sgiss
Member
What is a general range for delta T in a minisplit? I have a Mr. Cool and am wondering if it is up to par.
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Minisplit expectations?
- Thread starter sgiss
- Start date
justinjoyal
Well-known member
15-25F dT
matt_i
Well-known member
Knowing some more information like the BTU capacity of the Mr Cool, the square footage of your indoor area and how its insulated walls and ceiling would help get a better answer.
Just saying if you have a 12k BTU unit and there is 12k BTUs of heat delivered you're not going anywhere fast.
Just saying if you have a 12k BTU unit and there is 12k BTUs of heat delivered you're not going anywhere fast.
12,000 btu Mr Cool. Less than 500 sq feet, insulated, but not well.
Setting the unit at 68 or 70 degrees gives me 75 room temperature. That is fine, just surprised I can not get it lower. It is about 85 outside.
Intake at the blower is 76.6 (near the ceiling) and it blows out 48-50.
This is at 48% indoor humidity.
Setting the unit at 68 or 70 degrees gives me 75 room temperature. That is fine, just surprised I can not get it lower. It is about 85 outside.
Intake at the blower is 76.6 (near the ceiling) and it blows out 48-50.
This is at 48% indoor humidity.
Last edited:
12,000 btu Mr Cool. Less than 500 sq feet, insulated, but not well.
Setting the unit at 68 or 70 degrees gives me 75 room temperature. That is fine, just surprised I can not get it lower. It is about 85 outside.
Intake at the blower is 76.6 (near the ceiling) and it blows out 48-50.
This is at 48% indoor humidity.
it may take a few days of running before the walls and items cool down, the delta seems pretty good, just keep it set there and see what happens.
12,000 btu Mr Cool. Less than 500 sq feet, insulated, but not well.
Setting the unit at 68 or 70 degrees gives me 75 room temperature. That is fine, just surprised I can not get it lower. It is about 85 outside.
Intake at the blower is 76.6 (near the ceiling) and it blows out 48-50.
This is at 48% indoor humidity.
What is your indoor unit fan speed? Those numbers look like either the fan is set too low or the unit is running wide open trying to hit set point. I doubt the unit would have that large a delta T if the temperature sensor was off ~5*.
I agree with PoorOwner that your next step should be to run the unit a few days to see if things stabilize. If you're still climbing into the mid 70s it's probably an issue with your building. Probably either air leakage or solar gain.
Matt and Poor Owner - thanks for the replies. This is getting interesting! I have been running and checking for a number of days. I have been running the fan on the highest setting. Yes, the house has low ceilings and a greenhouse attached that pumps some heat through the wall. The system has been in a few years - I think it did much better in the past. Wish I had taken some numbers in the past. It did get the room down to 68! But end of last summer the indoor unit froze up. It did have slow leak. I had it charged - the tech did not evac and weigh in the exact charge - just used gauges. He did not look for a leak because the quote for LOOKING FOR a leak was $800.00! ( paid less than $1000.00 for the system. He suggested I buy some gauges and refrig, let it leak, and recharge it once a year instead of paying his company $120.00 to do it. I decided it was a very slow leak at the Schroeder valve, bought the tool and replace the valve.
justinjoyal
Well-known member
Matt and Poor Owner - thanks for the replies. This is getting interesting! I have been running and checking for a number of days. I have been running the fan on the highest setting. Yes, the house has low ceilings and a greenhouse attached that pumps some heat through the wall. The system has been in a few years - I think it did much better in the past. Wish I had taken some numbers in the past. It did get the room down to 68! But end of last summer the indoor unit froze up. It did have slow leak. I had it charged - the tech did not evac and weigh in the exact charge - just used gauges. He did not look for a leak because the quote for LOOKING FOR a leak was $800.00! ( paid less than $1000.00 for the system. He suggested I buy some gauges and refrig, let it leak, and recharge it once a year instead of paying his company $120.00 to do it. I decided it was a very slow leak at the Schroeder valve, bought the tool and replace the valve.
You *decided* it was a valve leak? I would love to decide where leaks are!
Find a reputable company who is not into ripping people off and have your system inspected.
Knowing the charge was guessed in and you now apparently have problems, I would have the charge recovered, any leak fixed, evac and weigh refrigerant back in according to factory charge. Then at least you know you have that part properly covered.
minytrker
Well-known member
I can get the AC portion of my shop (42x26) in the 60's....keep it 72 in there right now and its been in the 100's here.
BuickFarmer
Well-known member
Curious as to how long it took to accumulate THAT much mold and how difficult was it to clean. Pictures? Is this a common problem with these systems, all mini's or just Mr Cools. Considering a couple for the BS&SG is my reason for askin
Curious as to how long it took to accumulate THAT much mold and how difficult was it to clean. Pictures? Is this a common problem with these systems, all mini's or just Mr Cools. Considering a couple for the BS&SG is my reason for askin
In a humid environment MS's can easily grow mold, That is why when installing them it is essential to set the mounting bracket correctly to ensure that the drain pan is totally draining. Make sure the top corners of the bracket are toggled through the sheetrock. If you don't do this the bracket may look secure and well mounted, but when you hang the unit, the top corners will tip into the room and you can create water pockets. If there is any residual moisture in there, along with some dust, you make a nice organic matter that will grow. My Fujitsu's have a "Coil Dry" feature that will run the fan for a time once the AC is off to dry the coils and trays. It is dry as a bone...and burning, here in CA, but when I was in MA I used coil dry all the time. It is a good feature. If you are running the unit in a humid environment and simply turn the unit off and go in the house the coil and drain pan are wet and that is the start of mold growth. A cleaning regiment is essential on MS's. Do a thorough cleaning, or at least an inspection, at the beginning and end of the cooling season, at least until you know how your unit operates. The fan is a giant pita to clean. Also, about 40% of the coil surface area angles down towards the back of the unit. That too is where dirt accumulates and must be tended to.
In response to BuickFarmer. In VA it was two years for the mold caused issues. Cleaning is an adventure. I did not remove the cover - as I am not sure how it is attached. (That is for next time.) There are foaming cleaners for this purpose. I used a product designed to kill the mold, but it was not a cleaner. It did slosh most of the dead mold off. I accessed the blower through the outflow vent - not easy - the portion of the coils I can see looked clean, but could be different in back. Next time, I will hopefully figure out how to remove the housing. I am being more careful about using the Coil Dry feature or just switching to fan for a long period if I am turning it off. Units should be designed for easier cleaner I am thinking.
eddieK
Well-known member
You *decided* it was a valve leak? I would love to decide where leaks are!
Find a reputable company who is not into ripping people off and have your system inspected.
Knowing the charge was guessed in and you now apparently have problems, I would have the charge recovered, any leak fixed, evac and weigh refrigerant back in according to factory charge. Then at least you know you have that part properly covered.
Here's the rub. To have this done properly...it costs money. You have two choices here...pay a reputable tech what it costs to fix it right, so it stays fixed...or rip out the 1,000.00 system and install a new one(because it's so Damn cheap and disposable).
A proper leak search and seal with weighed in charge costs $800.00. That is how it works if you want long compressor life...and don't ice the coil, calling for too low temps over night (68F)...that sends liquid to the compressor.
BuickFarmer
Well-known member
Thanks Jackfre, thanks sgiss. I am typically slack on maintenance of things such as heat pumps, whole house well water filters and even gutters so suspect I will be the same with a mini. I should be able to handle a once a year cleaning though. Thanks again for your responses.