APPLICATION CONSIDERATIONS • MQL

Application Considerations Model MQL blower coil units offer a wide range of application flex- ibility, while maintaining a simple, easy to install unit design. These units are intended to provide comfort cooling and heating within a small footprint. They may be applied in many types of building structures including schools, office buildings, hospi- tals, condominiums, assisted liv- ing facilities, apartments or stores. Applications can be constant or variable volume.

There are many applications in which the MQL product can be utilized. Some examples include:

Constant volume applications

•Two-pipe hydronic system for cooling and/or heating

•Two-pipe hydronic cooling system with electric heat

•Four-pipe system with dedi- cated heating and cooling coils

•Direct Expansion (DX) split systems with hydronic heat

•Direct Expansion (DX) split systems with electric heat

Variable volume applications

•Two-pipe hydronic system for cooling and/or heating.

•Two-pipe hydronic cooling system with electric heat.

•Four-pipe system with dedi- cated heating and cooling coils.

Acoustics

Control of noise within both occu- pied and unoccupied spaces has become increasingly important to designers and building own- ers/occupants. Proper considera- tion must be given to placement of indoor air conditioning units, particularly in the occupied space.

Inherent flexibility of the fan and coil combination in the vertical configuration allows application in sound-sensitive areas. In such instances, a fan running at low speed with a high capacity coil normally yields satisfactory results. It also may be desirable to select a larger nominal capacity unit and operate it at a less than nominal airflow for further acoustic benefit.

Three phase motors are recom- mended for sound-sensitive appli- cations to avoid potential single phase motor hum. Unit operation in the stall region of the fan curve is not recommended since it may cause unsatisfactory noise levels and excessive unit vibration.

Installation

These floor mounted or ceiling hung units can be installed on a base rail or hanger rods at the cor- ner points. All units have internally isolated fan decks; therefore, flex connections are not required, which will reduce installation costs. One of the most important and basic IAQ issues is condensate management. The first step to ensure trouble-free operation is proper installation. It is very important that the unit be mounted high enough so that the condensate drain from the unit may be properly trapped. Please refer to the MQL IOM Manual at www.enviro-tec.com for specifics on this issue. As with all HVAC sys- tems, these units should be installed according to all applica- ble ASHRAE standards, SMACNA and local code requirements.

Operating Limitations

Units must not be operated above maximum fan speed or unit air- flow as listed in the Fan Performance section of this cata- log. Unit operation at greater than maximum fan speed could drastically reduce bearing life and may result in a catastrophic fail- ure. Operating at greater than the maximum allowable airflow in the cooling mode may result in unsatisfactory operation due to moisture carry over from the coil. In addition, it is often not eco- nomical to operate a unit at its maximum fan speed due to the greater motor power require- ments.

Units with electric heat should not be operated with leaving air tem- perature greater than 104°F, to prevent excessive leaving air tem- peratures and electric heat limit trips. A hydronic (or steam) coil and electric heat should not be operated simultaneously to pre- vent excessive leaving air tem- peratures and limit trips. Electric heat units are equipped with a lockout switch that disables the electric heater if the temperature of the hydronic (or steam) coil is greater than 104°F (40°C).

Water coils must not be operated above a fluid velocity of 8 ft./sec. to reduce the possibility of veloc- ity induced erosion and flow noise. Water coils must not be operated below a fluid velocity of 1 ft./sec. to prevent degraded coil performance caused by laminar flow. These high or low fluid flow rates may not be included in the ARI coil certification.

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Enviro 170S5FG manual Application Considerations MQL, Constant volume applications
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170S5FG specifications

The Enviro 170S5FG is a cutting-edge hybrid vehicle from the renowned Enviro brand, designed to meet the evolving demands of public transportation while prioritizing sustainability and passenger comfort. One of the standout features of the Enviro 170S5FG is its hybrid powertrain, which effectively combines a diesel engine with an electric motor. This dual system significantly reduces emissions while ensuring optimal fuel efficiency. The vehicle is engineered to operate in various urban settings, making it an ideal choice for cities aiming to enhance their environmental impact.

In terms of performance, the 170S5FG boasts impressive acceleration and smooth operations, thanks to its state-of-the-art torque management system. The hybrid technology ensures that the vehicle can switch seamlessly between electric and diesel power, allowing it to conserve energy during low-speed travel, such as in stop-and-go traffic. This feature is particularly beneficial for reducing urban air pollution, as the vehicle emits fewer greenhouse gases compared to traditional diesel-only buses.

Passenger comfort is a priority in the Enviro 170S5FG, reflected in its thoughtfully designed interior. The spacious cabin can accommodate a significant number of passengers, with comfortable seating arrangements and ample standing room. Large windows provide natural light and enhance the overall travel experience. Additionally, the focus on accessibility means that the vehicle is equipped with features such as low floors, ramps, and designated spaces for wheelchairs, ensuring that it caters to all members of the community.

Safety comprises another area of excellence for the Enviro 170S5FG. Equipped with advanced safety technologies, including electronic stability control, anti-lock braking systems, and high-visibility LED lighting, the vehicle prioritizes the protection of passengers and drivers alike. The ergonomic design also includes enhanced visibility for the driver, contributing to safer navigation in complex urban environments.

Moreover, the Enviro 170S5FG incorporates intelligent connectivity features that enhance operational efficiency and passenger convenience. These technologies support real-time tracking and monitoring of bus performance, allowing transit authorities to optimize routes and schedules effectively.

In summary, the Enviro 170S5FG is a forward-thinking solution that combines hybrid technology, passenger-centric design, and advanced safety features. Its commitment to sustainability, performance, and comfort makes it an ideal asset for modern public transportation systems aiming to create greener cities while enhancing the commuter experience.
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