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Going to get some quotes on new furnace/ac

PaidSubscriber
12 years ago

Back around 1993 or so my original furnaces crapped out and the original HVAC contractor for the building contractor sold me on a pair of 92% high-efficiency TempStars with supposedly stainless lifetime heat exchangers. They also set up these homes weird, two zone/two systems with a single return trunk feeding into a "Y" but no automatic damper. So now I have one heat exchanger with a 1/8" long stress "crack" emanating from under a screw head. The new service people said the crack warrants a red tag but at this point its a little line in the metal, nothing open. My original guy retired 10 years ago and is probably somewheres in Florida LOL.

One system is 2.5 tons and the other is 2 tons IIRC. One AC has a brand-new compressor installed 3 months ago. The AC works beautifully now. And while they are HE units they are the old refrigerant style. So they are recommending replacing the two furnace/two condensor-compressor setup with a single 4 ton 92% efficiency unit, and adding an electronic damper to deal with the returns. And a single, modern refrigerant compressor outside.

Initial price for the new 92% HE furnace/ac was $12.7K and $2.5K for the damper system with two new electronic thermostats and a hard-wired CO2 detector in the furnace area. System would have 1-year free service, 10-year warranty. They would leave my Aprilaire 2210 filter and my existing humidifier and only need a minimal amount of new duct work to work with the existing trunks. No brand is cited, and they said its not the brand but the install & maintenance.

The alternative is to replace the heat exchanger and I've written to TempStar's parent company but haven't heard back yet. My new service company estimates $600 for the part and $2200 to install. They could theoretically add the damper system in to make it work better, but that does add probably $2700. Right now when ground floor calls for heat its freely drawing return air (and some heat) from second floor returns. The damper supposedly will do a better job than the current system but I don't really know how if there's a common trunk. Maybe somebody could explain that... maybe its a dual-damper setup but there's probably no way _not_ draw air from the entire house with a common return trunk... right?

Anyway, are the prices high or average sounding? I live in Western Mass, and of course the furnaces are gas-fired. This is a very unexpected event and the crack showed up in the Fall routine service.

Thanks in advance for any.all advice.

Comments (3)

  • mike_home
    12 years ago

    I have a similar set to what you described. There are two furnaces and two condensers connected to a shared return. I lived with the original furnaces for 18 years. There were no dampers between the returns and furnaces. Two years ago I replaced the furnaces and condensers. The contractor I chose insisted dampers needed to be added in order to keep the blowers in each furnace from spinning backwards. This added $400 to the installation cost. In the past two years each damper has failed and has been replaced under warranty. I am still not convinced these dampers are necessary. I have variable speed furnace blowers, so I can't say for sure.

    There is nothing wrong from drawing return air from both floors. Most systems don't have enough return vents. Consider this a plus with your set up.

    In my opinion the two system set up is very nice to have and would not replace it with one large system. I am not sure if a 1/8 inch crack in the heat exchange warrants a replacement. I would be a second opinion on this.

    This contractor seems very anxious to sell you a new furnace and AC. I think you should investigate the warranty replacement. A labor charge of $2200 seems excessive. I get the feeling they are trying to discourage you from this route. Also the statement about not telling you what brand of furnace or AC you will get for your $12.7K is a major red flag to me. You should have the brand and models numbers of all equipment and a list of all items which will be changed in the installation.

    I recommend you have additional contractors inspect your furnace and review the possible options.

  • PaidSubscriber
    Original Author
    12 years ago

    I've had a my second local HVAC company come out and look at my setup. He also recommended a single 110,000 BTU furnace/4-Ton AC system with an electronic damper system that would direct the heat to 1st or 2nd floor trunk lines. He noted that heat rises and since my returns and vents are all baseboard, cooler air near the floor is supposed to come back via return and he kind of agreed that the return system isn't truly optimized regardless of single/dual system but the system should work just fine pulling from all returns... as it has since the house was built.

    Now this guy came and proposed a 98% efficiency 14 SEER system that achieves 16 SEER somehow, and his pricing was about 30% less than the 1st HVAC company's 92% system. Warranties and service were identical, and in this case, he was proposing a top of the line Lennox furnace system, and Lennox is offering great rebate deals if I decide to go forward by Dec 2nd. The 4 ton AC unit in his quote was adequate, but not one of their 18 SEER or 21 SEER models.

    In a couple of days, my third guy will come over and check things out. This guy I know is very practical, and he might suggest fixing the furnaces and trying to get 5 more years out of them. But he will quote me on a new system as well as repairing the old ones.

  • neohioheatpump
    12 years ago

    You have the right idea. Get several quotes. Consider repair along with going new. 92% efficient furnaces are very efficient and might be worth repairing if price isn't too high.

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