Saving on A/C Costs

[LostCause]

You could install a water softener, but the payback period from saved vinegar, detergent, and energy would probably be ~60,000 years.

I wouldn't put vinegar in the filter. I have no idea how long its effectiveness would last or whether it might degrade the media, as RH77 noted. I'd just use a polyphosphate filter and clean the condensor with vinegar on the rare occasions it is needed.

- LostCause

[RH77]

So, I spent most of the evening trying to diagnose the low fan speed issue for the A/C

I cracked-open the furnace blower cover and found the schematics. According to the wiring, the relays should allow full speed in A/C. It wasn't working. The wiring made no sense either -- color-coded motor wires weren't translating into expected speed output. The circuit board was thought to the be culprit.

Thanks to HVAC-Talk.com, the techs there helped trace it back to the thermostat. There was a dual-speed dip-switch that needed flipped. In the meantime, I ran all current through the "heat" side of the relay since the board was likely slowing it down unnecessarily. It was an intimidating looking SPDT switch relay, but had the strongest output at the heat connector.

Now, I'm pleased to report actual flow of cool air in the upper floor, corner of the house.

Why this whole essay?

The higher speed pulled a LOT of humidity out of the house and cooled it down in a reasonable amount of time.

Bottom Line: The Cool-N-Save. Determining savings will be tough without an unmodified baseline. If it's more (using last years climate data), then we know that either 1) the blower is using more juice, or 2) the CNS is BS.

Stay Cool

RH77

EDIT: Safety First -- I disconnected the power at the breaker box first. Just if someone goes fooling with wires.

[Lazarus]

Well it looks like the Cool-N-Save may be a bust. It's been a mid to high 90's all week so the AC has been getting a little bit of a workout. We have extremely hard water here and although we have a water softner it is not plumbed to the outside supply. This is the build up after 5 days of fairly hard use. The filter is not able to filter out the deposits. I'll see how hard it is to clean off the stuff this weekend.

[COMP]

get the coil cleaning spray,,,,can you run a soft water line to it ???

[dremd]

Or use an under sink filter in addition. . . ..

[LostCause]

How have your energy costs altered?

You can install a water softening filter at the spicket. The cheapest I've seen online is ~$55 for the assembly and cartridge, but you could probably source stuff cheaper if you built it yourself or did more research.



If worse comes to worse, you could run a hose from the kitchen sink...

- LostCause

[Lazarus]

Thanks LostCause I have to check into that. The vinager did not remove the junk. I'll try some CLR or something in the next couple of days.

Usage is impossible to tell. We have done a complete makeover with CFL and insulations and a power monitor for the house. Our bills have been the lowest ever and every month I keep expecting it to jump. With summer officially here this would have been the real test. I'll see if I can find some kind of filter to add to the filter. The theory behind it makes since so I think it would work but I really don't have a base line now so it would be pretty hard to tell.

[redbeardatxm]

I asked an HVAC guy about doing this sort of thing once. He recommended against it, said that the minerals in the water (I live in Orem UT and have quite hard water) would block up and corrode the the condenser coil. Using soft water might help, I'm not sure.

[phleas]

I have some experience with cool-n-save in Houston, TX.

I installed a cool-n-save mister on my 3 ton upper AC unit last May. I used it all summer and reduced my KWH usage by 31%:

2006 Apr - Oct KWH: 10510
2007 Apr - Oct KWH: 7187.

It saved me over $400 in electricity. The mister used about 1 gallon water per hour and I saw no increase in my water consumption in 2007 vs 2006.

HOWEVER: Even with the phosphate filter, there was much scale buildup on the condenser. I don't believe it would have come off easily. I did not have to clean my coil because it was replaced this winter. My Amana coil that was Mfg in 1999 was defective and was replaced under warranty. I lucked out.

I am NOT using the mister this cooling season. I have plans for a rainwater collection system and when built, I will be comfortable using rainwater on the coils. Timing for build will be next year...I am very busy with other projects this year.

[Lazarus]

I think I've worked my way around the scale biuld up. If I can fashion up a 20 gallon or so rainbarrel I can use either rainfall or soft water from the house. The only snag may be that I can't get enough elevation to get the pressure required to activate the misters. I think it requires at least 20 PSI.

I'll see if I can't get a cheapo beta proto-type going next month.