A/C in the schools

[bob]

I don't believe there was a room when a class was in session that was 105 degrees.

[Arch]

bob said:

I don't believe there was a room when a class was in session that was 105 degrees.

May Watts, 5V read 105-108 and yes, class was in session.

[bob]

Windows in that room?

It is tough to believe that a teacher would continue class in a 105 degree classroom.

[Arch]

bob said:

Windows in that room?

Top floor, faces west w/ window

This was right after lunch.

[gatordog]

bob said:

Some weather average for Naperville
www.weatherreports.com/United_States/IL/Naperville/averages.html


Average number of 90 degree days over the last 30 years in Sept : 1

May: .5

Numbers can make all kinds of arguments, cant they?

I think a better representative number, than just days >90F may be "cooling degree days" indicated in your table
www.wunderground.com/about/faq/degreedays.asp


For which your link shows on avg "98 cooling degree days for Naperville in Sept.

Energy utilities and consumers use this to estimate cooling and (also heating) cost/usage. Also it can be used to compare different parts of the country in terms of heating or cooling cost/usage.

Maybe an HVAC expert can fully speak on this....
But following a comparision:
Naperville June avg "cooling degree days"=177
Naperville July avg "cooling degree days"=279
Naperville Aug avg "cooling degree days"=229
Naperville Sept avg "cooling degree days"=98


So lets compare A/C use in relative terms, relative to various summer months. Thus avg A/C use in Sept is:
about 55% of June usage (from 98/177)
OR about 35% of July usage (from 98/279)
OR about 42% of August usage (from 98/229)

There is a subjective value in cooling degree day calc (the temp to maintain for "comfort"). But the point here is that if you look at
the air conditioning usage in comparison to other months....its still a fairly significant fraction of use. (I think this fits with my home experience.)

My "take home point is:':
While the "need" or "usage" for A/C in Sept is only a half or a third of that needed for the summer months....this still amounts to a significant usage. The resource definitely would not be sitting idle, as implied by the argument that "there are only a handful of scorching hot days in Sept"

For me, this thinking in terms of "relative usage comparted to other summer months" is helpful. As we all know, numbers can make many arguments!

[bob]

So over 30 years there was only 98 cooling days in September?
May is 53

[bob]

from google

A cooling degree day is a unit used to relate the day's temperature to the energy demands of air conditioning. Cooling degree days are calculated by subtracting 65 from a day's average temperature. For example, if the day's high is 90°F and the day's low is 70°F, the day's average is 80°F. Eighty minus 65 is 15 cooling degree days. Cooling degree days can be used to compare the current summer to past summers. It can also be used to compare the heat in one part of the country with another.

[Arch]

Bob, go to Watts right now if you can.

Nice and breezy outside.. Inside: swamp-like, muggy muggy muggy, humid.

[gatordog]

bob said:

So over 30 years there was only 98 cooling days in September?

98 is avg for each Sept, over last 30 yrs.

I am just thinking of ideas to quantify "need", not always an easy thing to do...ask my teenage

[Arch]

Averaging temperatures that include the lows (pulling down the avg temperatures) that are reached at 3-5AM is nothing but silly because children are not in class then. They are there in the hot times of the day. Their bodyheat and exhales add to the inside temperature.

Actually GO there and see what is being talked about.

[bob]

Arch, I trust you.

Like I said before, let's bring it to a vote.

[gatordog]

archwinsome said:

Averaging temperatures that include the lows (pulling down the avg temperatures) that are reached at 3-5AM is nothing but silly because children are not in class then. They are there in the hot times of the day. Their bodyheat and exhales add to the inside temperature.

Actually GO there and see what is being talked about.

Good points. This cooling deg day stuff is I think largely used for residential, so its based on 24 hr days...so you get credit for low night time temps. Also it ONLY looks at ambient temps since residents of course dont have large numbers of bodies.

I think its true for auditoriums, and such, sometimes the dominant factor in sizing the A/C unit isnt ambient conditions...but the human occupancy load.

[bob]

My spouse would vote for a AC referendum.

Divided house!!!!!

[gatordog]

bob said:

My spouse would vote for a AC referendum.

Divided house!!!!!

Is this an extension of a common (at least at my house) spousal "dispute" ....who gets control of the thermostat at home?!? ;D

[Arch]

"Let's compromise... go take a cold shower!"