Your action has resulted in an error. Please click the Back button in your browser and try again.Vertical-Horizontal Air Handling Unit Multi F The vertical air handler can be installed with most Multi F systems. Designed for ducting in a main branch. Select BTU (Cooling / Heating) Vertical-Horizontal Air Handling Unit Multi F * Inverter variable-speed fan * External Static Pressure control Available models: LMVN240HV, LMVN360HV SmartCool™ 11kW – 233kW SmartCool™ Inverter Compressor 5kW – 83kW EasiCool™ 6kW – 64kW Ecotel™ FreeCool 5kW – 15kW Ecotel™ DX 5kW – 15kW OnRak™ 3kW – 35kW InRak™ 10kW – 67kW Echo™ up to 20kW AireTile™ Up to 1.2m³/s DeltaChill™ & DeltaChill™ FreeCool 110kW – 1080kW TurboChill™ & TurboChill™ FreeCool 200kW – 1830kW TurboChill™ Water Cooled 150kW - 1576kW OptiChill™ & OptiChill™ FreeCool 500kW – 1365kW LogiCool™ FreeCool 20kW – 40kW

Ultima™ Compact & Ultima™ Compact FreeCool 30kW – 450kW Ultima™ Remote Air Cooled 75kW – 450kW Ultima™ Water Cooled 75kW – 450kW Chilled Water Cassette 2kW – 11kW BluCube™ 10kW – 48kW Air Cooled Condensers & Dry Coolers 12kW - 174kW Condensing Units (CU) 3kW – 80kW Ultima™ Compact Condensing Unit 30kW – 450kW AireFlow™ 100kW – 440kW Showing results 1 - 1 of 1 Designed for roof and wall connections and requires minimal mechanical cooling, delivering huge free-cooling potential to significantly reduce operational costs. People Who Viewed This Also Viewed... Air Handling Unit range Designed to perform, our highly versatile range of Air Handling Units (AHUs) are configured for wall or roof mounted applications. Requiring minimal mechanical cooling and offer huge free-cooling potential - maximising efficiency and minimising operational costs.By Lu Ping, Pan Asia Technical Automotive Center, Shanghai, China

The number of car owners in China is increasing exponentially. China will soon have nearly as many drivers as the U.S. With this band of newly qualified drivers, a demand for higher standards in vehicle ride “comfort” is developing. car ac repair youtubeOne such area is the standard of cabin comfort. heat pump unit stopped workingThis is directly related to a car’s air-conditioning unit with discharge temperature uniformity which is one of the key factors impacting perceived comfort levels.air conditioner unit on roof On the one hand, discharge air temperature from the HVAC air box has to be uniform for passenger comfort, but on the other, uniformity can reduce the extent of the automatic air-conditioning calibration workload. However, due to packaging limitations in typical vehicle development, its air conditioning unit has to be as compact as possible, which usually make it a poor or inadequate mixture of cold and hot airflow inside the air conditioning unit and finally leads to an non-uniform discharge temperature.

In the development of automotive HVAC air handling units (AHU), to control the discharge air temperature uniformity, performance is key, and it is important to consider the factors mentioned above for the development of a car’s HVAC air handling unit (AHU). Figure 1 shows the specific AHU being evaluated in this study. Flow through it involves complex tortuous passageways and the mixing of both cold and hot airflows. The unit has one inlet and two outlet zones, and its complex geometrical nature means that it is most realistic to simulate fluid flow and heat transfer inside a CAD package using a CFD tool such as FloEFD. The AHU itself consists of air box housing, an evaporator, a heater, and flap door components. During normal operation, airflow enters the air conditioning unit through the intake housing, and then flows through the evaporator to be cooled down. After cooling, the airflow partially goes through the heater core to be warmed up while part goes towards the outlet area with the flow guiding of a temperature flap door.

These two hot and cold air streams then re-converge and mix to achieve a proper and comfortable temperature. Conditioned airflow is finally delivered to passengers through the air box outlet. A typical FloEFD simulation prediction for airflow vectors and temperature effects inside the AHU is shown in Figure 2. The position of the temperature flap door effectively acts as a control valve inside the unit and ultimately determines the hot and cold airflow “mixing ratio”. It can be altered to different positions (Figure 3). The “hedge angle” and “area ratio” of the cold and hot airflow channel have an important influence on the final mixed airflow temperature distribution. The CFD boundary conditions simulated in this AHU study extended from airflow rates of 15l/s to 60l/s at an air inlet temperature of 20°c with 875W heat transfer rate from the heater component. Nine parametric CFD simulations inside FloEFD were used to determine an optimized cold and hot flow channel “hedge angle” together with runner “area ratios” as shown in Table 1.

This parametric study focused on the AHU outlet airflow temperature distribution under different temperature flap door setting. More focus is around the middle position, that is, for angle degree of outlet damper door from 25° to 50°, considering the middle position is relative to a customer’s actual high frequency usage scenario (see Figure 4). The temperature difference is seen to be optimal for Case 3 for the two temperature flap door conditions. Hence, the cold and hot airflow channel hedge angle and runner ratio area under this case is the most ideal which was verified visually (Figure 5) by outlet CFD temperature contours under these two temperature flap door positions. Finally, we validated the CFD simulation Case 3 prediction against an experimental test of the actual car AHU. We chose an air conditioning box inlet temperature of 0°C, and the heater inside operating with a 90°C fluid so as to replicate a real vehicle use of air conditioning over cold and hot atmospheric conditions.

By adjusting the temperature flap door in the AHU to control air-conditioning of cold and hot air mixing, we were able to verify the box’s linear temperature uniformity performance target. We positioned 4 thermocouples on each outlet and measured the average exit air temperature. Figure 6 shows the actual measured performance data of the AHU. Aligned with the CFD simulation results, we achieved the maximum temperature difference within 4°C among four vent outlets when the temperature flap valve is adjusted between 35% and 65%. We reached the requirement of a linear thermal design, while at the same time it was basically consistent with the virtual design CFD results. In conclusion, we adopted the commercial CFD software, FloEFD, for this study because of its ease of use in meshing when compared to the tetrahedral or prismatic meshing approaches in traditional CFD codes. We found that FloEFD gives more accurate and more efficient CFD simulation results. Since it works within the mechanical CAD environment, it is a highly engineered universal fluid flow and heat transfer analysis software.