Apologies for the long post...
Over the last five days I’ve been comparing the wave 2 and its standard modes (no modifications) against a 5000 btu Toshiba window unit that I had out in my garage. All tests were started at ~4pm and ran for one hour to try and get similar sun loadings across days. The garage door and back door were opened for ~30 minutes prior to each test to allow temperatures, thermal mass, and humidity in the garage to equalize to the exterior. The Toshiba has a slight advantage over the wave 2 for its test because I had previously built an insert with 2” of xps to match the window unit’s size. The Wave 2 only had 1” of xps and 1/8” sheets to finish closing the gap under the door. There was also some light rain ~20 minutes into the Toshiba’s test and my exterior thermometer got wet so there is some question in the final exterior temperature for that test only. The interior thermometer was unaffected. The garage is uninsulated (except for a couple panels on the door), and is ~2000 cu ft so definitely bigger than either a/c is intended for.
The Toshiba is rated for 4 amps at 115v AC (460w). I didn’t think to take power data during its test, but a separate 15 minute followup test using my delta mini showed that AC power draw was slowly ramping up to at least 400w. A longer test may have grown closer to the 460w rating. A short 5 minute test in low mode only used ~380w AC, but I don’t have any hour long cooling tests to look at temperatures in low mode.
In MAX mode, the wave 2 peaks at 470w DC. The wave 2 does do some aggressive throttling of the compressor during its operation in all modes. I believe it targets a delta temperature of ~18F between ambient and outlet temperatures in MAX mode. If the delta temp is >18F, it will ramp down the compressor, if it’s <18F it will ramp up the compressor. I didn’t record power data during the MAX mode test, but on a shorter 15 minute test MAX mode ranged from 440-470w DC. If you start getting closer to your set point I bet it would reduce further.
In ECO mode, the wave 2 cycles through a number of “modes” to save power. It starts with the compressor on high and low fan speed for 5 minutes. It ramps up over those 5 minutes to ~380w dc power draw. Then it switches to a low compressor and low fan speed for 15 minutes. In this mode it draws ~200w. Now comes the bad part, it runs on FAN ONLY for 10 minutes, only using ~10w. The cycle then repeats. I suspect that the same compressor limiting based on delta T could reduce the 5 minute high compressor numbers if you are near your set point. Overall, without compressor limiting, the ecoflow averages ~150w DC.
The issue with ECO mode is that the residual water in the base of the unit is re-added to the air during the fan only portions of the cycle. This is BAD for overall comfort. The RH in my garage actually INCREASED during the test which should definitely not be happening while an air conditioner is running.
In sleep mode the aggressive throttling of the compressor actually made a difference in power consumption. The wave 2 targets a 20F (11C) delta t in this mode, and with the fan on such a low speed there’s significant mixing of the outlet/inlet air streams (and not enough mixing with the room air) so it ends up throttling the compressor down quite a bit. This has a significant effect on overall cooling ability of the room. At the start of the test the wave 2 was using ~250w DC, but within 20 minutes it dropped down to ~200w for nearly the remainder. Total energy use ~220w DC for the hour. I did run this test for an additional hour and room temperatures didn’t drop much further, but humidity levels did continue to drop (~1.5% RH/hr).
Today I ran the last test, manual mode with high fan. The compressor throttling still occurred, targeting ~17.5F (~10C) delta t. I saw a max of 400w DC near the beginning of the test, dropping to 370w by the end. This is the most interesting test to me, because I got almost the same drop in temperature as my max mode test, but only used ~85% of the power. The difference may be due to different clouding on the two days (it’s a bit overcast and hazy today, I think it was only light clouds on the MAX mode day).
Overall thoughts so far:
Over the last five days I’ve been comparing the wave 2 and its standard modes (no modifications) against a 5000 btu Toshiba window unit that I had out in my garage. All tests were started at ~4pm and ran for one hour to try and get similar sun loadings across days. The garage door and back door were opened for ~30 minutes prior to each test to allow temperatures, thermal mass, and humidity in the garage to equalize to the exterior. The Toshiba has a slight advantage over the wave 2 for its test because I had previously built an insert with 2” of xps to match the window unit’s size. The Wave 2 only had 1” of xps and 1/8” sheets to finish closing the gap under the door. There was also some light rain ~20 minutes into the Toshiba’s test and my exterior thermometer got wet so there is some question in the final exterior temperature for that test only. The interior thermometer was unaffected. The garage is uninsulated (except for a couple panels on the door), and is ~2000 cu ft so definitely bigger than either a/c is intended for.
The Toshiba is rated for 4 amps at 115v AC (460w). I didn’t think to take power data during its test, but a separate 15 minute followup test using my delta mini showed that AC power draw was slowly ramping up to at least 400w. A longer test may have grown closer to the 460w rating. A short 5 minute test in low mode only used ~380w AC, but I don’t have any hour long cooling tests to look at temperatures in low mode.
In MAX mode, the wave 2 peaks at 470w DC. The wave 2 does do some aggressive throttling of the compressor during its operation in all modes. I believe it targets a delta temperature of ~18F between ambient and outlet temperatures in MAX mode. If the delta temp is >18F, it will ramp down the compressor, if it’s <18F it will ramp up the compressor. I didn’t record power data during the MAX mode test, but on a shorter 15 minute test MAX mode ranged from 440-470w DC. If you start getting closer to your set point I bet it would reduce further.
In ECO mode, the wave 2 cycles through a number of “modes” to save power. It starts with the compressor on high and low fan speed for 5 minutes. It ramps up over those 5 minutes to ~380w dc power draw. Then it switches to a low compressor and low fan speed for 15 minutes. In this mode it draws ~200w. Now comes the bad part, it runs on FAN ONLY for 10 minutes, only using ~10w. The cycle then repeats. I suspect that the same compressor limiting based on delta T could reduce the 5 minute high compressor numbers if you are near your set point. Overall, without compressor limiting, the ecoflow averages ~150w DC.
The issue with ECO mode is that the residual water in the base of the unit is re-added to the air during the fan only portions of the cycle. This is BAD for overall comfort. The RH in my garage actually INCREASED during the test which should definitely not be happening while an air conditioner is running.
In sleep mode the aggressive throttling of the compressor actually made a difference in power consumption. The wave 2 targets a 20F (11C) delta t in this mode, and with the fan on such a low speed there’s significant mixing of the outlet/inlet air streams (and not enough mixing with the room air) so it ends up throttling the compressor down quite a bit. This has a significant effect on overall cooling ability of the room. At the start of the test the wave 2 was using ~250w DC, but within 20 minutes it dropped down to ~200w for nearly the remainder. Total energy use ~220w DC for the hour. I did run this test for an additional hour and room temperatures didn’t drop much further, but humidity levels did continue to drop (~1.5% RH/hr).
Today I ran the last test, manual mode with high fan. The compressor throttling still occurred, targeting ~17.5F (~10C) delta t. I saw a max of 400w DC near the beginning of the test, dropping to 370w by the end. This is the most interesting test to me, because I got almost the same drop in temperature as my max mode test, but only used ~85% of the power. The difference may be due to different clouding on the two days (it’s a bit overcast and hazy today, I think it was only light clouds on the MAX mode day).
Overall thoughts so far:
- I think ecoflow could eek more performance out of the wave 2 with some firmware updates. An advanced user mode that lets you set the target delta t between inlet/outlet and allowed for memory of automatic external drain mode would be awesome! You would use more power this way, but I think you’d gain performance.
- Unmodified, the wave 2 is coming up a bit short compared to a standard window AC.
- I thought energy use might be better for the Wave 2 but was shocked at just how little draw my little window unit had. For some reason I thought it needed significantly more energy. Even accounting for inverter losses of 10%, you’re roughly even in power draw with the Wave 2 in MAX Mode but cooling better and at 1/5-1/10 the cost (you can buy it for $170 from Home Depot)
- Ecoflow uses the ASHRAE method to report BTU's which is unfortunately not applicable for portable units because it doesn't account for the heat generated by the unit being in the room (as opposed to outside with a window a/c), leakage through the ducts, and heat being radiated to the room from the ducts. The DOE recognized that portable a/c's have these limitations and started requiring manufacturers to run a new test with portable units to give an "equivalent" rating to the old test. If you look for portable a/c's you'll see two ratings now, ASHRAE and DOE SACC. I learned about this discrepancy after purchasing the wave 2 and estimated a de-rating of 70-75% for the ASHRAE to DOE SACC conversion on the wave 2. My tests are showing the Wave 2 performed at 71% of the capability of the window unit in MAX mode and used similar amounts of power after adding in inverter losses for the window unit.
- One benefit of the wave 2 is how low it can throttle itself down and run its compressor. If you are in a well insulated or very small volume environment, or just trying to keep humidity levels down compared to exterior, it does seem like the wave 2 may be able to cool/heat for surprisingly low amounts of power (200w DC minimally). That’s better than any window unit that I know of.
- Portability and adaptability to a wide variety of use cases is definitely better with the Wave 2 than a window unit.
- ECO mode is worthless unless you’re in a dry desert environment without any humidity.
- 200w DC seems to be the lower limit for the Wave 2 with the compressor running and on low fan speed.
- Fan power draw appears to be ~10w per increment (10/20/30w DC for low/med/high)
- Unmodified, I don’t see any reason to run the wave 2 in any mode but MAX or manual/high fan. I’ll have to test some more, but I suspect that any mode will throttle the compressor down as that same delta t is reached between inlet and outlet (or your set point). If that’s the case, you’re going to want the fan on high to mix the conditioned air with the room air as quickly as possible. Eco and sleep modes force you into low fan speed.
- I plan to continue testing doing some “mods” like insulating the condenser hoses, running the unit outside and ducting the conditioned air in, sealing up some of the duct connections, and adding insulation around the wave 2. Those should all improve the Wave 2’s performance somewhat. Results will have to wait until I return from vacation though.
