Fast, Accurate HVAC Load Calculations — Nationwide Service
Stop Guessing the Size of Your HVAC System
Most heating and cooling systems are sized by a rule of thumb — and that guess is why so many homes are humid, drafty, and expensive to run. We’ve fixed that with real numbers since 1995. You send the plans; we send back a system designed to fit your home exactly.
An HVAC load calculation is the math that sizes a heating and cooling system to your house — its windows, insulation, direction it faces, air leakage, and local weather — instead of its square footage. We do the full ACCA process: Manual J finds the load, Manual S picks the equipment, and Manual D designs the ducts. The result is a home that’s comfortable in every room, pulls humidity out of the air, and doesn’t cost a fortune to run.
Why does the wrong size cause so many problems?
Because an air conditioner does two jobs — it cools the air and it pulls moisture out of it — and an oversized one only does the first. It blasts the room cold in a few minutes, hits the thermostat, and shuts off before it ever dries the air. So the house feels cold and clammy at the same time, the unit clicks on and off all day, and all that short-cycling wears it out years early.
Bigger is not safer. An oversized system short-cycles, leaves humidity behind, runs up your power bill, and fails sooner. “Round up a half-ton to be safe” is the single most expensive guess in the trade.
How do you get the size right?
Three calculations, in order, each one feeding the next. It’s the method the pros use, and it’s all we do.
Manual J — the load
Room by room, we measure exactly how much heating and cooling your home needs from the real house, not a rule of thumb.
Manual S — the equipment
We pick equipment whose real output on your hottest day meets that load — not the tonnage stamped on the box.
Manual D — the ducts
We size and draw the ductwork right on your plans, so the right amount of air reaches every single room.
What do you actually get?
Not a spreadsheet that stays in the truck. You get real, permit-ready reports a builder, installer, or inspector can use on day one — the load, the equipment, and the ducts, documented.
Who runs the numbers matters as much as the software
We use Wrightsoft Right-Suite Universal, the ACCA-approved standard the industry has trusted for decades. But software only calculates what it’s told — feed it a wrong window or a guessed insulation value and it hands back a clean, official-looking, wrong answer. The skill is knowing what to enter and whether the result makes sense. That’s the part we’ve been doing since 1995.
The details a rule of thumb never sees
Square footage can’t tell you any of this — but it’s exactly what makes a house comfortable or miserable. Each one has its own deep-dive if you want it:
Heat Gain & Heat Loss
The simple physics of where heat comes in and goes out — and why humidity is half the battle.
Hot & Humid Climates
Why a sticky climate needs special math, and the moisture load most estimates skip.
Airtight Homes & Ventilation
Sealing a house tight is smart — but then it has to breathe on purpose. Build tight, ventilate right.
Range Hood Makeup Air
Why a big kitchen hood can pull a house dangerously negative — and what the code says about it.
Who we work with
Builders who need a permit-ready calculation for every plan. Contractors who want the design nailed down before the equipment is ordered. And homeowners who’d rather not let a guess decide whether their house is comfortable for the next 20 years. Houses are our specialty — we also take on select light commercial like small offices and recreation centers — and we work remotely, nationwide. Send the plans, get back a complete design.
Frequently asked questions
What is an HVAC load calculation?
It is the math that determines exactly how much heating and cooling a specific home needs, based on its construction, windows, orientation, air-tightness, and local climate — not its square footage or the size of the old system.
Why can’t I just match the size of my old system?
Because the old system may have been the wrong size to begin with, and homes change with new windows, insulation, or additions. A load calculation sizes to the house as it is now, not to a past guess.
What’s wrong with an oversized air conditioner?
It cools the air so fast that it shuts off before removing humidity, so the house feels cold and clammy. It also short-cycles on and off, which wastes energy and wears the equipment out years early.
How long have you been doing this?
Since 1995. Residential load calculation design is our specialty, and we also take on select light commercial such as small offices and recreation centers.
Do you work in my area?
Almost certainly. We work remotely and nationwide, preparing load calculations for residential projects anywhere in the country from your plans and details.
What do you need from me to get started?
Your floor plans and project details, including construction, windows, and location. From those we calculate the load, select the equipment, and design the ductwork.
Send us your plans — get a system that fits your home
A complete, permit-ready Manual J, S, and D, sized to your actual house, by someone who has done this since 1995. Nationwide and residential, with select light commercial.
See pricing & start your project →Licensed. Certified. Accredited & 30+ Yrs of HVAC Design
We work closely with homeowners, builders, and architects to find cost-effective solutions while prioritizing energy efficiency. Because of our commitment, we consistently deliver exceptional results. We utilize Wrightsoft Software to ensure every Manual J heat gain/loss analysis is optimized for high-efficiency inverter systems and geothermal applications. Additionally, our extensive industry expertise ensures reliable and efficient solutions. Therefore, clients trust us to meet their unique needs with precision. The team's dedication sets us apart in the industry.