You love your commercial furnace when it keeps your office warm and your employees happy to come into work during the year’s coldest days—but what about those days when you can’t be sure whether it’s working correctly? You may struggle to love your furnace if it is not working as expected, especially since an unpredictable furnace can spell dissatisfaction and discomfort for you and your staff. However, a little knowledge can go a long way towards making your commercial facility more comfortable. One of the key areas you should study when it comes to your furnace is Btu. If your furnace has the wrong Btu rating, it can spell trouble for your office, and you should take appropriate steps to solve the problem as soon as possible.
- To diagnose Your Furnace: What is Btu?
What is Btu and what does it mean for a malfunctioning furnace? It is important to have a thorough understanding of this vital acronym before you start thinking about how it may affect your furnace, so don’t skip this paragraph. Btu stands for British thermal unit. It is used to measure quantities of heat, although when applied to devices that produce heating or cooling effects it is more commonly understood as a measure of the heating or cooling power that these devices have.
British thermal units came into vogue near the end of the 19th century, appearing widely in the British engineering community by 1897. A single Btu was initially defined as the amount of heat needed to raise the temperature of a pound of liquid water by a single degree on the Fahrenheit scale, although this changed in 1956. The reason for the change was that liquid water could still exist at different temperatures, meaning that a Btu would represent a different amount of heat depending on the temperature of the water used in any given experiment. Today, a Btu is defined as approximately equal to 1055 joules.
- What is Btu Used For?
Btu has fallen out of use in most industries, but it remains a widely-used measurement in heating and air conditioning. Each compliant climate control system in the United States—whether it is a furnace or an air conditioner, and whether it is for commercial or residential use—should have a Btu rating listed somewhere on it. The Btu rating provides essential information about the size of the building in which the unit is intended to function efficiently.
Simply put: systems with higher Btu ratings are intended to heat (or cool) larger areas. However, ballpark estimates will not help you choose an efficient furnace for your space. While a furnace with a Btu rating too low for your space will fail to produce enough heat to keep it warm, furnaces with Btu ratings that are too high for the space will suffer from efficiency problems. They will heat the area too quickly, then turn off until it becomes cold, and turn back on again. This constant switching between off and on is called “short-cycling,” and it will cause your furnace to use more power than necessary. Not only will this drive up your utility bills, but it will also cause the components in your furnace to wear themselves out prematurely and require you to spend more money on repairs or replacements.
- The Simple Way to Assess Your Commercial Furnace Btu
Here is a simple method to help you determine whether the Btu rating on your commercial furnace is appropriate. First, consider the region of the country in which your facility is located. The United States is home to five distinct climate zones, each of which requires a different amount of Btu per square foot for a furnace to heat it adequately. Most of California falls into Zone 2, which requires 35-40 Btu per square foot. However, specific regions in the State’s interior may need less (down South) or more (up North).
Once you have determined the number of Btu per square foot needed to heat your building, simply multiply it by the number of square feet in your facility to find the total Btu required to heat the space. If you have a 2000 square foot office and you live in Los Angeles (where the Btu/square foot rating is roughly 40), then you will need approximately 80,000 Btu to heat the space. However, this doesn’t necessarily mean that a furnace with 80,000 Btu listed on the side of it will be adequate for your office. You’ll also have to factor in the efficiency rating to know how many Btu your furnace produces. If your furnace is only 93% efficient, multiply that 80,000 by 0.93. You’ll end up with 74,400—which will be the actual Btu output of your furnace. As you can see, this is somewhat less than what your office needs. The final numbers should be within 10% of each other for your system to work efficiently.
- Check Your Furnace Btu and Seek Professional Advice
The method above can help you ballpark the Btu your furnace needs to work properly, but other factors can also affect the furnace Btu your system produces. Remember that the number of people, windows, and outside walls in a building can all have an impact on the Btu a furnace in a given space will need. For best results, contact a qualified professional and have them assess the Btu rating on your furnace.