HVAC in San Francisco is mostly a heating problem in a city that skipped central air. Radiators, steam boilers, wall furnaces, and floor furnaces still carry these houses. Ductwork is rare because plaster walls, tight chases, and multi-story flats were never planned around it. Summers stay foggy and cool, so a condenser on the roof is not the default need. The complaint is a room that never gets warm, a furnace that smells, a radiator that bangs, or a thermostat that does nothing for the back bedroom. A rare warm week only shows that there is no cooling path, and that is a different project from making the heat work.
Old heat equipment wants respect, not a shrug. A wall furnace that rolls out, a floor furnace over a crawl that has debris in it, or a boiler that leaks at the near piping is a safety conversation as well as a comfort one. Steam and hot-water systems need the radiators they have, the vents that work, and a look at whether the pipes are still sound. Adding cooling to a house with no ducts may mean a ductless approach in the rooms that actually overheat, which are often the ones under a flat roof, not the whole building. Forcing a full duct system through ornamental plaster is how a simple comfort job becomes a demolition.
Fog and wind change the load. Infiltration through old sash makes the heater run while the room still feels raw, which is a window problem wearing a heating complaint. Insulation is often thin. Closets that hold a furnace are tight, and they need combustion air and a service path. Roof equipment, if any, sits in salt damp and wind. Say whether you are cold all season or only miserable on the few hot days. Those are not the same call, and the building will not forgive the wrong one.
Tell the truth about what heats the house today. Name radiators, steam, a wall furnace, or nothing adequate. Say which rooms fail and whether you also want relief on warm days under the roof. The plan has to fit a foggy, duct-poor San Francisco building.
Call the number on this page.