Replacing a tired central air system or adding cooling to a house that has only ever had heat? Confluence Heating & Air designs and installs split-system air conditioners for Dayton and Miami Valley homes. Free in-home estimates, sized for your house rather than the old label.
Tell us what the Dayton property is doing and we'll take a look.
Dayton's cooling load is modest on paper, about 900 cooling degree days a year in the 1991-2020 normals, but the air is wet. Morning relative humidity in July averages above 80 percent in the long-term records for the city. That changes how an air conditioner should be sized. The temptation is to go big so the house cools fast. The result of going big is a unit that hits the thermostat setpoint in ten minutes and shuts off before it has removed much moisture, leaving the house at 72 degrees and clammy.
The right approach is a Manual J load calculation that accounts for both sensible heat (temperature) and latent heat (moisture), then a unit that matches the total closely. In most Dayton homes that comes out smaller than what is being replaced. A right-sized system runs longer cycles, pulls more water out of the air, and is quieter and cheaper to run. Two-stage and variable-speed outdoor units make this easier still, running at low capacity for hours on a muggy 80-degree day and only stepping up on the handful of 90-degree afternoons the region gets.
An air conditioner is a system, not a box in the yard. The outdoor condenser, the indoor evaporator coil, the refrigerant line set and the furnace blower all have to be matched. Putting a new high-efficiency condenser on a fifteen-year-old coil with a different refrigerant or the wrong capacity wastes the efficiency you paid for and, on mismatched refrigerants, is not permitted at all. Replacement estimates include the indoor coil, and the blower speed is set for the coil and duct system at startup.
The line set is checked as well. Older copper runs may be undersized for the new unit, kinked, or contaminated with mineral oil from an R-22 system that is incompatible with current refrigerants. When it can be flushed and reused, it is. When it cannot, a new line set is in the quote.
Ductwork in Dayton's older houses is the limiting factor more often than not. Supply runs that were adequate for heating are often too small for the higher airflow cooling needs, and returns are almost always short. The estimate includes a static pressure reading and, where needed, the duct corrections that let the new system actually deliver its rated capacity.
The old condenser's refrigerant is recovered, not vented, and the unit is removed. A level pad is set outside with clearance from the house and vegetation for airflow and service. The new indoor coil is installed on the furnace or air handler and sealed to the plenum; the condensate drain is run with a trap and a float switch so a clogged drain shuts the system off instead of flooding the furnace.
The line set is brazed with nitrogen flowing to keep the inside of the copper clean, pressure-tested with nitrogen to confirm there are no leaks, then pulled into a deep vacuum to remove moisture and air before any refrigerant goes in. Those steps are the difference between a system that runs for eighteen years and one that has a compressor failure in five. The refrigerant charge is weighed in per the manufacturer's data and then verified by superheat or subcooling under running conditions.
Electrical work includes a new disconnect at the unit and a whip to the condenser, with the breaker sized for the new unit's rating. Permits are pulled where the jurisdiction requires them. Startup records the temperature split, pressures, amp draws and static pressure, and you get the sheet.
Many Dayton homes built before the 1950s have a furnace and ducts but have never had central air, or have a window-unit habit in every room. Adding a coil and condenser to the existing furnace is often straightforward if the ductwork can carry the airflow and the blower can be sped up. When the ducts cannot, the options are duct modifications, a high-velocity small-duct system, or ductless mini-splits in the rooms that matter most. The estimate visit looks at all three and gives you honest numbers for each.
For houses with radiators or baseboard heat and no ducts at all, ductless is usually the practical route, and that work is covered on the heat pump and mini-split page.
Questions
It depends on square footage, insulation, windows, orientation and air leakage, which is what the load calculation measures. Many Dayton homes being quoted for 3.5 or 4 tons on the old unit's label come out at 2.5 or 3 tons on the calculation. Smaller and right is more comfortable than bigger and wrong, especially for humidity.
If the furnace is healthy and its blower can move the air the new coil needs, it can stay. If the furnace is near the end of its life or is a single-speed unit that limits the AC's performance, doing both at once saves labor and lets the equipment be matched. Both numbers are in the estimate.
New residential systems have moved to lower-global-warming-potential refrigerants under federal rules. The technician will explain what the quoted equipment uses and what it means for service and parts going forward.
Only if the cause is capacity. More often the cause is ductwork: not enough supply to the second floor and no return up there. The estimate identifies which it is. Sometimes a duct correction or a ductless head for the upstairs solves it more cheaply than a bigger system.
Call the local line or send the form, and we will get back to you to set up a visit.
Request a free estimate Call (937) 719-5148