Is Mini Split Good for Sunroom? (Sizing & Installation Guide)

Sunrooms can get too hot in summer. Mini splits are known for their high-efficiency operation. However, is mini split good for a sunroom? So, I did some research to find out.

It turns out that a mini split is an excellent choice for cooling and heating a sunroom. A ductless mini split ceiling cassette air conditioning unit can be hung conveniently at the center of a sunroom to distribute air evenly throughout the sunroom while maintaining the aesthetic of the sunroom.

Many people don’t realize that they can actually air condition a sunroom with a mini split. However, choosing the right mini split is the key to improving the comfort in a sunroom while keeping the beautiful look of the sunroom.

Why Mini Split is Good for Sunroom?

Based on my research, it seems like a ductless mini split air conditioner (or heat pump) is the best air conditioning system to be used for sunrooms. Here are the reasons:

Mini Split is Very Quiet

Mini splits are known for their incredibly quiet operation. A typical portable air conditioner creates around 60 dB of noise level all the time. A noise level of 60 dB sounds like a normal conversation between two people.

Often, a sunroom is meant to be quiet. It is a place we get to relax and enjoy the sun. Perhaps, it is a good place to do some reading. So, it is pretty annoying to have a noisy air conditioner in a sunroom.

On the other hand, a ceiling cassette mini split produces only about 30 dB of noise level when operating in a low fan speed setting. Such a noise level is equivalent to a whisper. In addition, the ceiling cassette is installed up high at the ceiling level (8-10ft height) and thus, you can barely hear any noise.

Mini Split is Minimal

Sunrooms are meant to have great aesthetics. We like the sunroom to be clean, open and minimal. A window air conditioner will take up one of the sunroom windows and it doesn’t look nice at all.

Furthermore, extending the ductwork of a central air conditioner involves too much work and it doesn’t look good either unless you have a ceiling to hide all the ductwork.

Conversely, putting a ceiling cassette mini split at the center of a sunroom blends very well with the aesthetics of the sunroom. It doesn’t matter if your sunroom has a ceiling.

Besides, you can paint the front panel of the ceiling cassette to match its color with the rest of the sunroom interior. A stretch of refrigerant pipes covered with a nice length of perforated trunking is all you need to get it to work.

Mini Split is Very Efficient

Mini splits are highly efficient. According to Energy Star, ductless mini split heat pumps cut cooling costs by 30% compared to conventional room air conditioners. For heating, they are 60% more energy efficient than traditional electric resistance-based heating systems.

In short, mini splits are quiet, minimal and efficient which makes them an excellent choice for cooling and heating a sunroom. However, you need to select the right size of mini split to avoid insufficient cooling.

What Size Mini Split Do You Need for Sunroom?

A sunroom can gain an exceptionally large amount of solar heat during the day. Hence, sizing the cooling capacity of a mini split for a sunroom is very different from a typical bedroom or living room.

Generally, there are two types of sunrooms; a) 3-season and b) 4-season. 3-season sunrooms are built with poor insulation or no insulation at all. Meanwhile, 4-season sunrooms have good insulation.

Furthermore, there are 4 different types of sunroom structures as shown in the following:

• Conservatory – Full of windows including the roof in dome shape.
• Solarium – Full of windows including the sloping roof.
• Gable – Plenty of windows with a triangle-shaped roof.
• Shed/Studio – Plenty of windows with a sloping roof.

In short, conservatory and solarium have a glass roof while gable and shed/studio has a ceiling. Conservatory and solarium sunrooms have more effective cooling/heating space than gable and shed/studio sunrooms due to the high ceiling.

More windows mean more solar heat gain. Thus, a mini split must have sufficient capacity to handle the solar heat gain in order to provide sufficient cooling/heating to the sunroom. However, sunrooms with insulated glass and ceiling have less solar heat gain and hence, don’t need a large capacity mini split.

Mini Split Size for 3-Season Sunrooms

3-season sunrooms are built with poor insulation or no insulation at all. Hence, a bigger size mini split is needed to provide adequate cooling and heating.

Below is the estimated mini split size for different sunroom structures and floor areas:

Sunroom Area	Conservatory & Solarium	Gable & Shed/Studio
150 sqft	9,000 BTU	9,000 BTU
200 sqft	12,000 BTU	9,000 BTU
250 sqft	15,000 BTU	12,000 BTU
300 sqft	18,000 BTU	18,000 BTU

Mini Split Size for 4-Season Sunrooms

4-season sunrooms are built with good insulation. They are meant to be cooled and heated. So, a small size mini split is all they needed to provide adequate cooling and heating.

Below is the estimated mini split size for different sunroom structures and floor areas:

Sunroom Area	Conservatory & Solarium	Gable & Shed/Studio
150 sqft	9,000 BTU	9,000 BTU
200 sqft	9,000 BTU	9,000 BTU
250 sqft	9,000 BTU	9,000 BTU
300 sqft	9,000 BTU	9,000 BTU

Nonetheless, other factors such as sunroom orientation and windows quantity need to be considered. Hence, getting yourself a few local HVAC contractors for comparison is advisable.

3 Types of Ductless Mini Splits for Sunroom

Most people know that the air handler of the ductless mini split is a wall-mounted type. So, if their sunroom is full of windows, they have no idea how to install a mini split in their sunroom.

However, there are 3 types of ductless mini splits suitable for a sunroom. Let’s take a look at how each type of mini split is installed in a sunroom.

1. Ceiling Cassette Mini Split

The best type of ductless mini split for sunrooms is a ceiling cassette type. It can be hung at the center of a sunroom and distribute air evenly throughout the sunroom.

To install a ceiling cassette mini split in a sunroom, the sunroom roof support must be strong enough to take on the weight of the ceiling cassette unit which is around 40 lb (18kg). A ceiling cassette unit needs 4 support points and hence, you may need to add two perpendicular beams.

The refrigerant and drain line as well as the power and control cables of the ceiling cassette unit can be hidden on perforated cable trunking and run on the ceiling level towards its outdoor unit.

It looks even better if your sunroom has a ceiling. The ceiling cassette unit will flush with the ceiling and all the pipes will be hidden above the ceiling.

So, if your sunroom is full of windows, you may consider installing a ceiling cassette type of ductless mini split heat pump. Not only it distributes air evenly, but it also maintains the aesthetics of your sunroom.

Many people are not familiar with ceiling cassette types of ductless mini split heat pumps. They can be hung with long rods from supports such as wooden beams and soffit slabs.

See my post Most Efficient Mini Splits: Cooling, Heating & Different Types to find out which ceiling cassette mini splits have the highest heating and cooling efficiency.

2. Floor Mounted Mini Split

If your sunroom doesn’t have full-height windows, you may consider using a floor-mounted type of ductless mini split heat pump. However, if your sunroom does have full-height windows, a floor-mounted unit will block a portion of the windows and it doesn’t look very nice.

3. Wall Mounted Mini Split

If your sunroom is not full of windows and there is space for you to put a wall-mounted mini split, you may consider it since it is simpler and cheaper. However, if a wall-mounted unit is positioned such that it blows air directly towards the hot windows, the total cooling effectiveness may drop.

Conclusion

Mini splits are very efficient and operate quietly. Hence, they are an excellent choice for cooling and heating a sunroom. However, the capacity of the mini split for sunrooms must be increased to compensate for the additional solar heat gain from all the sunroom windows.

In addition, a ceiling cassette type of ductless mini split heat pump is the best type of mini split for conservatory and solarium type of sunrooms. For sunrooms with fewer windows, a wall-mounted ductless mini split is a simpler way to cool and heat the sunroom.

For a reliable mini split, I recommend getting the Daikin 19 series.

If you need me to help with your HVAC system, consider my Email Consultation service.

This article was originally published on aircondlounge.com. Actions will be taken for unauthorised republication of this article.

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