Sunroom Air Conditioners: How to Cool a Sunroom in Summer

Sunrooms are a handy addition to a home. They can also be a great way to enjoy the outdoors without having to step outside, and can be excellent spots for parties, gatherings, leisurely activities, or simply lounging.

Convenient and useful as they may be, cooling a sunroom can create a bit of a challenge during summer time. Given that they aren’t normally linked to the house’s central AC, cooling a sunroom may be necessary if you wish to use it year-round, even in the baking heat of summer.

To help you out, we’ve compiled a list of cooling options for your sunroom, as well as ways to maximize cooling efficiency without breaking the bank.

What is a Sunroom?

First let’s define what a sunroom is. Also known as a solarium or a Florida room, a sunroom is a specially designed room that provides a bright and airy space where occupants can enjoy natural light and outdoor views, while being sheltered from the elements. It offers a cozy retreat to soak in the warmth of the sun during colder months and provides a serene environment to relax in during the warmer seasons. 

Sunrooms are used for various purposes, such as a relaxation space, a greenhouse, a dining area, or an extended living room. They are particularly popular in regions with moderate climates where homeowners want to enjoy outdoor views without being exposed to extreme temperatures. They are especially prevalent in the Midwest and Northeast, where people seek to maximize sunlight during colder months. In the South, sunrooms are often used to escape the summer heat while still enjoying natural light.

Sunrooms can be categorized into:

The typical sunroom: majority of the walls or even roof are made of glass to maximize views and sunlight.

Four-season room: a climate-controlled version of the sunroom that allows it to be used year-round.

Screen room: instead of glass windows, the windows are merely screened. This allows it to be aired and cost less than glass-filled sunrooms.

The Importance of Cooling Sunrooms

Sunrooms are primarily constructed with glass to allow an abundance of natural light to enter. These rooms are typically attached to a house and feature large windows, glass walls, or even glass ceilings, designed to create a seamless connection between the indoors and outdoors. 

Because of their glass construction, sunrooms are typically among the hottest parts of a house during summer. Unless they are properly shaded or adequately cooled, this limits their usefulness during particularly hot days. 

In addition, a hot sunroom can increase cooling costs for the rest of the house, even if it doesn’t use air conditioning. The heat can be transferred via conduction to adjacent rooms through the walls. This temperature imbalance can cause your central AC or other air conditioning units to work harder, even if the sunroom isn’t occupied.

Finally, the advent of climate change means that temperatures are soaring ever higher with each passing year. Data from the US Environmental Protection Agency shows that the average temperature in the continental USA has risen 0.17°F every decade, with 2023 being the warmest year on record. This makes uncooled sunrooms more susceptible to excessive heat. 

How to Cool a Sunroom

1. Fans

Pros:

Energy Efficiency: Fans consume less electricity compared to air conditioners, making them a cost-effective option for maintaining air circulation.

Airflow: They enhance the movement of air within the room, which can help to reduce perceived temperature.

Aesthetic Appeal: Ceiling fans can add to the decor of the sunroom while providing functional benefits.

Cons:

Limited Cooling: Fans do not lower the room’s temperature but only move the air around, which may not be sufficient during extremely hot days.

Noise: Some fans can be noisy, which might detract from the peaceful atmosphere of the sunroom.

What to Look For:

☑ Choose between a ceiling fan if you have a non-glass ceiling, or a wall-mounted fan if there is no room to install on the ceiling, 

☑ You may also consider a floor-standing fan, at the expense of floor space.

☑ Ceiling fans with a reverse function can also help push warm air down in the winter and circulate cool air in the summer.

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2. Ductless Mini-Splits

Pros:

Zoned Cooling: Ductless mini-splits allow for targeted cooling of the sunroom without affecting the rest of the house.

Efficiency: These systems have the highest energy efficiency among AC units and offer precise temperature control.

Quiet Operation: Mini-splits are known for their quiet operation, enhancing the tranquility of the sunroom.

Heating and Cooling: Mini splits can also provide heating function in the cold season through heat pump or electric heating.

Cons:

Installation Cost: The initial cost of installation can be higher compared to other cooling options.

Aesthetic Considerations: The indoor unit of a mini-split system, though sleek, is still visible on the wall. They also protrude more into the room compared to through-the-wall ACs.

What to Look For:

☑ Cooling capacity: Make sure the mini split is properly sized for your sunroom. Use our handy Mini Split BTU calculator to estimate the cooling capacity needed.

☑ Single vs multi-zone: If you have mini splits in other parts of the house, you may be able to connect an additional indoor unit for your sunroom to your mini split compressor, if you have a multi-zone system.

☑ Energy efficiency: The efficiency of mini splits is measured in its SEER rating. If you use the sunroom often or it gets excessively hot in your region, you may want a high SEER rating for increased efficiency and lower cooling costs. 

Recommended Mini-Split for Sunroom:

Friedrich FSHW183A 18000 BTU, 21.0 SEER2 Floating Air Select Series Single Zone Mini Split – Heat and Cool – 230V – R32 Refrigerant

This 18,000 BTU single-zone mini split features high efficiency ratings including a 21.0 SEER2 and 11.95 EER2. This is made possible by the inverter technology used in the Floating Air Select series, where the compressor runs at a lower speed instead of shutting off completely. This helps the system to maintain the set temperature, alleviating the need for the system to start up again from a completely shut down state.It can service a sunroom up to 800 sq. ft.

In addition, it uses the new R32 refrigerant standard that has Global Warming Potential (GWP) of 675. The larger the GWP, the more that specific gas warms the Earth.

Friedrich’s Select Series Floating Air wall units are Smart Home Ready with built-in WiFi and access to FriedrichGo App for wireless control as well as Google Assistant and Alexa voice commands. With the FriedrichGo App you can also create customizable, 7-day schedules for your total comfort.

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3. Window Air Conditioners

Pros:

Affordability: Window AC units are relatively inexpensive and easy to install.

Efficiency: They can cool the sunroom quickly and effectively, especially in smaller spaces.

Space-Saving: Window AC units do not take up floor space, making them a good option for sunrooms with limited room.

Cons:

Aesthetic Impact: The presence of a window unit can obstruct the view and may detract from the overall aesthetic of the sunroom.

Noise: Some units can be noisy, which might be disruptive.

Seasonal Usage: These units may need to be removed or insulated during colder months.

What to Look For:

☑ Cooling capacity: Make sure the window AC’s BTU capacity meets the size of your sunroom. Use our general AC BTU Calculator to help you out.

☑ Energy efficiency: The efficiency of window units are measured via the CEER rating. You may want a high CEER rating if the sunroom is used frequently.

☑ Noise level: Window ACs are typically noisier than other air conditioners. The lower the decibel (dB) rating, the quieter the window unit is. 

Recommended Window Air Conditioner for Sunroom:

Friedrich CCV24A30A 24000 BTU Chill Premier Inverter Smart Window Air Conditioner – 230V – Energy Star – R32 Refrigerant

This EnergyStar-certified window AC is part of the Chill Premier Inverter Series is Friedrich’s Premium Line of “smart” room air conditioners with inverter technology. The Premier Inverter units allow for the compressor to operate at the capacity needed at any given time, for increased efficiency and lower energy consumption.

This model has 24,000 BTUs of cooling, a CEER rating of 12.7. It also uses the newer, efficient R-32 refrigerant that is up to 12% more efficient than the R410A refrigerant.

Other features include WiFi connectivity and Amazon Alexa voice support and Friedrich’s QuietMaster technology that uses heavy duty insulation on the inner wall for sound absorption as well as a stiffened sheet metal casing to help block external noise. This makes it perfect for sunrooms that need peace and quiet.

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4. Through-the-Wall Air Conditioners

Pros:

Permanent Solution: Once installed, through-the-wall units are a permanent fixture that does not block windows.

Efficiency: These units are powerful and can cool larger sunrooms effectively.

Space-Saving: Similar to window units, they do not take up any floor space.

Cons:

Installation: Installation is more complex and may require professional assistance.

Aesthetic Impact: The unit is visible both inside and outside the room, which could affect the appearance of the sunroom and the exterior of the house.

What to Look For:

☑ Cooling capacity: Make sure BTU capacity meets the size of your sunroom.

☑ Front protrusion: Through the wall ACs protrude slightly in the front. If you want a built-in look, opt for units with slim front designs.

Recommended Through-the-Wall AC for Sunroom:

GE AJCQ12DWJ 12000 BTU Through-the-Wall Room Air Conditioner – 208/230V – WiFi Enabled – Energy Star – R32 Refrigerant

This through the wall air conditioner features 12,000 BTU cooling capacity, 10.5 CEER and EER, ENERGY STAR Certified and 208/230 Volt electricity. It offers a true built in look with only a minimal 5″ extension into the room with front, while competitor units require a 7.5 minimum extension into the room with front.

It is WiFi enabled with a built-in GE SmartHQ communication card built right in. WiFi lets you communicate with your AC unit, allowing you to monitor and control it from your phone! A full function remote is also included with this unit.

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5. Portable Air Conditioner (PTAC)

Pros:

Quiet operation: Has less noise than window ACs

Multi-function: Also available with heat pump function

Cons:

Installation: Requires professional installation and cutting into an exterior wall.

Placement: Placed lower near the floor, and must not be obstructed.

What to Look For:

☑ Cooling capacity: Make sure BTU capacity meets the size of your sunroom.

☑ Heating function: A PTAC with heat pump can also serve as a heater for your sunroom during the cold season.

Recommended PTAC for Sunroom:

GE AZ65H15DAB 15,000 BTU Class Zoneline PTAC Air Conditioner with Heat Pump

Silent operation is the hallmark of this PTAC. With a sound transmission class of 29, GE’s Zoneline units are the quietest PTACs on the market at reducing outside noise when compared to leading competitors. A large cross-flow barrier optimizes airflow for a low, balanced sound that is hardly noticeable, while a heavy-duty, baked-on mastic barrier covers the back of the unit for superior sound insulation. A weather barrier system seal around the perimeter of the unit keeps all noise and dirt outside, ensuring a better and more comfortable environment while the PTAC is in use.

This model has 15,000 BTUs of cooling. It also has a heat pump that can put out up to 13,400 BTUs of heat. Features include a reverse cycle defrost feature that boosts efficiency by allowing the unit to run in heat pump mode longer. Specially designed heat and freeze sentinels also prevent damage caused by overheating or freezing, prolonging the life of the unit and adding to even more energy savings in the long run.

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5. Portable Air Conditioners

Pros:

Flexibility: Portable air conditioners can be moved, allowing for targeted cooling where it’s needed most.

Easy Installation: They are easy to set up, requiring only an outlet and a window or vent for the exhaust hose.

Cons:

Space Usage: These units can take up floor space, which might be limited for smaller sunrooms.

Noise: Portable ACs can be noisy during operation.

Drainage: They require regular drainage, which can be an inconvenience.

What to Look For:

☑ Cooling capacity: Make sure portable AC’s cooling capacity is enough for your sunroom.

☑ Vented vs ventless: Vented units require an exterior outlet for the exhaust hose, while ventless models need to be periodically drained.

Recommended Portable Air Conditioner for Sunroom:

Friedrich ZCP12DB 11000 BTU Class ZoneAire Dual Hose Portable Air Conditioner with Built-In WiFi – R32 Refrigerant

This unit features 11,000 BTUs of cooling capacity. In addition, you get three functions in one compact unit: air conditioning, fan and dehumidifier. It can cool and dehumidify a sunroom that is about 400 sq. ft.

This unit also includes built-in WiFi for on the go control through the FriedrichGo app. It also works with Amazon Alexis and Google Home. Other features include a 3 speed fan with Auto setting, auto restart after a power outage, and a washable anti-microbial air filter for easy maintenance and clean air.

The unit includes a self-evaporative condensate system so there is no bucket to empty plus it has condensate overflow protection which will shut the unit off to prevent overflow if the tank becomes full. Its dual hose exhaust snaps in and can be extended from 24″ up to 60″ and should be vented to the outside through a window or wall opening.

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6. Central AC

Pros:

Integrated Cooling: If your sunroom is connected to the home’s central HVAC system, it can benefit from the same consistent cooling as the rest of the house.

Whole-House Control: HVAC systems provide comprehensive climate control, allowing for seamless integration with smart thermostats.

Cons:

Ductwork: Extending ductwork to a sunroom can be challenging and may require significant modification to the existing system.

Cost: The cost of extending HVAC services to a sunroom can be high, especially if additional insulation or ductwork is needed.

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How to Improve Sunroom Cooling and Ventilation

There are other ways you can improve the shading and ventilation of your sunroom before resorting to a cooling system:

✔ Optimize Insulation

Ensure the sunroom is well-insulated to prevent heat from entering during the summer and from transferring it to adjacent rooms in the house.

✔ Install Operable Windows

Use windows that can be opened to allow for cross-ventilation, which helps in regulating temperature and reducing humidity.

✔ Use Vent Fans

Consider installing exhaust fans to remove hot air from the room, particularly during the summer.

✔ Incorporate Window Treatments

Use shades, blinds, or thermal curtains to block out the sun during peak hours, reducing heat buildup.

✔ Add Plants

Indoor plants can improve air quality and add a cooling effect through the process of transpiration.

✔ Use a Dehumidifier

Excess humidity can make your sunroom feel hotter than it is, especially if you live in a humid climate or you have several plants in the sunroom. A dehumidifier can improve cooling by lowering the moisture content in the air and removing that hot, sticky feeling.

Enjoy the Sun Without the Heat

Cooling a sunroom requires careful consideration of the different cooling options and the specific needs of the space. Whether you choose a fan, standalone AC, or integrate your sunroom into your home’s central air system, each option has its pros and cons. Check out our extensive catalog of air conditioning and ventilation systems, so you can enjoy your sunroom year-round, no matter the weather.