Based on the energy costs you provided, the approximate cost per kW of heat delivered into your home with the Greenspeed gas furnace at full theoretical efficiency of 98.5% would be about 4.3-cents/kW, with a Greenspeed HP (COP-3.3, HSPF 11.3) and all electric fan coil it would be about 5.78-cents/kW if you lived in region 5 and about 5-cents/kW if you lived in region 4 (HSPF 13). This has to be balanced against the cost differential of the 2-systems including the cost of the gas line installation and chimney/liner installation (particularly if you wouldnâÂÂt be using gas for anything else) minus any promotions by Carrier and the various utilities or governments. You might want to consider which type of system may have the longer life cycle and lower maintenance costs. Regarding the HRV, you might want to ask the contractor if the Infinity T-stat will control the Venmar WITHOUT the Carrier NIM (Network Interface Module). If it wonâÂÂt, there goes your $230 savings! SR

The person visiting the home needs to be able to answer the customer's questions. If he or she cannot then you need to find another contractor. Here are some basic questions you can ask: How long have you been in business? Are you insured and licensed to install HVAC systems? How many trucks and employees do you have? Are you a factory authorized dealer for the equipment you sell? Will you do a load calculation before signing a contract? Will you show me the load calculation and explain the results? Will you review the duct work to determine if it is the proper size? Will you quote several configurations of equipment and explain the benefits and costs? Will your quote provide the model numbers of all the equipment and services you propose to provide? Will you file for the required permits? What are the terms of the warranty and is it backed by the manufacturer? Will you register the equipment for the warranty? Are there any manufacturer's rebates and who will receive the funds?

Mike_Home - Thank you for the answers and advice. Here are some responses and follow-up questions. 1. SEER/EER - your answer is what I had been slowly understanding that these numbers are what drive the efficiency numbers. Rough calculations comparing my older 10 SEER unit to a 14 and 16 SEER unit plus using 1 year of energy bills, show a potential electricity improvement of $184/year for the 14 and $238.31 for the 16. Of course this is all dependent on a quality install as well as proper ducts, etc. as you've outlined in other points. 2. Payback will be uncertain as I was relocated for work. Not sure how long we'll be here and at this point, the energy savings per year is still important. 3. Understood. Before my research, I didn't realize that the furnace played such an important role in airflow. 4. My zoning explanation might have been poorly stated. The gist of what was mentioned, was that based on proper zoning, the more efficient airflow distribution within the home may allow for a 4 ton condenser. The condenser potentially wouldn't have to push air through all of the ducts at the same rate. Does that logic track with your experience? 5. Appreciate thermostat advice and handling all the features, etc. 6. The annual maintenance contract was from the contractor providing the detailed Goodman quotes. Participating in the yearly maintenance contract covers 100% of repair costs (Contractor backed, not OEM), includes a 10 year replacement warranty, and there are no dispatch or service fees for service calls. The replacement warranty is the full replacement of the failed unit rather than just repairing under the 10 year labor warranty with Goodman. If I don't do the yearly maintenance contract, there is no replacement warranty. Ever heard of this? The contractor (Goodman quotes) may have mentioned "calculations" at one point but I don't remember hearing about them doing a manual "J" load calc. As far as I can tell, Title 24 doesn't require the J calc. It does require a duct leak test performed by a certified 3rd party HERS testing company. This is required on ALL HVAC projects in CA. Rebates are only available as part of CA's Home Upgrade Program. This program has required testing and upgrades on items like ducts, whole home envelope, attic insulation, etc. I will go back to two of the contractors and ask them about performing the calculation. I am looking to replace the whole system at this point to make sure the equipment is compatible and most efficient. Goodman is making me increasingly nervous, especially with the Class Action lawsuit that was just set back last week based on a judge's ruling... As for the use of a different coil with the Goodman equipment, it seems to be very common with Goodman quotes (based on board postings like this). I think there is a relationship or commercial connection between Goodman and Aspen to drive the high use with Goodman systems. I don't know the true specs on the Ruud equipment, I was guessing a bit; I will ask for the models, etc. Thanks again!

The summer design temperature for Las Vegas is 106 degrees F. Your 5,500 sq. foot house has a big cooling load. Have any of the quotes provided a load calculation? If not then I suggest you keep looking for an installer. The quotes should have details of all the model numbers and a description of the work. A good installer should also provide 2-3 equipment options and pricing. Amana, Maytag, and Lennox can be good. However most brands have a range of equipment from the low to high end. I recommend you stay away from the entry level model and target a SEER 16 rating. Pay attention to the EER rating. In your climate the EER rating is more important than SEER in my opinion. This assumes you will be paying for the electric bill. I usually advise going with the brand that is popular in your area and has a good installer. The most recognized brands are Carrier/Bryant, Trane/American Standard, and Rheem/Rudd. In some parts of the country Goodman is popular. Where I live it is almost nonexistent. The prices of houses are going up in most areas. It is hard to say how much of your AC investment you will get back on a resale. Normally I think it would be half. I would be interested to know what equipment is currently installed. If it is 25 years old then that would be impressive surviving the heat in Las Vegas.