Lighting is one of the most significant expenses in operating a building. Typically, lighting is
actually the largest cost component of a commercial buildings energy bill.
So a lighting upgrade can be benficial in 2 ways; reducing power consumption and reducing power consumed by your oversized HVAC system.
How Does Lighting Impact Heating and Cooling Loads?
Older lighting systems are major producers of heat. For example, by comparing a 400 watt metal halide to a t5 energy efficient replacement you will see roughly 500 degrees difference.
The metal halide operates at 700+ degrees Fahrenheit compared to the 200 degree t5 fluorescent. This amount of drop will drastically impact your cooling loads (may have an impact on your heating load as well depending on your climate)
Most people think that weather is the largest influence on interior cooling loads. Not true though, lighting is the largest source of heat gain inside a commercial building.
While building owners are appreciative of that heat in the winter months, most often it is counterproductive when the hotter months come along. By updating your facility to energy efficient lighting, you will add less heat to a space per unit of light output than inefficient lighting.
When you reduce the overall heat gain in a building, energy efficient lighting reduces the building's cooling requirements.This can impact your building in many ways:
- Reduced loads mean cooling capacity can be used in other areas.
- When time comes to replace existing HVAC equipment, you should be able to utilize smaller equipment reducing capital expenditures.
- Future additions may not need updated equipment as you will have freed up capacity in your existing system.
The overall effect on HVAC energy use depends on several factors including;
- Type of building
- The climate
- Existing efficiency of HVAC equipment
- The size of existing HVAC equipment
How Much Can Energy Efficient Lighting Reduced Your Heating Load?
If you have a large building with large internal loads, and you use much more air conditioning than heating, it is possible for you to see a 40% reduction in HVAC by updating to an updated, more energy efficient lighting system.
Therefore, each kilowatt-hour (kWh) of reduction in annual lighting use, can equate to an additional .4 kWh reduction in HVAC use by reducing overall cooling loads more than it increases required heating energy.
Can A Energy Efficient Lighting Upgrade Actually Be A Penalty?
In small buildings, where the building already has a tight building envelope, the benefit may actually be a penalty. Instead of each kWh reduced, you actually increase the amount of annual heating energy required because you have reduced the heat gain within a building.
Overall, most energy efficient lighting upgrades in commercial buildings equate to a positive gain by reducing total energy consumption. The best way to know is to do your research upfront so you know what your getting before you make the installation.
Learn More About Energy Efficient Lighting
There are many factors to consider when updating your facilities energy efficient lighting system. To help you sort out all the facts, we created an e book to walk you through all the benefits of energy efficient lighting. Click on the book below to download your copy now.
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Metal Halide:The "Shocking Truth" In The Life Of A Metal Halide Bulb
How To Calculate Watts: 400 Metal Halide vs. T-5 High Bay Fluorescent
