Westfield Chatham Hills: Best HVAC Setup for Custom Builds

Chatham Hills in Westfield is a different scale of project than most of what we work on in Boone County. We're talking 740-plus acres, a Pete Dye 18-hole course, a 9-hole executive layout, and a buildout targeting 1,500 homes spread across sections including Hampton Park and Lindley Ridge. The custom homes here run 4,000 to 8,000 square feet, with ceiling heights, room configurations, and glass areas that make standard HVAC sizing formulas useless.

If you're building in Chatham Hills or replacing a system in an existing home there, here's the honest technical rundown on what works.

Why Standard Sizing Fails Here

The rule-of-thumb sizing method — 1 ton per 600 square feet, or some similar ratio — was calibrated for tract homes with 8-foot ceilings, moderate insulation, and predictable window areas. A 5,000-square-foot Chatham Hills custom home breaks every assumption in that formula.

• Ceiling heights of 10–14 feet in main living areas increase the air volume being conditioned by 25–75% over a standard 8-foot ceiling
• Large window walls — especially south and west exposures — create solar heat gain that dwarfs what the square footage alone would suggestFinished basements, 4-season rooms, and bonus spaces add conditioning load that doesn't map neatly to above-grade square footage
• Complex floor plans with long duct runs create delivery challenges that affect how much capacity actually reaches each room

We've seen load calculations vary by 20–40% between rooms in the same 5,000-square-foot custom home. That's not an edge case — it's the norm at this build quality.

Manual J Is Not Optional

Manual J is the ACCA-standard load calculation method. It accounts for square footage, ceiling height, insulation R-values, window area and orientation, infiltration rate, internal gains, and local climate data. For Chatham Hills homes, it's the only sizing method that produces a defensible number.

A properly done Manual J for a 5,000-square-foot custom home takes 2–4 hours of data entry and calculation. Contractors who skip it and size by rule-of-thumb are guessing. Oversized equipment short-cycles — it satisfies the thermostat before it dehumidifies properly, leaving the home feeling clammy even at 72°F. Undersized equipment runs continuously and still can't hit setpoint on peak days.

We run Manual J on every new installation over 2,500 square feet. On custom builds, we coordinate with the builder or architect to get insulation specs and window performance data before the house is closed in.

Variable-Speed Multi-Stage Furnaces for Large Square Footage

A single-stage furnace has one speed: full blast. On a mild February day in Westfield when the heat load is 40% of design, a single-stage furnace fires at 100% capacity, overshoots setpoint, shuts off, and repeats. The result is temperature swings, uneven heat distribution across large floor plans, and excessive cycling that wears components faster.

For Chatham Hills homes, the choice is between two-stage and modulating (variable-speed):

• Two-stage furnace: Runs at 65% capacity on stage 1, full capacity on stage 2. Better than single-stage, still cycles on/off. Appropriate for homes in the 2,500–4,000 sq ft range with simpler floor plans.
• Modulating furnace: Adjusts output from roughly 40% to 100% in small increments, matching actual heat load continuously. Runs longer at lower capacity. Dramatically more even temperature distribution across large homes. The right choice for 4,000+ sq ft custom builds with complex floor plans.

Carrier's Infinity 98 and Trane's XV95 are the modulating units we install most in this range. Both pair with variable-speed air handlers for matched system efficiency.

Zoning: Not Optional Above 4,000 Square Feet

A single thermostat controlling a 5,000-square-foot home is a compromise. The thermostat is comfortable. Somewhere else in the house is not.

Our standard recommendation for Chatham Hills builds:

• 2-story homes, 2,500–4,000 sq ft: 2-zone minimum — main level and upper level on separate thermostats with motorized dampers in the duct system
• Homes 4,000–6,000 sq ft: 3 zones — basement/lower level, main level, upper level
• Homes over 6,000 sq ft or complex layouts: 4 zones, potentially with a dedicated zone for a master suite wing or primary entertaining space

Zoning adds cost — typically $1,500–$3,500 for dampers, zone controller, and additional thermostats, depending on the number of zones and duct configuration. It pays back in comfort and reduced runtime on every zone that isn't calling for conditioning at a given time.

Carrier Infinity vs. Trane XV Series

Both are legitimate options at the top of their respective product lines. Here's the practical difference for a Chatham Hills installation:

• Carrier Infinity: Greenspeed variable-capacity compressor, Infinity touch thermostat with system diagnostics, Côr connectivity. Strong dealer support in central Indiana. The Infinity system's diagnostic capability is genuinely useful — the thermostat logs fault codes and runtime data.
• Trane XV series: ComfortLink II controls, XV20i heat pump or XR17 AC paired with XV95 or XC95m furnace. Trane's reputation for cast-iron durability holds in the variable-speed line. The XV20i variable-speed heat pump is a strong performer in Indiana's climate range.

We're not brand loyalists. We stock both and spec based on the job. For Chatham Hills custom builds with zoning, the Carrier Infinity's integrated zone control compatibility gives it a slight edge on commissioning simplicity.

Humidity Control: Chatham Hills-Specific Problem

Pete Dye course design uses water extensively — Chatham Hills has lakes and water features throughout the development. Combined with Indiana's July and August humidity (dew points regularly hitting 70°F+), homes adjacent to the course deal with higher ambient moisture loads than a comparable home in a drier neighborhood.

Your air conditioner dehumidifies as a byproduct of cooling — but only when it's running long enough to pull moisture out of the air. Oversized AC that short-cycles doesn't dehumidify effectively. Properly sized variable-speed equipment that runs longer at lower capacity dehumidifies much better.

For Chatham Hills homes, we treat a standalone whole-home dehumidifier as part of the base spec, not an upgrade. It operates independently of the AC, handles shoulder-season humidity when it's 68°F outside and 65% relative humidity, and keeps indoor RH in the 45–50% range year-round.

In-Floor Radiant and Forced Air: The Hybrid Approach

Some Chatham Hills custom builds include in-floor radiant heat — either hydronic (water-based) or electric mat systems — in primary living areas, bathrooms, or the master suite. Radiant heat is superior for thermal comfort at floor level. It doesn't move air, which means no forced-air drafts in rooms where you spend significant time at ground level.

The practical approach for 4-season Indiana comfort: radiant heat in primary living areas and bathrooms, forced-air system handling the rest of the home, the whole-home dehumidifier, and central AC. The forced-air system handles cooling, ventilation, and filtration. The radiant system handles the low-level comfort heat that forced air doesn't do as well.

If you're in the design phase, flag the radiant question early — hydronic radiant requires a separate boiler or integration with a water heater, and that affects your mechanical room sizing and rough-in requirements.

Whole-Home Dehumidifier: Aprilaire 1870 as Standard Spec

At the build quality level of Chatham Hills, we spec the Aprilaire 1870 as the standard whole-home dehumidifier. It's rated at 95 pints per day, handles homes up to 7,200 square feet, and integrates with the forced-air duct system — no separate ductwork required in most configurations.

It includes an automatic digital humidistat, drain connection or pump option, and an Energy Star rating. At $1,200–$1,800 installed depending on duct access, it's a fraction of the cost of the damage a season of high indoor humidity does to hardwood floors, cabinetry, and structural millwork in a $1M+ custom home.

For Chatham Hills specifically, we install it as part of every new system package. If you have an existing system and no dehumidifier, we can add it as a standalone installation. Call us at (765) 894-0047 to discuss — we'll do a load and humidity assessment before recommending equipment size.

Frequently Asked Questions