How can I cool the upstairs better with A/C?

We just had our 3 ton A/C replaced with 4 ton A/C due to adding A/C and heat to rear addition. Our overall house sqare footage is 2500 sq ft.





Problem: The 2nd floor even after upgrading to 4 ton unit still is warmer than 1st floor.





How can I get more airflow to the second floor? Add another return to the second floor?





More details: The HVAC guy ran 1 ton to the addition with 5 branch supply registers. He added a 2nd return register at the floor level below the ceiling return. He did this by cutting into the exsisting return trunk on the first floor. When he replaced the furnace he also cut a small return duct 14 x 7 on the opposite side of the main return on the furnace.





How can I correct the problems?


2 hours ago - 3 days left to answer.


Additional Details


2 hours ago





- Furnace - Airstrong Oil Furnace; blower and A/C rated at 4 Ton





- Duct size: Main supply and Return is 23" x 8". Return is centralize in the house as a box accending 1st and 2nd floors. The 1st floor return is 14 x 14 and then reduces at floor level of 2nd floor to about 14 x 10 probably because I have an open foyer. We have added 14 x 8 supply at plenum for 600 sq ft addition off the back of the house. We added a small return to the existing return in 1st floor return riser to pull air from addition. The HVAC guy also added basement return at other side of furnace return to draw more.


Upper floor is fed by 6" round supplies that are converted to 8"x 4" square risers to get to the second floor through exterior walls.





-Static pressure: no idea





-Installation and windows: new double hung windows and R13 in outside walls and about 6" blown insulation in attic





Is a basement return on the furnace any good? Seems to me it will just recirculate already dehumified cold air...


2 hours ago





Outside condensing unit is a Payne 48,000 btu 4 ton a/c


2 hours ago





This is very annoying. I have just had the 3 ton unit replaced with 4 ton unit and I think the HVAC guy did a band aid on the duct work.





As mad as I am, I am ready to cut drywall and enlarge the returns if need be....

How can I cool the upstairs better with A/C?
I have had this same problem for 40 years, and there is no real cure. Warm air rises, and cold air falls. My basement rec-room is always 7 to 10 degrees cooler than the upper floor. In the summer I close the vents in the basement to force more cooling to the upper level. In the winter I close the upper level vents to force more heat down. A lot depends on the location of your thermostat also. Be advised, I don't think you can win this one.
Reply:First if you have attic make sure exhaust fan is working...Next you can close a few registers downstairs to try and push more air upstairs..or you can ask the company who installed your system to balance it..also you went from 3 ton to 4 ? Did they make sure your ductwork could handle it..and is there a return upstairs?





Sorry didn't read completely close or block basement return
Reply:As much as you may hate to admit it, the air conditioner itself is just a band aid for the heat problem, and a costly one with energy prices rising in the near future. It would almost be better if you can afford it to do some home renovations that will keep your house cooler and prevent the need to run the A/C as much and give your unit an easier time of its job.





Some things which I think would definitely help would be a few extra attic fans to suck some of the heat out of the top of your house. They make some fairly inexpensive and handy self-powered solar fans that do a good job with a phenomenal warranty. You can probably find them locally but this site gives some details which are helpful:





http://store.altenergystore.com/Lighting...





Also, though it is pricey, in the long term a good investment which has many other benefits beyond reflecting most of the sun's rays is a metal roof. Unlike standard roofs which absorb and soak up the heat of the sun, heating your home, new metal roofs are designed to reduce the heat in your home quite a bit. And new ones can look just as stylish or even better than a standard asphalt and shingle roof. This site has some details about them:





http://www.hometips.com/cs-protected/gui...





Another thing is do you have carpeting, wood, or tile upstairs? Funny as it may seem, slate is a good option for flooring and stays nice and cool to walk on even in the summer (compared to carpet). You have to consider winter though...





Not sure what the UV rating is on your new windows, but they make tinting for home windows which you could add to the windows if they aren't rated very high, which again will cut back some of the heat coming into your place, although this option probably won't be as effective as the above mentioned renovations.





Don't know if it's any help but good luck!
Reply:Sounds like you have too much cold air return from the lower floors. Changing to or adjusting(restricting) adustable diffusers on the 1st floor may help. There is also inline booster fans that can be installed to bump up the force. Why are you pulling air from the basement; is it finished and heated? The math gets rather extensive. Square inches of duct openings on supply? Square inches of duct openings on returns? You sound like a good tracker. Air flows better without resistence!
Reply:what your a/c guy should have done is left the three ton for down stairs then install a 1.5 or 2 ton unit depending on second floor sq ft . without a second unit or a zoning system there is not much you can do . 2500 sq ft is too much for 4 ton unit to cool adequately anyway you should have had a five ton unit with zoning system installed in the first place
Reply:Yep, your problem is that heat rises. And I think you have a good concept of the venting situation.





Your setup of return air sounds good for heat but poor for cooling.





And your idea for adding a return upstairs and maybe reducing it downstairs is a good one. I would say you want that return as high as possible for cooling and the trouble doing that depends on the home.





That would pull more cold air out your upstairs vents and remove the warmer air to be cooled.





BUT you want the opposite for heating needing to pull more out the downstairs vents and pull warm air down because heat rises in the winter too. (grin). In the winter you want more return downstairs.





So implementing that would mean you need a way to switch back, to manually change from heat to cool modes with duct shuttering to close off the return upstairs in the winter and opening the one downstairs, and vice versa for cool.





Or you can run the constant fan to constantly circulate the air. But most tire of the noise. And the "fan on" setting runs on high if you have a/c.





It is possible with a switching relay to wire it up so that when the unit is not running in either mode it runs the blower on the slow speed constantly. That is fairly quiet and most don't notice it. I see that where people have electronic air cleaners and want their air to be constantly circulating being cleaned. But it also evens out the temp in the house.





Good Luck.