Return Air Plenum

The Honeywell discharge air temperature sensor (DATS) is a duct mounted temperature probe that provides capacity control of heating and cooling equipment. The Movincool LAY84 Condenser Return Air Plenum is a 12 inch white plastic plenum for return air to condenser. , we are proud to be the leader in HVAC supplies, parts and equipment. Size 1120 x 355 - 2 x 400. Does a furnace cold air return duct have to be ducted to the heated air space of a home? Yes. whereas in open ceiling plenum return system, return air temperature or on-coil temperature is slightly higher than the room temperature, due to addition of heat through roof (approx. Concentric supply/return diffuser with plenum. Without a return air duct, the air would not properly circulate and your energy costs would rise. Duct silencers, flat acoustic foam and plenum return silencers are used to help decrease the amount of sound or noise that may travel through the open channels in an HVAC system. indicated in UFC 4-510-01; Computed on a per-occupant basis, minimum outside air ventilation shall meet the worst-case requirements of either UFC 4-510-01, or ASHRAE Standard 62. Plenums & Return Air. Inspected this house this morning. Find duct plenums at Lowe's today. York stocks a vast selection of HVAC equipment, parts, and supplies for residential and commercial uses. (Lead times apply) Side and End entry Return Air Plenums also available. supply plenum has ample time to slowly mix with the return airflow. "The furnace has a negative pressure on the return air and a positive pressure on the warm air side. Lambro 4-in x 96-in Foil Flexible Duct. • • • • INSTALLATION TIP: If necessary, use a flat head screwdriver to slightly adjust the gap of the (S-Lock) RECEIVING EDGES to more easily accept the STRAIGHT EDGES. If so, did you perform a complete detailed cleaning of this plenum at the end of construction? You might be surprised how much. Our return air cabinets are made to fit stock sizing of basic home furnace filters. You have the duct connections to the plenum in addition to where the plenum attaches to the equipment. Amazon lists the TopTech 14″ UV light for $129. Return Air Elbows, Plenums & Canvas; Refine results Search. 17 in Air Handler Unit (1) 21 in Air Handler Unit (1) 4TGB 18 - 36 E Damper (1) Cooling Modular 2430 (1) GAF2 Series Air Handlers (1) M2430V1 Vertical Plenum Heating Air Handler Module (1) M3642V1 Vertical Plenum Heating Air Handler Module (1) PEFY-P24, P27, P30-NMAU-E2 City Multi Models (1) PEFY-P36, P48-NMAU-E2 City Multi Models (1). Down Flow Plenum Sliding Edge Seam Flanged Top : No. We own worldwide rights to this proprietary ActivePure ® Technology and it is the only Certified Space Technology that works to continuously clean and protect air and surfaces 24 hours a day. Uniform Mechanical Code - 2015, 2012, 2009, 2006 International Mechanical Code - 2015, 2012, 2009, 2006 Do Spears® CPVC products have other fire performance. 90% of return air ducts are the space between the wall studs an sheetrock. See illustration on next page. plenum by using a capillary tube or a special averaging wire approximately 15 to 25 feet long. Re- turn fans, on the other hand, must be located near the supply fan and upstream of the mixing plenum (Figure 1C). A person can be forgiven for not knowing much about their home's air duct system. Side-Feed Air Intake Plenum by Skunk2®. Plenums & Return Air. 3 only requires FT-4 except for voice and data wires which are required to be FT-6. Echoes Return Air Plenum reserves the right to change any information about this product, its design, configuration, materials, method of manufacture and price without prior notice, obligation or liability. 17-1/2" x 21" x 18" Return Air Box Plenum - R8 Lined Product Highlights A Return Air Box is the ducting that is attached to a furnace or air handler for that return air to flow through. Temp-Cool 14" Condenser Return-Air Plenum (CP-2B ) Description Reviews 14" Condenser Return-Air Plenum (CP-2B) For unit TC-18B The condenser return-air plenum allows supply-air to be ducted to the condenser coil. How can and attic be held to the same standard as a plenum when its used for storage and water heaters and such. Support feet or base; Return air grille between feet; Rear skirting support and rear painted panel; Single- or dual-deflection diffusion grille; Supply air plenum in kit for sizes 1 to 6 diameter 200 mm or 160 mm; Resilients mounts (lot of 4 pcs). Supply and Return Plenums: What do they do? Supply Plenum. The CE Code defines plenum as follows: Plenum—a chamber associated with air-handling apparatus for distributing the processed air from the apparatus (supply plenum) to the supply ducts or for receiving air to be processed by the apparatus (return plenum). Features & Benefits. I keep the house temperature at 69. An easy way to seal the base of the furnace. To measure the pressure drop over a return air ilter grille, use only one hose, pierce the ilter, the pressure drop over the ilter and grille will be displayed on the monometer. Picture a gas furnace or air handler and the attached duct system in your mind. Despite their name, it's also through these outlets that the air conditioner takes in air. Return vents don’t have louvers. Today a return air plenum is required to be insulated and sealed, and they are usually constructed of pieces of insulated duct board, taped and sealed. Check building codes to see if external insulation is required. As this high temperature/high pressure gas moves through the inside coil, the blower in the air handler blows cool inside air (cooler than the refrigerant) over the coil and the gas moving through the coil cools. You will oftentimes find air filters in the return plenum, because the air that's currently in your room is pulled in through this section of your system. They are designed to be used with multiple different brands and can be customized for your ductwork needs. com - Our plenums and fitler boxes are used to join your new units to your existing ductwork or for new construction. How to attach plenum to rear of air handler? I just bought a new house in Florida and it looks like the AC was installed incorrectly. 001 Family. 2 These cavities or spaces shall not be part of a required fire-resistance-rated assembly. designed and built Return Air Plenum (RAP) is easily installed with the matching. How to Size an Air Conditioner Return Air Duct x 144 square inches = return air duct in square inches. By and large, open plenum ceiling grid systems are intended to provide a low-cost air return solution for office spaces and buildings. Looking for SPACEPAK Plenum Duct, Square Fiberboard, 4 Ft. So to reply to your last post, yes, if this individual mechanical system is providing conditioned air to the Corridor ONLY, the return air can (and should. (311 Pa) in Plenum B. With our plate design we open up the plenum area to the starving rear cylinder by a full 20%. You need a load calculation to make sure the furnace is large enough to supply the new room. The acoustic plenum may be connected to a fan discharge or return opening to aid in the distribution of ventilation or conditioned air. This is most common in commercial buildings, schools, hospitals, or libraries. 1 friction rate. Outside Air. There is a 3/4" hem flange on one 25"x20" end Outside the plenum (around the flange) has dimensions 26-5/8 x 21-5. The common arrangement in commercial buildings is to use the space above a drop ceiling as a common air RETURN plenum. For most types of humidifiers, it really doesn't matter, notes Lewis. Duct & Duct Accessories. ducted and plenum return air systems to interzonal contaminant transfer and to investigate the impact of parallel fan powered VAV boxes on transport of contaminants from the plenum to conditioned space. 5 ton system. Any rooms with a lack of sufficient return airflow may benefit from relatively simple upgrades, such as the installation of new return-air grilles, undercutting doors for return air, or installing a jumper duct. I found the code that allows for zero crawlspace ventilation if there is a proper vapor retarder, insulated perimeter foundation wall and an HVAC supply and return. Plenum wrap is a blanket insulation that has a robust fire rating and is commonly used in plenum spaces. If the furnace is decommissioned and removed then I would think running through the duct wouldn't be a problem. A plenum box fits over the inside unit and is the first stage of the air supply. Return Air Drop - brings air from living space to air handler for conditioning and re-distribution. The return and supply flex ducts connect directly to the furnace - no sheet metal ductwork/plenum at all. Be careful not to tear the soft lining material. Environmental air, The Article in 450 does not apply to transformers in environmental air, otherwise we would allow transformers to be installed in metal ducted plenums which are void and empty as defined by the term hollow. 2 requires materials exposed to the airflow in ceiling cavity plenums used for supply, return or exhaust air from the occupied area to be noncombustible, limited combustible, or have a flame spread index not exceeding 25 and a smoke-developed index not exceeding 50. In homes with a single central return-air grille, return air often struggles to find its way back to the furnace. Furnaces and air handlers should have a return air plenum so that they can operate at their maximum efficiency. Hoods Ship in 3-5 Business Days. Duct work is sized according to CFM (cubic feet of air per minute) needed in a room. Alpinehomeair. Designed for heat pumps. designed and built Return Air Plenum (RAP) is easily installed with the matching. Unfortunately, the fresh-air intake you have described is the second type and does not provide direct combustion air to the furnace room, as it is directly connected to the return-air plenum for the furnace. 075 Family. Within air ducts, only specified air-monitoring instrumentation is allowable therein. This is the best configuration, and mandatory if the unit has a 5-ton blower. Clean the air filters. More return air can also improve indoor air quality. T … read more. It helps prevent negative pressure, while decreasing the “workload” on the portable air conditioner. This filter rack connects to the return side of the furnace or air handler. Johnson Controls M9208-GGA-2 - M9208 24V Proportional Spring Return Actuator w/ Plenum Cable (70 lb-in) - 24v Spring Return Actuator w/ Plenum Cable (70 lb-in) [pool1] Free shipping on orders over $99. See All Products. But when return air enters the furnace from both the side and the bottom (or both sides), airflow increases. Space between the structural floor and the dropped ceiling or under a raised floor is typically considered plenum; however, some drop-ceiling designs create a. White powder coat finish. The return air duct was fairly close to the wall. return air plenum for acoustical benefi t, the unfaced insulation has been tested according to UL 181 air erosion test and can be used for air velocities up to 1000 fpm. You can identify return vents by turning on the system fan and holding your hand or a piece of paper up. Plenum Innerduct is a supplier of Emerson Water Cooled Racks,Liebert Water Cooled Rack,Cool Therm Cabinet, Knurr Water Cooled Data Cabinet, Water Cooled Data Cabinets, Water Cooled Data Cabinet Supplier, Water Cooled Data Cabinet Supplier, Wholesale Fiber Optic Enclosures including Rack Mount enclosures, wall mount enclosures, Fiber Optic Patch Panels, 24 Port Fiber Patch Panels, server racks. For example, NFPA 90A Section 4. Return Air Elbows, Plenums & Canvas; Refine results Search. With some certainty the open air return system does not provide the asepsis ventilation requirements of most health care facilities licensed in the USA. Home / Plenums & Return Air. Stop in the shop, call us o. Looking for SPACEPAK Plenum Duct, Square Fiberboard, 4 Ft. 16x16x12 C-Box Ceiling Register Box is designed for a transition from round pipe or insulated flexible duct to an air register or grille. Designed for heat pumps. The theoretical mixed air temperature is found using the following equation: Tmix = Where: mhot = Hot air mass flow (lbs/min). Welcome to the eCommerce website for Benoist Brothers Supply Co. I'm not sure that making the plenum or return air inlet is the fix - but of course I cannot possibly be smarter than your onsite people who know the. I then manually type in an air flow value into the Air Terminal in order to put Return Air into the system. And then sending that bad air right into the home for the lucky family to breathe. Our Type 1 Hood is designed for use over cooking equipment to remove heat, smoke and grease laden vapors. Return air temperature is nothing but the room temperature which is normally from 22 to 26 Dec C, in duct return system, room temperature is equal to on-coil temperature. 4001 Mark IV Parkway Fort Worth, TX 76106 Phone: 817-336-2311 Fax: 817-625-0756. In Phoenix, our homes are being built with these gizmos typically attached to a special filter on the return air filter grille plenum (with a small air filter inside it). indicated in UFC 4-510-01; Computed on a per-occupant basis, minimum outside air ventilation shall meet the worst-case requirements of either UFC 4-510-01, or ASHRAE Standard 62. This fresh air will enter the air circulation system of the heating system, which is separate from the combustion chamber on your furnace. Concentric supply/return diffuser with plenum. do we expect that the cooling coil entering dry bulb temperature will be the same or not?. A plenum, whether underfloor or above the ceiling, is used as a large air supply or air return space. 1 Return air systems. o The Return Plenum is at the end of the return duct system (behind the filter). Easy online ordering for the ones who get it done along with 24/7 customer service, free technical support & more. Price $361. 5-in x 21-in x 28-in Return Air Box Assembly Duct Plenum Lambro Rigiflex 4-in x 96-in Aluminum Semi-rigid Flexible Duct Lambro 4-in x 96-in Foil Flexible Duct IMPERIAL 6-in x 300-in Insulated Polyester Flexible Duct. Side-Feed Air Intake Plenum by Skunk2®. Your order will also include Alpine's exclusive free instructional video on DVD!. Description: Plenum Return Silencers are designed to fit into standard 2' x 2' ceiling grid systems. Get free shipping on qualified Plenums & Air Returns or Buy Online Pick Up in Store today in the Heating, Venting & Cooling department. Condenser return air plenum allows for connection to space outside of the conditioning area for more efficient cooling. Environmental air, The Article in 450 does not apply to transformers in environmental air, otherwise we would allow transformers to be installed in metal ducted plenums which are void and empty as defined by the term hollow. The space providing air is called a supply plenum and the space providing air return is referred to as a return plenum. Diameter Inlet Flange, Reusable Cotton Element, Kit ( 13 ) Part Number: SPE-733 More Detail. This area is the chamber behind or below the air filter depending on if the filter is located behind the grill or located under the air handler unit. Return air temperature is nothing but the room temperature which is normally from 22 to 26 Dec C, in duct return system, room temperature is equal to on-coil temperature. Furnace Return Air Plenum Fabrication - Duration: 16:43. (5 Pa) relative to the space for Application 5 and 0. This is an undesirable setup, for a number of. During a major energy upgrade that we recently completed, we had two return ducts- a 14" in the main house and a 12" return duct in the master bedroom. Installing a restricting hand damper in the bypass is the perfect way to ensure sufficient differential pressure across the bypass duct and proper mixing of bypass air with return air. Depending on the type of furnace in your home, the plenum is secured to either the top of the furnace or over the supply air opening with sheet metal screws. I don't have a digital copy of the Building code to past here. PRIMARY AIR SYSTEMS – TECHNOLOGIES • Bypass Central Station Units Underfloor Air Highways Pressure Control Dampers • Air Towers (Column Fans) Direct. For Model(s): Office Pro 18 (OP18). 6 out of 5 stars 157 $21. Flame spread and smoke development requirements are generally irrelevant to pipes outside a return air plenum. Nailor Plenum Slot Diffusers are designed to integrate and blend with T-Bar suspended grid systems, available for Standard Lay-in and Narrow Regressed T-Bar systems. All brands of furnace and air handler have a side cut-out to accommodate return air plenums or cold air boots to fit common filter sizes i. Slams: Your air filter could be restricting airflow. Homeowners will need to pay attention to what size supply air plenums correctly attach to their furnaces. This Spectre Air Intake Plenum has a single inlet with a 4 inch outside diameter. •a pair of offset transfer-air grilles in room walls that connect to hallways, or other open spaces directly linked to the central return • short "jump ducts" (typically located in ceilings) that allow room air to flow back to hallways • any method of pressure balancing that, during operation of the HVAC blower, creates no more than a 2. FREE Shipping by Amazon. 49-52) by author David Dykeman. Tractorman44 6,599 How to prepare the plenum adapter for smaller or bigger size air handler - Duration: 6:02. At Budget Heating and Air Conditioning Inc. Plenum for Linear Slot Diffuser. For more information on duct cleaning or if you have questions about musty odors in your return air ducts, contact the expert staff at Air-Tro, Inc. COURSE CONTENT 1. You agree to comply with all applicable export and re-export control laws and regulations, including the Export Administration Regulations maintained by the U. X 2020-06-22 - IAC Acoustics is open for business. You can contact us or ask your home heating expert to find which return air plenum and filter. 1 Materials exposed within plenums. Simply enter your zip code and the square footage, next click update and you will see a breakdown on what it should cost to have Return Air Plenums installed in your home. Products by page Previous. A plenum may also be under a. FR1625 - 16″ x 25″ x 1″ External Filter. Most of the time, the desire to reduce costs and an increased ease of maintenance will lead to the elimination of most of the conduit used for these cables in favor of j-hooks, cable trays, or other open air hangers. The Reflectix® RAP Return Air Duct Panning is an excellent alternative to conventional sheet metal and corrugated aluminum panels for return air ducts. We are a full line wholesaler of commercial and residential HVAC products and equipment for the heating and air conditioning industry. There is an HVAC supply and return in the crawlspace. • Velocity Pressure – The forward moving force of air within a duct, measured in inches of water column. Starting at the supply side duct connection of the equipment we have a plenum attached to the equipment with the potential for leaks. The beautiful face of a modern HVAC system is often a Linear Slot Diffuser. Plenum spaces are the open spaces above the ceiling or below the floor that are used for air circulation. Cross Section: Square / Rectangular; Inlet Placement: End; Mounting / Attachment Features: Other. The ability to util ize air-handling spaces for cable and equipment installation without conduit lowers cost. Anything installed in a plenum must be plenum rated or made of metal (no burn. 14 = return air duct in square inches. 2 Return Air Duct Installation Sizes (Based on. A calibrated blower was attached to a return grill of the air-distribution system to measure the leakage of the air-distribution system, or a portion of that system. ducted air returns with higher static pressures and fan horsepower in open-plenum systems. That was for a 1. For example, NFPA 90A Section 4. In these homes, builders sometimes install a furnace or air handler right on the return plenum, which is ducted to the central return or, occasionally, a hole in the wall with a grille on the other side. Spectre Air Intake Kits are universal and designed to fit a number of applications. Air-handler platforms used as return-air plenums can draw air from vented attics and crawlspaces through other connected framing cavities. Maintaining Your HVAC Plenum. Plenums & Return Air. Combustion Air Duct Connected to the Return Plenum By Reuben Saltzman In Combustion Air Ducts , HVAC On April 9, 2013 Two of my recent blog posts have been about the need for combustion air ducts and common problems with. Brand National Air Parts. He gave me a lot of very helpful information and advice. See illustration on next page. Alpine's return air plenums are manufactured with a 1 inch filter rack as part of the plenum, and include one appropriately sized filter. It is made from inorganic fibers that are encased in a scrim-reinforced foil, and it can withstand exposure to flames for 1-2 hours. Does an attic-mounted air handler require a return air plenum mounted between the duct work and the unit if your duct work is mounted directly to the return side of the unit the supply side has. There is a 3/4" hem flange on one 20"x20" end Outside the plenum (around the flange) has dimensions 21-5/8 x 21-5/8" and height 5-1/8" , and the other side is fitted with an end cap with a 18" collar. Optional Liebert Air Economizer™ for Liebert CW Figure B-1 Liebert Air Economizer ducting data Outdoor Relief Opening ROOM RETURN (by others) Return Air Sensors (Field install above damper) RELIEF AIR Room Relief Air Discharge Plenum (Sized and provided by others) Outdoor Air Sensors (Field install inside duct) Filter. It helps prevent negative pressure, while decreasing the “workload” on the portable air conditioner. Positioned directly above return grilles, the RAC prevents the transfer of occupant noise into the plenum above and prevents mechanical noise in the plenum from flanking through return grilles, or open vents. commissioned its sheet metal shop in downtown Cincinnati and Seal-Tite® was born. All Return Air Cans are manufactured from the highest of quality galvanized steel. Cresline Plastic Pipe Co. When eliminating other factors, such as the overall increase in the number of travellers using air transport, the launch of new flight connections and various discounts, the. You can contact us or ask your home heating expert to find which return air plenum and filter. 3 only requires FT-4 except for voice and data wires which are required to be FT-6. Long flex-duct runs can restrict air flow, so they must be installed carefully. Add to wishlist. Holes, usually 2, are cut out of the box. Hello Baltien and welcome to the How-to-Community. Constructe d of select grade materials and assembled to precise specifications WoodAirGrille Return Air Filter Grilles are ready to finish with your favorite paint or stain. “And when you're running air through both supply ducts and return air ducts, the sheer friction of the duct requires higher fan horsepower. Some cities like Vancouver require all jacketed cables to be FT-6 in a return air plenum of a non-combustible building but 3. Corporate Headquarters. Easy online ordering for the ones who get it done along with 24/7 customer service, free technical support & more. Return Air Plenum Space. Supply and Return Plenums: What do they do? Supply Plenum. This air handler has a desiccant wheel so it has a built-in energy recovery system. If a homeowner is unsure, the contractor hired to install the supply air plenum will be able to assess the system. This fresh air will enter the air circulation system of the heating system, which is separate from the combustion chamber on your furnace. METALAIRE is the flagship brand of Metal Industries Inc. I needed this for a large model I doing to post. Original Poster. Louis Hearn. When return-air plenums are installed, it results in energy loss, an increase in energy bills and a less efficient HVAC system. Alpinehomeair. Locate your plenums. T … read more. Air-handler platforms used as return-air plenums can draw air from vented attics and crawlspaces through other connected framing cavities. Corporate Headquarters. the whole of space regarded as being filled with matter (opposed to vacuum). 49-52) by author David Dykeman. Installing a restricting hand damper in the bypass is the perfect way to ensure sufficient differential pressure across the bypass duct and proper mixing of bypass air with return air. For Daikin: FDYQ200LBV1 & FDYQN200LBV1. It's better. With these roof curb equipment rails it is simple and quick to mount and secure condensing units to the roof of a metal builiding. Ventilation - Systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more; Related Documents. Unfortunately, the fresh-air intake you have described is the second type and does not provide direct combustion air to the furnace room, as it is directly connected to the return-air plenum for the furnace. It is made from inorganic fibers that are encased in a scrim-reinforced foil, and it can withstand exposure to flames for 1-2 hours. 5 in Winchester residential electric furnace application with this easy to assemble return air box. But when return air enters the furnace from both the side and the bottom (or both sides), airflow increases. T … read more. Add to wishlist. PLENUMS 602. When the combustion air duct is connected directly to the return plenum for a furnace, the blower fan on the furnace pulls outdoor air in to the return plenum. (Fittings) Therefore, all FlowGuard Gold pipe and fittings are acceptable for use in return air plenums. This Spectre Air Intake Plenum has a single inlet with a 4 inch outside diameter. Corrective measures are also suggested. Flexible duct can be installed in place of galvanized pipe in many applications if allowed by your local HVAC codes. Page 1 of 2 - Plenum cable for cold air return? - posted in Home Automation: I'm starting to run some low voltage wire for motion detectors, door/other sensors, network, cable TV, etc. The negative pressure is created by an opening into the plenum from the return side of the rooftop unit, and perforated openings or grills in the ceiling plane admit the return air from the occupied space. Does anyone know of an insulation product to be spray applied to the underside of a metal deck, in a return air plenum? This is a LEED project. Author: Blake ShurtzMuch like the recommendation to install dampers, I almost always emphasize adding a second return when replacing ductwork. Hello Baltien and welcome to the How-to-Community. An open-air return permits air to cycle into the plenum, but it also allows sound and conversations to pass with it. Buy your Plenums and Filter Boxes online with HVACDirect. This is a good model for a 2 x 2 ceiling grid. ducted air returns with higher static pressures and fan horsepower in open-plenum systems. Dropped ceilings or suspended ceilings are often installed so that the space between them and the floor above or the roof deck can be used as a return air plenum. I then manually type in an air flow value into the Air Terminal in order to put Return Air into the system. 5 ton system. 1, item 1, allows that assemblies which have been shown to meet the requirements of ASTM International E119, Standard Test Methods for Fire Tests of Building Con-struction and Materials, fire test or equivalent without ceiling radiation dampers may be left unprotected. Positioned directly above return grilles, the RAC prevents the transfer of occupant noise into the plenum above and prevents mechanical noise in the plenum from flanking through return grilles, or open vents. Discussion. FDXS 50F Return Air Plenum. The velocity of the overall air movement within the two spaces would be substantially different at the same CFM. After the air is conditioned, a blower or air handler blows the air through supply ductwork, which delivers it to rooms throughout your house, where it emerges from registers and vents. Some level of positive differential pressure in the data center is not necessarily a bad thing as it helps with moving the air into IT cabinets while using strategies such as hot aisle containment. Be careful not to tear the soft lining material. Looking for SPACEPAK Plenum Duct, Square Fiberboard, 4 Ft. Without a return air duct, the air would not properly circulate and your energy costs would rise. 17 in Air Handler Unit (1) 21 in Air Handler Unit (1) 4TGB 18 - 36 E Damper (1) Cooling Modular 2430 (1) GAF2 Series Air Handlers (1) M2430V1 Vertical Plenum Heating Air Handler Module (1) M3642V1 Vertical Plenum Heating Air Handler Module (1) PEFY-P24, P27, P30-NMAU-E2 City Multi Models (1) PEFY-P36, P48-NMAU-E2 City Multi Models (1). Plenum-rated cable gets its name from an HVAC term—plenum spaces. If on a plenum you may be able to lower the return plenum height as long as it is of adaquate size for the return giving you enough space for your supppy connection OR can your cased coil (a frame I suspect) AND furnace be placed horizontal (Coil has to be made for it with an alternated condensate drain. Return Air Cans the fitting to use when you need to put a return air register in the wall or ceiling to return the air to your furnace. As an experienced licensed home improvement contractor, I know first hand what it should cost for various levels — from Basic, Better, and of course the best. (Pipe) NIBCO Inc. See All Products. 8 out of 5 stars 87 $41. Manufactured from polished cast aluminum, this plenum is designed to be compatible with Spectre 4 inch tubing, filters, and accessories. So to reply to your last post, yes, if this individual mechanical system is providing conditioned air to the Corridor ONLY, the return air can (and should. Miro Czernek 12,952. This is a 25"x20" Sheet Metal return air filter rack plenum. Ceiling tile barriers and light hoods reduce sound transmission and cross talk when using in ceiling grids and plenum spaces. The Air-Boss VP is an internally elevated plate designed to flow as much air as possible to cylinders 4, 5, and 6. Lightweight and easy to install, this innovative product provides an economical solution for return air noise and improved speech privacy. Page 1 of 2 - Plenum cable for cold air return? - posted in Home Automation: I'm starting to run some low voltage wire for motion detectors, door/other sensors, network, cable TV, etc. It fits carburetors and TBI throttle bodies with a 5-1/8 inlet. The Low-Static Horizontal Ceiling-Recessed Rear Return-Air Plenum (LH-R) comes with a coil, blower/motor assembly with quick-connect plug and a galvanized steel, powder-coated epoxy drain pan covered with ⅛-inch thick insulation. October 26th, 2015. (12 Pa) for Application 7. In this case, the return is in the return chase downstream of the filter and the OSB subfloor is saturated at the supply. Where installed in an air-handling space (not in conduit), these cables and supports are required to be plenum rated. A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric. The beautiful face of a modern HVAC system is often a Linear Slot Diffuser. So to reply to your last post, yes, if this individual mechanical system is providing conditioned air to the Corridor ONLY, the return air can (and should. Despite their name, it’s also through these outlets that the air conditioner takes in air. This is most common in commercial buildings, schools, hospitals, or libraries. There's such a volume of air coming down through that duct into the house when the furnace isn't running that I think it's even passing through the furnace filter and through the return air plenum which is right below the furnace. Department of Energy. Hovercrafts fill plenum chambers with air when they hover above the sea or land. If the above grid AC unit pulls return air from the office space below, through a ducted return air grill, then the return air does not circulate among the wiring methods above ceiling. Positioned directly above return grilles, the RAC prevents the transfer of occupant noise into the plenum above and prevents mechanical noise in the plenum from flanking through return grilles, or open vents. He argued that we need to have more stringent fire and smoke testing standar. Flexible Acoustical Sound Boot for Return Air Grilles FlexaBoot is an inexpensive, lightweight, and flexible acoustical sound boot for return air grilles that eliminates sound transfer in open plenum ceilings. This is a 20"x20" Sheet Metal return air filter plenum. Space between the structural ceiling and the dropped ceiling or under a raised floor is typically considered plenum; however, some drop-ceiling designs create a. 3 only requires FT-4 except for voice and data wires which are required to be FT-6. Technically, any ductwork is considered a plenum space too. In the case of single-story malls, a return air plenum has the advantage of heating the ceiling space and keep the plumbing pipes from freezing. Get 2020 Return Air Plenum price options and installation cost ranges. There is an HVAC supply and return in the crawlspace. Depending on the type of furnace in your home, the plenum is secured to either the top of the furnace or over the supply air opening with sheet metal screws. 14" X 14" Steel Return Air Filter Grille for 1" Filter - Removable Face/Door - HVAC Duct Cover - Flat Stamped Face -White [Outer Dimensions: 15. Diesel Ops is committed to providing our customers an unparalleled shopping experience. Low voltage wiring in HVAC return duct. Made in America by hand from American made 24 Gauge Steel Galvanized Sheet Metal ( heavy duty housing and rails 24 Gauge Steel ). So to reply to your last post, yes, if this individual mechanical system is providing conditioned air to the Corridor ONLY, the return air can (and should. Article codes:. Every forced air heating and air conditioning system requires a filter of some kind to protect the equipment. View; List; Grid Add to cart. Some rooms may also be hard to heat and cool because of inadequate supply ducts or grilles. Re: When is a drop ceiling considered a plenum? Plenum. The Low-Static Horizontal Ceiling-Recessed Rear Return-Air Plenum (LH-R) comes with a coil, blower/motor assembly with quick-connect plug and a galvanized steel, powder-coated epoxy drain pan covered with ⅛-inch thick insulation. Compatible with the following: Glacier Aire 3. 1 Materials exposed within plenums. (And when I say lucky, I mean the opposite. 8 out of 5 stars 87 $41. 1) Where: L = the thickness of the wall in inches. Starting at the supply side duct connection of the equipment we have a plenum attached to the equipment with the potential for leaks. "More than a 90-percent increase in return air tickets from abroad to Bratislava and Vienna is really unprecedented and there is no other explanation," said Jozef Rybar, PR manager of Pelikan, as quoted in a press release. Within air ducts, only specified air-monitoring instrumentation is allowable therein. A plenum space is a part of a building that can facilitate air circulation for heating and air conditioning systems, by providing pathways for either heated/conditioned or return airflows, usually at greater than atmospheric. Non-Ducted Return Closet Installation The air handler can be installed in a closet with a false bottom to form a return air plenum or be installed with a return air plenum under the air handler. Plenum and Return Air boxes are the source to attach the ductwork connections to. COURSE CONTENT 1. Tractorman44 6,599 How to prepare the plenum adapter for smaller or bigger size air handler - Duration: 6:02. Get 2020 Return Air Plenum price options and installation cost ranges. Price $361. Higher priced Return Air Plenums typically offer more durable material, extended warranties and enhanced appearance and finish options Return Air Plenum installation costs are commonly quoted from a standard rate and can be estimated/quoted by the service professional after measurement and visual inspection at the job site. The return air plenum must be air sealed so that the only air that enters the plenum is air coming from the house through the filter-backed grille. It made a huge difference, dropping the pressure in the bedroom (relative to the hallway) from about 6. ducted air returns with higher static pressures and fan horsepower in open-plenum systems. There is an HVAC supply and return in the crawlspace. Single Spigot. Diesel Ops is committed to providing our customers an unparalleled shopping experience. If the furnace is decommissioned and removed then I would think running through the duct wouldn't be a problem. Show items: 30; 60; 90; Cold Air Boxes & Return Air Plenums Reviews. The Air-Boss VP is an internally elevated plate designed to flow as much air as possible to cylinders 4, 5, and 6. Rectangular supply air sleeve for direct distribution in soffit; Factories accessories supplied in kit. Inspected this house this morning. By and large, open plenum ceiling grid systems are intended to provide a low-cost air return solution for office spaces and buildings. return air plenum for acoustical benefi t, the unfaced insulation has been tested according to UL 181 air erosion test and can be used for air velocities up to 1000 fpm. These holes, typically 12” or 14” diameter round are cut out by the HVAC contractor during the install. 2006 IBC, IMC. The perfect way to get the conditioned air to your grilles. But when return air enters the furnace from both the side and the bottom (or both sides), airflow increases. In an effort to meet IMC 602. The return inlet airflow values shown in Figure 1 are airflows required when the VAV boxes are at maximum cooling and the return fan is operating at maximum design airflow. Importance of. 1) Where: L = the thickness of the wall in inches. Sometimes the Happy Harry Homeowner just cannot help themselves. Electrical wiring methods used in these areas should neither add to the fuel load of a. PRIMARY AIR SYSTEMS – ISSUES • Required Supply Air Dry Bulb Temperature • Required Supply Air Dew Point Temperature • Required Plenum Pressure • Adequate Supply Air Distribution 28. I am trying to create a return air system where the room air enters a return air grille, flows through a duct, enters a plenum box where it is mixed with the outside air, passes through a short flexible connection and then enters the return air spigot of the fan coil unit. Does adding a cold air return help with a cold basement? Yes, it does, but adding a heat run is a must. 6 out of 5 stars 157 $21. The supply side diffusers require insulated plenum boxes to deliver the air,. Theoretical Mixed Air Temperature: The mixed air temperature based on a calculation of the combined mass flow of two air streams. "The furnace has a negative pressure on the return air and a positive pressure on the warm air side. The flex-duct must also not be pinched or constricted. Metal is used and insulated on the supply side because of condensation, there isn't any. Even if return air openings to the plenum are generously sized, a congested return air plenum will restrict airflow and may still result in undesirable airflow patterns as noted in Item 1. Constructe d of select grade materials and assembled to precise specifications WoodAirGrille Return Air Filter Grilles are ready to finish with your favorite paint or stain. The study attributed the energy performance advantage of suspended ceilings to the use of a return air plenum with low static pressures and fan horsepower vs. 7 Stud wall cavities and the spaces between solid floor joist to be used as air plenums shall comply with the following conditions: 7. the position of the return and exhaust air dampers, to exhaust the proper amount of air. Picture a gas furnace or air handler and the attached duct system in your mind. From standard grilles and registers, to its architectural line of Formations® linear slot diffusers, along with a newly released series of displacement diffusers, METALAIRE has the air devices to meet every need. I also have a regular 1" filter downstairs at the return air intake. com - Our plenums and fitler boxes are used to join your new units to your existing ductwork or for new construction. The plenum spaces are those that lie between a drop and standard ceiling (or a similar version in the floor space) and it is this section where the air in a building circulates, thus aiding in heating and cooling functions. Hissing: Leaks from the air ducts will create hissing sounds. 5 in Winchester residential electric furnace application with this easy to assemble return air box. Plenum air in most VAV box applications is also, usually, the return air for VAV air handling unit. Return Air Plenum. The contractor that installed the system used nothing but flex duct throughout. Despite their name, it's also through these outlets that the air conditioner takes in air. First, calculate the percent of outside air compared to system airflow by dividing the outside air CFM by the total supply airflow. Add to wishlist. I have a wood burning stove heating up my basement but the heat can't get to the upstairs because of the home design. These ducts typically start with vent grates in the wall, on the ceiling, or in the floor. Pressure – Air outlet pressure data is required to properly size the air delivery system within a building. Perimeter Return Air Access Panel for Heat Pump with Hinged Door - Keylock. These air-flow silencers are designed to reduce the office to office and mechanical noise caused by standard plenum openings in a ceiling system. MFR: DFP202530-R6-1-1. Modifying Your Fire Protection System When Using A Return Air Plenum June 17, 2015 June 22, 2015 staff To combat heating challenges in today's mission critical facility, consideration is often given to using the space above the suspended ceiling as a return air plenum. § The purpose of this Plenum is to create an equal flow and pressure across the filter (which is sized according to the cooling capacity of the air conditioning system). Should the system have an outside air intake, you must reduce the amount of required return air into each return grille and duct to provide for the outside air entering the return side of the fan. Major remodel of a single story building w/ full basement, non sprinklered, type V-B, proposed B occupancy. Furnace Return Air Plenum Fabrication - Duration: 16:43. We designed this plenum wrap as a strong, lightweight and flexible material for easy installation. Flexible Acoustical Sound Boot for Return Air Grilles FlexaBoot is an inexpensive, lightweight, and flexible acoustical sound boot for return air grilles that eliminates sound transfer in open plenum ceilings. When these return air volumes are associated with variable supply air volumes for a given area, the ability to balance these return inlets requires some thought and evaluation. In homes and businesses, a plenum chamber is an alternative to traditional duct-based ventilation systems. It plays a vital role in the home's forced-air heating and cooling system, performing its job quietly and without much attention. These return air grilles feature 27° down deflection with a turnback frame and countersunk screws. Selkirk Canada Corporation. The return air duct was fairly close to the wall. AIR CUTOUT, and will be used later to attach the return air drop. The negative pressure is created by an opening into the plenum from the return side of the rooftop unit, and perforated openings or grills in the ceiling plane admit the return air from the occupied space. The flex-duct must also not be pinched or constricted. Air-handler platforms used as return-air plenums can draw air from vented attics and crawlspaces through other connected framing cavities. Which means that it's under negative pressure. Beamgrid® is available in a range of cross sections and module sizes which can be selected to suit the scale of the space. More return air can also improve indoor air quality. T … read more. 4 Ambient Design Dry and Wet Bulb. Idle, shunting, heated plenum and loosing the plot. Thanks! John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1103 Registered: 03-2002. We sell a comprehensive range of air plenum boxes to suit Daikin split system and VRV ceiling concealed ducted air conditioning systems. This Spectre Air Intake Plenum has a single inlet with a 4 inch outside diameter. There are also ready-made plenums of sheet metal. The ideal way to introduce outside air is to first duct the return air to the air handler. This return air package features the return air plenum with 1" filter rack and ships knocked down in one carton. Does a furnace cold air return duct have to be ducted to the heated air space of a home? Yes. 3 only requires FT-4 except for voice and data wires which are required to be FT-6. 0 reviews write a review. Particle Diameter - Strainer and filter - mesh size vs. I needed this for a large model I doing to post. Brand new in the box; fits John Deere 102, 115, 125, 135, 145, 155C, 190C, X110, X120, LA105, LA115, LA125 (taken from John Deere part site. 1-2007 and 2010; 2009 and 2012 IMC Table 6. Short answer: I don't. This is an undesirable setup, for a number of. For instance a 2. Clean off the surface. Supply Boots / Return Boxes At Budget Heating and Air Conditioning Inc. Where installed in an air-handling space (not in conduit), these cables and supports are required to be plenum rated. Typically a plenum is relatively large in volume and thus has relatively low velocity (compared to other components of a system). Brand: Bosch. About the Product: The Reflectix® RAP Return Air Duct Panning is an excellent alternative to conventional sheet metal and corrugated aluminum panels for return air ducts. 16×25, 16×24 and 16×20. Therefore, with a centrally located air handler, this duct system can be installed in homes up to approximately 50 feet long. Louvers or return air grilles are field supplied. The plenum and cold air drops in this case were pretty big it's why an installer used these complicated transitions. In wood frame construction, it may be used to enclose the bottom of return air plenums, between the joist spaces, stud cavities, and wall ceiling cavities. FAN WALL air handlers can be designed to fit in a space that would be impossible for any other air handling unit. A cold duct can be put between the studs in your wall. Conversely, in return plenum the air is generally ducted to the space, whilst the return air is extracted through the plenum. Buy your Plenums and Filter Boxes online with HVACDirect. They work in both residential and commercial settings, and are used for both supply and return air. One of the most common questions is where to mount it — on the return or supply side. What is often overlooked is the need for speech privacy and sound control. ducted air returns with higher static pressures and fan horsepower in open-plenum systems. San Diego, Orange County, San Bernardino, Riverside Jake Gaeta Director of Business Development [email protected] If the paper is pulled toward the. If there is a common plenum above the ceiling, then return air can be pulled from rooms through open return air grilles in the ceilings and back to the mechanical equipment room without the cost of rigid, return-air ductwork. Description: Plenum Return Silencers are designed to fit into standard 2' x 2' ceiling grid systems. Price $361. There's such a volume of air coming down through that duct into the house when the furnace isn't running that I think it's even passing through the furnace filter and through the return air plenum which is right below the furnace. One reason is the use of a return air plenum with low static pressures and fan horsepower instead of a ducted air return with high static pressures and fan horsepower. SUPPLY AND RETURN PLENUMS The Kooltech range of supply and return plenums are specifi cally manufactured to suit Mitsubishi Electric’s range of ducted air conditioning. (the larger line) and toward the inside coil (the finned-tube coil located in the supply plenum of the air handler/plenum assembly). Alpine AG RPL2516 25 x 16 Return Air Plenum. Add to cart. For most types of humidifiers, it really doesn't matter, notes Lewis. GMS8 Furnace pdf manual download. A return air plenum is the ducting that is attached to a furnace for that return air to flow through, and is used as a central manifold for other return air ducting. The exception to 300. Page 1 of 2 - Plenum cable for cold air return? - posted in Home Automation: I'm starting to run some low voltage wire for motion detectors, door/other sensors, network, cable TV, etc. SYSTEM XFR DWV PIPE AND FITTINGS. Spread the love. The Return Air Plenums estimator will provide you with up to date pricing for your area. In the Spring of 1900, the Peck-Williamson Heating Co. Heat Conduction and Thermal Resistance For steady state conditions and one dimensional heat transfer, the heat q conducted through a plane wall is given by: q = kA(t1 - t2) L Btu hr (Eq. Looking for SPACEPAK Plenum Duct, Square Fiberboard, 4 Ft. An air return duct is basically a concealed air passageway in a home or other building that acts as a channel for pumping air out of an enclosed room and into the air conditioning or central heating system. The plenum spaces are those that lie between a drop and standard ceiling (or a similar version in the floor space) and it is this section where the air in a building circulates, thus aiding in heating and cooling functions. Then duct the outside air into the return duct. When eliminating other factors, such as the overall increase in the number of travellers using air transport, the launch of new flight connections and various discounts, the. This is most common in commercial buildings, schools, hospitals, or libraries. Contact a Location Arizona Lake Havasu City, Arizona 928-846-8707 Peoria, Arizona 480-385-1380 California Anaheim, California 714-933-1777 Chatsworth, California 818-884-1100. HVAC Return Air Filter Box: Custom A/C return air ductThe project started when I decided to install central air in my house. These holes, typically 12” or 14” diameter round are cut out by the HVAC contractor during the install. The CE Code defines plenum as follows: Plenum—a chamber associated with air-handling apparatus for distributing the processed air from the apparatus (supply plenum) to the supply ducts or for receiving air to be processed by the apparatus (return plenum). As freshly conditioned air is blown out of the. designed and built Return Air Plenum (RAP) is easily installed with the matching. (Lead times apply). Plenums & Return Air. Relief fan location flexibility is particularly advantageous for large built- up systems. I wonder if the NEC definition of the word 'plenum' would actually apply to the entire attic space. This plenum or drop is usually attached to the side of the furnace or appliance with a filter rack and filter. (It must be. The system is having a hard time keeping up even in milder near freezing weather. 2 Next Reply Author. You need a load calculation to make sure the furnace is large enough to supply the new room. 2 and when used in noncombustible construction, high buildings and air plenums, they shall be tested and listed in accordance with CAN/ULC S102. Home / Plenums & Return Air. A plenum may also be under a. It can be installed in suspended ceiling systems by simply laying the product on top of the ceiling panels. No radios or storage. Where installed in an air-handling space (not in conduit), these cables and supports are required to be plenum rated. This is a 25"x20" Sheet Metal return air filter rack plenum. Supply air to vents is typically ducted. In the first winter of operation snow restricted air flow through the filters, eventually causing the building. Shop online now or apply for an online account today. Current Code Requirements 2018 Uniform Mechanical Code, Section 602. Description:. Generally, a return air plenum will cost approximately $50 to $60 per unit. Return Air Drop - brings air from living space to air handler for conditioning and re-distribution. 3 only requires FT-4 except for voice and data wires which are required to be FT-6. Article codes:. First, calculate the percent of outside air compared to system airflow by dividing the outside air CFM by the total supply airflow. Plenums & Return Air. Here we have 14 images about Return Air including images, pictures, models, photos, etc. A friend of mine just had a complete system changeout and his contractor put an Aprilaire model 700 (fan-powered) humidifier on the return air drop even though there was a brand new supply air plenum on top of the furnace. The velocity of the overall air movement within the two spaces would be substantially different at the same CFM. I was told by a HVAC contractor today that I only need the 4" filter and that having both filters will put extra strain on the blower and is bad. In homes and businesses, a plenum chamber is an alternative to traditional duct-based ventilation systems. Return air plenum with Hinged eggcrate Grill Filter N 900 x 550 F 950 x 550mm. 62/in) Get it as soon as Thu, Jun 18. Filter frame is the sheet metal profile that is normally placed in between the unit and the return duct (plenum). Holes, usually 2, are cut out of the box. How do I mount an air conditioning condensing unit to a pitched metal roof? Roof Mounted Condensing Unit Equipment Deck Mounting Platform for Pitched Metal Roof. You have the duct connections to the plenum in addition to where the plenum attaches to the equipment. Contact a Location Arizona Lake Havasu City, Arizona 928-846-8707 Peoria, Arizona 480-385-1380 California Anaheim, California 714-933-1777 Chatsworth, California 818-884-1100 Chino, California 909-267-1124 El Cajon, California 619-566-8130 Escondido, California 760-233-2545 La Habra, California 562-257-1133 Laguna Hills, California 949-598-8333 Oceanside, California 760-797-6234. 2 and clearly marked with the certification logo indicating a Flame Spread Rating not more than 25 and a Smoke Developed. Once the dampness is separated from the air, your AC unit cools the warm air, and sends it back into your home through the return air vents. A plenum space is the part of a building that enables air circulation by providing pathways for HVAC and return airflows at a higher pressure than normal. 5 ton system and the static was 0. A return air plenum is the ducting that is attached to a furnace for that return air to flow through, and is used as a central manifold for other return air ducting. Easy to install, the plenums are manufactured to the highest standard from lightweight ABS construction. It fits carburetors and TBI throttle bodies with a 5-1/8 inlet. 24", 36", or 48" long metal plenum with (1) end cap. While none of these spaces makes an acceptable air pathway on its own, some building cavities, such as floor joists, can make acceptable duct chases to contain an insulated, air-sealed, metal, or flex supply. Since 1946, Southwark Metal Manufacturing has established itself as one of the largest manufacturers of HVAC sheet metal pipe, duct, and fittings for residential and light commercial applications. 2018 Uniform Mechanical Code, Section 602. The back of the cans are flat sheet. Introducing Outside Air When outside air is introduced into a mechanical room that acts as a return air plenum, it will cause the equipment and ductwork to sweat. Return air duct in the ceiling plenum of the floor below the roof shall be insulated. Allows air to circulate directly from the furnace before the air is released into your ventilation system. A reducing plenum system uses a trunk reduction periodically to maintain a more uniform pressure and air velocity in the trunk, which improves air flow in branches and runouts closer to the air handler. It allows the system ductwork to be conveniently connected to the air h. A supply air plenum is a metal box that can be attached to the outlet of a furnace. Dropped ceilings or suspended ceilings are often installed so that the space between them and the floor above or the roof deck can be used as a return air plenum. Concentric supply/return diffuser with plenum. 7 Pascals (Pa) to about 1. The plenum and cold air drops in this case were pretty big it's why an installer used these complicated transitions. You'll even find cable that is "plenum rated" -- which means it has a lighter jacket on it -- that is specifically meant for use in plenums where it's less likely to encounter sharp edges or be overly stretched during pulls. Cable that is run in the plenum spaces of buildings. Plenum for Linear Slot Diffuser. Space between the structural floor and the dropped ceiling or under a raised floor is typically considered plenum; however, some drop-ceiling designs create a. Add to cart. Temperature-tolerant products, like plenum-rated cable, reduce the need for costly metallic conduit. Return Air Plenum Space. Alpine's return air plenums are manufactured with a 1 inch filter rack as part of the plenum, and include one appropriately sized filter. Supply and Return Plenums: What do they do? Supply Plenum. This is most common in commercial buildings, schools, hospitals, or libraries. Corporate Headquarters. 212 Plenum Corners - 60" Lengths: No. The path for return air is one of the most important aspects to consider when designing a low pressure supply air plenum system. Plenums & Return Air Products Shipped knocked down - 4 sides and top Plenums are made to your exact # ˘ ˘ W equipment without trimming ***Shown assembled 188 Plenum Sized to order ˘ˇ˘!˘ # ˇ [# -˘ ! - \ ] ˘^˘ _/- ˘' ˇˆ j ˇ$ j j + j # ˆ smaller sizes Panels can be # W Tops should be # # W widest panel PANEL Plenum Panel TOP. CMP17 - Plenum for 17 1/2″ Winchester Evaporator Coils $ 92. Add to cart. In other words, controlling the return fan via mixed-air-plenum pressure in the economizer cycle causes the return fan to track supply airflow. Which means that it's under negative pressure. Simple enough and a fairly normal HVAC system design. How can and attic be held to the same standard as a plenum when its used for storage and water heaters and such. Lengths (4MHP8)? Grainger's got your back. The best option is to build plenums on both sides and then use a self-filtered return grill for each access. Duct & Duct Accessories. 16×25, 16×24 and 16×20. Buy your Plenums and Filter Boxes online with HVACDirect. All brands of furnace and air handler have a side cut-out to accommodate return air plenums or cold air boots to fit common filter sizes i. ) can be considerable. The furnace is connected to the air plenum at the starting point. 2 and clearly marked with the certification logo indicating a Flame Spread Rating not more than 25 and a Smoke Developed. 8 out of 5 stars 87. § The purpose of this Plenum is to create an equal flow and pressure across the filter (which is sized according to the cooling capacity of the air conditioning system). 14" X 14" Steel Return Air Filter Grille for 1" Filter - Removable Face/Door - HVAC Duct Cover - Flat Stamped Face -White [Outer Dimensions: 15.