First house someone stole the AC unit.

[jeremp]

We are looking to replace the stolen AC unit and upgrade the HVAC.

The house was built in 78 and looks like it has the original HVAC. The exterior unit was stolen and will need to be replaced. We are a new married couple and are trying to save some $$ but at the same time we want to be be greener especially with the raising costs of energy.

The 30-year-old house is 1400 SQ FT, We live in the DFW area and we do not see much cold but lots of heat. We are replacing all the windows with double-paned low-e windows. We are going to radiant barrier the attic and add solar powered exhaust fans, we have two mature trees on the east side of the house to block the sun and two mature trees on the west to block the setting sun. So the house should be fairly easy to cool. What is the recommended HVAC /AC unit for a house in this climate, this size, and is energy efficient. We are willing to pay a little more for efficiency.

 

Thanks all

[Cactus Bob]

well if you just want to replace the outside unit   your old unit was a freon r22 unit  you have to be carefull if the unit was real old you furnance coil might be to small for todays SEER 13 OR 14  units  but theres no way to know -you unit is missing   if your furnance/air handler was made in the last 15 years or so . you can go with a  13 SEER  unit  and SHOULD have no problem  , good on electric and on repars  OR  if you want to SAVE more !   15-16-17 SEER units that work on FREON  R 410  . YOU WILL NEED TO REPLACE EVERTHING  air handler ,line set  EVERTHING !  and from what i have seen you will never make that back , unit costs more , breakdowns are offten with the big $$$$$ that go with them      the r22 system you had is still best   and untill 1/1/10 the factorys can churn them out  and  r22 freon will be made untill 1/1/2030  as will the parts to make you system stay working ...... SO BEWARE THE "GREEN" SALESMAN  ,THE ONLY THING GREEN ABOUT THEM IS THE DESIRE TO TAKE YOUR $$$$ GREEN$$$$$     ALL THAT SAID CALL YOUR LOCAL CONTRACTOR AND GET ESTMATES AND IDEAS

[BrntToast]

nice sammi

if you lived closer i would have tried offering you a unit installed for it:D

it would have been a used unit mind you... i'd have mine cut out and in the truck in half an hour for a rust free sammi, would have  had to tell the wife someone stole our a/c

[be12c]

High SEER is great but unless ducts are in excellent shape and don't leak, house is pressure balanced, and system is charged correctly, it's only numbers on paper.  I'd go with a 13 SEER and repair any ductwork.  weatherize the house and add more insulation before thinking about high SEER systems.  A bad install can mean a 50% decrease in efficiency, charged incorrectly can cost you 20%, too large a system can cause humidity problems (bigger does not mean better), so make sure it's done right...

[dkpd1581]

With your insulation improvements you are changing the Heat Loss Heat Gain characteristics of the house.  These changes can quite possibly mean that you do not need the same sized unit as you once had.  Furthermore, there is no promise that the first unit was properly sized to begin with.  After 30 years there could have been additions and renovations that were never planned for in the first design of the HVAC system.  Current codes and improvements over the years may require you make adjustments and upgrades to bring your home to current standards.  Until you know the needs of your home's heating and cooling requirements based on the construction materials, envelope tightness, orientation, design conditions, etc, you have no  basis with which to begin looking for the proper machine.

Once the load calculations are complete, then you have to verify that the  duct layout is  capable  of supporting the correct  machine for your application and that what is existing is in proper condition.  The SEER requirements of 30 years ago are far less than the current ones  in the U.S.  As of Jan 2007 the requirments are now 13 SEER, the days of the 8 and 10 SEER units are over.  So the SEER rating minimum is pretty well decided for you unless you can find someone with 10 SEER units still in inventory.  You CANNOT successfully pair a 13 SEER condensor with an 8 or 10 SEER evaporator coil and expect any reasonable performance or longevity from your unit.  In fact if there ever comes a warranty situation with your new condensing unit and old evaporator coil,  the terms of the warranty can be voided.  A good Tech or smart Manufacturer who notices the mismatch can sink your ship and you will spend more money in the long run to correct a problem that should have been addressed from the start.  This does not even address the dissatisfaction in the unit's performance and your happiness.

You must decide on how long you intend to stay in the house.  As of 2010, R-22 units are not going to be manufactured any more and the production of the R22 refrigerant will be phased out within the lifetime of your new machine.  R22 that once sold for $60 for 30 lbs just over a year ago now sells in my area for over $185 for the same 30 lb drum.  This cost will be passed onto the consumer; therefore, your initial investment savings in an R22 unit may be lost in long term costs of repair/up keep. 

R410 is here to stay and is the new standard for the foreseeable future.  It does offer some advantages over R22 and has its setbacks as well - irrespective of the arguments with regards to environmental impact/global warming/green living/etc..  You have to weigh the  pros and cons of whether to get an R22 unit or a R410  unit based on your future plans and commitment to staying in the house.   It seems fruitless to improve your house and not make similar improvements to the HVAC system.  Current technologies offer comfort, control, and financial savings unheard of and unrealized at the time of your original unit's design and commissioning. 

Answer the question of the home's true needs, your commitment to staying in the house, and the recommended unit question will answer itself.  The only question will be which brand name you decide to see in the back yard.

[applianceman18007260692]

You may want to place the newer unit where thieves would have a hard time getting to it If you opt for a newer unit then all the copper will need to be replaced anyway, because the line size is different using the newer style freon. If the unit was roof mounted near the A coil then the install would be cheaper.

[bulldog35]

jeremp,

I can't answer your questions, but I can recommend a good AC installer, if they service your area. I also live in the DFW area and I have used Advent Air Conditioning to install new AC systems in my current and previous house. They are very professional and perform a complete J load calculation to determine the correct size system for your house. My current house had a 2.5 ton unit for upstairs and a 3.5 ton unit for downstairs. Their calculations showed I needed a 3 ton unit for upstairs, but only a 2 ton unit for downstairs, so I ended up have 1 ton less capacity. I expect to be saving some money once the heat hits.

[RegUS_PatOff]

It won't be any less money to run, unless the SEER is higher.

Smaller units will just run longer than larger units, which is the preferred method with A/C to draw the humidity out of the air slowly, continuously.

To prevent thieves from stealing it, paint it, scruff it, dent it, ect, to make it look like an OLD unit.

Unless they actually want it for themselves (as opposed to selling it), they won't want it.

[applianceman18007260692]

They will steal it here no matter what it looks like for 2 dollars worth of scrap money to buy crack cocaine.