mahiluana
Well-Known Member
if you store your produced heat in a heatexchanger outside of your grow room,how to recapture the heat as energy to use for cooling the room in the summer.
you can keep your room temp. low by using hot water in kitchen, shower, washing-machine,
swimming-pool...........the temperature of your lamp can reach ~ the temp. of your incoming service water.
how can you be shure to reach 45% light efficiency ???The setup I have is more efficient than 25/75 light/heat, it's closer to 35-45/55-65
you can find out easiely the exact values for your chip(s) and driver.
and i guess you will be surprised.
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i did a strange, "exciting" test to know this a bit more accurate.
I wired a Cree 2530/ 5000K/ T4 to a 10W @ 300mA led driver.
I wanted to be shure to use a middle class quality chip and run it under low current efficiency.
My wattmeter showed 10,9W / Vf = 32,4V @ 300mA.
All calculations of temp. change and heat energy you can do here:
https://rechneronline.de/chemie-rechner/heat-capacity.php
I wrapped the chip into a waterfilled "ballon" 0,175kg of water and switched the light on.
After 30 min. the temp. rised from 25,4°C to 40,5°C ---> 6,2W during 1800 seconds.
I estimate the power loss for the led driver ~ 0,5W
So 10,9W(powermeter) - 0,5W(led-driver) - 6,2W(heat energy) leaves 4,2W for the light.
Light efficiency is 38,5%.
Today i repeated the same test, but only 20 min. - I wanted to know more about the heat loss
or heat transfer to the ambient.
After 20 min. the temp. rised from 28,4°C to 38°C --->5,9W during1200 seconds.
Following the water temp. of the ballon cooling down in the room i measured 9 min.
to take the temp. down from 33,7°C to 32,7°C. ---> 1,2W / 9min. = 2,6W / 20min.
This must be more or less my average heat transfer loss to the ambient and is bigger than i thought. You have to add it to the bill.
UUUUOUPS - that`s bad for light efficiency.
New calculation is: 10,9W total - 0,5W led driver - 8,5W heat energy --->
my light efficiency is just 26,6%.
Any coments, questions and critic is welcome - on the pics you see simple things for the measurement,
that you can find in smart lighted household.