This can result in substantial savings, $500-$1500, depending on size and cost in new home construction. The efficiency rating of a furnace is called AFUE (annual fuel utilization efficiency). The combustion air flow through the furnace must be controlled or its efficiency will decline. They go toward the flue pipe, traversing their way through and all the way outside. Gas Venting Basics Most homeowners are aware of the need for chimney cleaning and inspection if they own a wood-burning stove or regularly use their fireplace, but many don't realize that a gas heating appliance-whether it is a furnace, boiler or even a hot water heater-also relies on the chimney for proper venting of the exhaust. The furnace pipe is horizontal and relatively short, and it's this way for a reason. If you decide to install this type of heating system, take extra precautions to make sure all ventilation systems are properly placed and working correctly. It is widely used in industries such as grain, fertilizer, chemical, printing and dyeing, vegetable dehydration, residue drying and mine heating. The H2O in the exhaust mixes with CO2 in the exhaust and creates Carbonic Acid, H2CO3. Natural or "type B" vents are the most common and economical option used with gas furnaces. For high-efficiency furnaces, there is a second heat exchanger involved. Retrofit venting for new, high-efficiency appliances When replacing a mid-efficiency appliance with a new condensing 90+ appliance, you can use the existing B vent (any brand) as a chase for the new appliance with PolyPro®. The furnace has two pipes entering the chimney, one for the inflow and one for the exhaust. As the name implies, hot exhaust fumes from the furnace rise naturally up the pipe and vent through the rooftop. High-efficiency furnaces are often known as condensing furnaces because they have a second heat exchanger that extracts additional heat from the air that passes through the first heat exchanger. This is an alternative to the standard two pipe intake/vent shown in the basic furnace installation instruc-tions. The installation instructions of these furnaces must be followed precisely for safe installation and operation. You need to use an auxiliary power inducer. The combustion air flow through the furnace must be controlled or its efficiency will decline. I live in a center chimney cape. vent pipe, blocking the exhaust flow. Here are the most common high efficiency furnace problems that I have encountered: Plugged condensate drains. High-efficiency furnaces require 2- to 3-inch diameter vent pipes; a nondirect-vent system requires one pipe and a direct-vent system requires two, one to take in the air and the other as an . The barometric damper will prevent pulling additional excess air through the furnace. I think don't it is possible to vent a 95% efficiency furnace up through an existing chimney. While the furnace runs, those combustion gases rise up. Both of these pipes are directed to the outdoors at about 95% of the furnaces that I inspect in Minnesota. It is classified as "Type BH" venting. High-efficiency furnaces are becoming more popular today. HIGH-EFFICIENCY FURNACE . Depending on the style of home, the flue may even be attached to the upper portion of the chimney. High-efficiency condensing furnaces have two-stage combustion to extract as much heat energy as possible from burning gas. A high-efficiency furnace uses a different type of venting system because it extracts the heat that remains in those combustion gases before venting the resultant mixture of water and carbon dioxide. An orphaned water heater is one that vents into a chimney flue liner that used to accept the exhaust gas of the water heater and usually a furnace. The perfect solution for utilizing the B Vent already in place, just … PolyPro® Flex Read More » High-efficiency furnaces come with two pipes; one pipe brings combustion air directly into the furnace and mixes it with fuel. This forms a corrosive exhaust that will, given some time, eat holes in your metal venting pipes, as seen in the photo above. High-efficiency furnaces capture the residual heat lost through the venting process and extract the heat before venting a highly corrosive condensate made up of carbon dioxide and water. Run the vent pipe up through the roof and install a metal or PVC flashing collar over it. If you're unfamiliar with the venting and combustion processes of high-efficiency furnaces , take a few moments to learn the components involved to help you maintain a safe and . When installed correctly, this venting arrangement works with an 80% gas furnace (or lower than 80%) + gas water heater. Can anyone tell. The barometric damper will prevent pulling additional excess air through the furnace. They are vented outdoors horizontally through a wall by a small plastic pipe. For furnaces that are high efficiency (above the 90 AFUE mark . The pipe is typically 2 inches in diameter. Our old oil furnace was vented up the chimney, but the high efficiency new gas furnace apparently cannot go up the chimney, but has to vent out the side of the house. Leaking combustion products—which may include carbon monoxide—can cause severe A conventional furnace vents these combustion gases through a vertical exhaust system that is attached to the furnace. You usually see the PVC pipe extending from the furnace through the wall to the outside. The main byproducts of condensation are in liquid form and must be drained rather than dispersed into the atmosphere. High-efficiency furnaces are effective at conserving energy and reducing your heating costs because they convert up to 98 percent of the fuel they burn into heat for your home. Blocking the fresh air intake in a small or restricted space containing a furnace can lead to negative pressure and can cause a back-draft of toxic fumes and carbon monoxide to flow back down the flue vent. Chimney Thimbles: Passing Safely Through a Combustible Wall. New furnaces are built to be highly efficient, which means they don't give off a lot of heat during ventilation—most of it stays in the air. Because there are fewer byproducts to vent, your chimney may be too wide, which could result in improper ventilation. If you see a white PVC vent pipe coming out of the side or top of your furnace, you have a high-efficiency condensing furnace. Since they use a different venting system than traditional furnaces, you'll want to understand some things about high-efficiency furnace venting before you install one of these units. What is vented is a residual corrosive condensate of water and carbon dioxide. The deck is 15'x35′ with Timbertech decking and railing and has solid wood skirting around the sides. Because the exhaust gases are so hot, they rise quite naturally into a vertical flue that runs up a standard chimney and out of the house. However, they are the best in the market till now. Can a high efficiency furnace vent through a chimney? The most efficient furnace units available today are gas-condensing models, which can achieve efficiency ratings of 90 or above. When the High Efficiency Gas Furnace is running, a water spot forms at the base of the Flue chimney where the Flexible PVC pipe, enters the chimney and then vents to the roof. Show activity on this post. The high-efficiency furnace venting process is a two-step exchanger method to create, retain, and separate additional heat from the byproduct. There is NO liner in the chimney. Appliances fueled by natural gas or propane may not produce the visible soot that appliances burning other fuels do, but they can deposit corrosive substances in your chimney. Standard-Efficiency vs. High-Efficiency Venting A standard-efficiency or midefficiency furnace may waste some energy, but the venting system itself is a marvel of simple physics. vent pipe, blocking the exhaust flow. They often do not even use the chimney. The barometric damper will prevent pulling additional excess air through the furnace. In high-efficiency models, the lower temperature of the exhaust can allow moisture (a by-product of combustion) to condense in the flue, especially when outdoor temperatures drop into the 20's or below. The venting was run to the side of our house (& there may someday be an addition @ this location). Have a conventional furnace? Furnaces with an AFUE of 90% and greater use special venting material such as PVC or stainless steel. I believe high efficiency furnances must be vented horizontally through a wall. If the flue is made of PVC pipe, you have a high-efficiency furnace, also . If the condensate drains outside, it may freeze and block the vent with ice. What is needed to fix this problem? It is not uncommon for your gas hot water heater and furnace to vent into the same chimney. Olsen still makes the same furnace with the same physical dimensions. With the 1/8″ gaps between all the deck and skirt boards, I estimate there . Twist the . The existing furnace was built on 1992, not sure when it was installed. Venting Gases: High-Efficiency Furnaces. High-efficiency (or "condensing") furnaces exhaust the combustion gases and bring in fresh Due to the condensing nature of a high-efficiency furnace, its venting must be made of a material that is resistant to corrosion. With a conventional furnace (under 90% efficiency), combustion gases are exhausted through a vertical vent that's attached to your system. The hot surface of the warming component touches off the gas burner. They go toward the flue pipe, traversing their way through and all the way outside. May 4, 2016; A major cause of chimney related fires, is failure to maintain required clearances (air space) to combustible materials. High-efficiency furnaces use this type of venting the most. This allows any condensate in the vent to run back to the furnace so it can be collected and carried away. The combustion air flow through the furnace must be controlled or its efficiency will decline. The exhaust runs vertically through the roof, and at about 20 inches above the roof it terminates in a 135 degree PVC gooseneck. Venting Gases: High-Efficiency Furnaces. Remember, you do have a choice of venting through your roof. If those corrosive vapors condense on your brick wall, it will do damage. clearance Run furnace through a complete heat cycle to ensure Procedure 3 - Multi venting Terminations When two or more direct vent furnaces are vented . These high efficiency units use PVC pipe to pull air in for combustion and vent the by-products to the outdoors. Set the collar . First of all, venting must be planned in order to be sized properly. All of which is fine 9 months out of the year. Venting for high-efficiency gas furnaces - Materials. Read our first section titled, "Why your high-efficiency furnace is leaking water". On the other hand, the higher the efficiency of a furnace, the lower the flue-gas temperature. The corrosive condensate would ruin the venting equipment used in conventional gas furnace ventilation. The chimney was originally sized for the furnace (probably coal) AND your hot water heater. I would be very leary of a HVAC contractor would not do this. admin Furnaces March 4, 2020 March 4, 2020 Fresh Air, Furnace, High Efficiency, Single Vent, Two Pipe, Venting 1 Comment Since the mid 1980's high efficiency furnaces have seen a popular growth in part due to government requirements to reduce energy cost and green house gases. In a great majority of cases, plastic piping is used to vent high-efficiency equipment. It uses a venting system to extract that heat before venting. If you see a metal vent pipe instead, you have a conventional furnace. Direct Vent Forced Hot Air Gas Furnace With Cooling Unit High Efficiency 1. This means that such furnaces lose 10% of the natural gas energy that can be utilized for heat during combustion as a result of venting. After the first stage, the hot exhaust gasses are cycled through a second combustion stage, resulting in exhaust with very little heat. Below you will find some of the most common problems involving PVC intake and exhaust vent pipes and how these installation deficiencies allow the formation of ice to occur. The vent should slope up away from the furnace at a quarter-inch per foot. This allows your furnace to get more heat out of the gas that it consumes. Some furnaces have flues that point up and through your roof. Current Gas and Building Codes allow venting through the sidewall. Most vent icing problems involving high efficiency furnaces are not a direct result of the weather, but an improperly installed venting system. The Concentric Vent allows both the intake for combustion air and the exhaust vent to pass through a standard roof or sidewall. I had an interesting repair job on a furnace venting certically. Table & illustrations of the required space between a direct or side-wall vent for a gas fired heating appliance and building windows, doors, corners, gas meter, air intakes, sidewalks, balconies . Hello all. Push the male end of a new vent pipe up through the bottom of the roof flashing and set its female end on the male end of the vent pipe that connects to the gas furnace. A 90% furnace should never dump flue gases into a chimney. Introduction: JLG--Ⅲ series furnace is a new type of combined heating equipment pioneered in China. Easily recessed or surfaced-mounted options are great in homes, schools, cabins, apartments, offices and shops. I a trying to reroute the venting that was done for a high efficiency furnace (~3yrs ago). It is of utmost importance that the Insulated Thimble be . An improperly vented system may reduce the unit's efficiency or prevent the unit from operating. Can a furnace be in a closet? Jul 11, 2016; . "PVC Pipe Venting. Furnace venting should be in good condition and free Natural gas's high "source efficiency" helps make it an excellent energy value, Roof Installation Maintain 12" (18" for Canada) Min. INSTALLATION GUIDE FOR EXISTING HOUSES. Important Considerations for Contractors and Homeowners This Guide was developed to provide . Gas Appliance Direct Vent Clearances Distances from direct gas vent to building features Sidewall vent, direct vent, direct exhaust systems for gas fired heaters, water heaters, other appliances. Match the vent pipe to the furnace maker's recommendations, either sheet metal or vinyl. This practice is common with standard efficiency (80%) furnaces. Higher BTUH furnaces produce higher flue-gas temperatures. High-efficiency furnaces are also known as condensing furnaces. Proper installation of a high efficiency gas furnace requires attention to many details and interconnecting systems: heating capacity (sizing), consideration for duct distribution systems, gas piping, vent systems, provision for combustion air, flue gas condensate disposal, electrical Have a high-efficiency furnace? Read the installation manual for the furnace you are interested in to check on venting that particular furnace vertically. Currently the exhaust is a 5 inch (I think) pipe running into the bottom of my chimney. The condition of the chimney is a factor because new super-efficient gas furnaces do not vent up the chimney. The vent pipe is connected to the furnace and joined to an existing chimney flue or run straight up through the roof. High efficiency furnaces These furnaces are also known as "90 percent furnaces" because they have an AFUE rating of 90. Do all furnaces have vents? You CANNOT just take the vent off an 80% efficient furnace and run it out a side wall. But the chimney must be decommissioned and not used to vent other appliances. The new high efficiency furnaces often are required to vent to the exterior through PVC pipe. The exhaust is now directed under the deck. (This is mostly stuff I learned during a training session from IPEX, one of the major manufacturers of plastic piping, with a little of my personal experience and tips.) A PVC vent pipe will likely indicate a high-efficiency gas heating system. In high-efficiency models, the lower temperature of the exhaust can allow moisture (a by-product of combustion) to condense in the flue, especially when outdoor temperatures drop into the 20's or below. When the vent is withdrawing air from the house, it expels the gas outside through the vent. 29 How does an architect design a building? We are having a new gas furnace installed this coming week. In comparing the venting of exhaust gases from a high efficiency furnace, boiler or water heater with the venting of exhaust gases from a conventional heating system it will be immediately obvious that the high efficiency equipment exhaust is produced at a low-enough temperature that it is vented through comparably small-diameter plastic piping . This fix often makes sense if you've got a really old furnace or a big external chimney that stays cold throughout the winter. If you've got metal pipes coming out of your high-efficiency gas furnace, it's only a matter of time until this happens. You CANNOT just take the vent off an 80% efficient furnace and run it out a side wall.You need to use an auxiliary power inducer. However, if an outside wall is inaccessible, most manufacturers offer alternatives for venting through an existing chimney. Follow these instructions as well as the basic furnace Natural Vents. High efficiency furnaces produce high amounts of condensation moisture in the exhaust vent, which is designed to run back into and through the furnace in order to drain out into either a floor drain or other approved draining system . This video is for the professional HVAC installer. This and other tips are available at http. Proper venting of high-efficiency condensing furnaces is extremely important to the proper operation of the equipment and to the safety of the building's occupants. 34 What pest is in . 2. My plan was to just swap out the old furnace for the new one of the same model. High-efficiency furnaces use sidewall vents for "breathing" in outside air for fuel combustion, and "exhaling" cooled exhaust gases nearly depleted of heat. The first benefit of a direct venting system is that it eliminates the need for a chimney. A new high-efficiency furnace may now vent through a plastic pipe that exits a sidewall of the home, not the chimney. Most 90% furnaces can be vented vertically, and through a chimney if desired. This process creates condensate, or moisture, from the furnace's heat exchanger. Learn the important factors of venting high-efficiency furnaces. When your furnace burns natural gas to heat your home, it produces combustion gases as byproducts that need to be vented out of your home. Gas furnace exhaust vent options - HVAC-Talk best hvac-talk.com. The vent length can often be as much as 60 feet (90-degree elbows count for 10 feet). I have a HE tankless boiler that exhausts via a PVC vent onto my driveway. of the vent plus the furnace input and efficiency are factors affecting the temperature of the flue-gases. The 2″ pipe leaves the furnace and connects to the 3″ pipe at the first turn.