How do I evaluate a minisplits performance

Thepprof · 07-19-13, 08:30 AM

Hi; I have a number of regular HVAC units that I maintain in my rentals. for a quick scan I use a ir thermometer and looks for 14 - 18 degree difference in air temperature outside and 12 - 20 degrees inside. If the difference gets off I break out the gages and test the long way.

I have two Klimaire 12K minisplits. Since I cannot do super/sub heat/cool tests to evaluate these unit what do I do. I do not want to evacuate and refill to be sure they are serviced properly. One unit that I setup in my shop and serviced using a thermal camera to observe the compressor coil activity is kicking 30 degrees difference on a hot day while the other unit is only kicking 20. I cannot get any information from Klimaire. I figure that on a given day say 95 degrees outside and 78 degrees inside I should see a given pressure on the service valve. Any one have any thoughts? thanks Owen.

jeff5may · 07-23-13, 06:11 AM

I found an install guide for a 12k unit here.

If you have a "standard 13 SEER" unit, you can do superheat and subcooling measurements on the unit any time you want. They work just like a window unit. Most smaller capacity sets run with cap tubes as metering devices.

If you have an "inverter" unit, you may or may not be able to do superheat and subcooling measurements on the unit.

If the unit has cap tubes or tx valves, you can set the unit to "Super-cool" or Max-cool" or whatever Klimare calls full throttle. Let it run flat out for a few minutes, then check p and t.

However, if the unit has electronic expansion valve metering, you shouldn't check superheat nor subcooling. With these units, you must recover and weigh in charge to eliminate all doubt. The unit has a pt map in the microcontroller that actively adjusts the valves to maintain proper flow, much like fuel metering in a car.

From the install guide, it says on page 16 that when outside temp is 95 degF, the pressure on the low side service valve should be between 57 and 85 psig. It also says that under normal operation, you should have at least 8 degC delta t indoors.

WyrTwister · 07-25-13, 04:22 PM

8 degrees C is 14.4 degrees F ? If I did my math correctly ?

I have an about month old 12,000 btu Comfort Aire 13 SEER non-inverter mini split . It is about 95 F predicted high for today . If you like I will try to measure the indoor and out door delta T ?

Wish I could find or get a service manual for this unit ?

Correct me if I am wrong , but the relitive humidity will have an impact on the indoor delta T ?

God bless
Wyr

jeff5may · 07-26-13, 03:43 AM

A lack of detailed information is the status quo for pretty much all chinese or korean knock-off products. Even the dealers can't get good training or service info. It's the price you pay for getting an otherwise $1000 unit for $599.99 or less. We as consumers are not supposed to care what's inside the box, let alone try to fix or adjust anything.

The good news is someone designed the product, then sent the job of building the stuff to China. With a little detective work, one can quickly find out the original designer of the product. Usually with hvac equipment, the compressor and the logic board will tell you where the unit was conceived.

WyrTwister,

Please measure and post as much info about the unit as you can manage, it will be greatly appreciated. If you can provide baseline performance data for a virgin system, that would be great. There is an aura of mystery about how these units operate; your data will be very enlightening.

The OEM's have trouble helping themselves figure out how to repair the expensive units, much less you or I. And the Chinese name tag holders don't even try. Like xringer's mini-split sanyo that sprung a leak: they just shipped him another new outdoor unit and didn't even want the broken one back. He kept it, did an easy repair, and now he has two. This is the new way.

If you can post the model Number of your unit, I will try to find out what I can about it.

WyrTwister · 07-27-13, 07:29 AM

Quote:

Originally Posted by jeff5may

A lack of detailed information is the status quo for pretty much all chinese or korean knock-off products. Even the dealers can't get good training or service info. It's the price you pay for getting an otherwise $1000 unit for $599.99 or less. We as consumers are not supposed to care what's inside the box, let alone try to fix or adjust anything.

The good news is someone designed the product, then sent the job of building the stuff to China. With a little detective work, one can quickly find out the original designer of the product. Usually with hvac equipment, the compressor and the logic board will tell you where the unit was conceived.

WyrTwister,

Please measure and post as much info about the unit as you can manage, it will be greatly appreciated. If you can provide baseline performance data for a virgin system, that would be great. There is an aura of mystery about how these units operate; your data will be very enlightening.

The OEM's have trouble helping themselves figure out how to repair the expensive units, much less you or I. And the Chinese name tag holders don't even try. Like xringer's mini-split sanyo that sprung a leak: they just shipped him another new outdoor unit and didn't even want the broken one back. He kept it, did an easy repair, and now he has two. This is the new way.

If you can post the model Number of your unit, I will try to find out what I can about it.

It is a Comfort Aire

A-SMH12SC DSS

B-SMH12SC DSS

If the temp gets to 95 or above , I will try to record inside and outside temp .

God bless
Wyr

jeff5may · 07-27-13, 08:04 PM

I found some interesting things about this model.

First, here's the install manual and charging bulletin:
http://www.alpinehomeair.com/related...2012-04-07.pdf

http://www.comfort-aire.com/index.ph...673&format=raw

Comfort-aire is a subsidiary of Heat Controller, Inc. Heat Controller, who also owns the Century brand name, just got purchased by MARS, an OEM manufacturer of mainly blower motors and control boards. So Comfort Aire is now owned by MARS, and will probably be with us for a while.

The unit has a Toshiba compressor and most likely has Mars controls, with some other brands of "stuff" thrown in the box to make it work. I guess comfort-air sounds better than "toshimerson-sungyo".

And here is the service manual:

http://www.aitons.com/Ductless/SMA-S...eManual-ml.pdf

Enjoy!

WyrTwister · 07-28-13, 01:50 AM

Quote:

Originally Posted by jeff5may

I found some interesting things about this model.

First, here's the install manual and charging bulletin:
http://www.alpinehomeair.com/related...2012-04-07.pdf

http://www.comfort-aire.com/index.ph...673&format=raw

Comfort-aire is a subsidiary of Heat Controller, Inc. Heat Controller, who also owns the Century brand name, just got purchased by MARS, an OEM manufacturer of mainly blower motors and control boards. So Comfort Aire is now owned by MARS, and will probably be with us for a while.

The unit has a Toshiba compressor and most likely has Mars controls, with some other brands of "stuff" thrown in the box to make it work. I guess comfort-air sounds better than "toshimerson-sungyo".

And here is the service manual:

http://www.aitons.com/Ductless/SMA-S...eManual-ml.pdf

Enjoy!

Thank you VERY MUCH ! :-)

God bless
Wyr

jeff5may · 08-03-13, 03:28 AM

Wyrtwister posted this info here

Default 07/31/2013 Mini split data
Unit set for 74

Temp across room 76

Indoor discharge temp 48

Outdoor air intake temp 98

Outdoor air discharge temp 108

Weather.com reports current temp 97 & RH 33%

All temps in degrees F . Accuracy of the thermometer is not guaranteed .

Comfort Aire 12,000 btu HP - A/C 13 seer 120 VAC .

Some one requested this data , last week , I think ?

God bless
Wyr

07-19-13, 08:30 AM	#1
Thepprof Lurking Renovator Join Date: Jun 2012 Location: Virginia Posts: 28 Thanks: 0 Thanked 4 Times in 3 Posts	How do I evaluate a minisplits performance Hi; I have a number of regular HVAC units that I maintain in my rentals. for a quick scan I use a ir thermometer and looks for 14 - 18 degree difference in air temperature outside and 12 - 20 degrees inside. If the difference gets off I break out the gages and test the long way. I have two Klimaire 12K minisplits. Since I cannot do super/sub heat/cool tests to evaluate these unit what do I do. I do not want to evacuate and refill to be sure they are serviced properly. One unit that I setup in my shop and serviced using a thermal camera to observe the compressor coil activity is kicking 30 degrees difference on a hot day while the other unit is only kicking 20. I cannot get any information from Klimaire. I figure that on a given day say 95 degrees outside and 78 degrees inside I should see a given pressure on the service valve. Any one have any thoughts? thanks Owen.

07-27-13, 08:04 PM	#6
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	I found some interesting things about this model. First, here's the install manual and charging bulletin: http://www.alpinehomeair.com/related...2012-04-07.pdf http://www.comfort-aire.com/index.ph...673&format=raw Comfort-aire is a subsidiary of Heat Controller, Inc. Heat Controller, who also owns the Century brand name, just got purchased by MARS, an OEM manufacturer of mainly blower motors and control boards. So Comfort Aire is now owned by MARS, and will probably be with us for a while. The unit has a Toshiba compressor and most likely has Mars controls, with some other brands of "stuff" thrown in the box to make it work. I guess comfort-air sounds better than "toshimerson-sungyo". And here is the service manual: http://www.aitons.com/Ductless/SMA-S...eManual-ml.pdf Enjoy! Last edited by jeff5may; 07-27-13 at 08:11 PM..

07-23-13, 06:11 AM	#2
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	I found an install guide for a 12k unit here. If you have a "standard 13 SEER" unit, you can do superheat and subcooling measurements on the unit any time you want. They work just like a window unit. Most smaller capacity sets run with cap tubes as metering devices. If you have an "inverter" unit, you may or may not be able to do superheat and subcooling measurements on the unit. If the unit has cap tubes or tx valves, you can set the unit to "Super-cool" or Max-cool" or whatever Klimare calls full throttle. Let it run flat out for a few minutes, then check p and t. However, if the unit has electronic expansion valve metering, you shouldn't check superheat nor subcooling. With these units, you must recover and weigh in charge to eliminate all doubt. The unit has a pt map in the microcontroller that actively adjusts the valves to maintain proper flow, much like fuel metering in a car. From the install guide, it says on page 16 that when outside temp is 95 degF, the pressure on the low side service valve should be between 57 and 85 psig. It also says that under normal operation, you should have at least 8 degC delta t indoors.

07-25-13, 04:22 PM	#3
WyrTwister Master EcoRenovator Join Date: Jun 2013 Location: USA Posts: 543 Thanks: 6 Thanked 44 Times in 38 Posts	8 degrees C is 14.4 degrees F ? If I did my math correctly ? I have an about month old 12,000 btu Comfort Aire 13 SEER non-inverter mini split . It is about 95 F predicted high for today . If you like I will try to measure the indoor and out door delta T ? Wish I could find or get a service manual for this unit ? Correct me if I am wrong , but the relitive humidity will have an impact on the indoor delta T ? God bless Wyr

07-26-13, 03:43 AM	#4
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	A lack of detailed information is the status quo for pretty much all chinese or korean knock-off products. Even the dealers can't get good training or service info. It's the price you pay for getting an otherwise $1000 unit for $599.99 or less. We as consumers are not supposed to care what's inside the box, let alone try to fix or adjust anything. The good news is someone designed the product, then sent the job of building the stuff to China. With a little detective work, one can quickly find out the original designer of the product. Usually with hvac equipment, the compressor and the logic board will tell you where the unit was conceived. WyrTwister, Please measure and post as much info about the unit as you can manage, it will be greatly appreciated. If you can provide baseline performance data for a virgin system, that would be great. There is an aura of mystery about how these units operate; your data will be very enlightening. The OEM's have trouble helping themselves figure out how to repair the expensive units, much less you or I. And the Chinese name tag holders don't even try. Like xringer's mini-split sanyo that sprung a leak: they just shipped him another new outdoor unit and didn't even want the broken one back. He kept it, did an easy repair, and now he has two. This is the new way. If you can post the model Number of your unit, I will try to find out what I can about it.

08-03-13, 03:28 AM	#8
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Wyrtwister posted this info here Default 07/31/2013 Mini split data Unit set for 74 Temp across room 76 Indoor discharge temp 48 Outdoor air intake temp 98 Outdoor air discharge temp 108 Weather.com reports current temp 97 & RH 33% All temps in degrees F . Accuracy of the thermometer is not guaranteed . Comfort Aire 12,000 btu HP - A/C 13 seer 120 VAC . Some one requested this data , last week , I think ? God bless Wyr