US 3384155

Patent Overview — US 3,384,155

Title: Air conditioning system

Assignee: Borg Warner Corp (original and current assignee as listed)

Inventor: Alwin B. Newton

Key dates: Priority/filing — 1966-01-24; granted/publication — 1968-05-21; anticipated expiration — 1985-05-21 (status: expired).

Purpose and plain-language scope:
The patent addresses a multi-room air conditioning installation in which a single main water supply-and-return conduit (constituting a "single pipe system") interconnects a water chiller, a heater/boiler, and multiple room units via supply and return risers. Unlike a conventional two-pipe system—limited to circulating either hot or cold water to all units at once, making accurate control impossible under intermediate conditions—this arrangement permits heating in some rooms and cooling in others. Hot and cold water are circulated alternately through the single line; the cycling time (ratio of cold-water to hot-water circulation) is varied according to overall cooling and heating needs, and cycling occurs often enough to maintain good temperature control in all zones. Each room unit withdraws water from the supply line only when the circulating temperature matches its thermostatic demand (hot for heating, cold for cooling); otherwise it bypasses. The disclosed control (FIGURE 4) uses switches responsive to room temperature and water temperature, with a solenoid valve opening only when the corresponding contacts align. A modified form (FIGURE 5) varies fan speed via a solid-state motor speed controller signaled by two thermistors in thermal relation with the conduit.

Source: https://patents.google.com/patent/US3384155/en

What the excerpt does not establish: The supplied text is excerpted and does not establish the full claims, the complete specification, the exact operation of all figures (e.g., FIGURES 6–8 are only captioned), the identity or content of any prior-art references, or any legal conclusions regarding validity, enforceability, or ownership transfers.