New Unit Issues????

[adamwhatley]

Guys here is what i have got as far as equipment goes.

Trane XR 15 Model # 4TTR50E1000AB
TRANE V/S FURNACE MODEL # TUD2B080ACV32AA
ASPEN EVAP. COIL MODEL # CE30D44-175L-015


The problem is this. The customer says that they are having to run the temp. lower then they had to with previous system. The system size was the same for both the new and the old unit. I did Manual J on the house and the load came out to be right at 31,000 btu for cooling. I have already lowered the blower setting down to 350 cfm per ton and they say maybe a little better. What else can i do with the above listed equipment to help with this. What is the lowest cfm per ton setting on this furnace that i can run and what to set the dip switchs at to get there. Any other ideas would be great. I really want to correct this as this has never been a problem before.

thanks

[energy star]

Tell them the old stat was inaccurate. I mean if they set it on 70...does it cool to 70?
Set the thermostat on what the used to in the past.....leave a data logger or hang out for an hour or two and see if you hit set point.

Trane XR 15 Model # 4TTR50??E1000AB

Are you not missing some numbers?

[Todd S 2]

It looks like a 2.5 ton coil. What size is the condenser?

[skippedover]

Where is the job located? Did you adjust the equipment selection for the location? Sometimes the equipment capacity needs to be adjusted down for higher temperature climates and up for cooler climates. Remember, 95F @ 70/30 SHR is design. If your conditions are cooler than that, then it's likely the new 2.5-ton system is oversized. How much I can't tell from here but it's just a thought.

[adamwhatley]

sorry it is a 2.5 ton condenser as well... i am thinking old t-stat could be off a little. to be honest if i really wanted to i could just adjust the temp set points on the t-stat to where she thinks it should be but i am not. the equipment is located in NE Louisiana. So hot Humid Climate.

[udarrell]

sorry it is a 2.5 ton condenser as well... i am thinking old t-stat could be off a little. to be honest if i really wanted to i could just adjust the temp set points on the t-stat to where she thinks it should be but i am not. the equipment is located in NE Louisiana. So hot Humid Climate.

We need to know the temp & humidity that the system is capable of reaching & th outdoor conditions. Every home owner should have a humidity gauge.

In a humid climate, I question if the higher SEER units with lower BTUH compressors, can equal say an 8 or 10-SEER's capacity.

You need a blower door air infiltration check on that home. Get the infiltration rate as low as code will permit so it can better handle the latent heatload.

Ballpark Delivered BTUH:
Check actual CFM with an anemometer, check SA & RA wet bulbs, plot the difference on an enthalpy chart. CFM X's 4.5 X enthalpy difference = ballpark Delivered BTUH. Check Units Expanded Data for nominal BTUH comparison.

[adamwhatley]

My design temps where 96 degree summer 45 degree day winter. The system will maintain 72 degrees in the summer. Customer is running at 74 degrees to get the same temp as old system she said that was doing it at 78 degress.

[jimj]

Guys here is what i have got as far as equipment goes.

Trane XR 15 Model # 4TTR50E1000AB
TRANE V/S FURNACE MODEL # TUD2B080ACV32AA
ASPEN EVAP. COIL MODEL # CE30D44-175L-015


The problem is this. The customer says that they are having to run the temp. lower then they had to with previous system. The system size was the same for both the new and the old unit. I did Manual J on the house and the load came out to be right at 31,000 btu for cooling. I have already lowered the blower setting down to 350 cfm per ton and they say maybe a little better. What else can i do with the above listed equipment to help with this. What is the lowest cfm per ton setting on this furnace that i can run and what to set the dip switchs at to get there. Any other ideas would be great. I really want to correct this as this has never been a problem before.

thanks

Maybe this will help.