Announcements

Job offersmore »

Tweeting Growers

Top 5 - yesterday

Top 5 - last week

Top 5 - last month

Exchange ratesmore »




How much HVAC do I need to cool LED Lights?

At Thrive Agritech, they hear this question all the time, especially in the summer. "Our rule of thumb – it takes one watt of air conditioning to cool three watts of lighting. For a more precise calculation, there are a few things that we need to know about heat."
  • A BTU, or British Thermal Unit, is the traditional unit for heat or heat removal
  • A ton of refrigerant is 12,000 BTUs.
  • One watt of energy is equal to 3.412 BTUs
When you turn on a light some of the energy is turned into photons and some of the energy is turned into heat. In the case of LEDs, about 40% of the energy is turned into light and 60% is turned into heat.

Unfortunately…. you need to cool all of the energy, even the energy emitted as light. This is because the emitted photons will end up heating up the surfaces they hit. The heat/light ratio does impact your HVAC design but a good estimate is that you need to cool every watt of lighting.

Let’s assume you need to cool 10,000 watts. You will need about 2.85 tons of refrigerant
  • 10,000 watts x 3.142 BTUs per watt = 34,120 BTUs
  • 34,120 BTUs / 12,000 BTUs per ton = 2.85 tons
How many watts will 2.85 tons of HVAC consume? This is related to the EER, or Energy Efficiency Ratio, of the HVAC system.
  • kW/ton = 12/EER
Most commercial HVAC systems have an EER of 10-13 meaning the systems will consume 0.923 to 1.2 kilowatts per ton of refrigerant. A system with a 12 EER will consume 1 kWh for every ton of cooling.

In our example of 10,000 watts of light, an HVAC system would consume about 2,850 watts of energy to cool the room. This is very close to our rule of thumb of 3,000 watts.

For more information: www.thriveagritech.com

Publication date: 9/13/2017

 


 

Other news in this sector:

9/22/2017 UK: GrowSave urges growers to benefit from Climate Change Levy Discount
9/22/2017 UK: Making sense of changes to the Renewable Heat Incentive
9/20/2017 UK: GrowSave celebrates ten years of helping horticulture save energy
9/19/2017 US (MA): Oakham farm inspires 100 percent renewable energy goal
9/18/2017 "Energy storage is more than just batteries"
9/18/2017 Backup generation breakthrough for the smaller scale
9/15/2017 US government aims $50m at grid resiliency projects
9/13/2017 Don’t forget thermal storage along with batteries
9/13/2017 Positive forecast for CHP in post-election Germany
9/13/2017 Canadian geopower plant progressing steadily
9/12/2017 Koppert Cress shares experience with Certhon JSK units
9/7/2017 Minimizing the risk for your PV investment
9/4/2017 First Mexican industries to take advantage of cogeneration since energy reform
8/29/2017 UK: NFU buys FEC Energy
7/20/2017 Five advantages of energy curtains
7/19/2017 Canada: FPAC welcomes low-carbon economy fund announcement
7/18/2017 US: How cold climate communities eat and heat locally
7/14/2017 Greenhouses that generate electricity
7/13/2017 CAN (ON): Patrick Brown vows to scrap cap-and-trade
7/11/2017 US (CA): Automated water records to support Western growers