80% efficient versus 90% efficient Furnace?

Question

I had my furnace replaced, ordering a 90% efficient furnace. The company incorrectly installed an 80% efficient furnace - mix up at the warehouse.

The company is willing to obtain and install my original ordered 90% efficient order or refund the difference ($800). The sales person is saying it won't make much of a difference, since we don't live in extremely cold climate (San Jose, California), so they are trying to get out of replacing it in a way.

In the long run, is the 90% efficient furnace worth it?

Answer 1

the main diffrence in the 2 diffrent furnaces is how the venting is set up the 80% is set up with metal exhaust that is exhausted up a chiminy the 90+ is Vented using PVC and there is a build up of condensation which the pump provided will get rid of it or they will run a small 3/4 inch tube to a drain nearby In the Long run the +90% furcnace is the way to go for sure. especialy if you have a larger house. I have installed plenty of furnaces in my day to know that the +90 is eaiser to maintain also

I hope you didnt get a Janatrol furnace carrier is the way to go

Answer 2

90 Efficient Furnace

Answer 3

You definitely have some leverage here. First of all you need to figure out how much extra this is going to cost you.

To do this, you need to back your summer time heating cost from your winter time heating cost using the bills from at least the last 12 months. If you can get a good handle on the bill during June, July, August, you should be able to come up with an average cost without heat.

Back that amount out for all 12 months and assume that the remainder is the cost of heat.

I think you can probably assume that your old furnace was 80% efficient, at least for the purpose of this calculation.

If you then multiply that figure by 0.112 you will get your savings with 90% efficiency. (You save slightly more than 10%. I won't go into the details of the calc that shows that.)

That will give you your savings per year.

Personally I'd multiply that by 10 for a 10 year payout, and then provide escallation of 5% per year, which may be an underestimate, but it's anyone's guess.

So savings would be as follows:

Year 1 savings= (savings/Yr)*1.05
Year 2 savings= (savings/Yr)*1.05*1.05
Year 3 savings= (savings/Yr)*1.05*1.05*1.05
and so on until year 10

This would than give you a feel for your loss for 10 years.

I tossed this into a spreadsheet and came up with the following:


Yearly_____ Savings _____ 10 Yr Savings
Cost _____ 1st yr
1000 _____ 112_____ 1479
800 _____ 90 _____ 1183
600 _____ 67 _____ 887
400 _____ 45 _____ 592
200 _____ 22 _____ 295

(This Yahoo thing apparently doesn't like tabular formats, sorry for the dashes.)


This would suggest that if your yearly heating cost is under $550 or so you could be better off with the $800.

Remember that this is all calculated on a 10 year payback.

There is one other factor, if you are thinking of selling your house at any time in the next 10 years of so, being able to advertize a 90% efficient furnace may be worth money also, perhaps even more than $800 all by itself. (In Minnesota a 90% efficiency furnace is worth mentioning and worth money when selling a house. In California a 14SEER AC is probably worth advertizing. Don't know about heating units in California.)

You could potentially tack the $800 on to any of the above figures that apply and go for that amount from the company that installed the wrong one with an actual basis for your demand.

Answer 4

Two thoughts: First, you can get a $150 credit on your 2006 income taxes if the furnace qualifies, and the lower efficiency furnace may not qualify (see IRS link below). Second, you need to see what the "payback period" is for the higher efficiency furnace. In other words, how many years of energy savings will it take to save the extra $800 you have to pay on the 90% efficient furnace.
P.S. If the furnace was a new heat pump that both heated and cooled your house, the higher efficiency would definitely pay off because the furnace would be operating more of the time.
http://www.energystar.gov/ia/business/bulk_purchasing/bpsavings_calc/Calc_Furnaces.xls

Answer 5

90 Furnace

Answer 6

Yes, especially with the fuel costs rising. I did something similar in my old house a couple of years ago. It's hard to judge how much I saved, because at the same time I put in the furnace, the prices of Natural gas went up too. However, I'd guess it was a third less cost to run as the old furnace. My estimate: I'd pay $200 a month in the winter for fuel with my old furnace. I'd pay $130 for the new one in fuel costs. If you're something similar, you'd probably pay off the price difference in five years.

Answer 7

In San Jose an 80% efficient furnace would be just fine. If you lived in Duluth, MN it would make a big difference.

Answer 8

I'd hold them to the 90% furnace unless they are willing to pay 10% of your heating bill.

Answer 9

If you are staying there get the 90. what did they quote in the first place. if they screwed up they should eat the job

Answer 10

80 percent is way behind in technology, in 5 years you will be cursing your decision to keep it, also whoever installed it is a complete moron to not see the difference,or somebody is lying to your face.