T5, T8, T12
Designations of tubular lamps of 5/8, 8/8, or 12/8 inch diameter respectively. See comparison chart.

Tanks and vats
Process equipment in which there may be opportunities for reduction of heat loss (particularly from open liquid surfaces) and mechanical power used in stirring or agitation. More..

Either best achievable consumption - that which would be expected in the absence of avoidable inefficiency and loss (operating target) - or a lower, more challenging, level of consumption which may not be achievable without exceptional effort (aspiration target). Read about methods of setting operating targets

Total dissolved solids: measurable attribute of water in a steam boiler. High TDS levels cause operational problems but excessive use of blowdown to reduce TDS carries a cost penalty in wasted energy and treatment chemicals.

Test equipment
See this recommended list of test instruments.

See what courses are currently available from vesma.com. There is also a list of other known providers.

In steam systems a device which permits passage of condensate but not steam. Defective and bypassed traps waste steam.

Travel and transport
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Thermostatic radiator valve. Self-acting control device regulating the water flow to a heat emitter such as a radiator.

Transmission use of system: charges incurred for transmitting electricity across the National Grid network from the source of generation to the network of the local distribution company.

Twenty-year average degree days
Published for standard UK regions and used as a means of estimating future monthly degree-day values, principally for budget estimation. Download Excel tabulation