Are you considering installing a mini split system in your guest house or pool house? In this blog post, we will break down the process of installing a mini split system in a small structure, highlighting the challenges and solutions.

Mini Split Installation for a Pool House and Guest Space

In this project located in Dallas, TX in the lower greenville area, we installed a mini split HVAC system for a customer who was converting an old garage into a pool house with a small bedroom and bathroom. The customer asked us to explore different HVAC options, and based on the building’s layout, we recommended a 1.5-ton mini split system. The equipment we installed was a mitsubishi MSZ-GS18NA-U1 – 1.5 ton wall mount and MUZ-GS18NA-U1 – Heat pump.

Why a Mini Split System?

Mini splits are ideal for projects like this due to their flexibility and energy efficiency, especially when dealing with multi-purpose spaces. For a structure of around 400 square feet, a mini split can easily handle both heating and cooling demands, which is why we proposed it for this conversion. Since we have extensive experience with mini splits, we knew this would provide the best solution to meet the customer’s needs.

Insulation Considerations

One of the first steps we took was to recommend spray foam insulation for the roof deck and walls. Spray foam is an excellent insulator, helping to maintain even temperatures and improve energy efficiency. This is crucial for a space like a pool house, where maintaining consistent indoor temperatures, especially between different rooms, is often a challenge.

Temperature Control for Multiple Rooms

A common concern when using a single HVAC unit for multiple rooms is ensuring that all spaces maintain the same temperature. In this case, the main living area needed to stay in sync with the smaller bedroom. To address this, we installed a motorized wall transfer grille, which helps distribute air from the main area into the bedroom. This is a simple yet effective solution to maintain even airflow and temperature balance throughout the entire space.

One of the ways to overcome this was to install a motorized room transfer grill. The motor moves about 75 CFM of air but it wasn’t really needed once we turned on the system and the place started to meet temperature.

Strategic Placement of the Mini Split

Proper placement of the mini split unit is key to its effectiveness. In this installation, the most efficient location was on an exterior wall near the pool. This allowed the system to push air toward the back of the building, where the bathroom and bedroom are located. By leaving the doors open and leveraging the spray foam insulation, these rooms could maintain similar temperatures to the main living space.

Dealing with Condensate Drainage

One challenge in this project was dealing with condensate drainage. Ideally, we avoid using pumps by positioning the unit near a gravity-fed drain, but due to the layout, we had to route the condensate line up through the attic to the bathroom sink drain. While this required using a pump to move the water, our expertise ensured the system would function optimally without impacting the building’s design.

Final Thoughts

With the mini split system in place, the customer now has a comfortable, energy-efficient pool house. The system runs continuously, providing a consistent temperature across all rooms. Our combination of strategic placement, proper insulation, and expert installation techniques ensured that this project met the customer’s needs while keeping energy usage low.

Installation Pictures