Hundreds of people responded to our July 29 Tech Analysis on LCD vs. CRT monitor technology.Hundreds of people responded to our July 29 Tech Analysis on LCD vs. CRT monitor technology. A large majority of these respondents said we understated energy claims by not factoring in HVAC costs (which we did, albeit stealthily).
Others said that size does matter with LCDs because they can reduce cube and storage space and help curtail injuries for those who have to move them. Heres a representative sampling of letters:
I enjoyed reading the article "Are LCDs still a luxury?"
One thing to keep in mind, though: Switching from CRTs to LCDs helps save money by reducing air- conditioning costs, although I still doubt the energy savings would be enough to justify a price savings. —Mike Newman
A few things that I have found need to be included in the cost analysis that you didnt include:
1. For every watt of energy expended on a monitor, you have to use more energy to move that heat out of the office space with the cooling system. So you can usually double or even triple the energy differential due to increased cooling costs, depending on the efficiency of the cooling system in your office space.
2. One of the most common injuries I have had with my support staff is strained backs from lifting and handling CRT monitors. The [medical] costs and lost time this creates [are] highly variable but almost never cheap. If you are self-insured, this can easily run $50,000 to $200,000 per event.
3. Storage and work space for spares and to manage the repair return cycle. Usually, IT is crammed into small spaces for their work. Managing a stack of spare 17-inch CRT monitors in your [telecom] closet on Floor 27 is a real situation to most of us in the IT support business. These new monitors are so much smaller [that] they save lots of storage and work space for IT.
4. On the negative side, these units have "street appeal," and due to being smaller and sometimes fitting in a large briefcase, theft losses are a larger issue. We rarely see CRTs stolen, as the value per pound and cubic foot is much lower. LCDs are another story. —Jeff Johnson, vice president, IT, Callisma Inc.
One thing often overlooked in these calculations is the cost of cooling.
Much of the 100-or-so watts used by a CRT monitor becomes heat in an office space. Even in colder climates, this heat has to be sucked out of the building somehow (that is, air conditioning). While the difference is not great for a small office, the differences become more significant when you are in a building with 5,000 monitors, each kicking out 100 watts of heat all day.
My engineering expertise is not in the HVAC field, but in todays tightly sealed office environments, each monitor requires some incremental portion of the building cooling capacity. All other things being equal, the laws of thermodynamics say that it takes more than 100 watts of power to cool down the heat generated by 100 watts of monitor.
When you factor in building cooling requirements, LCD panels get even more of a boost.
—David Claiborne, owner, The Claiborne Co., Annapolis, Md.
Green IT and Green Computing 
