Many people have oversized furnaces in their homes. These appliances can cause quite a few issues in homes, such as higher energy costs and more wear and tear on the machine. It's generally best to replace an oversized furnace with an appropriately sized one. However, one alternative commonly suggested to deal with this issue is to derate the furnace. While this may seem like a good idea at first, here are a couple of reasons why you may not want to take this advice.

What It Means to Derate a Furnace

Derating a furnace involves reducing the amount of gas flowing through the appliance. It's commonly done to make a furnace operate better in high-altitude areas, but some people recommend it as a way to deal with an oversized furnace. The goal is to decrease the amount of heat the furnace produces to slow how quickly it heats up the home and prevent some of the side effects associated with furnaces that are too big for the space, such as short cycling.

There are a couple of ways a furnace is derated. The most common is to reduce the size of the burner orifices. Another way involves blocking off some of the burner ports. In some cases, these adjustments are accompanied by reducing the size of the ducts to decrease airflow. Regardless of the technique, because you're dealing with how gas is delivered to your furnace, derating should only be done by a knowledgeable professional.

The Drawbacks of Derating

Furnace derating can be an effective way of reducing the amount of heat a furnace produces, but it can also cause problems if it's done incorrectly. Furnaces are built to operate with a certain amount of gas and airflow. Therefore, reducing the amount of heat it produces can make it difficult for the machine to prevent condensation from forming in the fluepipe and firebox, leading to rusting and corrosion in those areas.

Another issue is that the air circulation and temperature may be too low to adequately eliminate carbon monoxide build up, which can create a dangerous health situation in your home.

Lastly, an uneven heating issue in your home may be even more acerbated by the reduction in heat production. The farther away a room is from the furnace, the longer it takes to get conditioned air too it. Meanwhile, rooms closer to the furnace will heat up faster. Depending on where the thermostat is located, the furnace may shut off before the rooms farthest away can get enough heated air to reach the desired temperature. With the furnace not producing as much hot air as it used to, this means those far away rooms may remain even colder.

As noted previously, derating a furnace is best done by a professional. If you still feel this is the best option for dealing with your oversized furnace, contact a local heating services business for assistance.

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