eco-conscious consumers.

Design flexibility is another key characteristic of the Heatiator fireplaces. The models in this series come in various sizes and styles, offering options that can blend seamlessly into any decor. Whether you prefer a traditional look or a more contemporary aesthetic, there’s a model to suit your taste. The large viewing areas provided by the glass front panels offer an unobstructed view of the flame, adding a cozy ambiance to your home.

The Heatiator NB4236MI and NB4842MI models feature innovative multi-function remote controls, giving users the convenience of adjusting settings from anywhere in the room. This built-in technology not only enhances user experience but also contributes to energy savings by allowing precise control over the fireplace's operation.

Safety is also a priority with the Heatiator lineup. Equipped with features such as an automatic shut-off system and tempered glass fronts, users can enjoy peace of mind knowing that safety is paramount.

In terms of customization, these models offer various finishes and log options, allowing homeowners to personalize their fireplaces to match their style and preferences.

Overall, the Heatiator NB4236MI, NB4842MI, NB3933M, NB4236M, and NB3933MI represent a perfect blend of technology, safety, and design sophistication, making them an excellent choice for anyone looking to add a reliable and attractive heating solution to their home. Whether for supplemental heat or a primary heating source, these fireplaces are built to deliver exceptional performance in any setting.
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