Furnaces with an AFUE of 90% and greater use special venting material such as PVC or stainless steel. A 90% furnace should never dump flue gases into a chimney. The installation instructions of these furnaces must be followed precisely for safe installation and operation.
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Can you vent a furnace without a chimney?

These high efficiency units use PVC pipe to pull air in for combustion and vent the by-products to the outdoors. Your furnace won’t exhaust gases into your chimney anymore. Instead, an HVAC contractor will install the system to expel the exhaust directly outside your home.

How do you vent a high efficiency furnace?

To avoid this problem, high efficiency furnace venting requires the use of PVC pipes instead of metal pipes to remove the acidic condensate from your home. These PVC pipes are connected to the furnace and expelled outside. This high efficiency venting system must be installed when you install the new furnace.

Can you install a high efficiency furnace with only one pipe?

It’s perfectly acceptable to have a high-efficiency furnace installed with one pipe.

Can I vent furnace through wall?

Direct Vents These furnace vents can be installed horizontally through an exterior wall, or vertically so exhaust fumes go out through the roof. Although more costly than a natural vent, a direct vent is also a more efficient and safer option.

Can high efficiency furnaces be vented vertically?

Sidewall Venting (High efficiency appliances) Venting can also be vertically vented through the roof (be wary as there can be unforeseen problems with venting through the roof as they are not easily maintained). Separate venting pipes are an optimal choice here as well.

Can a high efficiency furnace Backdraft?

High-efficiency or 90+% combustion furnaces and boilers do not vent flue gases through a standard chimney. … Since there is a fan pushing the combustion gases out of the building, there is no chance that these appliances will backdraft.

Can a high efficiency furnace be installed in attic?

Yes you can put a high efficiency furnace in an attic hose if allowed by your local code. I use self regulating heat tape if there is any chance of the condensate line freezing.

Why do high efficiency furnaces produce condensation?

High-efficiency furnaces create water because they have two heat exchangers, one more than a conventional furnace. The two heat exchangers absorb so much heat that the exhaust gas changes from a gas state to a liquid state. Condensation forms and then drains out through the condensate line.

What is the primary function of a high efficiency furnace?

Condensing Furnace:A high-efficiency furnace (90% AFUE or higher) utilizes a second heat exchanger to heat the air from condensed exhaust gases in order to reach higher efficiencies.

Do high efficiency furnaces produce carbon monoxide?

Many of the new super-high-efficiency gas furnaces (efficiencies above 90 percent) are also the safest. In addition to cutting your heating bills by 30 percent to 40 percent, their basic design and operation concept greatly reduces the possibility of carbon monoxide poisoning.

Do high efficiency furnaces pull air from outside?

The architecture of high-efficiency furnaces means that they have their own fresh air intake. This means that they don’t use the air inside your home; rather, they draw air from outside. However, this doesn’t mean you don’t need an external fresh air intake because you’ve installed a 90% furnace.

How far should furnace exhaust be from intake?

Make sure there is a minimum clearance of 5 feet around the intake and exhaust pipes.

Can PVC be used to vent a furnace?

Traditional gas-fired, forced-air furnaces produce hot combustion exhaust gasses and therefore need metal vent pipes, or chimneys. In contrast, modern high-efficiency condensing furnaces exhaust much cooler gasses and need only plastic pipe materials—such as PVC, CPVC, or ABS—for their exhaust vents.

Why does my furnace have a vent on the side?

High-efficiency furnaces use sidewall vents for “breathing” in outside air for fuel combustion, and “exhaling” cooled exhaust gases nearly depleted of heat.

Can you direct vent an 80% furnace?

An 80% efficient furnace CAN be side wall vented per National Fuel as Code 7.3. 4 with the use of a “mechanical draft system of either forced or induced draft design”. … 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.

Is a high efficiency furnace worth it?

Advantages of High-Efficiency Furnaces The greatest advantage of high-efficiency furnaces is that they can save you quite a lot on your energy bill. Heating and cooling typically account for more than half of the energy used in your home. A more efficient furnace can definitely make a difference.

What is the difference between mid and high efficiency furnaces?

High-efficiency furnaces, also called “condensing” furnaces, typically have AFUEs of 90% or higher. Mid-efficiency furnaces have AFUEs between 78% and 83%. Which type is best for your home depends mainly on your climate and how much heating you use annually.

How far can you vent high efficiency furnace?

The maximum vertical distance you can run a furnace exhaust vent is about 15 feet. If there is a forced air inlet within 10 feet of the exhaust vent, the exhaust gas ventilation terminal should be positioned at least 3 feet above it.

What type of appliance is most susceptible to back drafting?

Wood burning appliances installed in basements commonly operate in this negative pressure environment and are the most susceptible to backdrafting problems.

What is furnace Backdrafting?

Backdrafting is the reverse flow of gas in the flues of fuel-fired appliances that results in the intrusion of combustion byproducts into the living space.

What is water heater Backdrafting?

If a water heater backdrafts, it means that potentially hazardous exhaust gases are coming back into the home. … The one guaranteed fix for all of the issues that I’m going to discuss is to install a new powervent water heater that typically vents through the side of the house.

Why do builders put furnace in the attic?

Putting a furnace in the attic makes sense because it frees space for more family recreation room. In areas with high water tables, furnaces are installed on the main floor, taking up space. Putting them in the attic frees up valuable main floor living room.

Can you put a 90% furnace in attic?

Not so! As long as you have a fully insulated attic, there are rarely instances when we would advise against an attic installation. … The trick to the installation of a gas furnace in an attic space is routing the condensate drain from the attic down through the core of the house to the basement.

How much does it cost to install an attic furnace?

$5,000 – $6,000 The average cost for a new HVAC system is $3,250 to $12,550, which includes equipment and labor fees for the installation of a central AC unit and gas furnace.

Do high efficiency furnaces leak water?

When a high efficiency furnace releases the exhaust gases, condensation is created. This condensation is a significant amount of moisture on the PVC pipe, and it needs to be drained either into a floor drain or a condensation pump. A water leakage occurs when the condensation is unable to drain properly.

Does a high efficiency furnace need a condensate pump?

High-efficiency furnaces have two heat exchangers, primary and secondary. … As a result, high-efficiency furnaces require condensate drains because their exhaust gases cool enough to allow the moisture in them to condense from steam into water droplets.

Does a furnace need a floor drain?

In order for the furnace to work properly, that condensation needs to be drained out or else it would accumulate inside the heat exchanger, inducer and venting, impeding proper gas/combustion product flow. … The condensate trap is absolutely mandatory for a high-efficiency gas furnace.

Do high efficiency furnaces use more electricity?

A higher AFUE means you pay a lower gas bill. It does not mean, however, that your overall energy bills are lower. If you live somewhere with a mild climate, it may not affect you very much. The more that blower runs, though, the higher the electricity bill will be.

How much does a high efficiency furnace cost?

TypeAFUEApproximate Unit CostStandard Efficiency80% – 89%$500 – $1,500Moderate Efficiency90% – 95%$1,000 – $3,000High Efficiency96%+$2,000 – $6,000

What is the highest efficiency furnace?

The most efficient Furnace you can buy is a 98% modulating variable speed furnace. Almost every manufacturer has a variation of this type of furnace. With that said this is one of the most expensive to buy and install. Also, not every home can have this style of furnace due to various factors like duct system design.

How do you tell if your furnace is giving off carbon monoxide?

  1. Pilot Light Frequently Blowing Out.
  2. Fallen Soot in Fireplaces.
  3. Soot-Colored or Brown/Yellow-Colored Stains Around the Leaking Appliance.
  4. Solid Fuel Fires Burn Lower Than Normal.
  5. Smell of Gas (carbon monoxide is odorless, but a leakage may be accompanied by exhaust gases you can smell)
Do new furnaces produce carbon monoxide?

While old or poorly maintained gas furnaces and other older appliances are often the sources of CO, new heating appliances also cause CO problems. Many of these failures arise from improper installation. … Once the source of CO is located, it is important to discover how it enters the house.

What level of CO is acceptable?

0-9 ppm CO: no health risk; normal CO levels in air. 10-29 ppm CO: problems over long-term exposure; chronic problems such as headaches, nausea. 30-35 ppm CO: flu-like symptoms begin to develop, especially among the young and the elderly.

Should you run your furnace fan all the time in the winter?

Reduced Wear & Tear Furnace fans are designed to run all the time, so there’s no need to worry about it failing prematurely. Much of a furnace fan’s wear and tear comes from the starts and stops of the motor; keeping it running can eliminate this type of stress.

Does running furnace fan clean air?

By running the furnace fan all the time, you are also running air through your furnace filter constantly. If you have an efficient filter and a UV light, you are constantly filtering and cleaning the air. This results in healthier indoor air quality for your family and less dust on your furniture.

Does fan on furnace bring in outside air?

Circulating Air with Furnace Fan Running a fan for circulation requires looking at multiple factors including the weather, the age of the HVAC system, the home, and the people living in it. … Whenever the fan runs, some ambient exterior air (hot/humid/cold/dry) will be mixed into the circulating air in your system.

Why does my furnace exhaust smell like gas?

The issue: The gas from your furnace exhaust pipe (which expels outdoors) is blowing back through an open window or door to your home. It is totally normal to smell a gas smell in the exhaust from your HVAC system, as this is how it expels used fuel or gas that may not have been completely used in your system.

How do you tell if your furnace is venting properly?

How Do I Know If My Furnace Isn’t Venting Properly? Gas furnace fumes are moist, so if you notice “sweat” on your windows, this is a sign that your furnace isn’t venting correctly. When your furnace comes on in the morning, if it is venting into your house rather than outdoors, moisture will condense on the cold glass.

Do all furnaces have an exhaust pipe?

That depends on whether you have a standard efficiency or a high efficiency furnace. If your furnace has an AFUE rating below 90 percent, it will most likely have a flue pipe that goes up through your roof.

When Should ABS pipe be used for venting a high efficiency furnace?

PVC or ABS plastic piping is often used on high-efficiency heating and water heating systems as vent piping for the exhaust gases, since the exhaust temperatures are relatively low. This piping is often vented out the side of the home.