Boehmer Heating & Cooling Blog : Posts Tagged ‘Furnace Size’

Gibsonia Heating Tip: Signs of an Undersized Furnace

Friday, January 6th, 2012

If you’re purchasing a new furnace for your Gibsonia home, you want to avoid buying one that is undersized for your particular space. To do that, here are some common signs that the furnace isn’t powerful enough for the heating needs of your home. These signs might appear for an older furnace as well, especially as it ages and loses its ability to provide adequate heat for your home.

Maintaining Temperature

The most common (and in many cases only) sign that your furnace is undersized is that the device simply doesn’t maintain the temperature in your home properly. This means that when turned on to full and left for a few hours, your furnace doesn’t heat your home to the thermostat setting.

This can be due to an improper load calculation or a load calculation that wasn’t taken at all. The perfectly sized furnace will heat your home evenly on the coldest day your area is likely to have. So, undersizing should be pretty evident – if it doesn’t heat your home evenly and it’s not exceptionally cold outside, you might not have enough BTUs under the hood.

How to Fix the Problem

The problem is one that varies depending on the severity of the undersizing. Modern furnaces are often available with two stages, meaning they can operate at both a low BTU rating (often around 40K or so) and a higher BTU rating (70K or higher). This is the perfect solution for homeowners worried about undersizing because it ensures that your home always has enough heat in reserve should the weather get exceptionally cold.

For example, most furnaces are sized for extremely low temperatures, but if the temperature jumps up to 50 degrees F outside, your furnace is now oversized for that weather. A two stage furnace offers solutions for both common conditions and extreme conditions and will resolve most of the concern you have about undersizing and not having enough heat to offset outdoor temperatures.

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Oakmont Heating Tip: Signs of an Oversized Furnace

Wednesday, January 4th, 2012

Most people in Oakmont, when they choose a new furnace, think that “bigger is better”. However, an oversized furnace can present just as many if not more problems than an undersized furnace. So, if you feel you may have overdone it in the past or you want to avoid making a mistake in the future, here are some signs that your furnace may be oversized.

Short Cycling

The most common sign of oversizing is short cycling. Short cycling occurs when your furnace turns on and off frequently because it reaches the thermostat setting so fast. Basically, your furnace is so powerful that it can produce what you need rapidly and then shuts off. But, because it does this, the temperature in your home is likely to cool much faster as well since the furnace isn’t on all the time.

Additionally, the on and off short cycling has a negative effect on your furnace, causing excess wear and tear on the system and eventually leading to extra repairs and in some cases early replacement.

High and Low Temperatures

When your furnace is turned on for a comfortable indoor temperature like 70 degrees F, the high and low temperature between cycles should be relatively close to that temperature. In an ideal situation, you shouldn’t even notice a fluctuation.

So, if the high temperature gets close to 75 degrees F and the low temperature is around 66 degrees F, you have a furnace much too large for the size of your home.

Furnace Room Issues

You might find that the space and exhaust given for the furnace are not sufficient either, especially if your previous furnace was replaced with this oversized unit. Backflow of a gas or oil smell or excess heat in and near your furnace room are both common signs that the furnace is much too large.

So, what should you do about your oversized furnace? If you have had that furnace for some time or just moved into a new home, it’s a good idea to have a new one installed. Have a proper load calculation done and then get a new furnace installed so you don’t have to worry about the system cycling on and off so often. If it’s a newer unit, call your Oakmont technician and discuss possible options to reduce the negative effects of the miscalculation of its size.

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