Central air conditioning $$$???

[_RaT_]

Kubmech, are you considering installing a whole new set of ducts in the attic for cooling while using the heating ducts in the floor for just heating? I would indeed consider using the existing duct work and a cooling coil in the exisitng heater and or add a whole new heater/AC system. I am not familiar with the way New Jersey would do it, but out here, the common method is to do it that way. For heating, the ducts in the floor are best and of course, for cooling, in the ceiling. A compromise is to put them in the floor which I think is the next best option. I plan to install a radiant floor system and put the ducts in the attic for cooling. Out here, a AC/Heater is not much more then a AC onnly system, at least that is what I have been told. Hopefully Murph will check in on this as thats what he does. Rat...

 

[NY_Yankees_Fan]

Kubmech,

Go with using the existing heating ducts for the AC. Most of the homes in our 46 home development have it this way, except the homes that opted for hot water baseboard heat. In this case we have a separate duct system for AC only. Given the limited number of days we use ac in NJ, perhaps, 30-45 days a year , primarily in July and August, save the extra $$. You will be happy with the heating system doing double duty as AC in the summer time.

 

[ronjhall]

kubmech

4 years ago I replaced the furnace, humidifier, filter, thermostat and new A/C for $6000. The furnace was the latest 90+ variable speed and multistage burner.
I have overhead heat registers and floor returns.

I went to a local home show to find contractors. I had prices from $5000 to $9500 for the same equipment and install.

Buying 14 Seer A/C in NJ may never pay for itself. A 10 or 12 may be a better choice.

I have never seen a quote from Sears that could not be beat by a local contractor.
Have you tried Home Depot?

Here a couple of threads on HVAC that may help.

Click Here

Click Here

 

[tc35dforme]

My concern with underslab duct and air conditioning is condensation. How old is it ? Is it plastic or galv. metal or plastic coated metal ?? Well insulated ??? With a good vapor barrier ???? I'd worry about moisture from the soil forming on the outside of the duct and prematurely rotting it out. A lot has to do with how well the original installer did the job.

Get some more competative prices. Look at 12 SEER equipment as a comparison. In order to get to 14 SEER many manufacturers are using variable speed blowers, electronic control processers and tech items that are very $$. The 12 SEER are still using good ole' fashioned relays and switches that are cheaper to put in and cheaper to fix.

The biggest advantage to a company like SEARS is financing options. Try not to let this be your decison maker...many small companies now offer packages, card payments, or will even offer a short term payment plan.

Shop around and be sure that EVERYTHING is well documented in the agreement. Good Luck.

 

[kubmech]

Now I have alot better idea of my options. The ducts are encased in the slab so I don't think condensation will be a factor, they sort of provide a radiant effect now when the heat is on. The dogs find the warm spots in the floor and lay there. I imagine the cool air would provide the same effect. I have alot of shade in the summer and the floor stays pretty cool, I believe that's what helps keep the house cooler with just the window unit. 14 seer may be a bit too much considering how much the a/c would run on a yearly basis, it would take along time to see the cost savings, 10 or 12 seer may be more realistic. the split duct system warrants looking into and I'll have more "intelligent" questions to ask when speaking with the contractors. I will get more quotes from at least 2 other companies. I had a feeling Sears would be higher due to the "financing" issues. I think a more realistic number would be in the 4000-5000 dollar range in which case financing is out of the picture so I wouldn't have to deal with that aspect. Thanks again for all the help everyone and I'll let
you know how it turns out.......................

 

[PineRidge]

Adding AC to your existing furnace could work but remember that heated air best comes from a floor register since it rises. Cool air best comes from a register above since cool air is heavy and settles to the floor. That said if you have good air flow now from your existing floor registers then air added to your existing furnace would most likely please you. But if your current airflow is weak or lame then even bumping up the HP of the blower motor isn't going to cut the grade once the extra restriction of a wet evaporator coil has been added to the system.

 

[thcri]

</font><font color="blue" class="small">( Thanks for the input guys, I'm in central New Jersey. I've been running a window unit in the kitchen for years, it always kept the house pretty cool. What do you think about the lower priced option of running an A coil in the exsisting furnace and using the ducts in the floor? I know it's not the ideal way to do it but that qoute is 4000 bucks less. I will get more estimates, I just didn't expect that kind of price /forums/images/graemlins/shocked.gif I almost feel like I'm installing Mercedes seats in a Yugo. Thanks again for the help............ )</font>


Being in the HVAC business in Minnesota I will tell you to stay away from the ducts in the attic if at all possible. Your price is way outrageous. We install that size unit around here for less than $4,500.00. Cooling does work better if it comes out of the ceiling however, what we find is during he winter months the moisture in your house finds it's way into the attic ducts and then condensates from the cooler temperatures in the attic and the next thing you know you have water running all over the place. Go with the coil attached to your furnace. Cheaper and less problems.

murph

 

[slowrev]

No need to go higher than a 12 SEER unit. The payback takes the about whole life of the unit, so you gain nothing.

 

[thcri]

</font><font color="blue" class="small">( No need to go higher than a 12 SEER unit. The payback takes the about whole life of the unit, so you gain nothing.
)</font>

Typically that is true for the most part, however some manufactures are handing out rebates on the 14 SEER and then added with the utility companies rebates you end up paying less for the 14 than you do the 12. That is just the way it is around here right now. So I would check with your utilities for rebates available.

murph

 

[_RaT_]

So Murph, I plan to use radiant floor heating. I would like to install the air ducts for the AC in the insulated attic along with the air handler. Does that make sense and if you duct it, what is the preferable duct material? The compressor would sit outside of course, what would be the maximum distance the compressor could be from the handler?

Since you turned me on to expert GPS I have shown other folks and they too are amazed. Thanks, Rat...