Question: Newb here

[FMZ]

I have a Trane AC/Furnace that is 13 yrs old. The house is about 1700 sq. feet. Just today, my furnace went out and they guy told me its a radiant sensor and they need to replace it since they dont make it anymore. He talked about getting some kind of retrofit and the circuit board wasn't working. It cost alot and I was like ok how much a new unit cost and some guy comes over and gives me a quote. I didn't know you could replace just the furnace. Well, replacing just the furnace part is expensive. So for the heck of it, I asked him about the price of the whole unit and I about passed out. Its anywhere between good 4 digit number (10% more efficient) to high end 4 digit figures (64% more efficient). I asked him about the whole unit since my AC has problem keeping the house cooled during summer time and something always goes wrong with it. My question is should I just get the retrofit kit installed or does it make more sense to buy a new furnace. Or should I just get a whole new AC and furnace unit. (I can't believe how much it cost)

Thanks for any input

[lra]

More info. You said your current ac will not meet the demand. This begs the question, is your current system not functioning well due to lack of maintenance or is it undersized. Before I spent X amount of $ on a retro fit or upgrade kit, I'd like to know the system capacity. You may well be throwing money @ an undersized system that barely meets your comfort and/or utility requirements.

[FMZ]

I keep up with the service, have someone come here every year service the a/c and the furnace. The a/c is 80,000 BTU, 3.0 ton from what I know, but since its old, it wont cool that well. For example, if the outside temperature is 85-90, the house temperature would be around 75 and the a/c would stay on all day long if you have the thermostat set to 74F.

[lra]

Based on those outdoor temps, I'm guessing your location. w/o doing a heat gain/loss and That said, if you repair the furnace and later add a larger ac and appropriate duct work, an 80kbtu should move enough air w/o having to replace the furnace.

[FMZ]

Based on those outdoor temps, I'm guessing your location. w/o doing a heat gain/loss and That said, if you repair the furnace and later add a larger ac and appropriate duct work, an 80kbtu should move enough air w/o having to replace the furnace.

600 sq. foot per ton... i am not that underpowered. yea, that's what I am thinking. Should get the furnace repaired which itself cost a fortune and later take care of the ac unit.

[BaldLoonie]

Yea, watch the ducts. Often they aren't big enough for what you have so if you think about going bigger, they will need to be addressed! Could be just a case of lousy ducts and your A/C is fine. Or if ducts are in the attic, could be picking up so much heat that it can't cool. Reducing the heat gain would solve it.

That's a good furnace but they did have the issue of the flame sense and the new kit. You should have some life left in it if you replace the control.

[FMZ]

Yea, watch the ducts. Often they aren't big enough for what you have so if you think about going bigger, they will need to be addressed! Could be just a case of lousy ducts and your A/C is fine. Or if ducts are in the attic, could be picking up so much heat that it can't cool. Reducing the heat gain would solve it.

That's a good furnace but they did have the issue of the flame sense and the new kit. You should have some life left in it if you replace the control.

Do you know why I need the new kit? Why cant they just replace the circuit board?

[sumdumguy]

Do you know why I need the new kit? Why cant they just replace the circuit board?

could be a number of things. thers been some pretty good input so far. In respect to your a/c w/ur delta t(temp drop across the coil).
I retroed my dads 10 seer w/a 13 seer & was able to keep exsisting indoor unit - except for r/r metering device w/ a txv.
you could also have a dirty evap
low charge.
check your supply air temp & return & let us know.
ps. i saved my dad about6k. done correct costs$

[FMZ]

could be a number of things. thers been some pretty good input so far. In respect to your a/c w/ur delta t(temp drop across the coil).
I retroed my dads 10 seer w/a 13 seer & was able to keep exsisting indoor unit - except for r/r metering device w/ a txv.
you could also have a dirty evap
low charge.
check your supply air temp & return & let us know.
ps. i saved my dad about6k. done correct costs$

Yup, the service men come down here every year and check the coil. clean it, fill up the freon etc. They have cleaned the return line, which was clean to begin with. I went ahead and ordered the retrofit kit. Whenever it comes down here, they'll come down and install it.

[aac0875]

Yup, the service men come down here every year and check the coil. clean it, fill up the freon etc. They have cleaned the return line, which was clean to begin with. I went ahead and ordered the retrofit kit. Whenever it comes down here, they'll come down and install it.

Unless you have a leak, you should never have to "fill up the freon". I think this is a big misconception that homeowners have. The freon does not get use up. I think by law you can only "top-off" a system once, and then you had better find the leak and repair it.

[BigJon3475]

Unless you have a leak, you should never have to "fill up the freon". I think this is a big misconception that homeowners have. The freon does not get use up. I think by law you can only "top-off" a system once, and then you had better find the leak and repair it.

Only on 50 lb and up systems.is it required. You can top off one every year if you wanted for residential....although you'd be throwing money out the door. What this tells me is either he has a leak or his evap coil is getting more clogged every year and causing low air flow making it look like he needs refrigerant.....




Just curious how long does it take them to do the yearly service?

[aac0875]

I wasn't a 100% sure about the law and charging, but this is the first paragraph under "Refrigerant Leaks" EPA section 608:

Owners of equipment with charges of greater than 50 pounds are required to repair leaks in the equipment when those leaks together would result in the loss of more than a certain percentage of the equipment's charge over a year. For the commercial and industrial process refrigeration sectors, leaks must be repaired when the appliance leaks at a rate that would release 35 percent or more of the charge over a year. For all other sectors, including comfort cooling, leaks must be repaired when the appliance leaks at a rate that would release 15 percent or more of the charge over a year.

[BigJon3475]

Introduction

The leak repair requirements, promulgated under Section 608 of the Clean Air Act Amendments of 1990, require that when an owner or operator of an appliance that normally contains a refrigerant charge of more than 50 pounds discovers that refrigerant is leaking at a rate that would exceed the applicable trigger rate during a 12-month period, the owner or operator must take corrective action.

Leak repair provisions of this
regulation do NOT affect systems
normally containing 50 pounds or
less of refrigerant.

http://www.epa.gov/ozone/title6/608/...d/guidance.pdf


Section A covers what type of system (industrial)

Section B is where that quote is from in bold




This does not mean I would just keep charging until system dies later. It does mean however it's not illegal.