Weird OT mystery...

[Silvan]

I'm sitting here in my skivvies, sweating. I turned the air conditioner off an hour ago because it was getting cold in here.

This is November mind you. In the mountains of Virginia.

It got up reasonably warm today, maybe 70-something. It rained a lot, and was generally overcast. Not very much solar radiation getting in to warm the place up. Around 10:00 PM the heat became so intolerable that we actually turned the A/C on and let it go for around half an hour.

So now it's about 1:00 AM. Somewhen between then and now the air has picked heat back up from somewhere, and I'm scratching my head trying to figure it out. It's back up to 81 degrees in here, and it was down to 71 at 10:00 PM. No sun in that time. No electric heat, no propane heat...

Could be waste heat from the big dehumidifier that has been chugging 24/7 in the crawlspace for the last six months maybe.

Residual from the hot water heater that really needs replacing very soon now.

Halogen lights...

Still, adding all of this up, it's about 1500 sq. ft. of open space in here, and it would take a lot of BTUs of heat to raise that much air by 10 degrees.

Could it be a simple matter of body count? House empty all day, then four big'uns, two little'uns and three furry'uns? (Three medium sized dogs.)

I won't be complaining about free heat in a few more weeks, mind you, but it's a real mystery. I'm wondering if I have some problem developing.

[admin]

*Everything* contributes.

I forget how many BTU/hr a person puts out, at rest, but _occupied_ school buildings almost -never- run the heat plant at temperatures above *MINUS*

*TWENTY*FIVE* Farenheight. The warm-body factor is enough that they're dumping heat to the outside.

Other things, like the _refrigerator_, the dehumidifier, lights, the TV, computers, etc. -- they all add up. non-trivially.

Betcha you've got several kilowatts of electric load that you don't even

-realize- are running.

Plus all those "warm bodies".

An additional point -- *rain* releases _tremendous_ amounts of heat into the atmosphere. 1" of rain, over a medium-sized city, say one the size of Omaha, NE, releases more total energy than a mid-size atomic bomb. Not from lightning, etc. -- just from the reverse 'heat of vaporization' released by the water-vapor condensing out.

Now, +most+ of that heat is released at higher levels in the atmosphere, and you'll freqently get some 'evaporative' cooling at/near ground level. but, it's not uncommon for ground-level temperatures to climb by several degrees, several hours after the rain.

[Doug Miller]

[snip]

Possibly. I seem to recall reading that the heat output of an adult human is around 500 watts asleep, and 750 watts awake, but I could be imagining that. Dogs have a higher body temperature than humans, too.

Well, you might. Does anyone *else* think it's too hot? 81F isn't hot IMO. That's a comfortable-in-tee-shirt-and-shorts kind of temperature, not a sweating-in-your-skivvies kind of temperature. If you're the only one sweating, it might be time to call a doc (or at least get out a fever thermometer). Have you been drinking enough water?

-- Doug Miller (alphageek at milmac dot com)

How come we choose from just two people to run for president and 50 for Miss America?

[Silvan]

SWMBO stripped down to her skivvies too.

No, unfortunately, that didn't lead anywhere interesting. :(

The kids both kicked off their covers. It wasn't just me.

Maybe we got microwaved by aliens from another galaxy. :)

[Charles Krug]

Just for kicks, do a rough estimate of the volume of the space David Blaine occupied in that block of ice. Then using 2500Cal/day as a rough first-pass, figure out what the temperature of the air in that small space was. Heck, be generous and say he only put out 2000Cal/day.

Plus, he was given hot soup to eat.

Nice work if you can get it, assuming one isn't claustrophobic.

n.b. that keeping himself dry and keeping bare skin away from wet ice were nontrivial concerns.

[mrdancer]

Brick house? They can retain quite a bit of heat within the bricks for a few days. That or a very-well-insulated house and all them bodies....

Did you turn the oven off? ;-)

I have my computer in a bedroom converted to an office. That rooms stays pretty much five degrees warmer than the rest of the house just from heat generated by the computer. If you have a computer over 1Ghz, particularly an AMD system, it doubles as a room heater. Ditto for an inefficient computer monitor.

[George]

Cold fusion?

Come winter we're so desperate for heat and humidity that we filter the dryer outlet and dump it indoors. Makes the choice of fabric softener scent more important than in the summer when we hang out....

[mttt]

Spontaneous Human Combustion. I read about this... You're in the early symptoms phase. Start sleeping with a fire extinguisher.

[Charlie Self]

mttt responds:

My first wife works somewhere around B'burg: she'll do as well as any other fire extinguisher.

Charlie Self

"I think there is a world market for maybe five computers." Thomas J. Watson

[David Hall]

SNIP

Huh?! I am the Business Manager for a school district near Pittsburgh, PA. It NEVER gets to -25 F here. I don't think it even went below 0 last winter. We seem to run the heating systems all winter though and spent a total of $350,000 for natural gas last year for 9 buildings. I doubt that body heat can do much for heating significant spaces and if there were enough bodies in the space to heat it when it is -25 outside then the CO2 being given off would kill everyone if there wasn't a MAJOR fresh air exchange going on...not to mention the smell ;)

Dave Hall

[Joe Gorman]

[BRuce]

I think your numbers are correct but it is BTU per hour. Not trivial but not a huge source. my house here in NC gets much warmer after sunset. the heat trapped in the attic tends to start leaking into the living space after about 10 hours. Insulation only works so long. It is a cathedral ceiling so no way to exhaust the waste heat.

BRuce

Doug Miller wrote:

[Lewis Hartswick]

In the HVAC ( heating venilating & Air Conditioning ) racket we use to figure

500 Watts per person (warm body) :-) ...lew...

[ranck]

Same thing happened to me last night, and my friend at work and I were talking about it today. He had the same thing happening.

Yep, kicked in around 10PM last night. Even my wife thought it was hot, and she almost never thinks it's too warm.

Whatever it was, it wasn't just you and your place. It was happening on my side of town too.

I'm guessing some sort of atmospheric pressure change combined with the humidity.

Bill Ranck Blacksburg, Va.

[solarman]

Might be you are too close to all those politicians spouting a lot of hot air.... that or it is some sort of government experiment and you need that aluminum foil hat on... Same problem here in Atlanta...

[Nova]

-- Jack Novak Buffalo, NY - USA (Remove "SPAM" from email address to reply)

[mttt]

Now *that* made me grin! I'll confess there was a 5 second lag time before I got it... :)

[Charlie Self]

mtt responds:

Would have taken longer than 5 seconds if you'd married her.

Charlie Self

"I think there is a world market for maybe five computers." Thomas J. Watson

[Rick]

Dave,

The old science building at the University of Pittsburgh at Johnstown (built in the early 70's?) was so energy stingy, they only had to run the heat during the Christmas break ... because there weren't any bodies to keep it warm. Rest of the time they had a heat surplus without the stale air syndrome.

Also ...

shows record low temperature for Pittsburgh area ... pretty close to -25!

Rick

[Edwin Pawlowski]

Body heat sure adds up. I used to work for a company that built heating and AC units for commercial and industrial applications. Schools were one of their largest markets.

Body count is very seriously taken into consideration when calculating heat loads. IIRC, it is 485 Btu per person. or enough heat from 100 people to heat a small home.

Ever go to a concert or sports game in an arena? Notice how cool it is when you first arrive and how much warmer it is when the crowd fills the place? And yes, air exchange is also considered. Often the heat is off and the ventilation is bringing in the cold outside air to cool the place down. Ed [e-mail]