FV-T

The FV-T module is a packaged system that includes supply and exhaust air fans, outdoor and return air filter, and SEMCO's TEC total energy recovery wheel. The TEC wheel recovers both sensible (temperature) and latent (moisture) energy; it cools and dehumidifies the outdoor air during the cooling season, while heating and humidifying the outdoor air in the heating season.

The TEC wheel utilizes a fluted aluminum substrate that is uniformly coated with a fast-acting, adsorbent desiccant. As the transfer media slowly rotates between the outdoor and exhaust airstreams, the higher temperature air gives up its sensible energy to the aluminum. This energy is then given up to the cooler air stream during the second half of the revolution. Just as the temperature is captured and released, so is the moisture. The wheel’s desiccant coating has an enormous internal surface area and a strong attraction for water vapor. Since the opposing airstreams have different temperature and moisture contents, their vapor pressures differ. This difference causes the transfer of latent energy.

• Novel System Design
  • Efficient and economical design meeting the needs of the conventional HVAC market.
  • Compact, low profile design to conform to typical architectural requirements.
  • Easy access to all internal components through a large hinged access door and removable roof panel.
  • Outdoor air inlet and exhaust air outlet located at opposite ends of unit for maximum separation.
• The TEC Total Energy Wheel
  • Certified total energy (both sensible and latent) recovery performance.
  • Easily removable wheel cassette module.
  • Surpasses NFPA-90A requirements having a smoke and flame spread rating of 0 and 0, vs. 50 and 25 allowed by the standard.
  • Self-adjusting air seals.
• Cabinet Construction
  • Galvanized steel cabinet construction with enamel finish.
  • Entire cabinet insulated to minimize energy loss.
  • Hinged doors for easy access.
  • Floor of the unit built as a pan to ensure watertight design.
• Supply and Exhaust Air Fans
  • Sized for quiet and efficient operation.
  • Mounted and balanced.
  • Multiple speed motors or multiple motor/sheave selections for efficient adjustment of airflow.
• Filter Sections
  • Filtration provided for both the outdoor air and return air.
• Hoods and Dampers
  • Airflow balancing dampers.
  • Unit provided with an intake hood with cleanable filter to limit rain and snow introduction.
  • Exhaust air back draft damper.
• Electrical Package with Single Point Connection
  • All motors wired to starters.
  • Accepts contact inputs for supply fan start/stop, wheel start/stop and unit start/stop.

Economical Compliance With ASHRAE Standard 62

• To achieve acceptable indoor air quality, ASHRAE Standard 62 recommends a three-to-four-fold increase in the amount of outdoor air provided to most facilities. In addition, the ASHRAE Standard recommends that this increased outdoor air quantity be introduced continuously while spaces are occupied. By recovering up to 80 percent of the total energy normally exhausted from occupied spaces, the FV-T preconditioner enables the Trane Voyager unit to effectively handle this increase in outdoor air load without the need for a larger sized package and without increasing energy consumption.

Reduced Equipment First Cost

• Without the addition of effective energy recovery, the capacity of HVAC systems must be increased greatly to handle the greater outdoor air loads. Increasing equipment size often requires the addition of reheat and sophisticated control sequences to control both humidity and temperature. The FV-T preconditioner often reduces project first cost by allowing a smaller Voyager unit and duct system to be used without the need for reheat or complex controls.

Improved Cooling Season Humidity Control

• Operation of conventional HVAC systems is governed by a thermostat, i.e., in response only to the conditioned space temperature. When the cooling coil is cycled off, the outside air fan is typically shut-off as well. Thus, no ventilation is provided to the conditioned space until the thermostat calls for cooling. If the outside air fan is allowed to run while the cooling coil is off, then warm, humid air is directed to the space. In both of these cases, indoor space humidity levels will increase above guideline levels, i.e., 60 percent relative humidity.
• Since the FV-T unit dehumidifies and cools the incoming outdoor air, the supply air conditions are close to the return air conditions. This effectively produces a buffer against high outdoor latent loads resulting in acceptable indoor humidity levels.

Reduced Humidification Requirements During the Heating Season

• Supplying 15 to 20 cfm/person of cold, dry outdoor air to a facility during the heating season can result in unacceptably low indoor relative humidity. Most facilities require humidification which is costly to operate and maintain. The FV-T unit captures the moisture generated within the space to provide free humidification during the heating season, therefore maintaining a healthier indoor environment.
• In moderate climates with short heating seasons, this may be sufficient to completely eliminate the need for any humidification equipment.

Improves the IAQ of Existing Facilities

• The compact yet versatile design of the FV-T unit allows for easy installation in existing facilities and eliminates additional ductwork and disruption of the occupied space below. It can either be used as a stand alone unit serving multiple HVAC units or as a dedicated preconditioner ducted directly to a single unitary HVAC system

Improved Comfort of Occupied Spaces

• As outdoor air is supplied to the space, the heating/cooling source is cycled on and off to maintain temperature. When it is cycled off, very cold or very warm/humid air can be "dumped" on the occupants, causing wide temperature fluctuations that makes for a very uncomfortable environment. The FV-T module solves this problem by providing moderated supply air conditions even as the Voyager unit is cycled on and off.

CASING - Standard panels shall be 20 gauge galvanized steel. The housing shall be supported by a formed structural base that forms a pan to ensure weather tight construction. Lifting holes shall be provided at the unit base. Units shall have a weatherproof sheet metal roof. Insulation shall be thick closed-cell neoprene for wash down capability and include antimicrobial protection. Insulation shall meet or exceed requirements of UL 181, ASTM G21/C 1338 and ASTM G 22 for resistance to mold, fungi and bacteria. The outdoor air intake opening shall be protected by a galvanized steel sheet metal weather hood and include an automatic rotary blade damper with blade seals and an electric actuator. The exhaust air discharge shall be covered with a gravity back draft damper and weather hood. The exterior of the unit shall be coated with an epoxy primer and a polyurethane enamel painting system for added protection. Painting system shall be rated to meet a 1500-hour salt spray test.

ACCESS - Access to components shall be provided through a large, tightly sealed and easily removable access panel. Access panels shall be constructed of the same materials as the unit casing and use SEMCO's standard hardware. The wheel cassette shall be easily removable from the unit. The roof of the unit shall also be removable for access.

UNIT CONFIGURATION - The supply air inlet and exhaust air outlet must be oriented at opposite ends of the Energy Recovery System to maximize the distance between the two airstreams in order to minimize the risk of short circuiting exhaust air into the supply air intake.

FANS - Fans shall be double width double inlet design with forward curve type wheels. The blades shall be designed for maximum efficiency and quiet operation. Impellers shall be statically and dynamically balanced.

Fans shall be driven by direct drive motors located at the fan inlet or by motors using belts and sheaves. Motors shall be standard NEMA frame with open drip-proof enclosures. V-belt drives shall be designed for a minimum 1.2 service factor.

For more information about Sample Specifications go to Semco´s website >>