Where two quotes stop being comparable

What a normal ductless quote assumes: one outdoor unit, the indoor heads for the zones being served, mounting brackets or a ground pad, basic electrical connections at both ends, refrigerant line, evacuation and charging, and a standard line-set run of about 15 feet ^[1]. That last number is the one that quietly does the most damage, because it is an assumption about your house that nobody stated out loud and that the estimator may not have measured.

Refrigerant line is not cable. Past a certain length manufacturers require additional charge, and past a further length a different line diameter, both of which change the equipment specification rather than merely the material bill. A quote that assumed a short run and encounters a long one on the day does not become slightly more expensive; it becomes a change order.

These are the items this site deliberately excludes from its own estimate, and they are excluded for the same reason they should be itemised on your quote — they vary far too much between houses to carry a default.

• line set beyond the ~15 ft a standard quote includes — no source we could cite publishes a price per foot, so we publish none
• a main electrical panel or service upgrade — our two sources disagree by roughly threefold, so we price neither
• removing and disposing of whatever is there now
• drywall patching, painting, and exterior siding repair around the wall penetration
• condensate pumps and any drain routing that cannot fall by gravity
• the permit fee, because we have only verified one jurisdiction's published schedule

Print that list and read it down the phone. Every line is a yes-or-no question with a dollar consequence, and asking takes two minutes. The electrical one is the most common surprise on a first install: if the panel is full, an electrician has to make room, and a dedicated circuit alone averages $650^[2] before anyone touches the panel itself.

What did you size this on?

The answer you want describes your rooms — areas, orientations, window areas, insulation. The answer you do not want is a square-foot rule of thumb, because the published table this site is built on implies anywhere from twenty to thirty-three BTU per square foot depending purely on room size. A single multiplier is wrong at one end or the other by construction.

How long is the line set, and did you measure it?

Not estimated from the driveway. Measured, including the vertical rise, because the vertical distance between the outdoor unit and the heads has its own manufacturer limits and its own oil-return implications.

Who pulls the permit, and is the fee in this number?

Both halves matter. An installer who intends to pull it will say so immediately; one who hesitates is telling you something. And if the fee is not in the quoted figure, it is about to be a separate invoice.

What happens to the condensate?

Every cooling head produces water and it has to go somewhere. Gravity to the outside is free and reliable; a pump is neither, and a pump that was not in the quote is a change order plus a component that will eventually fail in a wall.

Normalise before you compare. Write both quotes out as the same line items — equipment, heads, line set, electrical, permit, patching, disposal — and fill the gaps with the answers you got by phone. Very often the cheaper bid becomes the dearer one at this step, because its number assumed a short run and an available breaker.

Then look at what is left over, which is usually labour and margin, and be honest that this part is not a defect. A crew that measures the line set, pulls the permit, sets the charge properly and comes back when something drips is worth more than one that does not, and the gap between them is exactly the number you were about to treat as overpricing.