Las Vegas ductwork installation — new duct runs, additions, replacement
New ductwork installations for room additions, second-floor extensions, and finished basements. Existing ductwork resizing when replacing furnaces or ACs. Sheet metal and flex duct fabrication with proper insulation and sealing.
When we replace an old furnace with a high-efficiency variable-speed unit, the ductwork often becomes the bottleneck. Older Las Vegas homes were built with ducts sized for lower-airflow single-stage furnaces. A modern variable-speed unit pushes 20-40% more CFM at low speed and needs ductwork sized for that airflow.
Symptoms of undersized ducts: whistling registers, rooms that never heat or cool evenly, high static pressure showing on the furnace controls, and premature blower motor failures from working too hard. The blower isn't the problem — the ducts are.
A Manual D duct sizing calculation identifies the trunk and branch line sizes needed to move the calculated CFM at proper static pressure. When ducts need upsizing, we quote it as part of the furnace install package so you can see the full picture before saying yes. Related in Las Vegas: furnace repair.
New install
Duct install
How your Las Vegas HVAC install or service call works — four steps, no surprises
Manual D calc + route
Duct sizes calculated per Manual D, routing planned around joists, HVAC penetrations, and other trades. Return-air path evaluated separately from supply.
Written quote
Line-item quote covers sheet metal fabrication, flex duct where appropriate, insulation, register grilles, sealing materials, and coordination with drywall/framing trades if applicable.
Install (1-3 days)
Trunks and branch lines hung on straps, sheet metal joints sealed with mastic (not tape), all seams checked for leakage. Insulation wrapped where ducts run through unconditioned space.
Balance + verify
System commissioned with actual CFM measurements at each register using an anemometer. Dampers adjusted to balance airflow room-by-room. Static pressure verified within manufacturer spec.
Sealing matters more
Ductwork loses 20-30% of heated air to leaks
In a typical unsealed duct system, 20-30% of the heated (or cooled) air leaks out through joint seams before reaching the register. The most common failures: tape-only seals that fail over years, snap-lock joints that were never sealed at all, and boot-to-drywall gaps at register boxes.
We seal all sheet metal joints with mastic (a paint-on sealant that stays flexible for decades) instead of tape. Return-air leaks are checked with a smoke pencil during commissioning. Result: system loses less than 5% of conditioned air, which typically means 8-12% lower gas bill and dramatically more even room temperatures.
For existing ductwork with air leaks (evidenced by dusty attics/crawl spaces or uneven room temperatures), we offer duct sealing as a standalone service. Payback is usually 3-5 years just from the fuel savings. Related in Las Vegas: AC installation, AC repair, and gas piping install.
Las Vegas HVAC installation ductwork installation questions answered
New ductwork for a room addition (single supply run + return): $1,500-$3,500. Second-floor duct extension (full supply and return trunk + 3-4 branches): $3,500-$7,500. Full home reduct: $8,000-$18,000 depending on square footage and finished vs unfinished spaces.
Often yes — and it's usually cheaper. A single-zone ductless install runs $3,800-$5,500 vs $3,500-$7,500 for an equivalent duct extension. Ductless also has zero air leakage since there's no duct to leak. We compare both options during the assessment so you see the real cost trade-off.
Symptoms include: rooms that never reach set temperature, whistling registers, high static pressure reading on the furnace, premature blower motor failures, and dust settling behind registers indicating leakage. We measure static pressure during furnace tune-ups and flag ductwork issues if we find them.
Yes — aerosolized mastic sealing (Aeroseal) or manual joint-by-joint mastic sealing both work on existing ductwork. Typical result: leakage drops from 20-30% to under 8%. Gas bill savings of 8-12% typically pays back the sealing cost in 3-5 years.
We identify asbestos-wrapped ducts during assessment. Asbestos removal is done by a licensed abatement contractor (not us) — we coordinate the removal, then handle the new ductwork install. Total project takes 5-10 days including the abatement window.
Bedrooms upstairs never got warm. They ran new trunks up to the second floor, added returns properly, and now the whole house heats evenly. Took 3 days including framing coordination with our reno crew.
J. O'Donnell
Second-floor extension
★★★★★
Finished basement addition needed HVAC extension. They ran supply and return branches, tied into existing trunks, and balanced the whole system with a duct blower test at the end. Documentation was detailed.
F. Beauchamp
New basement finish
★★★★★
Rather than tear open ceilings to find leaks, they did Aeroseal. Blower test before and after showed leakage went from 28% to 4%. Gas bill dropped noticeably the same winter.
N. Al-Rashid
Aeroseal sealing
★★★★★
New variable-speed furnace was going to be undersized for our old ducts. They quoted the duct trunk upsize as part of the package. Furnace now runs at low speed most of the time, cost-per-month is lower than the old single-stage.
D. Vasquez
Furnace + duct combo
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