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Hersteller: Tradewins Furniture Dateigröße: 1.4 mb Dateiname: Unterrichtssprache:

When the outside air temperature drops below 27°F (-3°C), defrost is activated which provides for an automatic defrost cycle. During the automatic defrost cycle the fresh air supply is shut off while the exhaust fan continues to operate. This allows warm inside air to flow through the heat exchanger core melting frost accumulation. After the defrost period, the fresh air supply fan automatically returns to the normal speed and fresh outside air continues to be drawn into the building. Water from the melted frost collects in the bottom drip pans and drains out through the bottom drain connectoions. The defrost cycle repeats automatically until the air temperature rises above 27°F (-3°C). HS HS HS REMOTE REMOTE REMOTE DFR2 DFR2 DFR2 OFF DFR3 DFR3 DFR3 OFF ON ON SW1 SW1 *Lengthening the run time may result in ice build-up on the core. SW1 Dehumidistat Operation (HRV only) The optional HRV remote controls include a dehumidistat which controls humidity levels during the heating season. The control has a selector knob with setpoints ranging from 20% to 80% relative humidity (RH). Most people are comfortable when indoor relative humidity levels are in a range from 30 to 45%. The dehumidistat switches the ventilator to high speed when the moisture level in the home exceeds the desired setpoint. The dehumidistat switches the HRV back to low speed ventilation when humidity has been reduced below the set point. The dehumidistat should only be used during the heating season. It must be set to the OFF position throughout the rest of the year. 18 Air Flow Balancing It is necessary to have balanced air flow in an HRV. The volume of air brought in from the outside must equal the volume of air exhausted by the unit. If the air flow is not properly balanced, then: • The HRV may not operate at its maximum efficiency • A negative or positive air pressure may occur in the house • The unit may not defrost properly • Failure to balance HRV properly may void warranty CAUTION Ensure balanced air flow in HRV. Excessive positive pressure may drive moist indoor air into the external walls of the building where it may condense (in cold weather) and degrade structural components. May also cause key holes to freeze up. Excessive negative pressure may have several undesirable effects. In some geographic locations, soil gases such as methane and radon gas may be drawn into the home through basement/ground contact areas. Read the Application Warning in Clearances & Requirements section of this manual! WARNING Ensure balanced air flow in HRV/ERV. Excessive negative pressure may also cause the back- drafting of vented combustion equipment. Prior to balancing, ensure that: 1. All sealing of the duct system has been completed. 2. All of the HRV’s components are in place and functioning properly. 3. Balancing dampers are fully open. 4. Unit is on HIGH speed. 5. Air flow in branch lines to specific areas of the house should be adjusted first prior to balancing the unit. A smoke pencil used at the grilles is a good indicator of each branch line's relative air flow. 6. After taking readings of both the stale air to the HRV duct and fresh air to the house duct, the duct with the lower CFM ([L/s] velocity) reading should be left alone, while the duct with the higher reading should be dampered back to match the lower reading. 7. Return unit to appropriate fan speed for normal operation 8. A field-supplied balancing damper for the stale air side is required for system balancing. Balancing Procedure The following is a method of field balancing an HRV using a Pitot tube, which is advantageous in situations when flow stations are not installed in the duct system. Procedure should be performed with the HRV on high speed. The first step is to operate all mechanical systems on high speed, which have an influence on the ventilation system, i.e. the HRV itself and the air handler, if applicable. This will provide the maximum pressure that the HRV will need to overcome, and allow for a more accurate balance of the unit. Drill a small hole in the duct (about 3/16"), three feet downstream of any elbows or bends, and one foot upstream of any elbows or bends. These are recommended distances but the actual installation may limit the amount of straight duct. The Pitot tube should be connected to a magnehelic gauge or digital manometer capable of reading from 0 to 0.25 in. (0-62 Pa) of water, preferably to 3 digits of resolution. The tube coming out of the end of the Pitot is connected to the high pressure side of the gauge. The tube coming out of the branch of the Pitot is connected to the low pressure or reference side of the gauge. Insert the Pitot tube into the duct; pointing the tip into the air flow. For general balancing it is sufficient to move the Pitot tube around in the duct and take an average or typical reading. Repeat this procedure in the other (supply or return) duct. Determine which duct has the highest air flow (highest reading on the gauge). Then da...

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