TS compressors advance heat pump system operation beyond ‘stop’ and ‘go’

BRISTOL, Va. — A relatively new air conditioning technology called TS (Twin-Single) allows one a/c or heat pump unit to work like two separate systems. This gives the system two different capacities for different heating and cooling conditions.

The technology, developed by Bristol Compressors and formally introduced last year (The News, January 5, 1998), allows the system to match its performance to the capacity that is needed at the time.

“An air conditioning system is sized for a home based on the most extreme conditions that may be encountered,” said Michael Young, Bristol president. “That really means that it only operates at its top effectiveness for a few days a year.

“The rest of the time it’s working harder than it has to. It’s almost like driving a car as fast as possible between stoplights — it’s not the most efficient way to work.”

TS technology lets the system’s key component, the compressor, run at full or partial capacity. This allows the system to adjust to different conditions.

How TS works

The TS technology compressor is based on a two-cylinder reciprocating design that has been used in the industry for years. The difference is that the TS compressors can operate in both forward and reverse directions.

In one direction, both pistons operate, giving the system full power. When reversed, a special crankshaft design allows one piston to remain idle, allowing the system to operate at 40% to 50% capacity.

“It’s a very simple concept,” said Young. “But it has remarkable impact on how air conditioning system manufacturers can design their products.”

Young listed several benefits of the technology.

Improved comfort: The systems are said to control humidity and indoor air temperature more consistently, keeping the indoor envelope more comfortable. It is also possible to reduce fan speeds, resulting in less blower noise indoors.
Higher efficiency at lower cost: The technology allows manufacturers to step systems up to 12, 14, and 16 SEER more cost effectively than in the past. This may make higher-efficiency systems more price competitive, and save consumers money in both the short and long term.
Better-sized heat pumps: Since most air conditioning and heat pump systems are sized based on air conditioning needs, the heat pump is often undersized, Young said. The extra capacity of TS technology allows a heat pump to operate efficiently at lower outdoor temperatures, improving indoor comfort.
Greater reliability: The systems operate on lower capacity, reducing bearing loads and other stresses. The system cycles on and off up to 75% less than traditional systems, reducing wear and tear.
System standardization: Manufacturers can standardize production lines by building different SEER ratings using a single TS compressor. The smaller system chassis allows for more units to be shipped in a single truckload.
Multiple evaporator operation: The two capacities mean it is useful for operating multiple evaporators with one outdoor condensing unit. This cuts system costs and makes zone heating more effective.
“The system is more efficient, there is less stress on components, and ultimately, there’s more comfort in the home,” said Young.

The technology is currently being tested by more than 30 air conditioning and heat pump system manufacturers. The first production systems are scheduled for availability this spring.