Packaged terminal air conditioners and mini-splits have similar applications. Both are unitary systems, which means they are designed for individual areas, instead of entire floors or buildings. PTACs and mini-splits can operate independently from each other, which makes them a practical solution for building areas with different schedules.
Depending on the needs of each project, both units are available as air conditioners only, or as reversible heat pumps. In both cases, a heat pump eliminates the need for separate heating and cooling. When they are reversible, PTACs are called packaged terminal heat pumps (PTHP).
PTACs are very common in hotel rooms, and you may also find them in commercial offices or apartments. Mini-splits are also suitable for these applications, and they are very adaptable in general. This article will compare PTACs and mini-splits, based on the advantages and limitations of each system.
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Advantages of Mini-Splits over PTACs
The main advantage of mini-splits is energy efficiency. While a PTAC requires a large wall opening for the entire unit, a mini-split only uses a small opening for refrigerant lines between indoor and outdoor units. Since a mini-split creates a much smaller gap in the building envelope, it can achieve a higher efficiency.
The most efficient PTACs have an energy efficiency ratio (EER) of around 12 in cooling mode, while there are mini-split units with an EER above 15. In this case, you can expect electricity savings of over 30% with the mini-split. The efficiency difference is less drastic in heating mode, since you can find both PTHPs and mini-splits with a coefficient of performance (COP) above 3.
Mini-split units are also easier to install, since they use a smaller wall opening compared with PTACs. A mini split uses two smaller units, installed indoors and outdoors, while a PTAC is a bulky packaged unit that is more difficult to handle.
Mini-splits are also more adaptable, since you can install the indoor unit in any wall, and there is no need to match the position of the outdoor unit. On the other hand, PTACs and PTHPs can only be installed when an exterior wall opening is possible. A mini-split also produces less noise, since the compressor is contained in the outdoor unit, isolated from the conditioned space.
Advantages of PTACs over Mini-Splits
The main limitation of mini-splits is not having air ducts between the indoor and outdoor unit, since there are only refrigerant lines. As a result, they can provide heating and cooling but not ventilation. On the other hand, a PTAC or PTHP can accomplish all three functions. When a building uses mini-splits, separate ventilation is required to meet building codes and ASHRAE standards.
For a given capacity, a PTAC normally has a lower price than a mini-split, and this is an advantage when the project budget is constrained. However, energy efficiency must also be considered, and the extra cost of a mini-split is recovered many times as energy savings.
PTACs also have simpler maintenance requirements than mini-splits. Owners can simplify property management and maintenance by using PTACs, if they don’t mind their higher energy consumption.
Mini-splits and PTACs are both useful when you need independent HVAC for different building areas. For example, a centralized chiller and boiler may not be the best option for hotel rooms, or individual offices used by freelance professionals. Each area has different operating schedules in this case, and centralized HVAC can waste plenty of energy. On the other hand, unitary systems like PTACs and mini-splits provide the versatility to heat and cool each area independently.
- Mini-splits offer a higher energy efficiency, a simpler installation, versatility, and comfort thanks to their silent operation.
- PTACs offer built-in ventilation, a lower upfront cost, and simpler maintenance.
HVAC represents more than 50% of energy consumption in many buildings, and its performance has a major impact on indoor air quality. A professional HVAC design can keep an optimal temperature and humidity for occupants, while optimizing energy consumption. Selecting the right HVAC configuration for each building is critical - PTACs and mini-splits are suitable for buildings that are divided into small areas with independent schedules.