If you’ve ever shopped for an AC unit or system, you’ve likely heard of BTUs and EERs. With Sacramento’s hot temperatures, and our dependence on cooling our homes, it’s important to know what these two important acronyms mean.
The Technical Jargon
BTU – A British thermal unit (BTU) is a precise measurement that represents the amount of energy required to change the temperature a single pound of water by 1 degree Fahrenheit above or below the current temperature. It is the most commonly used way to measure the effectiveness of heating, ventilation and air conditioning (HVAC) systems. Nearly all air conditioners have a tested BTU rating. A higher BTU rating means that the air conditioner is capable of cooling a larger area more effectively. This measurement is one of the figures Sacramento homeowners can use to size an AC unit to fit a house or room. Air conditioners start at a few thousand BTU and go up to tens of thousands for full HVAC systems.
EER – The energy efficiency rating (EER) of an HVAC system or air conditioner is a measurement of how efficiently the unit will cool down a room in relation to power usage. The EER is calculated by dividing the BTU rating by the wattage the unit uses while operating. The EER is a measurement that is very helpful when comparing two different air conditioners because it takes into account the amount of energy needed to cool the room and not just the cooling power. An EER rating could be anywhere from the low single digits to over ten. Higher EER numbers mean less power usage and better energy efficiency.
Why It Matters
Homeowners considering a new Sacramento HVAC systems, will want to look at both BTUs and EERs when choosing what is right for them. The number of BTUs is important because it will determine how large of a space the unit can cool effectively. The EERs are important because it will directly affect the operating cost of the unit during the hottest months of the year in the city. Sizing is about more than the square footage in the house. It also accounts for heat-producing appliances, windows, doors and other features that will affect airflow.
Professionals use complex formulas to determine the correct size for an HVAC system. Higher BTUs do not always mean better performance from an air conditioner. A very powerful air conditioner with more BTUs than necessary, will cool the space quickly. The unit will then cycle on and off frequently throughout the day in short bursts to maintain this temperature. This can damage internal components and shorten the operational life of the AC. An HVAC system or air conditioner is the most efficient and effective when it is sized correctly using both BTUs and EERs.