AC Limiter Trick: Slow Your Heat Pump to Save Power (Airspool & EG4)

Hey guys, Dave with Airspool here, and we have a fantastic new feature that some of you are going to love, especially if you're an off-grid person or if you are a cheap person, a parsimonious person, we'll say. Some of you aren't going to care much about it at all. And if you happen to be an EG4 customer, this will work for you too, so keep watching even in that case.

So what this is, it's the energy saving mode, and it's something that was on the old 410A units, but what's different about it now is it can run the compressor at 25%, 50%, 75%, or 100% of max speed. Before, the old 410A units were just at like 35%. Here's how it works: there's a button on the remote called SE. We'll call it the save energy button. When you push it, this is our set point here. This plug icon shows that we're plugged into grid power, and this shows that we're connected to Wi-Fi. But when we press this, it's showing blue here, and that means it's in energy saving mode. You'll see it's set at three there. Think of it as one, two, three, and zero, where one is quarter speed, two is half speed, three is 75%, and zero is 100% of full speed.

So if we look at the remote here, this is what Todd refers to as the app, and this is the remote. If you look at the app, the Airspool app, it shows 762 watts right now running on grid power, and it was just running. We turn this off, which we can do. By the way, you can turn this on or off in the app, or you can turn it on and off on the remote. The problem right now with the app is that it's only on or off. So we hit the AC Limiter. The AC Limiter is the same thing as the SE button. When we hit the AC Limiter here, you'll see that it toggles back to full power. This is going to climb back up here, give it a second. Yeah, it was running at around 1,000 watts.

We're in Las Vegas, and it's still late August, still pretty hot outside, especially because we run this unit out on the tarmac. We're somewhat careless because we have a lot of these units floating around here, so we don't necessarily run things out efficiently. Don't put your unit on super hot tarmac on the south side of your house if you can avoid it, because you get close to the operating limit, which is around 135°F. If you hit the ground with an infrared thermometer on a tarmac like that, it's probably 160°F, and just above it isn't much cooler. So ideally, shade your units if you live in a super hot environment like Las Vegas. At least don't put them up on the roof or on tarmac without some type of shading.

Okay, so anyway, we're at about 1,042 watts here, and on the AC Limiter we'll try a different setting now. The way you change the speed is with this button that looks like the indoor unit icon here. If you hit it once, it goes to three, and this is going to start going down slightly. Give it a minute here. It was at 1,042, now it's dropping. Okay, now it's all the way down to one, which is 25% speed, and this will start dropping fast in terms of power. Eventually you'll be down to only around 300 watts.

So that's a pretty big advantage if you want to run this at nighttime and not have to dig into your batteries, or if it's in your garage or wherever. 300 watts, in most places, is going to average around three and a half to four cents a kilowatt hour. Your results may vary in Connecticut, New York, California, Hawaii, and so on, wherever you are. If you're in a high kilowatt-hour area, well, in most places at 25% speed you can run your garage and not feel too guilty about spending three or four cents an hour. So that's a reason to use this energy saving mode. But obviously you're not getting as much cooling, so that's the trade-off, because right now we're down to 320 watts.

The coil right now, instead of being at like 35 to 40°F, is at 62°F. And 62°F is still a lot cooler than the space in here, which is 80 to 85°F. You might ask, coming from a high-humidity area, how can you stand 85°F and not be all sweaty? Well, the humidity in this room is probably about 2% right now, so it works. We've probably been running it less hard than it could be because we've been playing around with different modes, and also because we've turned off units in other parts of the building at this late hour. So yeah, this is a great feature for both Airspool and EG4 units.

Right now we're running this solely on grid power, and we're running it at setting one, so it's at 25% speed, and there's still a little bit of solar left. Todd, push pause for one second, I'm going to turn this... okay, go. So now we've turned this isolator switch, which we provide with our units, to the on position, and we have enough solar hooked up to this that it's now running 100% on solar: 1,060 watts on solar, zero on AC. So the AC Limiter isn't going to matter a hill of beans whether you have it on or not, because the unit doesn't need AC power. Really, your system should be configured such that you have enough solar to run it the majority of the day, in which case the AC Limiter is really more about nighttime use, provided you have enough solar power to run your unit during the daytime.

A couple other things. One is that the AC Limiter is also a trick you can use if your space, say a little trailer or a bedroom, has a 12,000 BTU unit that's really oversized for it. This unit has an inverter compressor, and that's what makes all this magic happen. The compressor is able to run at quarter speed. Traditional air conditioners, you can see it, you can feel it, you can hear it when they first come on. There's an inrush current, and they're either on or off. This unit has a variable speed compressor and variable refrigerant flow, and that's what makes all this possible.

But even with these units, having said that, inverter compressor systems like to run continuously. So if it's a 12,000 BTU unit in a 10 by 10 foot bedroom, it might still want to run closer to full 12,000 BTU output, and that's maybe a controls issue. But a trick we've heard that works is running it with the AC Limiter on at 25% speed, and then you'll be more comfortable and you'll also be saving money.

How do you do that during the day? Because again, if you've got that 10 by 10 foot bedroom but you have 1,500 or 2,000 watts of solar hooked up to your unit, it's still going to be running full bore. Take away a panel or two, and again the compressor will run at quarter speed or half speed. The other thing I wanted to point out is that if you turn this unit fully off, unfortunately it forgets your energy saving settings, which is kind of inconvenient. But really you shouldn't need to turn it off; just keep it on all night long at whatever speed you're most comfortable with and leave it there, because you're going to be saving quite a bit of money by having it at the slower speeds at night anyway. Once you turn it off, you have to turn the save energy mode back on, and you might forget to do that. So hopefully you can just leave it on at the 25% speed.

So, we're Airspool. We talk about air conditioning, we talk about solar, and we talk about solar air conditioning and heating. If you liked anything you saw here, give it a thumbs up, leave a comment, and potentially subscribe to our channel. Thanks for your time.