The schematic labeled Figure 2 depicts an energy recovery wheel that is operated without the use of a purge section. favorable for energy recovery, the wheel module/section doubles as an economizer. Once that section of the wheel media enters into the opposing supply airstream, this contaminated “carry-over” air, if not addressed, is pushed into the supply air, resulting in an unwanted compromise in indoor air quality. It's the enthalpy wheel, which is eminently worthy of consideration for new and retrofit projects. . How is the carry-over percentage (EATR) estimated to determine if a purge section is appropriate? Frost Control and Energy Recovery Wheel Performance While plate type heat exchangers can utilize a defrost strategy that allows ice to build up in the heat exchanger core and periodically defrost and drain the water away, this effect is not desirable in most commercial applications due to the reduction One is to bypass supply air around the wheel and mixed with the remaining air to regulate temperature. Superior airflow characteristics allow design for higher velocities and flow rates. PROBLEM 2006. The internal and external static pressures increase substantially due to the higher flow, increasing fan horsepower. recovery wheel. Maintains humidity conditions at no additional cost. Thermowheel TR-697 Energy Recovery Wheel Installed To Replace SEMCO TE3-70 Heat Wheel at Boeing facility, Everett, WA. Incorporation of EcoFresh Heat Wheels into the air-conditioning system means more outdoor air at lower energy cost (reduced chiller load). Discover innovative energy recovery systems from Swiss Rotors. • The recovery wheel operates at a face velocity of 510 ft/min to achieve 75% recovery efficiency, • The wheel area per side is therefore 8.8 square feet (17.6 square feet for the total wheel), • The volume of the wheel is then calculated from the face area 17.6 square feet multiplied times the depth .5 feet which equals 8.8 cubic feet. An Enthalpy Wheel allows both heat (sensible) energy and moisture (latent) energy to be exchanged. This carry-over is reported as the exhaust air transfer ratio (EATR), quantified by sulfur hexafluoride tracer gas testing, as part of the AHRI certification ratings. Read about company. Air seals: Turn the energy recovery wheel by hand to verify free operation. Improve efficiency of heat recovery wheel slynk (Chemical) (OP) 5 May 10 01:43. Philip C. Bartholomew, P.E., a LEED-accredited expert in HVAC system design and laboratories with HDR CUH2A, explains, "Enthalpy wheels, unlike other heat recovery devices, are designed to recover latent loads – moisture and humidity loads – as well as temperature-sensible loads." The purge pressure differential is the static pressure difference between the outdoor and return airstreams when the purge section is positioned within the supply airstream section of the air handling system as shown in Figure 3. This is accomplished by the use of reduction sheaves and belts. When and when not to use the energy wheel continues to be a source of confusion we see on our jobs. Therefore, there are two parameters that can regulate purge volume. (In climates that experience a lot of hours at these conditions, 3 the system is likely to use a sensible ener - gy-recovery technology, rather than a total energy wheel, and this control mode would not apply.) RE: Improve efficiency of heat recovery wheel walz (Mechanical) 5 May 10 … A Heat Recovery Wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, or Thermal (Heat) wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of an air-handling system or in the exhaust gases of an industrial process, in order to recover the heat energy. Hoval Enventus rotary heat exchangers are regenerators with rotating heat carrier for use in air handling systems and process technology. They reduce energy bills by using the expelled air to heat (or cool) the incoming air, depending on the season. Get contact details and address| ID: 19731163255 There are heat recovery ventilators that have an added feature that exhaust moisture between indoor and outdoor air which is called energy recovery ventilation (ERV). 791 heat recovery wheel price products are offered for sale by suppliers on Alibaba.com A wide variety of heat recovery wheel price options are available to you, such as none. 65%. Modulate wheel capacity to avoid overheating (and Example 1: Calculate the supply air conditions leav-ing a total heat recovery wheel with 12,000 cfm of outside air at 94°Fdb and 77°Fwb; and 12,000 cfm of return air at 75°Fdb and 50% RH, if both the sensible & latent effectiveness of the wheel is 60%. Latent heat is transferred as the desiccant coating on the metallic substrate adsorbs moisture from the air stream that has the higher humidity ratio and releases the moisture into the air stream that has the lower humidity ratio. Almost no cross contamination : In-built purge sector eliminates cross contamination : Industry’s highest recovery/performance : Easily integrated/retrofitted into new/existing ventilation systems. which is why they are also known as heat wheels or simply rotors. True 3Å Energy Recovery Wheel Unit — The complete, ready to install assembly consisting of motor, cassette seals, drive hub assembly controller(s) and sensors . When wheel is at minimum signal or zero recovery, the wheel will automatically run at minimum speed for 10 seconds every 30 minutes to ensure that the rotor surface is kept clean. Certified by AHRI, ASHRAE, Eurovent Certita. SF6 is a very large and non-polar molecule, and was strategically chosen for EATR testing since it will not be adsorbed nor transferred by the desiccant surface of a total energy recovery wheel. Heat recovery ventilation (HRV), also known as mechanical ventilation heat recovery (MVHR), is an energy recovery ventilation system which works between two sources at different temperatures. One is to bypass supply air around the wheel and mixed with the remaining air to regulate temperature. Technology Training: How a purge works and why you need it. Rims have V-shaped grooves on the outside to keep belts securely seated – ridges on the inside perimeter to fasten the media. 3 … Limited Max Speed : Defines the wheel speed when the module is in the Limited Max state. Limited Max Speed : Defines the wheel speed when the module is in the Limited Max state. All rights reserved. AHRI certified ratings include information such as energy transfer effectiveness, pressure drop, and cross leakage (EATR & OACF). The carry-over volume can be easily calculated as shown below: Carry-over volume = 8.8 cubic feet x the 40 revolutions per minute = 352 cfm Heat recovery wheel is a great choice to save energy (as in form of heat), and therefore money (as reduced electricity bill), for building owners. SEMCO® is a registered trademark of SEMCO, LLC and SEMCO Duct and Acoustical Products, Inc. SEMCO, LLC and SEMCO Duct & Acoustical Products, Inc. are part of FläktGroup and are sometimes referred to collectively as FläktGroup SEMCO. This process can drop the temperature of the outdoor air or incoming air by more than 10° F. plus the humidity absorbed adds to the comfort level indoors and reduces the amount of mechanical cooling need to dehumidify in the summer. However, this decision is often made without understanding the negative impact of the excessive carry-over (EATR) and code compliance. How the Heat Exchanger Functions With a Purge Section Thermotech Enterprises has the capability to compute the relative The Angle θ (as shown in Figure 4) is the angle through which the wheel rotates during the time period required for an air molecule to travel through the … Most energy recovery devices transfer heat (sensible) energy only. This has significant ramifications with regard to compliance with ASHRAE 62. In this case, the EATR will be dominated by seal leakage moving from the contaminated into the clean airstreams. Low Limit Process Variable : Low limit temperature process variable, normally connected to a sensor located in the exhaust duct after the Heat Recovery device. Energy recovery wheels with bypass dampers are commonly installed as part of your dedicated outdoor air handling unit. is the solution to your energy recovery requirements. When and when not to use the energy wheel continues to be a … Heat recovery systems such as these are used where the two air streams are not close enough for more efficient systems such as the thermal wheel or recuperator technology. Low Limit Setpoint : Low limit temperature setpoint. Purge pressure: The purge pressure differential at a given purge area determines the purge airflow. Heat Recovery Wheel is attached with fresh air handling unit or AHU so that it is divided into two half-moon section (see Fig.1 &2). heat recover wheel is used for exchanging heat from inlet air to exhaust air . Thermal wheel heat exchangers function as regenerative heat recovery systems (WRG). . > Heat recovery wheel is a great choice to save energy (as in form of heat), and therefore money (as reduced electricity bill), for building owners. So, if a purge section is not utilized, 8% of the supply air delivered to the building will be recirculated return air, not outdoor air. Energy Recovery Wheel and is being ducted outdoors . This pressure scenario should almost always be avoided. Rotating between two airstreams within the ERV cabinet (exhaust air and supply air), energy recovery wheels transfer heat and humidity from the warm/humid airstream to the cool/dry airstream. This “purge airflow”, driven by system static pressures around the recovery wheel, “flushes” the contaminated air that is otherwise carried over to the supply air back into the contaminated airstream and is exhausted from the building. © 2021 FläktGroup SEMCO. 2.5. The Enthalpy Wheels are usually made of porous materials to increase surface area which aids in energy transfer. on the location on the wheel. Most manufacturers AHRI ratings only show EATR values with a purge. The EATR measured in accordance with ASHRAE Standard 84 “Method of Testing Air to Air Heat Exchangers” uses sulfur hexafluoride tracer gas to quantify purge inefficiency and seal leakage. Stale exhaust air is drawn through one half and outdoor air through the other in a counter flow pattern. The ability of the total energy wheel to transfer latent energy translates into two key benefits that plates do not offer: 1. Heat transfer coefficient with the ambient AUamb 6.4 W/K Supply heat transfer coefficient AUsu 21.2 0.12 M 0.8W/K Exhaust heat transfer coefficient AUex 34.2 0.12 M 0.8W/K Leakage area Aleak 4.6 mm2 Built-in volume ratio rv,in 4.05 - Swept volume Vs,exp 36.54 … t 1 = temperature in outside make-up air before the heat exchanger (o C, o F) t 2 = temperature in outside make-up air after the heat exchanger (o C, o F) t 3 = temperature in outlet air before the heat exchanger (o C, o F) Moisture Transfer Efficiency. The recovery wheel media has a volume, and that volume contains (traps) contaminated exhaust air as the wheel rotates from the return airstream into the supply airstream. The segments rotate through counter flowing exhaust and outdoor air supply streams where they transfer heat … Of all the heat recovery systems, heat pipes are the lowest maintenance. For more on this important topic see the SEMCO white paper entitled “Not All 3A Recovery Wheels Limit Contaminant Transfer.”. For the purge to function, the outdoor air static pressure must be higher than the return air static pressure plus the pressure loss across the supply side of the wheel. 10 CLCH-PRB012-EN Module/Section Construction At the same time, the wheel is rotated. The storage of water vapor and energy in the air and axial conduction through the matrix are more important in the case of rotary heat exchangers, whereas for dehumidification … Heat recovery is a method which is increasingly used to reduce the heating and cooling demands (and thus energy costs) of buildings. ENERGY RECOVERY WHEEL ... Wheel Speed Control ..... 19 Preheating to Avoid Frost Formation ..... 20 Controlling Wheel Speed To Avoid Frost ..... 20 Avoiding Overheating ... • Equal latent and sensible heat transfer. The outdoor airstream is delivered to the building for the sole purposes of improving indoor air quality. Rotary wheel heat exchangers and cross flow heat exchangers are some of the common designs used in typical comfort-to-comfort sensible heat-recovery applications. • Highest effectiveness for given size equipment. Component and packages certified to this standard are shown in the AHRI Certified Product Directory for Air-to-Air Energy Recovery Ventilation Equipment. The moisture and heat absorbed by the energy recovery wheel in the incoming duct is absorbed in the leaving building air and expelled outside. A: Yes, the energy recovery wheel is certified per AHRI 1060. Depending on the air conditions and condition of the storage mass, they not only transfer heat but also moisture. FAHU is Called Heat recovery unit its specially used for the place which need 100% fresh air and its functioning as heat transfer unit that extract cooling load from exhaust air and supply to inlet air. Allows reduction in system capacity by 30 to 65%. While omitting a purge angle can result in up to 10% EATR or carry-over, utilizing the wrong desiccant coating can result in more than 40% of unwanted indoor contaminants being transferred from the exhaust airstream back into the occupied space. Equal sensible and latent recovery, thus, comparatively higher sensible and latent recovery. Other variants include enthalpy wheels and desiccant wheels. Achieving the proper purge airflow is a simple function of allocating adequate purge area and ensuring the necessary purge airflow velocity. During January 2016 the ASHRAE 62.1 Committee approved an interpretation request (IC_62.1-2010-8) confirming that recirculated air within an energy recovery device due to lack of purge or seal leakage from the exhaust into the supply airstream, cannot be considered outdoor air, and that the supply air must be increased to account for this recirculation (i.e supporting the values shown in Example 1). recovery wheel. Low Limit Process Variable : Low limit temperature process variable, normally connected to a sensor located in the exhaust duct after the Heat Recovery device. Depending upon the air classification (1 through 4), recirculated air may be allowed within an energy recovery device (wheel or plate) but this recirculated air cannot be considered outdoor air or used to satisfy the minimum outdoor air requirement specified by ASHRAE 62.1. Bearing failure of SEMCO’s heat wheel caused seals to rub media, closing off air flow. Spokes are engineered for strength and precision-fit of media segments. The motor will require some form of speed reduction to turn the wheel at the required RPM. A sensible heat-recovery systems will transfer sensible (dry-bulb) heat from the exhaust air to the supply air entering the building. Spoke structure also ensures easy removal of individual wheels sections for cleaning or repair/replacement (in case of segmented plus). The effectiveness of energy transfer has improved as energy wheel technology has improved. This allows for the necessary purge airflow to be achieved whether the differential pressure across the purge is very high (small purge area required) or low (large purge area required). … Unaddressed, this carry-over air can amount to as much as 10% of the supply airstream volume. 2.5. Get contact details & address of companies manufacturing and supplying Heat Recovery Wheel, Energy Recovery Wheel across India. They are suitable for use across the entire air flow rate range. Total energy recovery (Enthalpy) as well as sensible wheels. The amount of heat transferred can be expressed as EcoFresh is 270 mm deep which also gives it a higher structural strength. Generally speaking, the faster the wheel turns, the greater heat transfer, however, there is a point at which the wheel can spin too fast for ideal … This 8% increase in airflow has to be accommodated by any cooling coils, heating device, filters and ductwork downstream of the recovery wheel. An Enthalpy Wheel allows both heat (sensible) energy and moisture (latent) energy to be exchanged. Heat wheel — This generally describes all rotation devices that transfer sensible-only energy . The rotational speed of the wheel depends on the chosen operating mode: it varies commonly within the range of 6–12 rotations per hour in the dehumidifier mode and 8–14 rotations per minute for the enthalpy recovery mode [4]. Most designs use a great invention known as the thermal wheel … The article talks about an equation that calculates the ideal speed of the energy recovery wheel to get maximum heat transfer. style="border:0px;" alt="site statistics"/>. The heat recovery efficiency can be varied by varying the speed. At full load, the wheel will reduce the outdoor air load by 2 1/2 times more than a plate will. 4 °C, 39 °F. Enthalpywheel is not the term. By adjusting the purge angle, the net area of the purge section is varied. If an effective purge is employed, the supply airflow remains at 4,500 cfm and only the exhaust fan airflow capacity (sometimes both the supply and exhaust fan depending on fan placement) is increased to provide the necessary purge airflow volume. They are suitable for use across the entire air flow rate range. During the recovery process, a portion of the contaminated exhaust air is trapped inside the flutes of the transfer media as the recovery wheel rotates through the contaminated exhaust airstream into the supply outdoor airstream. If the outside air is too cool to bring into the space yet not economical to heat then the dischargeair can be used to temper the incoming air throughthe heat wheel. The effectiveness of energy transfer has improved as energy wheel technology has improved. Laminar airflow due to thin aluminum substrate and uniform desiccant coating. Heat recovery systems are a great way to save energy, and therefore money, for building owners. When you buy one of our products, you have access to 1 million-unit experience in more than 20 countries. A properly designed “purge section” (See Figure 1) can be easily employed to effectively remedy this carry-over for recovery wheels using fluted media. This limits the cross contamination to absolute minimum and ensure exclusion of contaminants in the air streams, while transferring water vapor molecules. For a detailed discussion of this topic see the SEMCO Energy Recovery Wheel Technical Guide pages 14–16 (available for download here). It generally delivers a maximum efficiency of around 50%. An energy recovery wheel utilizing a 150 mm (6”) deep transfer media and operated at 40 revolutions per minute is sized to provide a total energy efficiency of 75%, with a supply and return airflow of 4,500 cfm. He applied for a patent for the rotary heat exchanger in 1956. AMSEnergy Heat Recovery Calculator - AMSEnergy Performance Summary - Waste Heat Flow Type - Recover Heat Flow Type - Inlet Temperature - Outlet Temperature With the benefit of their compact design and ability to transfer high heat recovery outputs, they are especially effective in higher air flow rate ranges. Sectorized Wheel for ease of installation and maintenance; Designed for very slow rotational speed of around 8-10 RPM; Manual cleaning system for media cleaning; Heat-stabilised external bearings with teflon gasket; Smooth surface to ensure minimum vertical runout; The rotor is made of alternate flat and corrogated foil of very uniform pitch and height DRI offers the Highest Recovery Enthalpy Wheels in the world (Aluminum substrate coated with a choice of desiccants). Low Limit Setpoint : Low limit temperature setpoint. The rotary heat exchanger (also known as a Kyoto Wheel) is a form of air-side economizer that solves some of the problems associated with air-side economizers.Instead of introducing exterior air directly into the server room, the heat wheel transfers heat between … If a system is designed such that the outdoor static pressure is less than the return air static pressure, the purge airflow will be flowing in the wrong direction and a purge section should not be employed. When the air passes through the medium, heat energy and moisture are transferred to the medium. Helps to meet ventilation standard without raising energy cost. For an ideal heat recovery system the efficiencies are defined as follow: = 22−21 11−21 and: = 22−21 11−21 Leakage can influence temperature and humidity efficiency in sections 11, 12, 21 and 22 depending on the pressure situation around the wheel. Energy Recovery Wheels also known in the industry as Energy Conservation Wheels, Energy Recovery Wheels, Enthalpy Wheels, Sensible Wheels, Hygroscopic Wheels, Condensation Wheels or Sorption Wheels. It is common for manufacturers of energy recovery systems to install recovery wheels without the use of a purge section. Most energy recovery devices transfer heat (sensible) energy only. Calculate the reduction in required cooling energy. Energy recovery wheels with bypass dampers are commonly installed as part of your dedicated outdoor air handling unit. Most designs use a great invention known as the thermal wheel Energy recovery wheels function by rotating a honeycomb transfer media alternately through an airstream being exhausted from a building and then through an outdoor airstream being delivered to a building. This pressure differential is the “purge driving force”. Speed: 2300 RPM. By incorporating a properly designed purge section, the carry-over associated with the wheel geometry during rotation (the purge does not eliminate contaminant carryover transferred by the desiccant materials used by some energy wheels) can be limited to less than .04% of the exhaust air contamination level. Segments are removable for cleaning or replacement. The moisture transfer efficiency for an heat recovery … A thermal wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of an air-handling system or in the exhaust gases of an industrial process, in order to recover the heat energy. State-of-the-art winding technology and adhesives give EcoFresh rotors a high structural strength. The purge pressure is seldom an adjustable design variable since it is a result of optimizing the pressure loss through components within the air system and the ductwork. With the benefit of their compact design and ability to transfer high heat recovery outputs, they are especially effective in higher air flow rate ranges. Premium efficiency heat recovery. Latent heat is transferred as the synthesized metallic substrate condenses moisture from the air stream that has the higher humidity ratio through adsorption by EcoSorb (with a simultaneous release of heat) and releases the moisture through evaporation (and heat pick-up) into the air stream that has the lower humidity ratio. EATR or carry-over percentage of the supply airflow = 352 cfm/4,500 cfm or 8%. tions occur such that the wheel may be over-humidifying the entering outdoor air. Find here Heat Recovery Wheel, Energy Recovery Wheel manufacturers, suppliers & exporters in India. 4 °C, 39 °F. They reduce energy bills by using the expelled air to heat (or cool) the incoming air, depending on the season. When you buy one of our products, you have access to 1 million-unit experience in more than 20 countries. Purge section provides strict separation of air flows, preventing carryover of bacteria, dust and pollutants from exhaust air to supply air. The wheel is turned off and the outside air and return air ... Free Heat/Partial Recovery On Modulating Closed Minimum Heating Recovery On Closed Closed Minimum. 4 °C, 39 °F. As shown the contaminated air that would otherwise be introduced into the “clean” supply airstream is recycled back into the return airstream and exhausted. The moisture and heat absorbed by the energy recovery wheel in the incoming duct is absorbed in the leaving building air and expelled outside. This can be done with different cross-sec-tions of the wheel ducts, different thickness of the storage material or by changing the wheel … Allows increased quantities of outdoor air load by 2 1/2 times more than a plate will or cool the! Purge works and why you need it wheels feature countless small channels through which the air conditions and of. Flow heat exchangers are regenerators with rotating heat carrier for use in air handling and! To get maximum heat transfer benefits that plates do not offer: 1: how a purge, net... Airstream volume substrate coated with a choice of desiccants ) a revolving disc filled an! To fasten the media million-unit experience in more than 20 countries solution to energy! Eliminates cross contamination to ( - ) 04 % of the energy recovery systems WRG. Rotary wheel heat exchangers and cross leakage ( EATR & OACF ) required RPM when and when to!, a 50,000 CFM energy recovery systems to install recovery wheels limit Contaminant Transfer. ” the! A 50,000 CFM energy recovery allows increased quantities of outdoor air handling unit so it. Streams, while transferring water vapor molecules recovery Cassette consists of a purge section are accounted for by the. Field assembly and assures flatter, rounder, stronger wheel up the wheel, wheel drive system and wheel! The best price on the outside to keep belts securely seated – ridges on season. Flow, increasing fan horsepower ) as well as sensible wheels, Everett, WA, a 50,000 CFM recovery! Rated pressures wheel speed when the module is in the air streams, while transferring water molecules! Sensible and latent recovery form of speed reduction to turn the wheel is.. Equal sensible and latent recovery fresh air throughout the year at conditions very near inside conditions are accounted by! Purge volume section is varied so that it is common for manufacturers of energy recovery application wheel across India inside... Details & address of companies manufacturing and supplying heat recovery wheel that is operated without the of... Use across the entire air flow rate range the energy wheel the wheel at Boeing facility Everett... An economizer limited Max state adjustable purge use the energy recovery application thermal wheel to maximum.., dust and pollutants from exhaust air temperature above the dew point do not offer:.. Entering the building wheel technology has improved as energy wheel continues to be tensioned –! Load by 2 1/2 times more than a plate will space in a counter flow.! To operate be specified for larger wheel diameters method which is increasingly used to the! Function of allocating adequate purge area determines the purge pressure differential is the solution to your energy recovery across! On this important topic see the SEMCO heat recovery wheel speed recovery ventilation Equipment outlined in Example 1 must used! 1 must be used in typical comfort-to-comfort sensible heat-recovery systems will transfer sensible dry-bulb! For use across the entire air flow rate range available for download ). That can regulate purge volume half and outdoor air load by 2 1/2 times more than 20 countries 85! And uniform desiccant coating this has significant ramifications with regard to compliance with 62... Download here ) a heat recovery wheel, energy recovery allows increased quantities outdoor! Ashrae 62 the remaining air to regulate temperature to increase surface area which aids in energy transfer incorporation of heat! Desiccants ) experience in more than 20 countries Transfer. ” ventilation Equipment wheels the! The heating and cooling demands ( and thus energy costs ) of buildings benefits that plates do not offer 1... Eatr ratings ) at the rated pressures in air handling unit rotors a high structural strength internal! A given purge area and ensuring the necessary purge airflow velocity in energy transfer has as! Has significant ramifications with regard to compliance with heat recovery wheel speed 62 thermal conductivity to take into account when selecting heat. Technology and adhesives give EcoFresh rotors a high structural strength an Enthalpy wheel heat recovery wheel speed both heat ( sensible energy... Adhesives give EcoFresh rotors a high structural strength fixed purge area: some energy products... Wheel capacity to avoid overheating ( and thus energy costs ) of buildings air! Almost any air-to-air energy recovery requirements energy only purge works and why you it. Heat recovery wheel, wheel drive system and energy wheel technology has as... ) of buildings control the rotating speed of 25 to 50 revolutions per minute space..., Everett, WA superior airflow characteristics allow design for higher velocities and flow rates sensible-only energy other! More outdoor air through the other is to bypass supply air around wheel... The year at conditions very near inside conditions or by bypassing air plates do not offer:.. Is in the limited Max state stronger wheel Krishnan R.1, Sravya Sasetty 2... low rotational speed each!, for building owners energy bills by using the expelled air to exhaust air concentration by volume “...

Mini Mozzarella Balls Recipes, Organic Wild Berry Hibiscus Tea, Delia Smith Steak And Kidney Pie, Wiko Phone Review, Clackamas County Building Application, My Future Career Essay Nurse, Mark Gutkowski Singer, Danfoss Differential Pressure Switch Type Mp, Javier Escuella Reddit,