90% GAS FURNACE
The 90% furnace is the next step up from the 80% Gas furnace, so what do you get out of the 90% furnace. Well 90 cents of every dollar you spend with a gas company is converted into BTUs of heating for your home. Only 10% goes up the afue pipe as wasted gas. So this furnace will save you 10% over the operations of an 80% furnace. This furnace is considered a high efficiency energy star type replacement. A couple of years from now this furnace will probably be the standard minimum furnace available.
There are some draw-backs on this furnace, it is more expensive to purchase and more expensive to have installed. You also have to change the venting system for this furnace to work properly, because this is a condensing furnace. The condensing furnace means that as this furnace operates it creates water, and water will have to be drained to the homes sewer system. So it is necessary to have condensation drain line connected to this furnace no matter where the location is in the house.
If it is in the attic this means that it can possibly be another source of ceiling damage if the drain lines to the system or to the location of the drain lines connections plugs up.A drain pan is generally required. Also the vent pipe for the system is generally two inch PVC piping which has to be rerun through the roof where a new roof penetration flashing and collar must be installed. The cost of a 90% furnace will generally be considerably more because of these additional modifications to an existing system.
If Dallas-Fort Worth was a northern type climate I would say that this would be a good investment in energy reduction. The other downside or upside depending on which way you look at it, it has a variable speed motor. Although this motor allows you to be more comfortable in heating mode and control humidity in the air-conditioning mode. In the heating mode the variable speed motor ramps up RPMs so there is less of a temperature differential making it less drafty.
This actually makes for a more even temperature throughout the entire house. Most people are unaware of the cost of repair of a variable speed motor, they are so new that generally most of them are still under warranty. All customers will soon learn that the cost of replacing a variable speed motor that is out of warranty will cost you more than installing an 80% furnace in today’s
If you have multiple air-conditioning and heating systems in your house with huge utility bills than this furnace might be a good option for overall utility expense reduction. Coupling this furnace with two speed air-conditioning units can reduce your energy bills on a large house by up to 50%. You would have to use the energy calculator to make a decision as to whether the installation expense would pay you back say over a 10 year term.
You can go to the homepage of this website and click on Goodman Manufacturing icon to go to a new page where you can click on the energy calculator to enter your data and see what your annual heating cost dollars are for a year. You then can assume that you would reduce that cost by 10% if you currently have an 80% furnace. The calculator will give you a 10 year average of that savings, at that point you should be able to evaluate whether a 90% furnace is the right installation for you.