Mr Cool DIY split system

[parshisa]

So, here the story: I'm in south texas (spring texas to be more exact) and it's pretty hot out here during the summer as you can imagine. The house we live in is 2,500sq ft 1.5 story, equipped with 3.5tons AC system with two zones (one - main area for downstairs, second - for the room in the second floor). Long story short - 3.5ton unit is just not enough to move and cool all that are during 100+ F days. AC constantly runs and barely keeps the house at 87F. Temperature delta is fine during cooler nights (15deg on average) but is really bad during the daytime on hot days - 8 deg or so at best.
What I was thinking to do is to install a split system in the living room/kitchen area which is a big chunck of the house area - around 1000sq ft. In particular, I'm looking at Mr Cool DIY. Does anyone has any experience with this system? anyone ever installed it? how do you guys look at this idea in general? I figured 2K is still better than 10K on an bigger HVAC unit. Thanks for the feedback folks

 

[hemitom]

How old is this system ??
How well is your house insulated ?
something is not right right here 3.5 tons in that size of house should drop the temp more than 13 degrees at 100f

 

[cpayne5]

I installed a 2 ton Mr. Cool DIY system in my mother's house last October. It's fairly straightforward to install and if you have some mechanical/electrical/construction ability, you'll be able to install it just fine.

My mother has a small house. Essentially single story, ~1000 square feet. It was built in the early 70s and is of dubious quality and poorly insulated. It's the house I grew up in and we never had A/C when I was growing up. She doesn't like it (A/C makes you weak! - essentially her thought) and so she still doesn't use it. She won't even use the dehumidifying feature of the unit. I've tried to convince her to do so, but she won't have it. Ha. What she does use it for, and what you may not be concerned with, is heating her home. She has a propane heater that she's relied on the past 12ish years, but she didn't like how expensive it was to operate. The minisplit heats her home nicely and does so with minimal energy consumption. Heatpumps are generally better air coolers than heaters, so our experience with heating her home would lead me to believe it to be a good candidate for what you want to do.

3.5 tons seems like a small system for a 2500 sqft home in Texas. My home here in Virginia is 2500 sqft finished living space, and we have 7.5 tons of HVAC capacity. On hot days, the systems work hard, but can keep the house at 72 degrees.

If you have any specific questions about the Mr. Cool system, let me know. I'm happy to help as best I can. I say go for it.

 

[JimPghPA]

Does you house have the electrical capacity to handle the additional load?

 

[parshisa]

Does you house have the electrical capacity to handle the additional load?

Do i really need to be worried about additional load from split system the plugs into the walls? I’d say central HVAC running less should compensate for additional load from the split. Correct me if I’m wrong, i am a mechanical engineer, not An electrician

 

[parshisa]

How old is this system ??
How well is your house insulated ?
something is not right right here 3.5 tons in that size of house should drop the temp more than 13 degrees at 100f

It’s not old. House was built in 2014, november. I’ve had the system checked and everything looks good. Talking to my friend HVAC tech the unit size is just not enough for the house footage. Once the temps go into low 90s range - no issues keeping the temp without running all time.

 

[parshisa]

I installed a 2 ton Mr. Cool DIY system in my mother's house last October. It's fairly straightforward to install and if you have some mechanical/electrical/construction ability, you'll be able to install it just fine.

My mother has a small house. Essentially single story, ~1000 square feet. It was built in the early 70s and is of dubious quality and poorly insulated. It's the house I grew up in and we never had A/C when I was growing up. She doesn't like it (A/C makes you weak! - essentially her thought) and so she still doesn't use it. She won't even use the dehumidifying feature of the unit. I've tried to convince her to do so, but she won't have it. Ha. What she does use it for, and what you may not be concerned with, is heating her home. She has a propane heater that she's relied on the past 12ish years, but she didn't like how expensive it was to operate. The minisplit heats her home nicely and does so with minimal energy consumption. Heatpumps are generally better air coolers than heaters, so our experience with heating her home would lead me to believe it to be a good candidate for what you want to do.

3.5 tons seems like a small system for a 2500 sqft home in Texas. My home here in Virginia is 2500 sqft finished living space, and we have 7.5 tons of HVAC capacity. On hot days, the systems work hard, but can keep the house at 72 degrees.

If you have any specific questions about the Mr. Cool system, let me know. I'm happy to help as best I can. I say go for it.

Thanks a lot mate. I’ll DM you if i choose to go this route (just waiting in the stimulus lol)

 

[hemitom]

It’s not old. House was built in 2014, november. I’ve had the system checked and everything looks good. Talking to my friend HVAC tech the unit size is just not enough for the house footage. Once the temps go into low 90s range - no issues keeping the temp without running all time.

Maybe it is to small for the texas heat !
i condition around 3000sf in my home which includes the basement in that figure , we have had a stretch of hot humid weather here and it has been over the 100f range a few days .
my system is two tons and it will hold at 73f with no issues so i find it odd a that 3.5 tons won't keep up.

 

[JimPghPA]

Do i really need to be worried about additional load from split system the plugs into the walls? I’d say central HVAC running less should compensate for additional load from the split. Correct me if I’m wrong, i am a mechanical engineer, not An electrician

If you are doing more cooling it will be because both the old and new system are running at the same time. That will draw more power. What is your fuse box rated at? If it is an additional system that plugs into the wall, what is the peak demand the unit will require (how many Amps must the plug be rated for)? Is the circuit breaker and wire and plug each rated to handle the load the new unit will draw?

With a large house, it is easy to have a fuse box (and power feed to the house) maxed out, and find that when you add some new significant load you are exceeding the ratings. Sometimes you find that the plug you are using is on a breaker that is also connected to a plug somewhere else in the house and that there is already something on that plug. And that the total of the existing load and the new load cause the breaker to trip. Or you may exceed the main breaker of the box and trip that and everything shuts off.

Usually you are OK when you add something to a house. But with larger houses it is something you should take a good look at before you invest in the new item, if you do not want any unpleasant surprises and delays.

Find out what the main breaker of the box is rated at. And try to find out how many amps each circuit actually draws. See what is left over when you subtract the total of all of the circuits from the rating of the main.

 

[skyactiv]

Your going to run a ductless system in addition to your existing central AC in a home less than 10 years old because a crappy builder undersized the AC system?

Than when your central AC needs replaced, what do you do?
What you should do is see if your HVAC friend will install you a proper system on his day off for $500.00. And get the system at a supply house or online. Your looking at $2600 for a 5 ton condenser and evaporator. Yes, the line set and furnace or air handler adds expense.
I'd do it right.

 

[Exit32]

Last month, I installed a 36,000 BTU Mr. Cool mini-split system in my four-bay 2,000-sq-ft garage. I needed a buddy's help to lift the indoor unit into place on an interior wall, and his help to lift the outdoor unit onto wall brackets. Other than that, I followed Mr. Cool's installation instructions, took my time, and now have a climate-controlled garage.

I'm amazed by how quiet the Mr. Cool system runs, and it cools and dehumidifies effortlessly. Highly recommended!

 

[Nick1994]

It's probably not enough tonnage, but have you had it checked out to make sure there aren't duct leaks or something wrong with the unit before you start bandaiding it?

Our home's A/C has a leak and it just couldn't keep up with cooling the house down. Had it topped off and it is an absolute beast again.

 

[PimTac]

I would go over the current system to make sure everything is tight and proper.

I don’t have experience with Mr Cool splits but I have bought and used Panasonic and Sanyo systems. They work very well. The noisy part is outside. If you decide to go this route look into inverter systems.

 

[Cujet]

That house, even if it has insulated windows and a white roof, very likely needs 5 tons as an absolute minimum.
2500 sq ft in TX = 5 tons

With that in mind, you really need another 18,000 BTU or 1.5 tons. (12,000 BTU=1 ton)

Possibly of interest: BTU/SEER=Watts
Example: 18,000 BTU/20 SEER=900 Watts.

Mitsubishi has a very good reputation for Mini Split systems. I don't have objective criteria to show who is better, but as a general rule here in South Florida, these systems work hard. Failed Chinese mini split systems almost always get replaced with Mitsubishi mini split systems.

 

[parshisa]

It is amazing how polar the opinions are on my current system. That is really confusing

 

[zzyzzx]

Is using a window unit to supplement your existing system an option?
It's not like you would need to keep it installed year round.

 

[parshisa]

Is using a window unit to supplement your existing system an option?
It's not like you would need to keep it installed year round.

It probably is. Although i’m not sure if window unit would be capable of covering 1000sq ft of open area. Actually i doubt it would. Plus, split system would be a “cleaner”, better looking solution.
Also, in general, this is my first house, and i’ve never lived in a climate controlled house. As a matter of fact, my home country rarely has climate controlled living quarters, so I don’t really know what to expect.

 

[dlundblad]

A coworker of mine added one 2 years ago. Can’t remember the brand, but he said it was pretty straight forward. He loves it. Uses it more for heat though as he specifically bought it to replace their wood burning furnace.

That said, I am thinking he said it did better with heat than AC?

 

[Amkeer]

You need to fix the current central system that is in the home. A home that new shouldn't have that type of problem.

The mini's are great. I have one in the detached garage and will be adding one to the attached garage once the weather cools.

 

[greenjp]

Than when your central AC needs replaced, what do you do?
What you should do is see if your HVAC friend will install you a proper system on his day off for $500.00. And get the system at a supply house or online. Your looking at $2600 for a 5 ton condenser and evaporator. Yes, the line set and furnace or air handler adds expense.
I'd do it right.

The trick is if the current ductwork isn't set up for the amount of supply and return airflow needed for a larger system, then that won't be a good solution either. If upsizing the system's going to require replacing/adding ductwork it's going to cost a lot more than $500 to install.

Assuming your current system is running correctly (CFM of airflow per ton correct? Right sized & clean filter? Static pressure OK?) and you don't have an insulation problem (what's your attic insulation like? Is the attic properly vented or sealed?), the mini split system is probably a good way to go. Be nice to have a redundant setup.

As for the electrical load, the central AC is going to draw whatever it draws any time it's on (assuming you don't have a variable speed or multistage type). So if it's running and your mini splits are going at the same time then yes it'll be an overall increase in the electric load.

jeff