HVAC Quote Request — 4000 Chamisa Dr

Jeff Brabant · Austin, TX 78730 · September 11, 2026 (v4, replaces everything earlier)

What we want

Quiet comes first. Outdoors at the pad, and in a sound room where you cannot hear the HVAC. Price is not the constraint.
Measured, not calculated. Sound-room airflow and grille face velocity are measured at commissioning.
Done once. Chases, pad, and controls sized now for a second sound-room unit later.

Where this document says "we", the owner is designing the acoustic side: the room's silencers, the wire port, the concrete walls. Your side is the equipment, the installation, and the numbers. Answer the questions in each section by email; there is no form.

Systems

System	Where	Nominal	Equipment
System 1 — Garage Attic	air handler in the attic above the garage; serves the first floor	4 ton	Carrier Infinity 27VNA348 heat pump + FE5 air handler + Infinity control
System 2 — Master Attic	air handler in the attic above the master bedroom; serves the second floor	5 ton	Carrier Infinity 27VNA360 + FE5 + Infinity control
System 3 — Sound Room	air handler in the garage attic, offset from the room	1 ton	Mitsubishi PVA-AA12NL + PUZ-AK12NL
System 4	future second sound-room unit for a 20×20 room	—	space in the chases and on the pad

Trane XV19 equivalents are an acceptable alternate for Systems 1 and 2, quoted separately. Tonnage is our estimate; your Manual J decides, and we want to see it. Use these system names on the quote, the labels, and the commissioning report.

Pricing

One price per system, one for the trench and chases, and, if you want the work, one for the pad and walls. Exact model numbers. Say what is excluded: electrical, permits, condensate, refrigerant for the actual lineset length. Commissioning measurements are part of the price. Valid 30 days.

Anything in this document you would price differently or leave out? Say what and why.

House systems (1 and 2)

The garage-attic air handler transmits sound into the framing today. It must not after replacement.

AHU-1 on spring isolation: hangers or an isolated platform, fabric connectors at the plenums, lines and drain on cushioned clamps, no rigid contact with framing. Price the same treatment for AHU-2 as a separate line.
Auxiliary heat sized from the Manual J, not a default kit.

Do the air handlers stay where they are or move, and what total static do you expect on each?

Which isolation will you use, and what is its static deflection?

Sound room (System 3)

Goal: a room you cannot hear the HVAC in. It already has one silenced supply and one silenced return, each a 10×12 duct into the garage attic. You connect to those two ducts. Nothing else penetrates the room.

Ducted heat pump that can work against 0.8 in WG of external static: Mitsubishi PVA-AA12NL + PUZ-AK12NL, which allows a 100 ft lineset. SVZ-AP12NL + SUZ-AA12NL is acceptable only if the lineset is under 65 ft; we would rather have the margin in case the pad moves. Not cooling-only.
Fan runs continuously on Lo, about 280 CFM, when the room is occupied. Mid only if your load calc requires it. Hi locked out.
Wired room sensor inside (PAC-USSEN002-FM-1 or PAC-SE41TS), controller outside. One low-voltage pair through our wire port and nothing else.
Spring isolation on the air handler and the ERV. Air handler offset from the room, not above it.
MERV 13 media cabinet at the unit.
Commissioning: measure delivered airflow with our silencers and the filter connected. Measured, not from fan tables.

Lineset length from the pad to your air-handler location?

Fresh air: we think an ERV running about 30 CFM for two people is the minimum. Agree? Which unit, and how does it tie in?

What isolation will you use, and what is its deflection?

Which fan tap and ESP setting will you commission, and what CFM does that give?

Anything you would do differently?

Room openings

Goal: air enters and leaves the room at 100 fpm or less. No draft, no audible rush at the grilles.

Each 10×12 duct ends in a lined box inside the room that opens to a grille face of about 3 sq ft free area, so a 24×18 egg-crate or perforated face, or equivalent. Supply and return both.
The duct enters the box from the top or side, not opposite the face, so the air turns before it reaches the grille. About 12 in deep, 1 to 2 in of duct liner inside.
No dampers at the faces. Balance in the attic.
Face velocity measured at commissioning, averaged over each face, at the commissioned 280 CFM: 100 fpm or less.

Will you build the two boxes and grilles, or leave them to us? If you will, price them as a separate line.

Your proposed face size and grille type, with its free area, for 280 CFM.

Does the box add enough resistance to change the fan tap you would commission?

Pad and outdoor units

Goal: every condenser on one ground pad away from the house, behind concrete walls, and the yard stays quiet.

Site plan — pad location

Location per the drawing, 3 ft off the west fence. Room for the three condensers now, a fourth later, and the existing pool equipment. Concrete L walls on the house side and the pool side.
Ground pad only. Nothing mounted on the house or the sound room.
Vibration isolation under every unit. Enable each unit's quiet or low-noise mode if it has one.
Trench and chases sized for all four systems with pulling room, plus a spare chase. Electrical in its own conduit.

Pad dimensions and stub-up locations you need. Mark them on the drawing.

Will you price the pad and walls, or should our concrete contractor?

Which isolation mounts?

Anything the walls or the fence do to airflow or noise that we should know?

Commissioning report

One page per system: weighed refrigerant charge for the actual lineset, measured airflow, measured static, fan and control settings, and photos of the isolation. For the sound room, the airflow and face-velocity numbers above.

Documents

Manufacturer data: Carrier 27VNA3 · Mitsubishi PVA-AA12NL / PUZ-AK12NL · Mitsubishi SVZ-AP12NL / SUZ-AA12NL. Full-lot site plan.