OT Which direction is your ceiling fan SUPPOSED to run?

[rickman]

What exactly is "cool red tile"? What is different in it's construction from hot red tile?

I looked at the reference and I'm not sure I understand what they are measuring. I learned many years ago that a surface can not have different abilities to absorb or emit heat. If it did it would spontaneously warm up or cool down. But I suppose it can be a matter of different rates of emission/absorption at different wavelengths. Solar is IR, visible and UV. Once warm, the heat from a surface would be IR, possibly long wave IR. So I suppose you can achieve an advantage by having a low coefficient at the shorter wavelengths and a higher coefficient at long wavelengths resulting in higher emissivity at night and a lower absorption during the day.

[Jeff Liebermann]

Thanks. I wanted to buy a house "away from it all" in about 1974. At the time, only about half of the houses in the neighborhood were occupied year round. The rest were vacation houses, Section 8 housing, and methamphetamine factories. It was common for the dogs to sleep in the roadway. That worked well until the 1990's, when living in the trees was deemed fashionable that everything I was trying to get away from moved in next door. That's not really bad news as the local infrastructure has gradually improved over the years, and rising home prices has introduced a better class of residents. Be careful. This type of progress can also happen to you.

Hmmm... that's about what I would expect from a concrete slab floor. The thermal sink it provides is substantial. If it has cold water pipes running through it, even better. You might try the same test with the HVAC and circulation fans turned off. I did that once (when I was complaining about the air conditioning not working) in my palatial office (thin carpet on slab with a 3ft suspended ceiling with minimal insulation). I vaguely recall almost no differences with the fans going, but about 15 or 20F difference after about 2 hrs in still air. This is measuring air temp with a thermocouple probe, not an IR thermometer. However, we had a new roof installed late last year and I should probably retest this again. The new reflective roof is noticeably better than the old asphalt black roof.

[trader_4]

That's true, but it has nothing to do with your claim that turning on the central AC and the heat at the same time is "exactly the same" as running a dehumidifier. They are very different.

The opposite of evaporative cooling is condensative

Which again, has nothing to do with the claim. If you run an AC, you're taking heat from *inside* the house and pumping it *outside*. Your suggest ion to turn on the heat to make the AC run more without lowering the temp, means that now you're burning gas or using electric resistance heat, etc, to make up for that lost heat that just went outside. It is not at all like using a dehumidifier. If you want to lower the humidity while not lowering the temperature, it's far more efficient to do that by running a dehumidifier than it is to do it by running the AC and heat at the same time.

It is the whole point, CL is right.

.

The guy is running a humidifier in his bathroom. That isn't going to raise the temp of the house by 2C. A dehumidifier is about 500W. Can you raise the temp of a whole house by 2C with just 500W? And even if it did, you'd be far better off running the dehumidifier to reduce the humidity and running the AC to reduce the temperature by the 2C, than you would be running the AC and the heat at the same time.

[Jeff Liebermann]

We're scraping bottom on my knowledge of construction practices. Other than falling off a tile roof, I've never build or specified one. I think the article refers to tile coatings, not the actual tile itself.

Googling for cool red tile coatings: Looks like you can get IR reflective roof tiles in any color EXCEPT red. Maybe they mean terra cotta which is kinda red and has the highest IR reflectivity? Oh wait, you can get the coating in cool red (also known as Thai Pepper):

Yep. That all makes sense. Looking at the definitions for SR and SRI, there are multiple factors (refection, absorption, emission, roof slope, etc) involved in calculating the indexes. Nothing is simple.

I found some detail on the difference between SR (solar reflectance) and SRI (solar reflectance index). (note the assumptions).

More:

[Stormin Mormon]

252 lines of text -- please trim.

A dehumidifier contains a motor of some number of watts. So it puts electric heat into the room.

If the dehum is broken and runs all the time without removing humidity, it can really increase your electric bill.

[Stormin Mormon]

Culturally insensetive. Like kicking puppies.

[DecadentLinuxUserNumeroUno]

On Sat, 05 Jul 2014 18:25:01 -0400, Stormin Mormon Gave us:

You have more on the ball than some folks give you credit for.

[rickman]

In what culture is kicking puppies acceptable?

[Arnie Goetchius]

I'm still working on the training issue, after 56 years :-)

[krw]

I was ready to say Democratic, but that would presume they have or even care about culture.

[krw]

Actually, I just got back into town for vacation. It's fun laughing at all the lefties, knowing that they're not getting any (well not much) more of my taxes.

[Stormin Mormon]

Thanks! Here is a self portrait.

[Stormin Mormon]

Usenet?

[krw]

Yes, quite nice. Do you have problems with mold/mildew because of the trees in such close proximity?

Larkin? Never. SF is too much of a dump. He's more likely to have a Google bus parked in his driveway while they pick up the illegal programmers next door. ;-)

I didn't like a slab floor of the Alabama house. Too cold on the feet. Even in the South, the slab made it cold in the Winter and I had to crank up the thermostat as the Winter went on (and the ground cooled).

[clare]

Did I ever try to suppress your views? Force you to be quiet? You are entitled to the opinion. I'm just giving you my opinion that it makes you look tike a totally unballanced fool.

[clare]

I think the LED potlights are going to appreciate the lower temperature too. And with the 6 workstations on the high step being so much higher than the 11 on the bottom floor, the fan keeps them a lot cooler without freezing the butts of the the other 11.(and cuts the run time of the AC significantly)

[clare]

Next time the flat roof on the neighbour's house leaks he's building a truss roof on top of it - solve the leak and heat problems in one fell swoop. Perssonally, I would NEVER own a building with a flat roof.

[clare]

exactly what I said Goodbye

[clare]

595 watts for my 40 pint dehumidifier (5.8 amps). My old 20 pint unit drew 200 watts (1.8 amps running) (just checked) That's less than the heat from my office lights (before I switched to LED lights)

[clare]

And she likely thinks she is making less headway in that department than you, if she's anything like mine