Sorry, I thought by matching we were talking about the refrigerate R-22 verses R-410a in the coils The coils will be First Co. Evaporation coils matching the existing air handlers I have. Apparently there is no AHRI reference number because First Co has not done any of the necessary testing. The dealer had told me this and that the system would not qualify for the tax credit. The third floor does not heat well with the present arrangement. All of the dealers have told me not to expected much cooling on the third floor. I did not question him as to what the "better options" might be.

Yeah, the 120v supply line is measuring 2.2 volts. Circuit breakers are fine I even replaced the one for the furnace yesterday. I noticed that the supply line doesn't run directly from the circuit breaker to the furnace, any idea on what else it could connect to (maybe the outside unit)?

That is one of the first things I am going to check. When I was checking it out a few days ago I noticed that gas was not coming out of the pilot tube and the vent fan wasn't coming on. I got the idea that the fan would need to come on before the gas would flow and there would have to be some kind of sensor to make sure it was on. Now I know the sensor is probably just a vacuum switch. It should be real easy to check that and power to the fan. And I found out that 27 volts is the correct voltage AND the expected life span of an ignitor is 3-5 years. Mine is just over the 5 year mark and the site recommends keeping a spare on hand anyway since Murphy's law says it will quit working during the coldest week of the year and the service guy won't have one in stock. Could take days to get one ordered. So I am considering going ahead and changing the ignitor anyway. I'll know a lot more when I do some tests this weekend. Thanks. Pooh Bear

swampwiz, Think of your home as a set of interconnecting elements that function in harmony (or not in some cases) to give you the environment that you desire. While there is certainly value in looking at the different elements individually, as Calbay noted in his post, and I agree, "...it is unclear how to apply it as a decision tool. There are too many unknowns." Also, I would suggest that since your premise is window performance, starting out by discussing "constant: BTU = .00024 KW-hr", "cost for power:", Coefficient Of Performance of an air source heat pump, etc. detracts from the basic idea of measuring or comparing window performance. These are variables that don't directly affect window performance, at least not as I read your intent. I am not suggesting that you don't need that additional information, but I am suggesting that you need to establish a baseline (in this case basic window performance) before you begin adding variables that are affected by, or affect that baseline. In your post you added variation, including at least one unsupported assumption, before you introduced measured or calculated window performance. In your post you suggested comparing a 10 sqft window with U-factor variations of .5, .3. and .25. The formula for calculating Btu from U value is Btu = U x # hours x ft² x Delta T (temperature difference - which I am going to assume 50° for these examples). So, if Btu = .50 x 1 hr x 10 ft² x 50° then Btu = 250 If Btu = .30 x 1 hr x 10 ft² x 50° Btu = 150 and If Btu = .25 x 1 hr x 10 ft² x 50° Btu = 125 These are really simple examples of the difference in Btu loss and window performance rating, it is possible to interpolate the value of improved performance when our only variable (so far) is the U-value (or U-factor) difference which is based on clear/clear (.050), clear/LowE (.030), clear/argon/LowE (.025). But your house isn't confined to windows. It has walls and things as well. Assuming for the sake of simple math that a house has 1000 sqft of exposed wall (125 linear feet x 8') and that 15% of the wall area is windows - we can calculate overall wall performance by changing window performance. By definition, while R-value defines thermal resistance of a material, U-value measures thermal transfer thru a material. The formula for computing U-value is: Btu / (hr x degrees F x sqft) and the formula for computing R-value is: (hr x degrees F x sqft) / Btu and the formula for computing heat transfer is: (BTU/hr) = (area / R) * ÄT With ÄT again representing the temperature difference between what is inside and what is outside the house. Using the formula U=1/R, we can convert U.50 to R2, U.30 to R3.33, and U.25 to R4. However, this time we will assume a less severe environment so that ÄT = 25° If ÄT = 25°, then (10 sqft / R 2) = 5 * 25° = 125 BTU/hr loss or gain If ÄT = 25°, then (10 sqft / R 3.33) = 3 * 25° = 75 BTU/hr If ÄT = 25°, then (10 sqft / R 4) = 2.5 * 25° = 62.5 BTU/hr Keeping in mind that the Btu losses or gains are based on one square foot for one hour and the example has 150 square feet if windows. Combined they equal: 125 Btu x 150 sqft = 18750 Btu 75 Btu x 150 sqft = 11250 Btu 62.5 Btu x 150 sqft = 9375 Btu I am also assuming a typical 2x4 wall with R-13 fiberglass insulation. The overall wall insulation value excluding windows will calculate out to a bit below R-10, but I am also assuming R-10 for simplicity (and laziness on my part). Wall = R10 or U.1 Window = U.5 Window = 15% of wall Wall area = 850 sqft and window area = 150 sqft Wall = 850 sqft x U.1 = 85 Window = 150 sqft x U.50 = 75 85 + 75 = 160/1000sqft = U.16 or overall wall R value including windows of 6.25. Wall = R10 or U.1 Window = U.3 Window = 15% of wall Wall area = 850 sqft and window area = 150 sqft Wall = 850 sqft x U.1 = 85 Window = 150 sqft x U.30 = 50 85 + 50 = 135/1000sqft = U.135 or overall wall R value including windows of 7.41. Wall = R10 or U.1 Window = U.25 Window = 15% of wall Wall area = 850 sqft and window area = 150 sqft Wall = 850 sqft x U.1 = 85 Window = 150 sqft x U.25 = 37.5 85 + 37.5 = 122.5/1000sqft = U.123 or overall wall R value including windows of 8.1. And assuming that I didnt make any errors in my arithmetic, Improving window performance from U.5 to U.3 results in an overall wall performance improvement of 18.56% in this example Improving window performance from U.3 to U.25 results in an overall wall performance improvement of 9.31% in this example And improving window performance from U.5 to U.25 results in an overall wall performance improvement of 28.46% in this example And finally, in my opinion, now would be time to begin discussing "constant: BTU = .00024 KW-hr", "cost for power:", Coefficient Of Performance of an air source heat pump, and any other variables that are affected by window performance rather versus effect window performance. And as a final, final aside, Btu actually = .0002931 Kwh, and there are large portions of the country, primarily California and New York and parts of New England, that have already exceeded the $.12 Kwh.