Open4Energy publishes lists of products that we believe make unreasonable claims in how they save consumers energy - which we define as "scams"
I have linked the three directories above for ease of review and not for seo placements - if you Google any of "power factor correction scams" or "renewable energy scams" or "free energy scams" you will find that the lists we publish are in the top results.
I am creating this post as an opportunity for energy professional to contribute their experiences with any of these products. In particular, to correct us if we are incorrect in our understanding of a particular product - or to add experiences that will help clarify.
Some products are near fraud, and without any redeeming possibilities. This is especially true in the FREE energy category. Others are less obvious, like the worthless plans to build impractical solutions .
The group that I believe needs most discussion is that pertaining to power factor correction. The science of electricity and how Kwh is calculated makes it clear that correcting power factor will not alter the Kwh on an electricity bill. At the same time there are honest people who are convinced that adding a pf correcting device to a home has lowered their electricity bill.
I was able to test the exact affect on watts when adjusting pf supply to a small fan
PF = 100% V = 121 A = 0.292 Watts = 35.4
PF = 033% V = 121 A = 0.912 Watts = 36.3
Based on the above I do see a change of 2.54% in the Watts drawn by the motor, or put another way, it may be that pf correction does not change any Kwh calculation, but it can change the efficiency of the motor.
I was able to test the exact affect on Watts when adjusting pf supply to a cfl
PF = 076% V = 121 A = 0.236 Watts = 21.7
PF = 020% V = 121 A = 0.901 Watts = 21.7
I would appreciate any expert measurements, where a motor is operated at differing PF values, so we can be clear on any actual electricity savings.
I would not buy a unit to correct PF for a small fan, or a fridge if the energy use change is 2.54% - and at such low values could be a measuring error. But if changing the PF supply to a large heat pump motor, from say 80% to 98% really does allow the motor to operate more efficiently, this should be known.
I will still argue that the simplistic assertion that correcting PF saves 15% or 40% in an electricity bill is a scam, but without harming the legitimate efforts of the PF industry to correct PF on a circuit or device where savings can be achieved.
I look forward to the discussion, by experts (no product promoters) in this arena.
Alex, a news station actually did the best test I've seen so far on residential power factor correction that we covered on Mapawatt. The problem with these hucksters is that it is pretty easy for them to use an amp meter to show potential customers how current is going down on inductive loads with their devices turned on, of course those customers dont understand how PF plays into it all. While you showed an energy reduction of 2.54% (I2R losses), keep in mind that a residential home is only partly made up of inductive loads. There is no benefit of PF devices on most lighting.
I would advocate for a 4th category shedding light on products and services routinely way oversold as to their conservation effectiveness / payback period. Examples which spring to mind:
1) Radiant barrier,particularly when rolled out on the attic floor.
2) powered attic fans installed without sealing celing penetrations
3) Windows - effective, but payback stretches out for decades, often well beyond expected life of windows
Go ahead and add solar attic fans to the list. According to the manufactures they defy the laws of physics by getting 800CFM out of a 20W motor. with a 10" or 12" propeller. Odd that hardwired attic fans typically use 150W+ motors.The sick part of the solar fan scam is manufactures known for other roofing products sell the solar fans at retail outlets. While we're at it add ridge vents that don't really work because the filters clog up (if they ever worked to begin with). Again sold at retail outlets...
What really DOES work are large passive openings such as attic fans w/o the fan and "whirlybird" style vents. Electric fans will move lots of air until the motor burns up from running in the hot attic, but they have their own set of issues I'll let others discuss.
Don't forget the SEER/EER scam either. Selling customers ultra high SEER units that will supposedly save them big bucks on their power bill. Ain't gonna happen unless their old system was in bad shape. EER is the number that really matters when it comes to saving the big bucks on summer A/C bills. Using 95 outside/80 inside (15 degree split) is a much more accurate indicator of energy use than the 80/82 to determine SEER ratings. Who cares about efficiency with a TWO degree difference between indoor/outdoor temps when the A/C rarely cycles?
What happens in the real world is EER starts at about 12 for a 13SEER unit, goes to 13 for a 14-15SEER unit and tops out at about 14EER for units rated 16SEER and up. That's right, EER does NOT improve once SEER goes over 16, but cost for the high SEER units skyrockets. To have high EER coil area (inside and out) in relation to tonnage needs to increase, this is why the larger sizes in a particular lineup tend to take a hit on EER.
Rarely is installing a unit over 16SEER going to be more cost effective than insulating/fixing leaks/ repairing ductwork unless there are substantial rebates/incentives involved. The solution is to downsize the equipment and fix the house.
I agree with most of that. The sweet spot for SEER is around 16, where the systems are two stage. I sometimes pick a slightly upsized air handler. The low stage really helps with efficiency as well as humidity control and noise.
We routinely downsize to get to the 3 ton sweet spot of efficiency for a given model lineup.
Several clients going from 10-15 year old 3.5-4.0 ton single stage systems with PSC blowers to 16-19 SEER 3 ton systems along with a heat pump water heater have had total (not just cooling) summer bills drop by 35-45%
We test and seal / replace ducts to insure the downsized system will keep folks comfy.
The 2 stage is nice but I prefer to slightly undersize a single stage system. Most customers are OK with the A/C not keeping up once temperatures are over 95 outside, even though systems around here are typically sized to handle 100-105 before loosing ground. (96 is design temperature for OKC)
The EER is normally the same as the single stage using the same cabinet/coil, one model number down the line. The 2 stage units get the high SEER ratings because the small compressor is the one doing the work when it's 82 outside. A 2ton compressor with a 3ton coil is the big boost to SEER for 2stage units. The 2 speed makes a big jump in wholesale cost of the unit that few customers are willing to pay for. 13SEER to 14-15 SEER has a much smaller jump in price and gets most of the extra EER. Once you go above 15SEER it's more about the extra comfort than saving on utility bills.
Has anybody else noticed that Geo systems don't list SEER, yet EER's in the 18+ range aren't uncommon?
We size for design temperature, in our case 94, and advise clients to "get a running start" by setting thermostat a few degrees lower on days forecast to near 100.
Around here, humidity control rules, and that is where two stage units shine. Most 2 stage systems I deal with, all except the Trane 20i, use just one compressor, a Copeland Ultratech, with a solenoid-driven partial bypass that reroutes refrigerant. The compressor motor turns at the same speed, but both indoor and outdoor fan motors slow down. Low stage is right at 2/3 high stage, so we look for low stage to carry the load until outdoor temp is 88-90. Trane 20i units switch sround 86-88, since their low stage is just 50% of high stage.
Geos are not SEER rated since outdoor air temp is irrelevant to efficiency of a ground source heat pump.
I agree that the first couple SEER points above 15 are much cheaper than the step up to two stage, of which manufacturers are very proud.
The humidity in Oklahoma isn't too bad most of the time, no need to design for high humidity. I can see where a 2 stage would be excellent for comfort in high humidity areas. Interesting that one model slows the fans while keeping compressor at the same speed, does it use much less power while fans are on low? Simple compressor/fan controls mean less things to go wrong over the long haul.
Don't assume that since the compressor remains at the same speed in low stage that it continues to consume the same power. The refrigerant bypass port solenoid serves to unload the compressor, and its amps fall proportionally to capacity, actually a bit more since compression ratio falls a bit when 2 tons of heat transfer is moved across nominal 3 ton coils.
Slowing the indoor blower reduces power and noise but maintains airside delta-T so as to provide dehumidification. CFM per ton is maintained.
Slowing the outdoor blower reduces power and noise, keeping the neighbors happy as well as increasing efficiency. Outdoor airside delta-T holds around 8-10*F in either stage, maintaining efficiency.
How are you/they tracking these savings? I'm trying to figure out an effective tool for tracking both savings, and projected savings.
The electricity utility obligingly reads the meter and mails out a summary every month...
Seriously, we compare same months in year before upgrades occur, adjusted for degree days
If something doesn't mesh, I'll install a TED energy detective on suspect circuits and the whole house feeds.
When a house fell short of my predicted savings, it was then we learned that Adult children were leaving TVs and gaming gear on all night - TED was showing 1000-1300 Watt base load all night.