HVAC installation & replacement
A new system in Memphis signs up for a long cooling season, river-valley humidity, and ductwork that runs either through a baking attic or a damp crawl space depending on the block. The box in the driveway matters less than every one of those conditions, and a quote that ignores them is quoting a different house.
What a complete quote includes
A load calculation done on your house, with humidity in mind — the oversizing habit costs twice here, because a unit too large chills the air faster than it can dry it and leaves a house cold and close at the same time. The quote should state the calculated load and the size chosen, and they should sit close together. Model numbers for every piece — indoor unit, outdoor unit, coil, thermostat — because matched components are what the efficiency ratings and the warranty actually rest on.
Then the parts that decide the next fifteen years. The ductwork assessed and addressed wherever yours lives: sealed and re-insulated in the attic, or sealed and re-supported in the crawl space with an honest word about why that space is damp. The condensate path rebuilt — pan, line, float switch, and a secondary pan under attic equipment. The refrigerant line set replaced or properly flushed and pressure-tested. Electrical verified against the new equipment, the old refrigerant recovered legally, the permit named. And commissioning: charge and airflow set by measurement, with the numbers left behind in writing.
Reading the spread between bids
Line three quotes up against that list and the differences explain themselves. The low bid reuses the line set, skips the load calculation and never mentions the ducts — it is not a better price for the same work, it is a price for less work, on the parts you cannot see from the living room and will pay for every cooling hour from now on.
Two habits keep it honest. Ask every bidder the same three questions — what size does the load calculation give, what happens to the ductwork, and what does commissioning include — so the answers are comparable. And in a city with both foundation types, make sure each bidder has actually looked at where your ducts run. On a two-story house, settle one more thing up front: whether the quote covers one system or both.
Quick answers
- Why are two quotes for the same house thousands apart?
- They include different work. The spread usually hides in the load calculation, the ductwork, the line set, the condensate safety switch and commissioning. Compare line by line, not total by total.
- Should I replace both systems in a two-story house at once?
- It costs more today and usually less overall — one mobilisation, one permit, matched equipment and a single clock afterward. Replacing one is legitimate too; being surprised by the second project a year later is the part worth avoiding.
- 1 Thermostat — The season’s odometer — a hundred cooling days pass through it.
- 2 Return and filter — The lungs, and the first thing a retrofit house sized too small.
- 3 Air handler and furnace — Up in the attic, asleep nine months, asked for everything in December.
- 4 Coil and condensate drain — Litres of river-valley moisture a day, leaving through one narrow line above your ceiling.
- 5 Attic ducts — The coldest air in the house, commuting through the hottest room on the property.
- 6 Outdoor unit — Full sun, full load — where August culls capacitors by the thousand.