# IT Employment

## General discussion

• Creator
Topic
• #2192136

### Calculating heat dissipation of CRT monitors

Locked

by kabongo007 ·

Hello,

I am curious if anybody knows a way to calculate the amout of heat given off by a CRT monitor. I am try to figure out operation costs right down to the finest hair (AARRRGGGG). And I need to find out how much \$\$ can be save by switching to LCD displays. I need to get an average on how much the cooling cost of my call center will be affected by the change.

• Author
Replies
• #2503403

### Measure the current

by benzzz ·

In reply to Calculating heat dissipation of CRT monitors

If you wish the type of accuracy you say, then measure the input current of the monitor. Obtain an AC multimeter and fashion a connection that allows current to flow through the multimeter. Power is voltage times current. Voltage is usually consistant. If the voltage is not consistent then you will need a second mulyimeter to measure the voltage. The best way is to read the power requirements on the back of the monitor. Good luck and be careful.

• #2524600

### More of a question than a comment/reply

by egbrown ·

In reply to Calculating heat dissipation of CRT monitors

Were you ever able to complete your calculations and if so are you willing to share your results?

Thanks,
egbj

• #2524595

### Not for nothing, but isn’t this being a bit too anal about details?

by why me worry? ·

In reply to Calculating heat dissipation of CRT monitors

I can understand calculating the cost of ownership based on power consumption, which equates to how much money is spent on electricity, but to go crazy and calculate the amound of heat a monitor produces and how it relates to operating costs is simply too anal. Heat calculations are more important for data centers where you need to determine your cooling capacity and cost of air conditioning and ventilation, but for a desktop monitor, it’s so miniscule that you’d be wasting your time on this.

• #2524591

### Heat is power

by dr dij ·

Every watt going into the monitor turns into heat. That is the easiest way to put it. The emitted light hits the surroundings also and turns into heat. LCDs are about half the juice or less.

So to calculate actual operating costs, every watt of heat is doubled to include the A/C electricity to remove it. You’d need to estimate how many hours monitor is on (8 or 9?) and how much it consumes when in power save mode.

I’m not sure you need an ammeter tho this would be more accurate – these figures are probably about the same for many monitors and they are in theh owners manual.

• #2909200

### Thermal Dissipation

by garen.martinson ·

In reply to Heat is power

Start with the monitor itself and find out what it’s Thermal Dissipation is in BTUs/hr. For a CRT monitor, this will range from 200 to over 300 BTU’s per hour. You can also determine BTUs by the formula- BTUs/Hr= watts x 3.41. Since 12,000 BTU’s equals 1 ton of AC, you can determine how many tons of AC are required. Depending also on the SEER (Seasonal Energy Efficiency Rating) of the HVAC system providing cooling, this cooling cost will range from 1 KW/Hr to over 2 KW/hr. The avg to use would be 1.335 KW/hr per ton of AC. Good luck.