Need advice... Trane XL16C or XL14C - Dual Fuel
I am at a crossroads and need to decide on which direction to go.
One of my systems is on its last leg. A Carrier 48GS gas pack 3.5 ton system which services my downstairs.
I have received bids from 4 different installers on systems. Two of them quoted Trane equipment. The company I have decided to move forward with is the best priced and has the best feedback / reputation in my area. 2 of the companies provided a load assessment that stated a 3.5 ton system was appropriate for my downstairs.
That said, I need to decide between the Trane XL16C or XL14C (both dual fuel) systems.
1) The XL16C does not come in 1/2 ton sizes. As such should I go with a 3 ton or a 4 ton? My concern is that the 3 ton will struggle to keep the house cool on those blazing summer days. **Over the last 3 years we have seen periods of extreme here in NC. i.e. 95+ for 2 weeks or more.
2) Would the XL14C in the 3.5 ton, although only single stage be the better all around system over the XL16C?
Since it serves the downstairs, I'd lean towards going smaller. It depends if they used the correct design temperatures or hte laod calcultion (some contractors use a higher number "to be safe". And then if it was closer to 36k BTU or 40k BTU. If it was lets say 38k BTU, I'd go smaller. IF it was more like 40k BTU, then go to 4 tons on a 2 stage unit. rmember, that a 2 stage 4 ton is 3 tosn on first stage, so you're arent; gaining a lot in terms of increased run times if you're load calculation is right in the middle.
Personally, I would underssize and be more comfortable 95% and save money form longer run and live with it falling behind 1-2F when it's above design conditions. Close all the blinds, set the thermostat 1-2F lower in the morning and DO NOT USE setbacks. They don't save money in cooling or with heat pumps unless you have a time of use meter.
Be sure to take advantage fo dehumidify on demand features of the vairable speed blower on the 16C by using a thermostat that cna read humidity and slow the blower down as needed.
You have a long cooling season in a humid climate. Go with the 16C for comfort and effciency. Again, I'd go 3 tons, but that's just me. If it falls behind, consider that an opportunity to improve you homes insulation and reduce air leaks to save more energy. Simple things like seals around doors and windows (vinyl windows on newer homes and pretty cheap, even the better ones and need rebuilding (new seals) or replacing after only 10-15 years) make a big difference.
Thanks for the info motoguy128.
What do you mean by:
In the summer, with my current system I have my thermostat set to allow the house to go up 2 degrees during the work day and cool back down before we arrive after work.
Originally Posted by motoguy128
With the upgraded equipment, I am hoping to be more efficient with a variable speed blower to help dehumidify throughout the day.
Based on the feedback from this afternoon as well as meeting with our chosen service provider we have decided to move forward with the 3 ton XL16C Dual Fuel system to replace our 3.5 ton Carrier 48GS.
The XL16C will be installed along with a Honeywell IAQ thermostat. I am told that if I tune the thermostat appropriately despite being .5 ton shy on capacity, the newer features of the system and the efficiency will be more than adequate for keeping our lower lever comfortable.
Any other advice is greatly appreciated. I still have a couple days to change my mind.
Keep in mind that unless the 3.5 ton was installed 100% correctly it's not actually delivering 3.5tons. This includes making sure the freon charge is right on the money (most are off, some considerably), the ductwork is size correctly and sealed well (most duct systems aren't big enough and leak considerably). The 3 ton if installed correctly will actually deliver the full 3 tons of cooling.
BTW I'm also a big fan of slightly undersizing to increase comfort 95% of the time, while letting it fall behind a few degrees on the hottest afternoons. Limiting use of heat generating appliances on the hottest afternoons is sometimes enough to make the difference.