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Trane XV20i and TAM9060 Recent Install/Performance
Hi, I recently had an XV20i and TAM9060 installed.
It's not acting as I thought it would.... I'm looking for some advice before contacting my dealer (again).
About a week ago my dealer came and made adjustments to my system. I could hear the air handler running wide open and suddenly stop. He said that he turned the fan down due to high back pressure and set it up to run on torque vs amps (maybe visa-versa). Since, I've been at home this week on vacation and my system seems to be acting like a conventional system. It starts and stops frequently and only seems to run at 43% output (like my old non variable speed one stage unit).
If I change set point (heat) it does seem to ramp at low speed (20%), but them goes back to frequent on/off operation at 43%.
My home is very well insulated (min 8" foam) and windows to match. I also realize there are a lot of variables that go into all of this, I'm just not educated enough in this area to provide all of them. Do I just not understand a variable speed system? I thought it was designed to run more constantly at lower speed vs on/off operation at close to half speed...? In addition, I'm not sure turning the fan down is the proper solution. It makes me feel like my system can't perform to it's full capability. My home also feels colder than I'm used to at the same setpoint.
Thanks in advance!
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What size equipment do you have?
What was the size of the equipment it replaced?
How long has this equipment been in service?
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Originally Posted by
pecmsg
What size equipment do you have?
What was the size of the equipment it replaced?
How long has this equipment been in service?
5 Ton currently installed
Old unit was 5 Ton
1 month since install
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WAG
1/2 - 3/4 of the jobs we see have...........Oversized equipment on undersized ducts!
Did the selling contractor perform a Load / loss calculation? See if the ducts could handle the air flow required for 5-Tons?
Might want to get a different contractor to review the entire install.
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How big is this well insulated home that requires 5 tons of cooling?
“I haven’t failed. I’ve just found 10,000 ways that won’t work.” - Thomas Edison
“It’s not whether you get knocked down, it’s whether you get up.” - Vince Lombardi
"In this house we obey the laws of thermodynamics" - Homer Simpson
Local 486 Instructor & Service Technician
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They did not. They did change the box on the outlet of the air handler from a sweep elbow to a 90 degree box...
The impression I was given in regards to oversize is that this system can adjust from 2-ton to 5-ton depending on demand. I was told that would eliminate an oversize unit. That's one reason I chose this system. I have been told in the past I didn't need a 5-ton.
What you say about the duct work makes sense to me, but wouldn't I have had high back pressure/less airflow with my old system?
He also verified charge and said it is right where it needs to be.
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Originally Posted by
rider77
How big is this well insulated home that requires 5 tons of cooling?
3000 square feet.
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On that equipment it's got to be size right especially on foam insulated house or you are going to problems with air flow and humidity.
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Your equipment is very likely oversized. Variable speed is not a cure or excuse to oversize the equipment.
If you have a foamed well insulated house what is being done for outdoor air exchange and humidity control?
Did you receive a commissioning report for the new unit startup?
“I haven’t failed. I’ve just found 10,000 ways that won’t work.” - Thomas Edison
“It’s not whether you get knocked down, it’s whether you get up.” - Vince Lombardi
"In this house we obey the laws of thermodynamics" - Homer Simpson
Local 486 Instructor & Service Technician
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I know of NO residential unit that can modulate from 2 - 5 tons. I hope you got that in writing!
BOSCH does have one that can be set up 3 - 5 tons.
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Originally Posted by
rider77
Your equipment is very likely oversized. Variable speed is not a cure or excuse to oversize the equipment.
If you have a foamed well insulated house what is being done for outdoor air exchange and humidity control?
Did you receive a commissioning report for the new unit startup?
I have a fresh air intake. It used to be manual, now it is tied into the unit and automated. Humidity is set on my thermostat, I don't know how it controls it.
My answer to a commissioning report will have to be "No". But to be honest I'm not sure what that would look like...
Is frequent start/stop a sign of being oversized?
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Originally Posted by
wolfewl
I have a fresh air intake. It used to be manual, now it is tied into the unit and automated. Humidity is set on my thermostat, I don't know how it controls it.
My answer to a commissioning report will have to be "No". But to be honest I'm not sure what that would look like...
Is frequent start/stop a sign of being oversized?
Yes or other issues or combination of!
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Originally Posted by
pecmsg
I know of NO residential unit that can modulate from 2 - 5 tons. I hope you got that in writing!
BOSCH does have one that can be set up 3 - 5 tons.
I think Bosch is design to be install on a standard air handler with standard thermostat. The Trane XV unit with Tam 9 unit is design to modulate blower air flow and compressor speeds to control temperature and humidity.
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Originally Posted by
sammyray
I think Bosch is design to be install on a standard air handler with standard thermostat. The Trane XV unit with Tam 9 unit is design to modulate blower air flow and compressor speeds to control temperature and humidity.
I don't know about the Bosch, but yes, that's what was explained to me.
That is exactly the reason I have questions about the way my system seems to be operating. Maybe it's normal, I don't know?!
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With it being grossly oversized it will never run at 100% and will have oil return issues for the compressor. Sweating issues the list will go on and on.
My company is dealing with a issue like this now. A previous sales tech sold a customer 2 XVs, total of 7tons of cooling on a 2200sq ft house. He told them the same thing you were told. Guess what both units are sweating like whores in church because the ductwork is not sized for the equipment that was installed. Multiple problems and the units are not even a year old. Already had to replace two ECM motors. Both units are running 1.03” WC We are going to rip them out and and install the proper sized units
What was the final total external static pressure?
Why didn’t the installing contractor do a load calc
Why didn’t the installing contractor do a commissioning report?
These are all questions you need to ask your installing contractor!!!
I’m willing to bet you could have had a 3 or 4 ton XV installed and be fine.
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What do we know about
your BUILDING THERMAL ENVELOPE?
3,000 Sq Feet
8" MIN FOAM __ Ceiling
It has good windows
_________________
What we do Not know?
Location: 36'N or 63'N Latitude / presume Western Hemisphere
______ ZIP _ _ _ _ _
__ Current control and equipment sizing issue is not specifically defined as Cooling or Only Heating
__ Elevation: 1,200' or 12,000'
__ Built in 1980 or 2010 ?
R- _ # _ Walls ( ? 5" Foam )
R- _ # _ Floor
One or two story with or without basement ?
IF basement, is it totally underground?
" Good " Windows:
… presume in the BALL PARK of U-factor 0.3, S.H.G.C. < 0.40
… Perhaps, triple Pane & Argon filled __ ?
< ~ 500 Sq Feet of Glass ?
Window Area per Orientation
N
S
E
West
__________________
Equipment:
TRANE XV20i with TAM9060 ____ 5-Ton A/C
________ Furnace: ?
Frequent Start & Stop recently
Heating source is NOT known.
Is heating the primary issue?
i.e. Location South of 29'N or North of 46'N latitude
Natural Gas, Liquid Propane, Electric Strips
Equipment Location:
1. Basement, Attic, Garage, Mechanical Closet on 1st Floor
2. Conditioned Space ?
Air Distribution:
Measured E.S.P.
Total Air flow rate is not stated.
______
Last edited by dan sw fl; 12-03-2019 at 06:46 AM.
Designer Dan __ It's Not Rocket Science, But
It is SCIENCE with
Some Art. _ _
KEEP
IT
SIMPLE &
SINCERE ___ __
www.mysimplifiedhvac.com ___ __ Define the Building Envelope & Perform a Detailed Load Calc: It's ALL About Windows & Make-up Air Requirements. Know Your Equipment Capabilities
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Originally Posted by
wolfewl
They did not.
They did change the box on the outlet of the air handler from a sweep elbow to a 90 degree box.. .
The impression I was given in regards to oversize is that this system
can adjust from 2-ton to 5-ton depending on demand.
I was told that would eliminate an oversize unit.
That's one reason I chose this system.
I have been told in the past I didn't need a 5-ton.
What you say about the duct work makes sense to me,
but wouldn't I have had high back pressure/less airflow with my old system?
He also verified charge and said it is right where it needs to be.
90 degree Box could create 8 times more local pressure drop
than a proper Sweep Elbow.
Designer Dan __ It's Not Rocket Science, But
It is SCIENCE with
Some Art. _ _
KEEP
IT
SIMPLE &
SINCERE ___ __
www.mysimplifiedhvac.com ___ __ Define the Building Envelope & Perform a Detailed Load Calc: It's ALL About Windows & Make-up Air Requirements. Know Your Equipment Capabilities
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Originally Posted by
Deathpunch0311
With it being grossly oversized it will never run at 100% and will have oil return issues for the compressor. Sweating issues the list will go on and on.
My company is dealing with a issue like this now. A previous sales tech sold a customer 2 XVs, total of 7tons of cooling on a 2200sq ft house. He told them the same thing you were told. Guess what both units are sweating like whores in church because the ductwork is not sized for the equipment that was installed. Multiple problems and the units are not even a year old. Already had to replace two ECM motors. Both units are running 1.03” WC
We are going to rip them out and and install the proper sized units
What was the final total external static pressure?
Why didn’t the installing contractor do a load calc
Why didn’t the installing contractor do a commissioning report?
These are all questions you need to ask your installing contractor!!!
I’m willing to bet you could have had a 3 or 4 ton XV installed and be fine.
I agree with you. With the right load and duct design a XV units work great.
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Well... Unfortunately most of you are speaking in terms I'm struggling to understand. Not to mention my disappointment as all of the comments point to my dealer putting in an over sized unit.
With that said, I do understand a 5-ton unit is more than I need. But, I was given the impression this system will modulate down and provide exactly what is needed and if extra cooling/heating is needed it will have the capability to overcome if that situation occurs.
I assumed it would run at very low output 95% of the time and didn't think that would be an issue. I have an appointment coming up with the dealer to discuss everything that has been brought up here. Unfortunately it's a week out. I'll follow up and let you know what resolution(s) are offered.
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The XV20i heat pump can modulate from 25%-100% capacity in 1/10th % increments allowing for a true 750 stage variable capacity. Yes, that means it can go as low as 1.25 tons. The straight cooling AC can go from 30%-100%.
This unit also encorporates an automatic oil return cycle if low speed is active for extended periods, and also for 1 min upon each start up. If the unit has been disconnected from power, the initial oil return cycle will be 15 minutes upon start up.
The variable speed blower motor should have constant cfm selected, NOT constant torque mode. They must be configured for 400cfm/ton.
It sounds to me like the system has not been set up properly. However, like the others have questioned, if it's over-sized for the ducting, it's not going to work as well as it should.
This is one of the best residential heat pump units on the market. This system can even tell you the calculated static pressure on the digital display of the air handler.
Does this system have a zoning control? Typically the set up for a non zoned XV is pretty straight forward and easy. Zoned systems can be a bit more challenging especially if the contractor is not familiar with the equipment.
"The only true wisdom is in knowing you know nothing" Socrates
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