t85808

for what size living area? this is upstairs or downstairs?

try to get the evap coil number so I can check AHRI for matching and tax credit qualifying system.

the last time I made a cost comparison between nat gas and electric in Atlanta mkt was basically a wash. if you will provide your rates on nat gas and electric, I will run an updated comparison cost for you. for an $875 upgrade price, I would not consider it. for $500, I would take a closer look.

I have never been a fan of EACs. I would however at a minimum put a 4-5" pleated filter media cabinet on that furnace like Honeywell or AprilAire. Can't say about the humidifier. Do you have one on downstairs system now?

I have to admit I suspect you are oversized on the furnace.

IMO

Thanks for the quick response tigerdunes. The living area is on the main floor with a finished basement (which has its own HVAC unit) underneath it and an unfinished attic above it. It is approximately 1300 sqft. I believe the current furnace is rated at 80k btu's.

Utility rates are .749 per therm for natural gas and as follows for electric (winter rates shown):
First 650kWh @ 4.5991 cents per kWh
Next 350kWh @ 3.9460 cents per kWh
Over 1000kWh @ 3.8737 cents per kWh

I would like to better understand why you aren't a fan of EAC's? I have one on my main floor unit and have been happy with it (I clean the prefilter every 4-6 weeks and the dealer cleans the rest of it every 6 months). I have terrible allergies and the EAC has helped reduce the irritants. Do you think a 4-5" pleated filter would do as good (or better) job?

I do have a humidifier on the main floor unit and it does an OK job of keeping the main living area at 35% relative humidity or so. It performs much better than it used to after I replaced my old furnace with a Trane XV80 variable speed a couple of years ago. The bedroom does dry out a bit even with the moisture from the bathroom. I have a hard time keeping it above 25% relative humidity when the temperatures drop and the unit is running frequently.

thats cheap electric. If your in atlanta (which has mild winters) you should upgrade your A/C to a heatpump. I don't see how you could go wrong with that in your climate.

t85808

those are abnormally low rates both for electric and nat gas. would you mind reviewing again and verify that this includes all related costs for nat gas and electric-cost of fuel, transmission rate, surcharge, flat mthly fees, etc. any cost that is reoccurring each month should be included. again, I would not pay $850 for upgrade to the heat pump model. ridiculous but typical for Trane dealers.

please provide evap coil mdl wnen it's available.

I would not add another humidifer without taking some readings in your home. combination digital temp and humidity can be purchased inexpensively at big box stores. humidity should be between 30%-40% for winter heating.

I have never been a fan of EACs because of the upfront cost, cleaning/maintenance requirede, electric use, and ozone produced. ozone can be an irritant. of course your call. may be beneficial to those with allergies and/or other medical conditions.

you do not need an 80K 80% furnace for Atlanta winters. Drop back to the 60K XV80 model. I would want a new refrigerant lineset.

IMO

tell the dealer if he upgrades for $500 to the heatpump model you will do it. His pricing isn't terrible. A little pricey but its good equipment also. I"m sure your electric is probably more than your current price you mentioned. Take the bill and divide the dollars by the KW's used. A heatpump is still probably very viable in your area. I don't think your electric is too pricey and you get alot of above 30 weather which is good for a heatpump.

Thanks for the responses. Tigerdunes - I will post the evap coil model # when I get it from the dealer - he went out of town for the holidays.

As far as the utility rates, the gas rate I posted earlier is current consumption rate based on a 12 month fixed price contract. On a bill prior to signing up for the new rate, there are the following additional fees: "Customer service charge" $5.95, "AGL pass through charges" $35.23 and "state and local taxes" 7%. For that bill, the total cost was 154.58 for 110 therms - or $1.40 per therm. This is based on the consumption rate of $.9390 per therm - so those fees really do add up!

As for the electric - that is a whole different story. I made the mistake of using the published rates on their website. What I didn't understand was there were several add on rate adjustments that were hidden in the fine print. I pulled a bill from earlier this year (winter rates) and here is the break down: On a $155.58 bill, there is an additional "environmental compliance cost" $4.59, "franchise fee" $4.11 and "sales tax" (7%). For this billing period I used 1612 KWH's for a per KWH cost of $.0965.

I didn't include all the add on fees originally since I believe I would still pay these fees (other that variable sales tax) no matter how much fuel/power I use. On closer look - it appears the "AGL pass through charges" are variable though - I will pull a few bills to see if I can determine if it is always a fixed # or a %.

As far as the humidifier, I do have a temperature/humidity gauge in the bedroom which is how I know that the humidity can drop down to 25% or less when it's cold and the furnace runs frequently. Most of the time it is OK in the 30-40% range, but for a month or two it gets very dry.

I will follow up with the dealer on the furnace size - I agree that the 60k one will be sufficient. Maybe he will lower the price enough to justify the HP. ;-)

your electricity is almost 1/2 cent below 10 cents per KW. Thats pretty cheap. You should upgrade to a heatpump and use it at 30 or 35 or 40 degrees and above. If gas spikes again you then atleast you have another option.

Just so it's been said, even 60k btus is total overkill. I live north of you and use that for 2000 sq feet, 20 windows, 11 ft ceilings and it is still overkill.

t85808

while the above poster may be correct about the 60K being oversized, I would not be concerned since it is a two stg VS 80% eff mdl and the low stg produces about 31 KBTUs. This furnace is a good choice for Atlanta area/winter climate.

you have to decide about the HP over the AC condenser. I ran some preliminary numbers and using $1.40/therm and $.10 KWH at 2.70 COP, on a BTU basis you would save about 30% in operating costs over nat gas when the HP can maintain your home's inside comfort temperature setting. of course the backup furnace would kick in at the lower temps that Atlanta can and usually does have.

So if operating costs are important to you, then a HP is a worthy consideration. I would not pay over $500 to upgrade to the HP model which should be more than fair. discuss with dealer and make the offer if interested.

post back with evap coil mdl number.

IMO

david_cary wrote:

"Just so it's been said, even 60k btus is total overkill. I live north of you and use that for 2000 sq feet, 20 windows, 11 ft ceilings and it is still overkill."

This is interesting. By overkill do you mean the furnace short cycles? Did you do a heat loss calculation? If so what were the results?

Overkill meaning it rarely goes to 2nd stage - only when I wake up and go from 64 to 70 which it reaches in 20 minutes (when it is 20 degrees out). The Man J was done and it is overkill (partly by design for soon to be finished space). Also overkill because I could only argue so much with the contractor.

I think the heat loss was around 30k btu. They also overestimated infiltration since it was done before the blower door test.

Big deal - no, since it is staged. And it is dual fuel so at least it isn't running during mild temps.

I am having the unit installed today. Ended up not going with the heat pump do to the payback timeframe, but got a $350 discount on the system.

Here's what they are putting in:
TUD2B080A9V3VA XV80 gas furnace
4TTR5024E1000A XR15 A/C unit
4TXCB032BC3HCA Trane coil
TFD175CLF000C Clean Effects air cleaner
Honeywell IAQ thermostat
AprilAire 400 humidifier

Thanks for all the advice. Looking forward to lower power bills in the summer and a less dry bedroom this winter!

why the 80K furnace? that's a mistake. the 60K would be more than adequate.

other than that a very nice system...

TD

Wow 80% furnace with straight a/c?
your missing an opportunity to have a much more efficient and flexible and comfortable system by upgrading to a heatpump. It would serve your climate well.

OP has the facts.

it's his money, his decision.

plus $850 upgrade price is rather frisky-typical from a Trane dealer. I may have tried to do some horse trading. But at the end of year approaching, homeowners are not in a very strong negotiating position.

TD

"why the 80K furnace? that's a mistake. the 60K would be more than adequate."

Sorry, my mistake - the furnace is the 60K - I had cut and paste from up above and forgot to change it to the 60K - which is what was installed.

As far as the HP - I have one on my main floor system that I replaced in 2008. I went with the XV80 and 15XLi for that system for several reasons: a $400 rebate from the electric company, this unit does most of the "heavy lifting" for the house and the anticipated ongoing savings. At that point gas was much more expensive than it is now.

I have been happy this this system and would have considered the exact same system for the bedroom - until I learned more about the XR equipment and did the ROI calculation on the HP.

Why I didn't do it this time: the $875 price difference (which he did offer to drop to $600 - but I got him to drop the price of the AC unit by $375 - the price difference was due to having to run a 6 wire to the HP which would be a PIA), no rebate from the electric company, the low price of gas right now, the already approved electricity price hikes (will be 40% more expensive within the next 8 years) and the fact that we will probably move within the next 5-8 years and I didn't see the ROI over that time frame.

Thanks again for everyone's feedback. I am happy with the direction we went in. The best part so far is that my humidity is already up to 34% in the bedroom from 25% this morning.

t85808

well, I am glad you got the XV80 60K mdl. you will probably use the low stg 95% of the time which is fine since you have the high stg for those extra cold snaps that can occur.

a heck of a nice system.

3427308 Active Systems XR15 TRANE 4TTR5024E1 4TXCB032BC3 *UD2B060ACV3 21000 13.00 16.00

low on cooling BTUs for a 2 ton but you should be OK.

TD

Thanks for all your help. I am pleased with the new system!

t85808

post back after a week of operation and let us know how it's performing.

TD

I am still very pleased with the new system. The variable speed is so nice - I can barely hear the unit running most of the time. The humidity level is where it should be and the air cleaner is doing a great job. I have bad allergies and used to wake up with gunk in my eyes - since I have put in the new air cleaner, my eyes are clear in the morning!

t85808

thanks for the update. always good to hear positive comments after a new install. plus with the frigid Atlanta weather today, I would think your furnace is getting a good test on high stage.

IMO

Tigerdunes - yes all my systems are getting a work out this week. We lost power for 4+ hours on Monday and all 4 HVAC units were working hard to get the house back to comfortable. The gas units (including the new bedroom one) warmed things up pretty quickly - all in second stage.

My basement unit (heat pump and electric strips) was a real problem. The condenser froze up with the rain/sleet and the defrost cycle wouldn't clear it. We ran until today on the strips only (can't wait to see the electric bill) before I could chip all the ice off the condenser and get it running properly again.

Forecast is for low teens the next day or two - so they will all be working hard for the next couple of days. Glad I signed up for a low 12 month fixed gas rate.

To the other poster - not sure why the comments on zoning - my house is zoned by having different units (one for each floor and a separate one for the master bedroom), not a mechanical zoning system.

t85808

just curious.

last year, many areas of the South and Southeast had terrible ice/snow storms and many HP systems were completely overwhelmed as far as defrosting cycles/capability.

do you mind sharing age,brand, and model of your HP system that iced over? it has time/temp defrosting method?

I am ready for a warm spell to melt all this snow/ice.

IMO

Happy to share - but I have to go look up and see if I have info on the unit. It is a Carrier system that was installed in 2000. As far as I know, it does a time/temp defrost - but I will check to make sure. It does seem to be working fine now that I removed all the ice off the unit.

Will re-post once I find the info on the unit.

Finally had a nice day here in Atlanta so I was able to get back behind the heat pump and get the model #. It is a Carrier 38YCC024300

t85808

new system still performing satisfactorily?

if and when you have to replace a HP system, make certain it has demand defrost rather than the inefficient and sometimes ineffective time/temp method.

IMO

Tigerdunes - Yes, it is working great. Thanks for the advice on the HP system - demand defrost it will be.