I'll be glad to offer some suggestions but first I have to ask why an 80% eff furnace in the day of high energy costs.

And I do suggest that you review both electric and nat gas rates to make certain they are all inclusive cost rates. Sounds too inexpensive.

And I would say you are are oversized on existing furnace.

Be thinking about asking for a professionally performed load calc both heating and cooling.

Post back.

IMO

tigerdunes, thanks for the reply. Yes, you are correct the rates I entered were not all inclusive. The revised rates are .102 for electric and 2.57 for gas.

I stated 80% as I am not sure if current venting would need to be changed with a higher efficiency unit. From what I understand the units that will be mandatory after May 2013 will require different venting. Again I don't quite understand the differences.

I have been told that the furnace is indeed oversized and that A/C is undersized.

Thank you for your reply.

The natural gas rate now seems too high. Check it again. It should be in the $1.00 - $1.25 range per therm.

The venting for a high efficiency furnace is typically done with PVC piping exiting through a wall of the house. You may be eligible of a local utility rebate with a more efficient furnace. It is worth investigating.

My gas bill for July is a Total of $28.60. I took my total bill $28.60/11.13 therms = $2.569.

Yes, the PVC piping is what I was referring to; I was trying to avoid due to additional cost.(?)

I checked rebate; Illinois' ENERGY STAR Appliance Rebate Program â¢Heating and cooling equipment rebates are no longer available.

The local ComEd / North Shore gas rebate Complete System Replacement (furnace and central air) 95% AFUE furnace and 14.5 SEER air conditioner or better $450*
92% AFUE furnace and 14.5 SEER air conditioner or better $350*

We have received one quote from a Lennox dealer. The first option listed is for both heat and A/C. The second option is for A/C only. I attached a jpg called Scan0003 that shows the detail.

Is there any other information that I can provide?

Thanks
Mike

Your gas bill likely has a fixed monthly service charge. You need to subtract that from the total bill before you divide by the number of therms. You want to calculate what you pay for each therm of gas after the monthly service charge.

The rebate will pay part of the additional cost of installing a 92%+ furnace. If you are really paying $2.57 per therm (which I highly doubt), then getting the 95% AFUE furnace is an easy decision. The savings would pay for the additional cost in a few years.

Are you going to get any additional quotes?

Hi,

I attached my July gas bill. When I ignored the monthly service charge it now seems too low when compared to the figures you provided.

I am trying to obtain some additional written estimates but my calls for estimates are slow in being returned.

An 80% efficient furnace in today's world is a dinosaur especially one with your location.

It will hurt you on resale if that is a consideration.

However, if there are venting issues with a 95%+ eff furnace, then go dual fuel with high eff HP with 80% eff at gas backup.

IMO

It looks like you paid about 44 cents per therm for the month of July after the customer charge. The September rate will be about 47 cents per therm above 50 therms. These are low gas rates, but they seem to be variable.

You used a lot of gas in February. See what rate you paid in the winter.

Here is a link that might be useful: North Shore Gas Rates

You might not want your name and address posted on the Internet. I would take that bill down if possible and repost it if you want without personal info. I don't know how you remove photos though.

Those are REALLY cheap gas rates, I pay 3 X as much. I'm impressed by how low the winter heating useage is, a higher efficiency furnace isn't going to pay for itself anytime soon at those prices.

Also, they'd have to be giving away electricity for a heat pump to be worthwhile in this location, don't you think, tigerdunes?

Using a summer bill to determine nat gas rate isventirely misleading.

I would like to see a bill for January and February.

Still my preference would be a 95%+ eff nat gas furnace with straight AC.

But one has to run the cost comparison numbers for a high eff HP to see if electric rate can be leveraged to make a high eff HP worthwhile in a DF system with an 80% nat gas furnace backup.

IMO

please block out your name and address.

I thought that 80% gas furnaces were not
being sold in the north anymore.
savings to upgrade to 90%+ offset costs
to make this change in efficiency.

not sure what date this goes into effect,
but when the hvac industry makes this kind
of change..its a big deal. doesn't often
happen that they change the minimum efficiency
that the law allows.

the minimum efficiency for a/c for example
changed from 10 SEER to 13 SEER because
of the difference in efficiency.
as energy raters we saw every rating the
savings between 10 & 13 SEER.
when the hvac industry makes this kind
of minimum standard change..there is
a good savings.

use the rebate to offset costs between
losing 20% of your heating costs to
losing only 10% or less. with 96% your
loss drops to 4%.

has any company done a load calculation
to correctly size the unit?
has any company tested or even inspected
duct work for duct loss?

if you air seal the ducts and returns
and invest in air sealing the house..
then the unit will perform better and
your comfort will improve. utility costs
will also be lowered.

check with Resnet for an energy rater in
your area to blower door test house
& test ductwork. make repairs, test again.
reducing air/duct leakage has a fast payback
plus other benefits.

best of luck.

Checking (sent an email to the contact us email) to see how to take upload off of site.

In regard to Feb gas rate. Total bill $155.69. Breakdown as follows:
Customer charge $19.57
Delivery charge $23.25
Gas Charge $107.40
Taxes $5.47

Had one of the contractors who provided a quote check the existing air ducts, number of returns, how well they were working, as well as, if the insulation is adequate (blown into the attic).
Also checked to ensure that the attic had Rafter vents and the soffit vents are clear and there was a channel for outside air to move into the attic at the soffits and out through the gable or ridge vent.

The only problem mentioned by two different contractors was
the size of the return in the basement(8X24)both stated it needs to be increased to at least 12X25 or 14X24.
May 2013 is when the sale of 95% efficiency equipment goes into effect.

Please let me know if I missed anything.

I'd upgrade to 95% now. I'm in a cooling climate
and just about all of my clients with ng upgrade
to this efficiency.

I'd also make sure that ducts were mastic sealed
and no duct or foil tapes used. plenums to equipment
should also be mastic sealed. supply boxes to sheetrock
where they enter the living space.
ducts leak more than hvac companies realize.
30% is not uncommon.

offhand I don't know what return size should be
but its hard to go wrong with an oversized return.
make sure it is also air sealed.

best of luck.

How many therms was your Feb bill? That would help to get a closer picture of your nat gas rate.

IMO

Sorry it took me so long to post but had to go out of town.

Feb bill was for 221.62 therms.

I'm still waiting for additional quotes to come in. Can someone tell me if the quote in this string for the Lennox units are reasonable?

I would also appreciate any recommendations for specific brands and model numbers if someone has an opinion on what I should replace my current units with. If 90%+ is the way to go I can start requesting quotes for specific units.

Thanks again for your responses.