Three hundred forty dollars was the August electric bill on a 1926 foursquare farmhouse outside town, eleven hundred square feet upstairs, two window units, and bedrooms still sitting in the mid eighties at four in the afternoon. There is no ductwork in that house, anywhere, which is why its owner spent a Sunday pricing a mini split air conditioner salisbury md crews can install without opening a wall. Here is the argument, stated plainly. In a house with original lath and plaster and no chases to work with, the building decides the system, and ductless zoning usually wins on install cost and on operating cost both. The equipment is almost never the expensive part.
Ductwork Costs More Than The Equipment
Ductwork is a distribution network, and distribution networks are where the money goes in any system. Ask anyone who has pulled fiber down a street that was paved thirty years ago. The cable itself is cheap; the trenching, the patching and the permits are the invoice. A duct retrofit in a plaster house works exactly the same way. The air handler is a box you can buy off a price sheet. The soffit boxed down through a hallway ceiling, the chase stolen out of a bedroom closet, the plaster keyed to hundred year old lath that crumbles the moment a reciprocating saw touches it, the plasterer who has to come back twice because the first coat cracked, that is the real number. House after house, what I find is that the mechanical quote and the restoration quote arrive from two different companies, and the second one is bigger. In an old house, the plaster gets a vote.
Put rough numbers on it, understanding these are illustrative and not a quote. Say the ducted proposal lands somewhere around fourteen thousand for equipment, duct fabrication and the electrical work, which is plausible for a two story house of this size. That figure covers the mechanical half only. Plaster repair in three rooms, paint across the entire second floor because nobody spot matches century old paint successfully, and two weeks of living inside a construction zone all sit outside it.
Three Options And What Each Demands
Three approaches genuinely apply to a house like this, and each one asks the building for something different. Window units ask for almost nothing, an open sash and a nearby circuit, which is precisely why they are still in the windows: they are loud, they leak conditioned air around the sleeve, and they cool the six feet directly in front of them. Ducted central air asks for volume, and a plaster house has no volume to give without soffits, chases and a hole cut through the second floor. The mini split air conditioner Salisbury MD installers mount high on an interior wall asks for a three inch sleeve through the exterior wall, a line set run down to a condenser on a pad, and one dedicated circuit.
Before any of that gets chosen, the electrical service gets evaluated. A 1926 house frequently still carries a sixty amp service, and some of them still have original knob and tube wiring feeding the upstairs bedrooms. Adding condenser circuits to either one is licensed electrician work, and no homeowner should be pulling new circuits into original wiring to save a few hundred dollars. Refrigerant lines follow the same rule: they are brazed, pressure tested and evacuated by a technician, never assembled in a driveway.
Zoning Beats One Big Machine Upstairs
One thermostat governing an entire second floor is a compromise wearing the costume of a system. The single upstairs return on this farmhouse sits in the hallway ceiling, so it reads hallway air and nothing else, while the southwest bedroom with two exposed walls and an uninsulated knee wall behind it runs six or seven degrees warmer than the number the thermostat is acting on. Ductless heads read the room they are hanging in. Two of them upstairs, one in each bedroom that actually gets slept in, means the guest room at the end of the hall stops being cooled in July for no reason at all.
What I cannot tell you is how that three hundred forty dollars actually splits. Some of it is two window units cycling against a knee wall with nothing behind the plaster, some is electric baseboard somebody left switched on in a back room, some is the well pump and the dryer and the second refrigerator in the pantry. Nobody meters bedrooms individually, and the utility bill arrives as one number, so a contractor promising a specific dollar reduction is guessing confidently. The honest version is that you cut the load you can see and then read next August’s bill.
Questions To Ask Before A Site Visit
The site visit is where a real contractor separates from an order taker, and the separation shows up in what gets measured. Anyone quoting tonnage off square footage alone has not looked at the house. Bring a short list and write the answers down.
- Will you run a room by room load calculation, or size this from square footage? A good answer names Manual J and includes window area and the knee walls.
- Where exactly does the line set run, and what does that do to the plaster? A good answer walks you to the wall and describes how the penetration gets sealed and patched.
- How many indoor heads, and why that number instead of one larger head in the hallway? A good answer ties every head to a room somebody uses.
- What happens to the existing baseboard electric and the window units? A good answer says which stay as backup and which come out.
- Which rebates or financing apply here, and who files the paperwork? A good answer names the specific program and admits what varies by utility and by year.
The contractor who tells you the guest room does not need a head, because nobody sleeps in it between Thanksgiving and June, is telling you something useful. They intend to size the system around the way you live rather than around a chart. That is the one you call back.
See also: How an Online Religious Christian Community Can Help You Stay Spiritually Connected Anywhere
Pick The System The House Allows
Efficiency ratings matter here more than they would in new construction, because you are buying cooling that has to fight an uninsulated plaster envelope every hour it runs. An August 2026 home energy resource from the University of Maryland Extension states it plainly: units carrying ENERGY STAR certification typically cost more upfront than the cheaper alternative, and deliver substantial savings over their lifespan through reduced operating expenses. On a house currently running window units, that payback arrives faster than most owners assume. Buy the rating, not the sticker price.
The framework reduces to one question, and it is not which system performs best on paper. It is which system this particular house will accept without the cooling budget getting spent on drywall compound and paint. A 1926 farmhouse with original plaster and no chases answers that before anybody writes a quote: cool the rooms you use, one zone at a time, and leave the walls alone. That plaster has stood for a hundred years, and a cooling system is a poor reason to start taking it down.
