How Many BTU's Do I Need For My Mini Split?
BTU ratings are estimates only, based on 10ft ceilings, with great insulation and windows. Some factors may alter this calculation: lack of insulation, heavy sun, excessively hot regions, & tall ceilings.
6,000 BTU 150 - 300 sq ft 9,000 BTU 300 - 500 sq ft 12,000 BTU 400 - 650 sq ft 15,000 BTU 500 - 800 sq ft 18,000 BTU 600 - 1,000 sq ft 24,000 BTU 800 - 1,300 sq ft 30,000 BTU 1,000 - 1,650 sq ft 36,000 BTU 1,200 - 2,000 sq ft 42,000 BTU 1,400 - 2,300 sq ft 48,000 BTU 1,600 - 2,650 sq ft 56,000 BTU 1,850 - 3,100 sq ft Make sure you install a unit that is going to properly cool your square footage. An over-sized air conditioner is actually less effective and wastes energy at the same time. Air conditioners remove both heat and humidity from the air. If the unit is too large, it will cool the room quickly, but only remove some of the humidity. This leaves the room with a damp, clammy feeling. A properly sized unit will remove humidity effectively as it cools.Here is a more in depth guide.
Sizing Your Mini Split Air Conditioner: What’s The Right BTU Rating to Effectively Cool or Heat Your Room?When buying a ductless mini split system, getting the right size matters—a lot. Keep in mind that size, in this respect, means capacity or BTU rating. While many other things have to be considered prior to a purchasing decision, making sure that you have chosen a properly sized unit should be on top of your checklist. To err on this aspect will have a huge impact on the level of comfort that you’ll be getting from your mini split unit and the amount of money that you’ll be paying for your energy bill in the long-term. Suffice to say, the correctness of the size, capacity, or BTU rating of the mini split system that you use determines the success or failure of your space cooling project. To help you make a smart buying decision, this article discusses the important things that you should know, consider, and be aware about when it comes to proper sizing of a mini split air conditioner.
AC Size Also Means Cooling CapacityWhen it comes to mini split air conditioners, size refers to the capacity of the unit to heat or cool a specific space or room. Now, here’s what you need to know: The size of air conditioners is measured based in tons or expressed in British Thermal Units (BTUs). To better understand these concepts, it is best to take note of the following:
- BTU is a measurement of heat, which by definition really means the amount of energy that is required to increase the temperature of water by one degree Fahrenheit.
- One ton is equal to 12,000 BTUs per hour.
- Basically, when we’re talking about tons, what we mean is the amount of heat (or BTU) that an air conditioner can remove in a space every hour.
All Ductless Mini Splits Are Built with a Specific SizeAir conditioners, including ductless mini split systems, are built in different sizes. Each unit is practically made for a specific size of a space. With ductless mini splits, the indoor and outdoor units have varying sizes or rated capacities. Knowing the size of each unit will guide you to properly install a correctly sized system. When installing a ductless AC solution to your home, your sizing consideration should factor in the size of the room for single-zone application or each of individual rooms for a multi-zone configuration. To put it simply, your outdoor unit may have a different but enough size to complement the size of each indoor air handler that are installed in different rooms inside the house. Because it’s more likely that each room in your home may have different sizes, the size or rated capacity of individual air handlers may also vary.
Bigger Size Doesn’t Always Mean the Right SizeContrary to popular belief, bigger doesn’t always mean better when it comes to air conditioners. This means that having a unit with a higher rated capacity or higher BTU rating doesn’t assure you that you’re actually getting the right size. The truth is, the size of your unit must be proportionate to the size of the space. So, when choosing a ductless mini split, it is important to make sure that its BTU rating is suitable to the size of the room where you will install the system. The rule of thumb is, the larger the space means the bigger size of a unit is required; conversely, the smaller the space, the smaller size of the unit that is needed. The key is just to make sure that your chosen mini split system is properly sized for the specific space that you need to heat or cool.
Why Proper Sizing for Your Mini Split Unit is Important?Because your comfort and energy-savings are stake, it is imperative that your mini split system is properly sized for the room that you will heat or cool. To put this another way, it is important that your system is not too big or too small for your specific space. Now, what would happen if you installed a mini split with a BTU rating that does not match the size of the room? What would happen if the system is oversized or undersized? Well, let’s say that your air conditioner is too big for your space. Based on what was discussed earlier about tons and BTUs in relation to the size of an air conditioner, this could also mean that your air conditioner packs more tons than necessary to cool a smaller space. What happens is your oversized air conditioner might quickly cool your home or a small room inside your house. The problem is it might undergo a process called short cycling, which is bad. In short cycling, your oversized air conditioner turns itself on, blows some good blast of air, then quickly shuts down only to run again. This cycle continues because your system, in this case, is trying to maintain the temperature that you specifically set in the thermostat. With your air conditioner turning itself on and off means it is only running for a short period of time. The immediate result is discomfort because the humidity from the air will not be sufficiently removed. Worse, short cycling forces your system to use more energy and sustain stress. When kept this way, your system will only be using more energy than necessary and the extra wear-and-tear can result to system breakdown. Obviously, wasted energy and system malfunction can translate to higher energy bills and maintenance costs. Now, what if your air conditioner is too small? Again, take this in the context of tonnage or BTU as units to measure the size or your unit or determine its capacity. Using an undersized air conditioner to cool a big space would not make any sense. It is downright impractical because it would not even be able to cool much of the space in your home even if it runs longer. The wasted energy, in this case, would be substantial and you can expect your electricity bill to skyrocket. So, what’s the best size for your air conditioner to achieve more efficiency? Obviously the right fit is always the best fit.
Your Mini Split System Sizing GuideDetermining the size of a space to figure out the right BTU rating of the unit to be used is usually done by taking into consideration the square footage of the room. But there’s a caveat. While you can accurately measure the size of the room based on the square footage, determining the right size of a mini split would be a little bit challenging due to several factors, such as the height of the ceiling, insulation, the climate in the area, and even the level of the room’s exposure to sunlight. The aforementioned variables normally affect or influences the size of the unit that you need to use. So, what does this imply? It means, that the BTU ratings are just general estimates, which are determined based on these factors. This doesn’t mean, however, that proper sizing cannot be established. By considering the environmental or external factors, we can still effectively determine the right size of a mini split unit that is needed for a specific space. While the requirements look a bit too much, it’s not as hard to handle as it looks. In fact, sizing guides are now very common.
For your guidance, here’s a sample of a sizing chart that you can use when buying a mini split unit: