Thermodynamics and Money Fun

[digitaldiscipline]

So, I got my IRS refund in the mail yesterday.

Rather than paying off a substantial chunk of what I owe the fine people at Discover, I may be turning it into a new air conditioner & heater.  The TECO auditor (Richard - looks a bit like the actor who played Sphinx in "Gone in 60 Seconds" - very personable and knowledgeable dude) has just been here and pointed out that the 2.5 ton a/c unit we've got here at GMBAN is running at nearly its full rated wattage, but only heating and cooling about half as well as it ought to be (heated air, with a strip-style system like ours, should come out of the vents between 90 and 100F, ours is in the 78-82 range; cooled air should be >15F below the ambient indoor temperature, ours is 8-10F), which means that it's running twice as long as it ought to in order to normalize or maintain ambient temps.  On the upside, the element I put in the hot water tank draws its rated wattage, and only takes ten minutes to do the job after I take a long shower.

Free energy tip:  If nobody's home for more than 4 hours, turn the a/c or heat off - it takes less energy to re-heat or re-chill the house than it would to maintain the temperature in your absence.  Cats & dogs can handle the temporary climate fluctuations (after all, they survived for thousands of years outdoors); not sure how well fish tanks are for maintaining thermal status quo.

R40 in the attic:  Big plus (R30 is all that's necessary, but it was a freebie when I bought the house).
Subfloor insulation: Also a plus, but not as big a deal
Double-paned windows:  He said that good, well-sealed (vinyl, or vinyl-coated) single pane units are sufficient, but if you can get double-paned ones for a similar price, to go for it.  This is -so- not in the budget right now. . .

Eliminate direct sunlight on East/South/West windows.  Either put up awnings, greenery, or trellis-style stuff.

Shit I didn't know:  Ceiling fans only help if you're in the room with them.  I had thought that moving the air around would help normalize temps.

So, I'm going to be comparison shopping for 12-rated a/c units with heat pumps (probably a couple grand, but there's a $250 credit from TECO for upgrading/replacement).

Comments

[angel-renewed.livejournal.com]

not sure how well fish tanks are for maintaining thermal status quo

Largely depends on the tank and the variation you're talking about. Stability is key. I had turned the a/c off on Sunday to open the doors and forgot to turn it on yesterday. The big tank can handle an increase of a *few* degrees in the house without a problem. The little tank cannot (partially it's because of where it is located) and the temp waivers a great deal easily. There were some *very* unhappy members of the CLO to deal with when I got home. I didn't have a tank for years because the Ghetthome in Indianapolis didn't have central air and I knew I couldn't keep the temp. stable enough for a reef tank.

we won't be turning the a/c off, but we do keep it in the upper 70s full-time. Also, we have no issues with direct sunlight. Our home is in the goth zone and gets very little light at all.

[hellsop.livejournal.com]

fishtanks normally have heaters to maintain temperature, and while those can't manage against freezing temps, properly-sized heaters are usually good for maintaining a tank temp against down to about 60F ambient. I've never seen a tank chiller though, so turning off AC in warm weather may not be a great plan.

('Course, my knowlege is 20+ years old, and I never dealt with anything pickier about water than piranha... Not NEARLY as fussy as the stuff Sil's working with.)

[trystbat.livejournal.com]

V. true about cats & dogs. I've read in many places that cats (bec. that's what I'm interested in ;-) can comfortably/healthily stand much hotter temps than humans bec. they're more efficient in temp. & how they conserve/use energy. Also, they can crawl under the bed & similar cool places, which helps. We have about a dozen 90+ degree days here & no AC, so this was all good stuff to learn. Don't really have to worry about the cold, tho' T&I were more bothered than the cats around xmas when our heater went out.

[micahra.livejournal.com]

I think if a fishtank would be able to get too cold, you should be using a heater in it anyway...

.02

[lil-m-moses.livejournal.com]

I imagine there's some exception to the ceiling fan thing if you have high ceilings and large volumes, though. If you find out otherwise, please let me know, as I'm about to own 17' ceilings in one large room (while the rest of the house is standard 8').

[etcet.livejournal.com]

I can't speak to that, since i'm in a uniform 7.5' abode. my gut says that, when you're heating the cathedral space, you'll want them on to push the warm air down to where humans inhabit, but that's about it.

ceiling fans are primarily to engender a bit of wind-chill factor to occupied rooms when it's warm, and diffuse any hot/cold spots in general.

[argylerockstar.livejournal.com]

One of the best investments that I ever bought was a thermostat that has several different programming options. You can program it for each day of the week. Monday thru Friday, in our house, the heater goes down to 55 at night and turns up to 70 at 5:45 a.m. It then goes back to 60 at 8:00 a.m. and comes back up to 70 at 6:30 p.m. The weekends have different things programmed, like to turn the heat on later in the morning because we are sleeping in. It also remembers the programming for the a/c. When summer comes, it knoes that it should cool and then shut off or increase the temp at certain times without me having to reprogram it for the new season.

[etcet.livejournal.com]

that is darn handy. was it expensive, or difficult to install?

[argylerockstar.livejournal.com]

It was about $75.00. They are extremely easy to install. When you remove your old one, there should be four wires connected to it. Just make mental note of which one went where. You should be connecting it up the same to your new one. It is also useful to wrap the wire around a pencil before you let it go. That will prevent the wire from falling into the wall.

Oh, and don't forget to turn the power off first.

[marchenland.livejournal.com]

We have one too. I think our was in the neighborhood of $35, and isn't smart to the seasons since we don't have AC.

[poisongirl.livejournal.com]

Wow. I did not know that. I also was under the impression that it was bad to turn the system off and on. Learn something new everyday. Cool!