HVAC, Case Study, HVAC replacement Guntown MS

HVAC Replacement in Guntown, MS: 5-Ton Payne Split System Upgrade for a Brick Home

A real-world look at how S.I. Service Group solved a comfort problem in a North Mississippi brick home by upsizing from a 4-ton to a 5-ton Payne split system—and backed it up with hard diagnostic data.

Textbook HVAC Performance on Day One

Real diagnostic data from a 5-ton Payne split system replacement in Guntown MS

Project Overview: When a 4-Ton System Just Can’t Keep Up

This HVAC replacement in Guntown MS started with a common complaint. The homeowner’s existing 4-ton split system struggled every summer. On the hottest North Mississippi afternoons, the thermostat was set to 72°F but the indoor temperature drifted into the upper 70s. The unit ran almost nonstop, yet the home never felt truly comfortable or dry.

S.I. Service Group—North Mississippi’s 4-in-1 trade contractor for HVAC, Electrical, Commercial Refrigeration, and Restaurant Equipment—was called in to evaluate. The home is brick construction with 12-foot ceilings throughout. That combination is a classic reason to consider upsizing HVAC. Brick walls store heat and release it back into the home well into the evening. Tall ceilings increase the cubic volume of air that must be conditioned. The original 4-ton system was simply undersized for this structure and load profile.

Why Upsize HVAC in a Brick Home with 12-Foot Ceilings?

Before recommending any 5-ton air conditioner install, the S.I. Service Group team performed a Manual J load calculation. This is the industry-standard method for sizing equipment based on square footage, insulation levels, window area, orientation, and construction type. In this case, the calculation pointed clearly to a 5-ton capacity requirement for both sensible and latent loads.

• Brick thermal mass. Brick absorbs solar heat all day and re-radiates it inward at night. That keeps the cooling load elevated long after sunset, especially in a North Mississippi summer.

• 12-foot ceilings. Compared with a standard 8–9 foot ceiling, this home has 30–40% more cubic volume. More air volume means more heat content to remove at a given temperature and humidity.

• North Mississippi climate. High outdoor temperatures and humidity increase both sensible load (temperature) and latent load (moisture removal).

The result of the analysis was clear. For this brick home HVAC in North Mississippi, a 5-ton split system replacement was not oversizing—it was right-sizing. The decision was made to install a 5-ton Payne split system using R-410A refrigerant, with an attic air handler and an outdoor condenser on a new pad.

Air Side Diagnostics: Textbook 18.8°F Delta T on Startup

After the 5-ton split system install, S.I. Service Group verified performance using a Fieldpiece meter. On the air side, the return air measured 79.8°F dry bulb. The supply air leaving the coil measured 61.0°F dry bulb. That gives a delta T (temperature drop across the evaporator) of 18.8°F. For a properly charged and properly flowing system, the target range is typically 15–20°F. This system landed almost dead center on the first run.

The Fieldpiece app also calculated enthalpy. Return air enthalpy was 33.2 Btu per pound of dry air, while supply air enthalpy dropped to 25.5 Btu per pound. That drop confirms the system is removing both sensible heat and latent heat (moisture) effectively. Even more telling, return relative humidity was 58.2%, while the supply stream at the coil surface showed 87.4% RH, indicating strong moisture condensation on the coil and active dehumidification.

💡 Key takeaway. A solid 18.8°F delta T with a clear enthalpy drop is strong evidence that upsizing to 5 tons matched the load correctly rather than simply overpowering the space.

Refrigerant Side: Verifying Charge, Superheat, and Subcooling

On the refrigerant side, the Payne R-410A system showed suction pressure around 130 psig and discharge pressure around 361 psig. Superheat stabilized near 18.5°F and subcooling in the 7–8°F range. Those numbers are right where you want them for a properly charged split system replacement in North Mississippi conditions.

The first Fieldpiece reading did flag low airflow. That was taken while the system was still pulling down the house from a warm starting point and before the duct temperatures fully stabilized. Follow-up readings—once the blower, coil, and ductwork reached steady-state—confirmed normal airflow and strong performance. This is a good example of why experienced technicians always verify with multiple readings over time rather than relying on a single snapshot.

Installation Details: Payne Split System and Outdoor Condenser Placement

Proper condenser placement and clear airflow are critical for long-term system efficiency.

The 5-ton air conditioner install used an attic-mounted Payne air handler paired with a matching outdoor condenser on a new level pad. Line sets, drain, and electrical were routed to maintain service access and airflow around the equipment. For brick home air conditioning, condenser placement away from radiant brick surfaces helps reduce head pressure on extreme days.

One detail still pending on this project is the final disconnect plug at the outdoor power connection. Dan from S.I. Service Group will return to install the disconnect and perform a full heat-side test once outdoor temperatures drop. Consider this case study Part 1 of the job, focused on cooling performance. Final commissioning and heat verification will follow in a separate update.

Results: Comfort, Capacity, and Data-Backed Peace of Mind

For this HVAC replacement in Guntown MS, the numbers tell the story. The old 4-ton unit ran constantly and still could not maintain setpoint on peak days. The new 5-ton Payne split system delivers a near-perfect 18.8°F delta T, strong enthalpy reduction, and refrigerant readings exactly where they should be. The homeowner now has a system sized for the true load of a brick, high-ceiling home in the North Mississippi climate.

📌 Key takeaway for homeowners. Upsizing air conditioner capacity is not about guessing bigger. It is about doing the math, understanding construction and climate, and then confirming performance with temperature, humidity, and refrigeration diagnostics.

Need HVAC Replacement in Guntown or North Mississippi?

If you live in a brick home with tall ceilings and your current system struggles to keep up, it may be time to evaluate whether a right-sized 5-ton split system install is the answer. S.I. Service Group brings a technical, data-driven approach to HVAC replacement, brick home HVAC in North Mississippi, and split system replacement across the region.

For a professional assessment of your system—and a replacement backed by real diagnostics—call S.I. Service Group at 662.523.5514. Ask about HVAC replacement Guntown MS, why upsize HVAC for your specific home, and how a properly designed Payne or comparable system can improve comfort, humidity control, and long-term reliability.