Control off or reduce lighting in a thermally light building

Electric savings is from the hours the lights are now off, compared to existing hours of operation (or reduced wattage if de-iamped).

Excess heat from inefficient lighting also adds cooling load during cooling season.

Excess heat from inefficient lighting is actually part of the building heating but at the efficiency of electric resistance heating This loss of beneficial waste heat in winter subtracts from measure savings. The winter energy loss is equal to the heat output saved from lighting.

The amount subtracted from the measure savings is the avoided lighting waste heat, less the corresponding HVAC heating input needed for the same amount of heat.

So, the reduced heat loss from better lights means the HVAC heating system must increase output to compensate Unless the building heating system is electric resistance, the HVAC heating system will be more efficient at producing heat than waste heat from lighting.

Note that for buildings with electric resistance heat this would result in no overall savings during heating season.

If heating and cooling seasons are reasonably balanced, it may be acceptable to ignore both effects, as counteracting.

Use night-time unoccupied mode and morning warm-up in lieu of constant conditioning

During unoccupied periods when the indoor temperature drifts between occupied and ambient temperatures, skin loads reduce proportional to the reduced dT.

Rule of thumb: 1 % savings per degree of setback, If kept there for at leasts hours.

If electric heat is used, a pitfall can exist in the morning warm-up by increasing electric demand, reducing or negating the measure savings, especially if there Is a utility ratchet clause.

Avoid this by bringing the building up in segments, allowing sufficient time between stages to prevent large demand events.

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