Electrical usage for your house???

[tallyho8]

Eddie, I hope that cures your problem though it may take you a long time to find out for sure.

I have replaced insulation like that in the past with the styrofoam insulation that Home Depot sells that has foil on one side. I cut it neatly to fit securely and glue it in place. It is much easier to get real clean when the ducts are cleaned and less likely to harbor mold and mildew.

That insulation looks like fiberglass and I don't like the idea of fiberglass fibers being blown through the air. I am afraid that in the future fiberglass will be regarded much as asbestos is today.

 

[heehaw]

IRVINJ: i always looked at the compressor as the same as a frig: its either on or off, or maybe like some i have seen, have two stages, which each use different amounts of power: did not realize there was something actually in the unit that caused a larger or smaller load on the compressor..thanks for this explanation...i really want to go to some hvac classes when i can..local school only about 35 miles away, i may try it yet.
thanks....
heehaw

 

[irvingj]

Heehaw-- You're most welcome. My deepest apologies, but, you see, I'm a teacher.... (we can't help it!)

Even in most household refigerators there's a device to control the amount of regrigerant that gets into the evaporator, based on load-- it's called a capillary tube, a very narrow-gauge tube of a specified length, dependent on application.

As head pressure rises due to load (more warm beer!!), more refrigerant is forced through the tube as a result of the higher pressure; as load drops off, head pressure also drops, less refigerant goes through the tube....

Cap tubes are not as "accurate" (responsive) as an expansion valve, but their purpose is the same. (And they have no moving parts and are inexpensive to produce.)

If you could see a graph of electric consumption, any refigerator unit --that's working properly-- will start off with a high load and then taper off until thermostat cut-off. Even your household refigerator.

Refrigeration is really only basic physics- quite logical, actually. It's amazing to me to think of the guy that invented the process ("Attaboy, Dave!") -- controlling pressure to control evaporation and condensation. Fascinating. Even if you don't choose HVAC as a line of work, it's still good stuff to know!

 

[heehaw]

sure not looking for any more work..just want the knowledge..in Arkansas, when you turn 60, you can go to about any school, tuition free: so i plan on taking advantage of that. i have put a kill-a-watt on several frigs an some freezers: other than the initial start up current, once they ran for a short time the current draw stayed the same after that..even when they had been turned off for months.. thats why i didn't think they would have anything that "varied" the load: either on or off..
thanks for the info.
heehaw

 

[tallyho8]

The way that I describe the difference in amperage that a compressor draws may be oversimplified but some can understand it easily when explained like this:

A compressor in an air conditioner is similar to an air compressor. If you put an ammeter on an empty air compressor and then turn it on you will see that it pulls low amps at first as the air pressure is low and there is no strain on the compressor motor. As the air pressure builds up there is more and more strain on the motor so it pulls more amps, and pulls the maximum amps just before it gets to the high pressure cut-off.

An air conditioner uses refrigerant instead of air. Refrigerants (freon) are designed so that they have much higher pressures when heated or compressed and much lower temperatures when cooled. If you put a pressure gauge on a can of freon and sit it in the sun you will notice a much greater pressure rise than in a can of compressed air. It may have 300 psi of pressure in the sun and 5 psi pressure when put in a freezer.

When the refrigerant pressure is high, just like in the air compressor, the compressor motor strains more to compress it thus pulling higher amperage. So if your condenser coil that cools the compressed refrigerant is dirty, the refrigerant stays hotter and has higher pressure and it makes the unit pull higher amps. Also, on a very hot day the refrigerant will be at much higher pressure than on a warm day, again making the unit use higher amperage.

So the exact same air conditioner that you are using in Michigan on a 80 degree day will pull lower amperage and use less electricity than the same one in Texas on a 90 degree day.

 

[MarkV]

Tally that was well stated. I have understood that, in a general way, but you sure put it in easy terms to understand.

MarkV

 

[PILOON]

I caught somewhere in this trend that you were 'commercially' rated or installed in anticipation of being so.

Could you then be on a 'demand' setup? or peak power? meaning that all consumption is priced out at that months highest 'peak' demand.

In that case if everything is switched on at the same time the start up power sets the rate for all that month.
AS you know, start ups always draw more than run.
That's why big commercial buildings leave lights on all night; cheaper than everybody flicking all the switches on at the same time.

If that's the case and the entire household rises at same time, cooks, air goes on and hot water tank heats up etc etc might explain it.

 

[heehaw]

"Could you then be on a 'demand' setup? or peak power? meaning that all consumption is priced out at that months highest 'peak' demand." thats exactly how i have been told commercial customers are charged for electricity in Arkansas: an i "think" they consider anyone with 3phase power to their place a commercial customer: i can see where that would really be some expensive electricity: turn on a big ac unit an you set the "usage" for the month..wow, thats gotta hurt.
heehaw

 

[EddieWalker]

heehaw,

I'm really unsure what I'm paying for. They used to have a demand charge, but now it's a dozen other charges that add up to the same thing. There is the amount of electricity that I use, and then all the service fees for getting it there.

What I'm really wondering is how much of a difference my usage will be with the fan unplugged in the AC unit. We've noticed a huge difference in how much more air comes out of the vents.

Eddie

 

[JoyJack]

Interesting Eddie.

Centrifugal fans pull more amps the more air they pump.
Thus, the partially blocked fan would pull less amps since it was restricted. Restricted it would probably run longer to try to cool the area. Now, with more air flow it should run a shorter time to cool the area, but pull more amps. I wonder if that will balance out the same or if the run time is short enough to give you a savings.

I am in East Texas, too, so I understand the need for the unit to run more to control humidity, too.