i would say in your climate dual fuel is over kill.

I don't see a home in your climate using the gas furnace backup that often, if at all most days, if it rarely gets below 30 degrees. Probably wouldn't see a return on the added cost in any reasonable period of time. Regardless of the setup you chose the IAQ is a great thermostat. Your electric rates are reasonable. I'd probably chose a heat pump with electric strip backup myself.

Make sure you have your system sized correctly and ductwork examined for maximum performance/efficiency.

Thanks, what do you think about the 2 stage compressor on the heat pump? Should I get a quote for a 2 stage?

tim,

I think your strategy is good with either type system. of course your dealer will need to check electric service/breaker panel to determine if any modification/ upgrade is required to handle backup electric heat strips if you elect air handler. not an issue if you go with VS gas furnace backup.

either way, you do want a system that qualifies for the fed govt tax credit up to $1500.

no experience with Heil. you should insist on a load calc. in writing. for downstairs,I question both the size of a three ton HP and backup furnace of 60K BTUs output.

IMO

I will talk to him about the load calc. He has not done one yet. I measured all of the rooms and put together a spreadsheet of LxWxH for every room as well as area of windows and doors and direction facing. He has only been in the business about 6-7 years and I do not know if he has software to do the manual J. Is there anything on the web I can complete?

Do you think the 3 ton HP and 60K BTU furnace are too small?

tim

"Do you think the 3 ton HP and 60K BTU furnace are too small?"

too large, especially for furnace.

TD

Here is a link that might be useful: Link to Load Calc Software

I don't see how dual fuel is overkill in ATL. Especially if you already have the gas line to the furnace. And your electric service may not be adequate for backup strip heat. That's what we have and a lot of other folks here have.

The issue, which has already been mentioned, is getting the system sized right, good/tight ductwork, and having the system set up to maximize the use of the HP's efficiency.

If you plan on keeping the house long term, why not look at it more holistically? You'll sweat for a few days in the meantime, but big deal. I'd find someone to do a blower door test and/or HERS rating to see where you stand on infiltration, ductwork, insulation, etc. You could see gains in comfort there without a huge investment, just by reducing how much of the greater ATL area you're trying to heat/cool.

Tim:

If I'm understanding this correctly, you can only get $1,500 max for your tax credit (even if you buy two units), and if I'm understanding these Carrier salesmen who are giving me estimates, the tax credit reduces your taxable income by $1,500. The true amount of cash savings that you realize at the bottom line of your tax return might be only half of that (it all depends on your tax rate).

I would ask for a copy of the ARI (Air Conditioning and Refrigeration Institute) certificate that shows that the entire unit, breaking down each piece that when installed together makes your system, qualifies for the tax credit before you put any money down. Only one of my four estimates came with a copy of a ARI certifcate showing that it qualified. The rest just didn't provide the evidence that the unit they were proposing met the tax credit requirements. You don't want any surprises next April, especially if you are really depending on that money.

Thanks cupofkindness. I appreciate the advice. The whole tax credit is very confusing. The way I understand it you actually get a tax credit rather than a deduction but it is capped at $1,500 or spending of $5,000.

I found a searchable database at ari.org that showed all combinations by manufacturer that qualified (link below).

The heil website (url below) has the Manufacturer's Certification Statement showing all combinations of heil products that qualify. I made sure the combination I selected matched up with their statement.

http://icpindexing.mqgroup.com/documents/086616/MC%20-%20Heil%20Split%20HP%20June%202009.pdf

It is a very nice credit but they definitely did not make it easy to figure out what qualifies.

Tim

Here is a link that might be useful: ahri directory

Thull - thanks for the suggestions. I agree with you on the gas furnace. It may not be a good payback but I would cringe every time the heat strips came on. I am going to go with the VS gas furnace for backup.

Based on your advice and TD and Ryan, I am going to have the load calc done. I will look into the blower door test and/or HERS rating.

I still wonder about the 2 stage HP. Would this be a big upgrade over single stage?

Tim

It would be an upgrade for a little added comfort with dehumidification during mild days. But, the 2-stage units should be bought for comfort, not to see a reasonable return on investment. A good single-stage unit with the Honeywell VisionPRO IAQ thermostat configured to control the variable speed blower for dehumidification should do a great job itself. The IAQ can also control the dual fuel system well.

Ryan,

Thanks for the advice. I have read this forum for the last year or so and you and Tigerdunes are so helpful to everyone. Many others too but you two consistently.

I entered all of my house data into a calculator I found at www.heatload.com. It came up with heat loss of 54,842 btu and heat gain of 33,966 btu. I will still ask my dealer to calculate but this would suggest 60K btu output and 3 ton HP would be about right.

The second story was only 29,543 btu heat loss and 22,552 heat gain. The 2 story family room and foyer are a big source of gain/loss for the first floor. When I replace the second story system (hopefully not for awhile) I will likely go without the furnace and with a 2.5 ton HP.

Tim

Southface Energy Institute is a local non-profit that specializes in this sort of stuff. Check their website, or even make a visit to their office to get a lot of info and suggestions on resources. They're next to the Civic Center in Midtown.

Here is a link that might be useful: Southface

Cupofkindness said: "If I'm understanding this correctly, you can only get $1,500 max for your tax credit (even if you buy two units), and if I'm understanding these Carrier salesmen who are giving me estimates, the tax credit reduces your taxable income by $1,500. The true amount of cash savings that you realize at the bottom line of your tax return might be only half of that (it all depends on your tax rate)."

I don't think that is correct. A tax credit is a direct reduction in tax liability (not dependent on the taxpayer's tax bracket). So it will reduce your taxes by the full $1500, if that equates to 30% of the total equipment plus installation costs.