I-35 North Corridor

The posted price to cool a tied-in room addition

A new room tied into the house still sits outside the original load. The old ducts were never asked to cover that extra floor and glass. Summer heat stacks in the addition while the hallway thermostat stays content. That is the standoff most owners meet after the drywall goes up.

Old West Minisplits posts the price before anyone drills a hole. One zone is $2,000, two zones are $3,700, and three zones are $5,400, with four or more quoted individually. These figures are for new installs only, never repairs or service calls. Describe the addition on the quote form at /#quote.

$2,000One zone
$3,700Two zones
$5,400Three zones
Installs performed by licensed contractorsMost jobs done in a dayNo trip fees or add-ons

The addition was never in the original load

Central systems get sized for the house that existed on permit day. A later addition, even one opened into the hallway, adds roof, glass, and floor the indoor unit never planned to serve. Pushing more air down an existing trunk usually leaves the new room warm and the old rooms noisy.

A ductless mini split is a heat pump that treats the addition as its own zone. It cools through brutal Central Texas summers and handles mild winters without a furnace. You arrange insulation, flooring, and any plumbing separately. We install the indoor head, the outdoor condenser, and the line set.

How to size a zone for a tied-in addition

Square footage is the start, not the whole story. A west-facing sunroom with a wall of glass needs more capacity than a shaded bedroom of the same size. Ceiling height, the insulation in the new walls, and whether the addition shares a long wall with conditioned space all change the load.

We do not pretend a public page can replace a licensed look at the room. Use the quote form at /#quote to describe the addition, the sun, and how many rooms need their own heads. One indoor head is one zone, and most single-room additions land on one. A larger suite with a bath and a sitting area may want two.

The cost breakdown, posted in daylight

The flat price covers equipment, labor, the line set, standard electrical, refrigerant, testing, cleanup, and a Home Depot run for touch-up paint. No trip fees and no weekend adders. Licensed contractors do the work. Other ductless installs in Central Texas commonly run $3,000 to $6,000 per zone on a custom quote after an in-home visit.

Honest exceptions sit up front, never buried. A very long line set, a panel upgrade the house already needed, or unusually difficult mounting can change the job, and electrical work beyond what is included is something a licensed electrician handles separately. These prices are new installs only. If you need a repair or a service call on an existing unit, this page is not that number.

Side by side

How we compare

FactorOld West MinisplitsExtending the old ducts
Upfront Cost1 zone $2,000, 2 zones $3,700, 3 zones $5,400, posted before any visitDuct change orders after the fact, or $3,000-$6,000 per zone from other ductless contractors after an in-home visit
Who runs the additionIts own thermostat on its own heat pumpThe hallway thermostat still decides, and the new room loses
Mild Central Texas wintersThe same heat pump warms the addition without a furnaceLeftover furnace air is asked to reach a room it was never sized for
A number before the visitOn this page, then confirmed through /#quoteMost custom quotes require an in-home visit first
Questions

Straight answers

Does the $2,000 flat price cool a single-room addition?

Yes for a new one-zone install. The $2,000 covers equipment, labor, the line set, standard electrical, refrigerant, testing, cleanup, and a Home Depot run for touch-up paint. Two zones are $3,700 and three zones are $5,400. Confirm the room on the quote form at /#quote.

Can I just tap a new vent off the existing ducts?

You can try, and many builders do. The original system was not sized for that extra roof and glass, so the addition often stays hot while the rest of the house short-cycles. A dedicated mini split zone keeps the old system on the load it was built for.

Do these flat prices cover service on a unit already in the addition?

No. The posted prices are for new installs only. They are not repair prices and they are not service-call prices. If the addition already has equipment that needs work, this page does not apply.

What if the addition is two rooms or a small suite?

Count indoor heads, not floor plans. Two zones are $3,700 and three zones are $5,400. Four or more zones are quoted individually. Use the quote form at /#quote and note sun, glass, and whether the rooms can share a head.

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