While it is not hard to install a external hot water coil to existing ductwork, many times you are restricted in physical size, number of rows & fins per inch because you cannot exceed the static pressure that the blower can handle with all things measured. All these plus CFM, GPM & water temp through coil dictates BTU output. Word of caution with an AC coil, filter, ductwork and adding a hot water coil, the airflow is many times restricted to a point of excessive loading and noise. Manufactures many times donÂt expect that much to be added and donÂt oversize their blowers and motors in an attempt to keep efficiency up and costs down. These issues usually restrict the size and type of coil that can be added. If you take a look at hi-velocity systems, hot water coil options tend to get bigger because the blower can accommodate it. ThatÂs why you will see low standard hydronic air handler performances as compared to their gas or oil brothers or AC capacities. Given a low heat loss requirement, you probably will be able to match one up. Hey solar is free, providing the sun shines, the expense is capturing it, sometimes storing until needed, and getting the heat dispersed to the space. That is a financial and part green choice you will have to make, most often dictated by your return on investment. Viessmann, is top of the line with all the bells and whistles available. Their Vacuum tube solar collectors that convert solar to steam, and heat the solution circulated to it are slick.

Rose, Did those prices include the rebates? They appear "reasonable" based on the equipment quoted, but the ductwork add-on cost is high in my opinion. I strongly recommend the duct replacement/improvement if it is 25 years old and in poor condition (i.e., not well sealed if at all, falling apart, etc.). For that price, I would hope it includes sheet metal plenums and trunklines, sealed with mastic and insulated with R8 fiberglass insulation along well properly done R8 flex duct branches to the registers. It makes little sense to me to invest big bucks on equipment and combine it with an inefficient and/or improperly sized duct system. I think your approach is right to get more estimates and see where they come in to get a proper feel for the pricing in your market -- it truly does vary by area. If they are actually considerably lower (and you'd have to wonder what corners they'd be cutting), it looks like the contractor you seem to prefer is willing to work with you. I am sure you have read enough to know that finding the right installer is very critical in having a reliable, well-performing system. It sounds like you have found a good one by what you describe. I take it he/she did a load calculation based on the information they gathered and verified 3 ton is the proper size? Lastly, Trane is the right way to go in my opinion especially in an environment such as yours where the air is highly corrosive over time to the units. I visit Ocean City, MD somewhat regularly and it is very evident which units hold up better over time and still seem to be working well: Trane. Also, some great questions to be answered as provided by TD above. There are lots of details that need to be included on the written estimate. The above is a good start. This post was edited by ryanhughes on Sun, May 12, 13 at 11:07

Nonsense about oil heat adversely affecting sale of my home in my area. As I have previously explained, I live in a relatively affluent subdivision of early 1970s residences in the MD suburbs of DC. The homes built in 1970-1972 all have gas heat. In 1973 a moratorium was created preventing any new gas hookups and thus the second half of the homes all have oil heat. I do follow property values in our area quite closely and the selling prices have no apparent correlation with heating fuel type. As a retired military service member, I have bought and sold many homes - likely more that most here. Heating method, while an item of immense interest in this forum was not at the top of the list of considerations re any home my wife and I bought. Schools, yes. # BRs and # baths, location, age of home, location, commute, condition, perceived re-sale, all yes. (And likely many other considerations, including working heating. lol) I'm a bit of a TV junkie now that I'm retired. I do watch "House Hunters" and I have NEVER heard a house hunter identify heating fuel as a consideration in their search. There is a lot of bad advice given here due to not "doing the math" - all things being equal, I would prefer to have NG heat rather than oil. Cheaper operating costs, not concern about deliveries, etc. However, I have done the best I can to insulate, reduce heating set point, shift the heating burden to heat pump, and closely monitor costs. I don't have NG available, but based on the costs to bring in NG (based on the experience of a few of my neighbors that were able) it makes absolute no economic sense IN MY CASE. If you don't use very much of an expensive product, your absolute costs may not be that great and the incentive to convert may well be lessened. If you visit the roofing forum, I suspect they'll identify the roof as the most important factor effecting price... in the landscaping forum it will be the grounds, in the kitchen forum, the kitchen and bath. Heating is certainly an important concern, but we need not cry wolf about it.

Where is the furnace located? What type of ducts to you have (flexible, rigid, etc.) and are they located inside conditioned space. A forced hot air furnaces are integrated with AC coils and condensers all the time. There should be no need to have a separate air handler and duct work. The only possible reason is you lived in a climate that requires a small furnace and and a big AC condenser. In that case the blower motor may not be large enough to provide the required air flow. But in you case the smallest furnace will work with a 2 ton AC. I would also think the duct work can handle the air flow for a 2 ton AC, but is should be measured by someone who knows what they are doing. The vents in my house are in the floor. They work fine and I would not be concerned about the placement.