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mrscoffield 04-18-2013 09:46 PM

Looking for new HVAC and move furnace?
I'm brand new here and looking for some advice on a huge investment. We live in Southern California and have a 12+ year old 3 ton Lennox system on our house and the original furnace, a 35 year old Carrier. We've been getting estimates to replace the whole system and just had duct work and registers replaced 2 years ago.

Right now our furnace is in the uninsulated garage and the cold air intake is on the wall in the dining room next to it. We can hang meat in the summer in the rooms near the garage, but at the end of the house where the bedrooms are, they are usually 4+ degrees warmer or colder, depending on season.

We are considering moving the furnace to the attic, we've been given estimates from reliable companies and they all say that it is a good idea for our house because that will place the blower and cold air intake in a more central location for better efficiency.

What's your take on this?? Also, 2 companies said they can just make modifications to our 2 year old duct work and 1 company said they need to redo all the duct work because elbows weren't put at all the registers, etc. We are feeling overwhelmed by the amount of info! Help!

keepinitcool 04-19-2013 05:39 PM

Centralizing in the attic is a viable option as long as it is installed correctly. Drip pan under the entire unit with a drain, everything insulated properly, unit supported properly with proper bracing to compensate for additional weight on the ceiling. How much duct work would need to be re-routed and insulated? A line set for the a/c and intake/exhaust pipes would need to be routed to the attic. Tstat wires fished down the wall, return air properly sized and installed, etc. If all this is done by a reputable company, then I say go for it!

keepinitcool 04-19-2013 05:42 PM

Oh and upgrade that dinosaur furnace to an energy efficient one while your spending the money. It will be a lot quieter as :D

mrscoffield 04-20-2013 07:01 PM

We were told by one company that only a little bit of duct work needs to be done because it's not that old, another company said that because no elbows were used above the registers, we should redo the whole thing because we aren't getting as good of air flow. Another company said that the duct work should be redone if we are moving the furnace from garage to attic and since we are looking at a 16 SEER system that the duct should be larger to have less (static resistance) something like that phrase.

Also, we were told that air filtration is a good idea because it keeps the system clean and were told by another company that they are a bad idea because they reduce air flow. Another company said that you should just use the tower room filtration systems because the ones attached to the machine are a waste because they are only used if you are using the system.

Also, we were told that a 2 stage unit is best for electric usage, but another company said not so much because they are more expensive if they need to be repaired and only save you less than 10%.

So confused!

nealtw 04-21-2013 10:02 PM

Sounds like you have to sort out the salepeople from the system designers that are just trying to make the system right for your house. The main duct always get smaller as the get away from the furnace. So is that guy intending to run the duct back to the garage? Are they saying to put a tower in each room? 10% over ten years may be a big deal.
And welcome to the site. If you can't sort this out you may want to consult an HVAC engineer that isn't selling anything but knowledge.

mrscoffield 04-22-2013 10:35 PM

Thanks for the input! Because we are looking to remove the system (and the extra duct work) in the garage and move it into the attic in a more central location with a cold air intake in the hall near the furnace. A couple of the companies say that means a complete redo of duct work. Some say they can just reconfigure what I've got. The house is 1 story 1600 sq ft, so we're not taking about a mansion. I was hoping to save the 2 year old duct work we just had replaced, but am concerned that the people saying duct work are just saying that to make the job cheaper and possibly less effective. Or people are saying I need the ductwork because they want to make more money.

Where can I find an HVAC engineer? Will they have any special license? The companies I'm getting estimates from are recommended from Southern California Edison or family/friends.

Thanks again for the help, this is the most expensive (and necessary) home improvment to date for us. And I don't mind paying a heafty sum, it I'm getting what I'm paying for.

Thanks again!!

nealtw 04-22-2013 11:36 PM

Heres a list:
But that might be expensive too. It's hard to say what to do, most times the old systems are dirty inside and hard to work with and could cost more in labour than they are worth but if he thinks he can move them and the sizes work, maybe. I would think quite a bit has to be changed anyway, how much can you save by re-using the old.

mrscoffield 04-29-2013 11:34 PM

Thanks for the input. I think my final question is whether or not a 2 stage unit is worth the price difference. We're comparing a 16 SEER 1 stage vs an 18 SEER 2 stage. The price difference is $1300 but we will be in the house a long time and are hoping we would recoup that expense. Any advice??

hvac122 05-05-2013 08:23 PM

A two stage system will not save you in utilities. It is designed to make your house more comfortable by running the unit longer at a lower rating. With the unit running longer utilities will stay close to the same. Assuming variable speed blower? If so then you should put in a media filter and fun the fan all the time for filtration if you need it.
The ductwork is hard to comment on without seeing. Has anyone run a manual j for there bid? This would size the equipment for you.

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