Welcome to Mini Split Unit
One of the appealing advantages of Ductless Air Conditioning (also known as “Split System” or “Ductless Mini Split”) is their nearly silent operation. Mini Split Air Conditioner (and Mini Split Heat Pump) produce half of the indoor operational noise as other forms of Ductless Heating and Cooling, including window units, on average. If you are looking for a Heat Pump System or Heating and Cooling Units to supplement your central airconditioning in a room where peace and quiet is essential, like a bedroom, a Mini Split Air Conditioning will likely suit your needs. There are many reasons you might need a little Mini Split boost in a specific area. It might be that you only have a small space to cool, to begin with (such as a single office space, wired storage space or work shop) or that you have central air and need a little boost of Split System Air Conditioning in one location or another. This is common in sun rooms, additions, and other spaces that are either Best Air Conditioner Units work or that do not receive enough air flow from the current Split AC System.
The central thermostat of a central air Mini Split system is not the greatest for monitoring and responding to these situations, even if you have a large capacity air conditioner which is capable of cooling the space. Warm air travels up ward, so, at times warm air may become trapped in spaces up stairs which the thermostat is incapable of monitoring. This can be a huge problem when the problem area is someone’s bedroom. Not only is it a regularly used space that is extremely important to keep at a comfortable climate, but it is also important that the mini split solution does not disrupt sleep with excessive operational noise.
Many people will turn to single zone, window unit air coolers to supplement their central air conditioner in spaces like this. Window unit air conditioners are a fairly inexpensive and effective way to cool and dehumidify spaces which can not be managed efficiently with your central air.
However, if you are prone to light sleeping and noise-induces sleep disturbances, you will have to be a little more selective when buying a window installed mini split unit, as many might produce too much noise to allow you to sleep comfortably. You may want to consider a Mini Split Unit air conditioner instead. Mini Split Unit air conditioners tend to run extremely quietly, and many customers claim that the operational noise produced by some Mini Split Unit is undetectable.
Selecting a Quieter Window Unit Air Conditioner
First of all, before you go looking for the air conditioner that is going to bother you the least as you try to sleep, you must consider how much ductless airconditioning capacity you realistically need. This capacity will be expressed in BTU (British thermal Unites per hour) and can range from 5,000 to 30,000 in window units. If you have less than 150 square feet (say, a10’ x10’ room) that requires cooling, you are looking at a fairly small 5,000BTU window unit to get the job done. However, a 30,000 BTU unit can cool up to 1,600 square feet. So, when it comes to cooling and dehumidifying a single bedroom, finding a suitable window unit should not be too challenging.
The Association of Home Appliance Manufacturers provides a sizing worksheet which can help you get started as you decipher how much power you will need to cool,heat, and dehumidify your space appropriately: http://www.cooloff.org/sub cool.html
It is important to note that, with the ductless mini split option being window unit air conditioning; more capacity is likely going to equal more bulk. Larger capacity, larger size is usually the case with window air conditioners. So, be sure to measure the opening of the window that the ductless window unit is going to be installed in, to be sure that you purchase a size that will fit. Open the bottom window and measure the height and width of the opening to find your maximum size limit.
Window unit air conditioners, although not requiring ducts, do require a proximal source of power. Window air conditioners come in both 120 volt (two-prong) and 240 volt (three prong) models, so be to sure to either buy a unit that will work with what you’ve got, or rewire the outlet for your new unit.
So, which window unit is going to be the quietest?
The unfortunate noise levels associated with window unit air conditioners is due to the fact that these easy to purchase and install “plug-and-play” split unit options are a packaged deal. All parts and mechanisms that must churn about to make split unit possible are in one, solid box. Even the compressor, the part of a central or Mini Split Unit air conditioning system which would remain outside, as far from sleeping ears as possible, is right there in the window unit air conditioning box. So, one of the greatest perks of a window unit (its compact size and mobility) can sometimes become its downfall, if quiet operation is a high priority.
Another important thing to note about window unit air conditioners, and their respective noise levels, is that proper installation is essential for quiet operation. Therefore, if a unit cannot be installed optimally, due to poor design, fit, or difficulty following instructions to a tee on the part of the installer, you will not necessarily end up with a quieter unit simply by choosing one.
Because it is difficult to assess how much actual noise will be produced by a window air conditioner, once it is installed, it is important to buy from a reputable dealer so that you can easily return the air conditioner if it does not meet your needs. If you are unable to keep your bedroom at a comfortable climate and sleep at the same time, there is not much sense in sticking with that particular air conditioner.
However, it never hurts to get off to a good start by purchasing a model that is well-reviewed and seems to satisfy customers who list operational noise as a major contributor to their purchase decision. Below is a description of some high-efficiency and high quality Mini Split Unit models that are also low on noise production, based on published reports of independent product testing as well as hundreds of consumer reviews posted online. These manufacturers and their respective models have received the most positive critiques in matters of minimal noise:
Although more expensive than many window unit air conditioners from other manufacturers, Friedrich window units do rank very high for noise control.
Other attributes that consumers appreciate about the Friedrich window units is that they are fairly attractive, as window units go. They are fairly efficient, and their high quality construction makes them some of the most reliable.
The Friedrich CP06G10 is a small capacity, 6,000 BTU window unit air conditioner that can cool a room that is up to 250 square feet in area. This window unit retails between $230 and $370. The installation of this particular unit can be tricky; however, if installed correctly it is a very quiet air conditioner.
The Friedrich Kuhl SS08M10 is as lightly larger, 7,900 BTU window air conditioning unit which can cool approximately 350 square feet. The Kuhl has a very good 11.7 EER efficiency rating, so it is one of the more efficient window unit air conditioners on the market. It also has many accessory features such as a seven day programmable timer and dimming controls. This model (which replaces the QuietMaster line of window units) is favored by customers that appreciate its stylish design and color choices. The Friedrich Kuhl is an upgrade from the QuietMaster in both style and engineering, resulting in a more attractive, user-friendly air conditioner that actually runs more quietly. However, this model runs more expensive than other window air conditioners of a similar capacity, retailing for $770-$900. Consumers also found the installation of the Kuhl room air conditioner more time consuming than average.
In general, LG models are preferred by customers because of their cooling capacity and effectiveness. LG is another window unit manufacturer that provides a model that is ranked highly for its lack of operational noise.
The LG LW1212ER is a 12,000 BTU window-installed air conditioner able to cool approximately 550 square feet. It has a decent efficiency ratingof 10.8 EER. This unit retails between $320 and $360. Customers review that this window unit is also difficult to install.
Mini Split Noise Levels
If keeping operational noise to a minimum is a major priority when selecting complete or supplemental ductless split unit for your home, Mini Split Unit might the solution that you need. While window air conditioners produce an average of 48-60 decibels when operating, Mini Split Unit air conditioners are notoriously quiet.
Mini Split Unit noise levels tend to be much more insignificant (if not completely undetectable) than that of window unit air conditioners. This is because, unlike window units, the hot and noise making part of the split system is located in the outdoor portion of the“split.” The compressor and condenser can be located as far as 50 feet away from the home, reducing the amount of noise that will actually be heard when it is operating. For this reason alone, window unit air conditioners will probably always be louder than their Mini Split counter parts.
In addition to the compressor being more remote, Mini Split air conditioners may also provide a little added prevention of outdoor noises. Window air conditioning units are often only minimally insulated; therefore, there is less sound proofing between the window unit and the window casing. So, even when your window unit is at a very low or off setting, the prevalence of outdoor noise may increase. You won’t have this problem with a Mini Split; since the small hole connecting the indoor evaporator to the outdoor compressor can be sealed and filled with foam so as not to allow any additional outdoor noise.
The evaporator of Mini Split air conditioners produce approximately 32 decibels, on average. That is right around HALF of the sound produced by many window unit air conditioners (which average between 48 and 60 decibels, right next to your sleeping head!), and likely will be less than your central air conditioner, if it is a little older.
PROPERLY SIZING A NEW MINI SPLIT
If you are looking to supplement or upgrade with a new Mini - Split air conditioner, one of the first and most important steps you must take towards your purchase is to properly determine what size Mini - Split you need. Although some important aspects of more complex HVAC design (for example, if you have a lot of stories, corridors, and hallways) might be best hashed out with an HVAC design professional, determining your basic capacity needs can be done with a little measuring and calculation.
This is one of the most important aspects of Mini - Split, or any, split unit installation, in that too little or too much capacity will compromise the efficiency of the system, as well as your convenience and comfort. With too little capacity, you will have a system that will not cool your space quickly and efficiently, and your Mini - Split will be working overtime, expending excess energy, without achieving your climate goals. Too much capacity can cause the system to “short cycle”; cool air may rebound against walls, bouncing back to the thermostat in the air handler, causing it to shut off and workless. Then, when the ambient temperature is correctly determined, it will turn on again, ultimately blasting cool air back at itself again and repeating the process. This is no good for you or your Mini - Split; it will shorten the life of the Mini - Split compressor, will run inefficiently, and fail you comfort-wise. Even if the air does not bounce back, and the system seems to cool properly, running for such a short time pretty much guarantees that your Mini - Split system will not dehumidify properly.
It is not overly complicated to calculate a general estimate of BTUs you will need to cool the space once you measure the area. Multiply the length of the room to be cooled by its width. If you take your area, and multiply it by 25 BTU, you will have a practical number of BTU to allow ample cooling in mild to hot and humid conditions, for most air conditioners, in general. Minisplits tend to get a little more square footage of cooling than other split unit options, so this will provide you with a high estimate to start will. Then, there are some additional factors (such as how the room will be used, and at what occupancy rate, etc.) which will tack on additional BTUs that are necessary to keep excessive heat out of the space.
So, if you have a room that is 14 feet wide and 16 feet long, you have 11x14=154 square feet. Multiplying that area (224) by 25 BTU, you get: 5600 BTU. So, in most circumstances you would need 5600 BTU of split unit capacity.
If the room is facing south, and has windows, you should add an additional 100 BTU per square foot of glass area. (This may be 50 or so more or less, depending on the quality of the window and the amount of shade or tint blocking the direct sunlight from radiating heat into the space.) So, let’s say that this room has 2 4’x3’ windows, facing south. You now have an additional 24 square feet to compensate for. So, if you add the additional 2400 BTU to the 5600 BTU, you now will need 8,000 BTU to cool this room.
You also have to consider the occupancy of the room the Minisplit will be cooling. You should add in an additional 450 BTU pereach estimated occupant of the room, on the hottest day of the summer (the“design cooling day”). Let’s say this is a single person’s bedroom, and add 450 BTU, bringing the total cooling needs to8,450 BTU.
So, you have pretty much arrived at a small capacity, single zone Minisplit (most likely, 9,000 BTU) to cool this space efficiently, throughout the season. This unit is capable of cooling the space onthe design cooling day, and will work on economical modes during the remainder of the season.
Other factors exist which affect the capacity of the Minisplit you might need, including how the space will be used. If the space that will be cooled by the Minisplit is a gymnasium or excursive room, you should add 2,000 BTU of capacity times the maximum number of people that you would expect to be exercising in that space on a design cooling day. If there will be cooking appliances in the space, capacity must also be added to compensate for them (3,500 BTU per kilowatt rating of the appliance.) Pretty much any heat created will need to be removed by the Minisplit, so, keep that in mind when as you consider what your split unit needs will be for a space in which additional heat will be created.
MINI SPLIT INVERTERS: PROS AND CONS
Federal regulations calling for all split unit appliances purchased or used in the United States to reach a minimum of 13 SEER (Seasonal Energy Efficiency Rating) has heating and air manufacturers doing all they can to raise the efficiency of their units. Minisplit manufacturers come on top in this regard; rather than simply meeting this 13 SEER goal, many Minisplit have been designed to reach into the low and mid 20’s. Some, such as Mitsubishi’s high efficiency Minisplit Unit even double the SEER of the lowest passable units.
A great deal of the exceptional efficiency of Minisplit Unit air conditioners is due to the use of inverter compressors, rather than standard rotary compressors. Both compressors work by self adjusting how they are running, in order to keep the temperature in line with the thermostat settings that the user has selected. While a standard rotary compressor simply turns on and off (like a lights witch), an inverter compressor is more specified, using just as much power as the machine needs to reach the requested setting.
Inverter compressors save a lot of energy, because they are programmed to run at optimum speed. The inverter compressor of a Minisplit Unit responds to the input frequency as it varies between heat load requirements. This uses only the amount of energy (RPM) necessary to correct small variances between desired temperatures and ambient temperatures, rather than ramping all the way on to close a small degree gap. In this way, the inverter compressor of the Minisplit Unit works like an energetic faucet, trickling in just enough to cool the room and maintain a nice equilibrium, which is much more efficient.
However, inverter compressors are capable of faster speeds (higher RPMs) than standard rotary compressors. This comes in handy when the system first comes on, or when a large change in temperature is needed. The Minisplit Unit inverter compressor can lower the temperature dramatically faster than a rotary compressor, reducing the need for it to turbo for as long. This contributes to as much as a 60% reduction in power consumption by a Minisplit Unit inverter compressor over its split system rivals.
During small fluctuations in temperature, the inverter compressor simply adjusts to meet the needs of the moment, and idles there until further notice. The fact that the compressor of the Minisplit Unit is not cutting off and ramping up to full speed throughout the day is also easier on the compressor itself, extending the life if the Minisplit Unit system.
Another benefit of the inverter compressor, other than that of efficiency and mechanical grace, is quieter operations. The compressor is generally the noisiest component of an split system. Inverter compressors tend to be significantly less noisy than standard rotary compressors. The inverter compressors of most Minisplit Systems operate at fewer than 50 decibels of sound.
The compressor is the most hard-working, aggressive part of an airconditioning machine. It is also the most expensive. This is the down side to the use of inverter compressors in Minisplit System air conditioners: they are more expensive, initially, than other forms of ductless split system. If something goes wrong with the compressor of your Minisplit System, it may be expensive to replace (if out of warranty.) However, over time this downside may be outweighed by all of the benefits of the inverter compressor. Enhanced efficiency and increased life span may eventually lead to savings, rather than added expense. Overall, the enhanced comfort and responsiveness you will receive from a Minisplit System with an inverter compressor might more than compensate for the added expense.
MINI SPLIT INSTALLATION: How to select and prepare for the Mini Split installer
If you have decided to purchase a Minisplit System air conditioner, remember that you will need aprofessional HVAC installer to at least finish the more technical aspects of the Minisplit System installation, in order to prevent injury to yourself or the warranty of your Minisplit System. Here are some steps you can take to though roughly prepare for Minisplit System installation, hire an appropriate HVAC professional, and ensure that the installation of the Minisplit System runs as smoothly and efficiently as your Minisplit System itself.
Prepare for installation.
Prior to the services necessary by an HVAC installer, some of the work, as well as some of the design aspects you have creative control over, can be performed or hashed out.
If you have selected a wall mounted Minisplit System, the horizontally oriented evaporator unit will be installed high on a wall. These units generally attach to a bracket, approximately 10” below the ceiling, allowing the unit to project its air flow downward into the room. Make sure that the location you select has enough room to hold the dimensions of the evaporator, as well as permit all of the wiring and lines to run out from the back of the unit.
The exterior compressor of your Minisplit System will require a flat, level surface in order to function properly. You can either install a cement slab near the exterior of your building, or purchase a plasticpad approximately 24” x 36” to lay out on your flay surface. Keep in mind how long of a line set you have to work with, and that the best area to house a condenser (beyond one that is flat and level) is somewhere well manicures and most likely to remain free of yard waste and debris.
Since your Minisplit System will be hard wired into your fuse box, installation does usually require and Electrical Permit, in addition to an HVAC Permit. Although the installer will often pull the appropriate permits for the job, you can be sure, and possibly speed things up,by obtaining them yourself prior to the installation of your Minisplit System. Information about what types of permits maybe needed, and their associated costs, can be obtained by contacting your city hall.
You must have aspot available in your electrical box for a dual pole circuit breaker, in order to accommodate your Minisplit System’s electrical supply. The Minisplit System will need its own designated circuit breaker. Most single Minisplit System run on a 15 or 20 amp circuit breaker.
Once you have got all of this under control, you are ready for your installer to pop in and finish up the job! Don’t have one yet?
Select a trust worthy installer.
These days, one o fthe best resources you have for finding a good contractor is the internet. If you want to get an idea of how many installers there are in your area, you could start at www.yellowpages.com, or simply Google “HVAC in (your city or town)”.
Some people find that they receive better pricing (and many times, more personalized customer service) from small or family run providers than from larger companies. There is also the added bonus of supporting a local business, and those that they employ, by selecting one of these smaller businesses. How ever, be sure that they are HVAC certified, and that the technician they will be sending has experience installing Minisplit System air conditioners.
You will require some electrical configuration for your new Minisplit System, as well as simply installing the air conditioner. Many HVAC technicians are also able to handle the electrical portion. However, make sure to ask and, if they do not, hire an electrician first in order to make sure your Minisplit System will have proper electricity before attempting to install the system.
Before you call, gather some information.
When you call the HVAC professionals, it is helpful to have some information on hand to provide, so everyone has as much information as possible prior to installation.
It will be helpful to provide the brand of the Minisplit you are planning on having installed. Although most Minisplit equipment is installed similarly, the technician may have experience with one or another might know a quirk or an extra tool they might like to bring, etc.
So that they know what size of Minisplit they will be dealing with, know the size of your Minisplit unit/s by BTU capacity. This way, they will not be surprised by a heavier load than expected, or bring (and possibly charge you for) an unnecessary additional hand.
Make sure to read and have handy the power requirements for your Minisplit. Know if it will require a 110 volt or 220 volt line, as they are likely to ask.
In case they need to use extra refrigerant to charge the line, it is helpful if you can provide them with the refrigerant information for your Minisplit unit. Most Minisplit take R22 or R410A.
You will also be more likely to get an accurate quote if you have a good general measurement of how far the condenser will be from the indoor evaporator of your Minisplit. More distance equals more line, and more refrigerant to keep the pressure of the refrigerant line correct. So, the farther away your condenser will sit, the more expensive your Minisplit installation may ultimately be.
Mini - split air conditioning is far less complicated and time consuming to install than central air conditioning. Once you are ready to install, and have a contractor informed and on the way, you are probably just a few hours of enjoying your new Mini - split air conditioning system.
The HVAC professional will start with some basic steps. They will run the coolant, electricity, and drainage lines from the evaporator to the condenser, via a small home in an exterior wall. If they are also doing the electrical work, they will configure the electrical in order to properly accommodate and manage the electrical needs of the Mini - split. Finally, they will set the gauges and charge the lines. They will test the lines in order to ensure that the refrigerant system is at the right pressure; if incorrect, they will add additional refrigerant to the system.
And, there you go! With a little routine maintenance and proper care, your Mini - split system is good to go, and likely to provide you with nearly effortless comfort for the next decade or so!
WHAT ARE THE DISADVANTAGES OF A MINI SPLIT SYSTEM?
With Mini - split air conditioners being some of the most efficient, attractive, and most quiet air conditioners on the market, there aren’t many reasons not to select a Mini - split for your air conditioning needs. However, there are a few down-sides that are worth considering, and situations in which Mini - splits might not be the best choice.
First of all, there is the fact that Mini - split are more costly, initially, than some other split system options. Although Mini - split can be cheaper than some central split systems (especially if you must retrofit ductwork), even today a single zone Mini - split air conditioner costs 3 to more times as much as a window unit air conditioner. If you do already have existing duct work configured into your building, you may also be able to get more mini split unit, for the price, out of a middle-of-the road central air system than a top-of-the-line Mini - split. So, ifyou are on a very tight budget, Mini - split air conditioning might not be the ideal option for you.
Mini - split air conditioning also requires more advanced installation that window units do not. If you are looking for a project that you can complete without any outside assistance, a Mini - split air conditioner may not be a good choice. Mini - split air conditioners will require at least a short duration of professional HVAC assistance, if you do not want to risk making a mistake and voiding the warrantee on your new Mini - split. So, if you are not willing to invest extra time on installation, and money on an HVAC tech, a window unit may be a more suitable ductless option.
Lastly, a Mini - split air conditioning system is a more permanent option than a window airconditioner. Like central air conditioning, the configuration of a Mini - split air conditioner is put in place and meant to function in a certain way. Some people enjoy the flexibility of a plug-and-go window air conditioning unit. You can pull it out during certain weeks or months, and relatively easily store it away for later use. You can also relatively easily move a window unit ductless air conditioner from one room to another; for example, if you change bedrooms, or no longer need the air conditioner in one room or another. This feature, which is not the case with Mini - split air conditioners, allows the air conditioner to come along if you move from one apartment or house to another. So, if you are renting and don’t want to make the investment for a large, permanent mini split unit solution, move frequently, or just like the flexibility of an air conditioner that can easily be moved around, a window unit offers an amount of versatility that a Mini - split will not.