Is HVAC Cycling Too Often? (AC)

[npalen]

Wondering if my house AC is cycling too often? (short cycling) The attached photo is a screenshot off my tablet which is running an app called "Intelligent Clamp Meter". The app connects via bluetooth with an amp probe attached at the house breaker panel.

The left column is amps and the timeline across the bottom showing a start of about 7:15 AM. The AC is a Lennox two stage which runs about nine or ten amps on Hi cool and about six or seven on Lo cool.
We've been having days in the 90F high temp and the AC doesn't normally get into Hi cool until the afternoon.

The stage one and stage two differential is set to 2.0 degrees but I never see the temp vary more than one degree from the set temp while the compressor is cycling as shown in the pic.

The five year old Lennox unit is a 36,000 BTU with inverter air handling cooling a 1600 square foot ranch style well insulated

Edit: As you can see, the unit cycled on four times between about 7:00AM thru 10:00AM with an outside temp of 75F to 80F. Thermostat is set to 73F.

 

[tallyho8]

It looks like it is cycling just right to me with more off time than on time. I like a unit that keeps the temp within 1 degree and runs for a short amount of time instead of a unit that lets it heat up 2 or 3 degrees and then runs for a long time.

 

[KennyG]

Looks fine. The better thermostats have options to cycle on different temperature gains. Keeping the variation low is usually better. It improves comfort by keeping humidity more consistent. The only time you will get into a short cycle problem is if you have an air supply blowing directly on your thermostat. I would guess yours is properly located.

 

[npalen]

My concern was that it was wasting energy by having to restart the compressor so often. It is a 16 seer unit so maybe that is not the case. I do appreciate the knowledgeable feedback.

 

[kenmac]

Looks fine. The better thermostats have options to cycle on different temperature gains. Keeping the variation low is usually better. It improves comfort by keeping humidity more consistent. The only time you will get into a short cycle problem is if you have an air supply blowing directly on your thermostat. I would guess yours is properly located.

My VRF Never, or hardly ever cycles on and off. It keeps a constant temp through the day, or night no matter the ambient temp.
It idles on low cool at about 15 HZ. and will ramp up if needed.

Most regular thermostats have a 2 deg. swing before cycling the unit on/off

 

[Dftodd]

Short cycling is pretty obvious if your outside next to the unit. Inside it will seem like everything is normal with the air handler running.

Outside the unit will start up, run for 30 seconds to a minute, shut down, then immediately start back up.

 

[KennyG]

My VRF Never, or hardly ever cycles on and off. It keeps a constant temp through the day, or night no matter the ambient temp.
It idles on low cool at about 15 HZ. and will ramp up if needed.

Most regular thermostats have a 2 deg. swing before cycling the unit on/off

I've not seen VRF in a residence although I understand they exist. Do you have ductwork or is each room individually controlled?

 

[kenmac]

I've not seen VRF in a residence although I understand they exist. Do you have ductwork or is each room individually controlled?

Mine is connected to duct just like a conventional system (one to one)

The smaller unit is for upstairs which we never use the up stairs So, I decided to just keep the Trane until it quits

 

[Sigarms]

I've not seen VRF in a residence although I understand they exist. Do you have ductwork or is each room individually controlled?

The issue it seems now is terminology as to what people actually mean by Variable Refrigerant Flow.

As far as a heat pump simultaneously heating and cooling at the same time with multiple indoor heads, the only thing I know that exist is 3 phase (some single phase out there, but they can not heat and cool at the same time with multiple indoor units).

I'd love to see a true residential heat pump VRF in single phase, but I have no doubt that when they first hit the market (which they will sooner or later), they will be so out of line price wise, most people will pass on them (as is commercial jobs are slowly coming down after 5-10 years in the field, but they are still higher than anything else out there).

As is now, even for conventional residential use multi zone mini splits, I try to stay away from having to use a branch box in existing homes.

Because Kenmac stated that his system is a 1 to 1 using a ducted air handler, I don't believe it's the "VRF" system you're thinking about used in commercial applications.

 

[Sigarms]

Wondering if my house AC is cycling too often? (short cycling) The attached photo is a screenshot off my tablet which is running an app called "Intelligent Clamp Meter". The app connects via bluetooth with an amp probe attached at the house breaker panel.

The left column is amps and the timeline across the bottom showing a start of about 7:15 AM. The AC is a Lennox two stage which runs about nine or ten amps on Hi cool and about six or seven on Lo cool.
We've been having days in the 90F high temp and the AC doesn't normally get into Hi cool until the afternoon.

The stage one and stage two differential is set to 2.0 degrees but I never see the temp vary more than one degree from the set temp while the compressor is cycling as shown in the pic.

The five year old Lennox unit is a 36,000 BTU with inverter air handling cooling a 1600 square foot ranch style well insulated

Edit: As you can see, the unit cycled on four times between about 7:00AM thru 10:00AM with an outside temp of 75F to 80F. Thermostat is set to 73F.

Get an app that Lennox uses to monitor their equipment. A two stage compressor in the summer, as I read the graph, should not be coming on and turning off within the hour.

That said, I'm an idiot so I may be reading the graph you posted incorrectly. If the app is stating the drop between stages, you would seem fine IMO.

Long story short, if you had the unit for 5 years, go to your electric bill and see how it varies. Could be some other variables at play, but that's where I would start. If it's outrageously high next bill, you have an issue somewhere. If it's the same, the app is haywire.

Not certain what inverter air handling cooling exactly is. I doubt you have a inverter air handler, most likly perhaps on the outdoor unit, which means it's not an XP16 unit.