Licensed Maryland HVACR contractor · 41 years in Montgomery County 24/7 emergency service
Poteete HVAC · since 1985

Maryland · Cooling

Air Conditioning Installation in Maryland

Right-sized air conditioning installed to Manual J load calculations, with the county mechanical permit pulled and the ductwork checked before we quote.

Most air conditioners in Maryland fail early for one of two reasons: they were oversized for the house, or they were bolted onto ductwork that could never move the air they produce. An oversized condenser satisfies the thermostat in eight minutes, shuts off before it has pulled any moisture out of the air, and leaves you with a cold, clammy 74-degree living room in July. We measure before we quote.

Every installation starts with a room-by-room Manual J load calculation and a static pressure reading on the existing duct system. That tells us the real tonnage the house needs, whether the return path can carry it, and whether the line set, disconnect and condensate route meet current code. Then we install equipment sized to the house instead of sized to the invoice.

Where we work
How a split system works An indoor air handler and evaporator coil connected by an insulated line set to an outdoor condensing unit, with supply and return ductwork inside the house. Conditioned space Supply Return Air handler + coil Condensing unit Suction Liquid
Heat is absorbed indoors at the evaporator coil, carried outdoors through the insulated suction line, and rejected at the condenser. The two halves are a matched pair — replacing one and keeping the other is what invalidates the efficiency rating on the label.

Scope

What the job actually includes

  • Room-by-room Manual J cooling load calculation, not a rule-of-thumb square-foot guess
  • Static pressure and airflow test on the existing duct system before equipment is selected
  • New matched condenser and evaporator coil — AHRI-matched so the rated efficiency is real
  • New line set or a certified flush and pressure test when the existing set is reused
  • Nitrogen purge during brazing, deep vacuum to 500 microns, weighed-in refrigerant charge
  • Montgomery County (or applicable county) mechanical permit filed and final inspection scheduled
  • New pad, whip, disconnect, condensate safety switch and secondary drain protection

Maryland specifics

Code, permits and rebates

Maryland has adopted the 2021 International Energy Conservation Code, and since January 2023 new air conditioners installed in the southeastern region — which includes Maryland — must meet a minimum of 14.3 SEER2 for split systems. Montgomery County requires a mechanical permit through the Department of Permitting Services for equipment replacement, and inspections are scheduled after the work is complete. Federal 25C energy-efficient home improvement credits and Pepco EmPOWER Maryland rebates can both apply to qualifying high-efficiency systems; we hand you the AHRI certificate and model numbers you need to file.

Licensing

MD HVACR Contractor License #01-XXXXX. All refrigerant handling is performed by EPA Section 608 certified technicians, and equipment replacement is permitted and inspected through the county.

Process

How we run a ac installation job

  1. Load calculation and duct survey

    We measure windows, insulation, orientation and infiltration, then read static pressure across the air handler. A 2,400 sq ft Bethesda colonial with original 1948 windows and a 1990s duct retrofit is not the same load as a 2,400 sq ft Germantown townhouse, and it should not get the same equipment.

  2. Equipment selection and written proposal

    You get two or three options with the AHRI match number, the SEER2 rating, the sound rating in decibels and the warranty terms in writing. Decibels matter more than most homeowners expect on the tight side yards common in Bethesda, Takoma Park and older Silver Spring neighborhoods.

  3. Permit and scheduling

    We file the mechanical permit with the county before the truck rolls. Permitted work is what keeps your manufacturer warranty and your homeowners insurance intact, and it is what a buyer's home inspector looks for later.

  4. Installation day

    Pads set level, line set brazed under flowing nitrogen, system evacuated to 500 microns and held, charge weighed in rather than guessed by gauge pressure, airflow verified at the registers and the thermostat configured for your equipment's staging.

  5. Commissioning and inspection

    We record superheat, subcooling, temperature split and total external static pressure on a commissioning sheet that stays with the equipment. We meet the county inspector so you do not have to take a second day off work.

Pricing

What moves the price

We do not publish a single number, because a number without your house attached to it is marketing rather than information. These are the variables that actually decide what a job costs, and we itemise all of them in writing before any work begins.

Tonnage and efficiency tier

A 2-ton single-stage system and a 5-ton variable-speed inverter system are not close in price. Variable-speed equipment costs more up front and earns it back in humidity control — which is the actual comfort problem in a Maryland August.

Condition of the existing ductwork

If total external static pressure reads above about 0.8 in. w.c., new equipment will run hard and die young. Return-side corrections are the single most common add-on we quote in older Montgomery County housing stock.

Access and placement

A condenser that has to be craned onto a Bethesda rowhouse roof, carried through a Takoma Park garden, or set on an Avenel screening pad approved by the HOA costs more to place than one set on an open Germantown side yard.

Electrical and code upgrades

Older panels sometimes need a new breaker, a properly sized whip or a code-compliant service disconnect within sight of the unit. We flag this at quote time, not on installation day.

Questions

Air Conditioning Installation questions

How long does an air conditioning installation take?
A straight condenser-and-coil changeout on an accessible system is usually one day. Add a day if the line set is being replaced, the air handler is moving, an attic platform needs rebuilding, or return ductwork is being corrected. Multi-system homes in Potomac are often scheduled across two or three days so you are never without cooling overnight.
Do I have to replace the furnace at the same time?
Not always, but the evaporator coil sits inside the furnace cabinet and the blower has to move the air the new condenser needs. If the furnace is over 15 years old or its blower is a single-speed PSC motor, matching both halves usually delivers better humidity control and a cleaner warranty than mixing new and old.
What size air conditioner does my house need?
The only honest answer comes from a Manual J calculation. Square footage alone routinely overshoots by a full ton in Maryland, because our older homes have been re-insulated, re-windowed and re-configured over decades. Oversizing is the leading cause of the cold-but-humid complaint we get every July.
What is SEER2 and does the higher number pay for itself?
SEER2 is the current efficiency rating, tested at a higher external static pressure than the old SEER standard so it better reflects real duct systems. Going from a failing 10 SEER unit to a 16 SEER2 unit is a large, real cut in summer electricity use. Going from 16 to 20 pays back more slowly, and is usually worth it for the comfort and quiet rather than the meter.

Talk to a technician

Tell us what the house is doing.

Describe the problem and we will tell you what it usually means, what it typically costs to diagnose, and when we can be there. No obligation, no scripted sales call.

Call (301) 555-0182 Request a quote

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