Gas and Flue Piping Installation is a more delicate process than you might think. The flue system is an integral component of your home’s furnace. Though, if improperly designed or installed, it could prove to be deadly. How serious is this possibility, and how can you avoid this danger? Let’s go through it.

The Combustion-Based Air System in Your Furnace

Condensing Forced Air Gas Furnace
source: wikipedia

Your furnace includes a combustion-based air system. This is composed of a venting unit that is attached to the enclosure of the furnace, the exchanger for the heat that is passed through the furnace, and the flue system.

For the purpose and intent of this article, we will place our focus on the flue system.

This system is responsible for allowing the combustible components being created within and by the furnace system to exit the interior region of the home and move to the outdoor region of the home. Essentially, it is the discharge unit for the furnace. It may also be referred to as the “air system”. If the air system becomes compromised, it could compromise the air within the home; therefore, compromising the health of those that live within.

The Pressure Differential

Most furnaces used in today’s homes use the process of a natural draft in order to aid in its combustion process. This is made possible by the flue piping that is part of the unit. It is the differential within the system that helps to push the gases that are within the furnace up and out of the home.

These gases are consistently heated; therefore, they go through a constant expanding process.

As a result, the weight of the gases is significantly lower than that of the cold air that is being moved from the outside of the home into the inside of the home. In fact, in order for a furnace to operate at a safe level, the heated gases must always be displaced and at a lower pressure so that they may move out of the home. If this does not happen, carbon monoxide is created.

Carbon Monoxide

If the pressure within the flue increases too much or the air that is combustible in the unit drops in pressure, it creates carbon monoxide. If the flue system is not drafting in an appropriate manner, this potentially dangerous substance becomes lodged within the interior regions of the home.

The overall pressure created by the furnace is considered to be highly delicate. Even the smallest disturbance may prove to be unhealthy and dangerous to the occupants of the structure because it will result in the creation of carbon monoxide.

Pressure Fluctuations

In terms of pressure fluctuations where the pressure is heightened within a flue system, there are two main culprits. The first is that the flue becomes restrictive and results in the pressure within it to rise.

The second is that the gas heat from the flue becomes dissipated and increases the pressure within the flue system of the furnace. Pressure fluctuations are not only dangerous to the overall furnace, they are dangerous to the occupants within the home where that furnace operates.

This is why it is essential for professionals to install, maintain, and/or repair flue piping and flue systems.

Failure to do so could result in many dangers.

What Would Cause a Flue System Restriction?

There are many common situations that may result in an increase of pressure in a furnace’s flue system due to increases in pressure. This is why you must have a HVAC professional regularly monitor and maintain the system. These include – but, are not at all limited to – the following:

  1. The flue piping is considered to be too small for the furnace unit.
  2. There are more than two flue piping elbows.
  3. The horizontal run of the flue is too high or too low.
  4. The vertical pipes exceed the amount of horizontal flue piping.
  5. The termination of the flue is considered to be imbalanced or improper.
  6. The cap of the flue is missing or is malfunctioning.
  7. There are obstructions within the flue system.
  8. The connector that attaches the vent system to the flue system has not been properly installed.

What Causes Heat Dissipation within the Flue System?

In addition to restrictions, improper heat dissipation within the flue piping unit of a furnace can result in the dangerous development of carbon monoxide. Again, a professional HVAC technician can aid in ensuring that the heat is moving properly within a home furnace. The following results in heat dissipation:

  1. The lining of the system becomes bent, therefore resulting in flow and pressure fluctuations in the furnace.
  2. The flue piping used within the home’s furnace is too big for that particular model.
  3. The flue piping used within the system is only single-walled and not double-walled.
  4. The furnace was improperly vented into a chimney that is not properly lined.

Proper Design, Installation, and Maintenance of Flue Systems

If your home has a furnace, it is imperative that the flue system is properly designed, installed, and consistently maintained. If this is not done, the risk for the development of carbon monoxide is greatly enhanced. While most are able to properly maintain their furnace, the flue system is one component of the unit that should only be cared for by a professional technician.

Carbon monoxide is a type of toxic gas that can be inhaled.

If inhaled in large amounts, death may occur. It cannot be seen or smelled. It is advisable that you install carbon monoxide detectors within your home if you have a furnace that uses gas, and any other gas-dependent object. Signs of carbon monoxide poisoning include the following:

  • Shortness of Breath
  • The Chest Becoming Tight
  • Headache
  • Fatigue
  • Dizziness
  • Confusion

If you have a flue system in your furnace, we here at Reynolds can help you. We specialize in the design, the installation, and the general maintenance of these systems.