How good is central air?

Geez, OP, are you posting from 1955?

I just sold my home in KC that had central air but it still needs booster window units due to duct work not optimal for such an older space. There's no other way around it with those summers there;

R2 Ah. I see. I'm in New York. Window and wall air-conditioners are very common but we have the sweltering heat in summer so central air probably wouldn't be enough unless it was a newer house and the duct work was more modern.

I'll assume all the photos of houses with central air that have window air-conditioners don't have the best duct work and will steer clear.

Central works a little differently than you might think it does. At least one side of your house will be exposed to the afternoon sun. That really heats up that side of the house/room. Central air usually is based in the middle of the house and the vents that go to the other rooms deliver air to them., but it's a decreased amount of air as opposed to the main unit. It costs a lot of money to cool down the entire house. You don't want to have to put the air down to 68 degrees just to cool down your bedroom. Some people put window units in their bedrooms or rooms that get the afternoon sun

Min split ductless AC is best.

Meh, there was somewhat of a void but by early 90's some good stuff started to appear.

OP, my family was in the biz for over 60 years...

Window A/Cs will not leak if installed properly. There’s something wrong with your installation. I’ve left mine in during hurricanes and have had no leakage at all. Get yours reinstalled by a qualified person. There’s no reason to move, for that alone.

When you have central air, you can still close the input vent to rooms you don’t care about. If you have multi thermostats, preferably one in each room, you can customize a cooling regime. If you only have one thermostat, you can use the vent-closure to do the same thing, but it takes a while to figure out hoe to do so.

Best,

Oh, how good is central air?

It’s the gold standard - if it is sized properly. It should be sized to handle those hottest of hot days. People skimp, to save money, and the result is poor service. You have to decide for yourself as to how you feel about that, but you shouldn’t need window units as boosters! .That defeats the whole purpose of having central air!

Often, central air is combined with a heat pump to provide heat in the winter. In times past, it wasn’t for deep cold climates, only for down to ~40°f, but I hear they’re more effective now, so that may be obsolete info.

R5 I've heard of those. I believe that's my next door neighbor recently had installed.

R7 The reason we've occasionally had leaks through the window air-conditioners is that the bottom strip of the two plastic wings (or whatever you want to call them) that unfold and reach each end of the window can fill up with water when the rain comes in at a certain angle and then that water runs down the length of that plastic strip toward the center of the (underneath of the) air conditioner.

Twice a room has been flooded (bedroom and living room) because the front of the air-conditioner started leaking even though they were tilted correctly the other way. Or, in the case of the bedroom, the water was not leaking so much as running constantly. We didn't realize right away because there's a cabinet underneath it and so it wasn't until the carpet got wet (after the water spread) that we realized something was wrong.

I've read that window air-conditioners are the most cost effective unless you use three or more at which point central air becomes cheaper. I live in New York and we've had so much rain this year. I'm sick of being stressed out of my mind every time it rains.

R9, it still shouldn’t happen.

When the wings get filled with water, which I’ve actually never seen, but, ok, the overflow should fall onto the window sill - the exterior window sill. And just like rainfall, it should then drip out.

I think I know your problem because I’ve seen a lot of incorrect installations that cause water damage. Can you take a picture and attach it here, and I will try to diagnose?

OP, picture please.

I have a very nice central AC but I shut it off at night and use my bedroom window AC instead. I like the temp to be 72˚ for sleeping.

It would cost a fortune and be very wasteful to use my central AC to cool my whole house to 72˚.

Central AC = 37¢ an hour. Bedroom AC = 6¢ per hour.

I live in Houston where central air is pretty much a requirement. That said, a good HVAC company is also pretty much a requirement.

In the Northeast, AC is usually adapted into old heating systems - so the flow is never great, especially in the top floor. I’ve always had to supplement with a window AC in the upstairs bedroom - which also allows me to keep most of the house set at a higher temp.

R7 / Frosty - I’ve heard that the “close vents” approach is not good and just makes the system work harder to cool the house. Is that not true? I have 2 BR I don’t use and was closing vents and doors in there - but was told by someone that it’s better to let the whole house circulate the air for efficiency.

R14, it depends on where your thermostat is, is how often you use the hot rooms.

If your thermostat is in the cool room, it will stop cooling when that particular room is cool. If in the hot room, or if you have multi thermos and the hot room’s is “on”, well, then the cooling will keep running.

Also, if you are in-and-out of the hot room “a lot”, which I can’t define for any other individual, then the hot air will billow out. Bear in mind, that hot air loves to push its way into a cool room. It’s pushy.

Also, you probably shouldn’t let a room heat up often as I’d guess it would get humidity damage, in areas susceptible to it. Don’t books suffer from this?

Be smart .. make your home more energy efficient before buying a central AC. Contact your local electricity provider for how-to.

More insulation and sealing air leaks mean you can buy a smaller unit, 2.5 tons instead of 3 tons for instance.

OP, still curious and would love to see a picture. Do you need help with instructions to post one?

A guy on the top floor of my condo association once mis-installed his window A/C unit, and it leaked at least two floors down. It ruined a fussy old Queen’s “custom“ wall paper. Thank God he was half blind and kept the lights down or it would have been quite a fuss.

Neighbors!

I have had several homes with central air and they all worked perfectly fine, in fact I have never heard of anyone really having a problem unless the are old and break down but nothing lasts forever. The house I am in now is 14 years old and the central air is working great but I figure it will probably need replaced in the next few years, hopefully not during one of the hottest days of the summer.

Oh I forgot the best thing about central air, except for the sound of rushing air you barely hear it, not like a window unit that sounds much louder.

Like some of the posters above, we have central air but it does nothing for our upstairs where there are two bedrooms. Thus we have window units in each bedroom. Some people in my neighborhood with similar style houses have upgraded to zoned air conditioning where there are two compressors outside and two different thermostats inside (one on the main floor and the other upstairs).

I have window A/Cs on the top two floors of a four story building. The top floor units do a good job, but it’s funny, if I raise my hands above my head, there is much hotter air up at the ceiling level. Which is fine.

So, get some ceiling fans to blend the air.

If you're "in the business" R7, you should also advise the risks of closing vents to redirect cool/heat where desired.

We closed vents to an unused bedroom during the winter months. This created backflow in the ductwork which caused the electric furnace to overhead and catch fire. We were lucky the furnace assembly was contained within the HVAC unit or the house might have caught fire, too. The entire furnace assembly had to be replaced since the furnace coils arc welded holes in the outer case. Cost was $1200 in 1999.

R24, I am not “in the business”. My family was. I left my hometown to work my Summers in Ptown when I was 19.

I’ve never heard of that problem. It sounds like you were ill advised in order to sell you a furnace, but my experience was many years ago, so maybe things have changed.

Oh, wait, you write “winter”. You seemed to have a furnace problem, not a cooling problem, right? Only now I see that.

R5 is correct. I live in the desert and I have that in my apartment. It works great! Also very quiet compared to central air heat pump systems.

Google seems to indicate that closing vents in unused rooms is a really bad idea.

Thank you R27 - maybe I was right after all

omg it's so so good. I feel like New Yorkers life in the twilight zone with no central AC . plus you have those ac units that could drop out the window and kill someone below.

I love the way those ductless split systems work, R5. I don't like the appearance of the indoor part that mounts on the wall but it is virtually silent and can make the room as cold as a meat locker.

I'm now in a 700 sq ft condo that has central a/c. Technically it's a closed loop system where the building has a cooling tower on the roof and each unit has a small compressor w/ the condenser and air handler (in a utility closet) that receives semi-cooled water from the rooftop cooling tower, chills it further, and exhausts heat into the water and re-circulates the water to the roof. You can definitely hear it run (but it's not too bad) because the compressor is inside the unit. But it works flawlessly and the in-unit components with this type of setup typically last 20-25 years.

Another place I had did all phases of cooling up on the roof....cooling tower and the chiller unit was up there, so inside the condos we only had the evaporator and air handler. That was a great system. You can run it as much as you want and your electric bill barely moves. There wasn't even a thermostat really. It was just a knob you could turn towards "warmer" or "cooler" and there was a separate knob for the fan (off, low, med, high).

So....even within the concept of "central a/c" there are different variations. All air conditioning works basically the same way, with the main difference being where all the various components of the process are located and how they interact (chiller/compressor, evaporator, air handler/fan, where the condensate water drains, etc.).

My Carrier can beat up your Lennox.

If you want to restrict air flow to a room, do not close the vent in the room. Do it at the furnace/duct if you have a plate at the beginning of the duct run from the furnace. There would be a lever on the duct that you turn to shut off air flow, increasing air to the rest of the runs. I would not close more than one duct. Balance is important.

So quiet. Aaahh. Retrofitted my old house for central a/c. The only time it’s not perfect is sometimes if it’s very humid without being very hot. I Don;t like the humidity above 60% and sometimes I have to cool the temp lower than I would prefer to get the humidity down.

Here, OP, read this insightful article:

The Google article, MyMillennelFriend, R27, is something a tradesman wrote. It’s just not clear to me, the mechanism of total destruction he describes. After all, the vent is adjustable for a reason.

Sorry, Frosty, you are incorrect about shutting off vents on a central sir conditioning system. It increases the pressure in the duct system, making the fan motor having to work harder. Also forces out more air from leaks in the duct system. All duct systems leak. In your case, a little knowledge is a dangerous thing.

Well, live and learn. Thank you, r34, r36 & R27. I’d still like to see a non-commercial source explain as to how the vents should be used.

OP .......... where do you live? Rural Poland.

Walk into any air-conditioned furniture store in the middle of summer, sit down and pretend to be checking out a couch.

Stay there for about 30 minutes, and evaluate how you feel.

That is exactly how you will feel with central air at home..............window units have not been used (except by the very very poor in the US) for decades..........

Central is MUCH MUCH superior.

R38 = provocateur.

For Frosty

I actually have found window AC units to be much more efficient for a house - if not quite aesthetically ideal. Central air circulation never works quite right throughout an entire house - especially if more than one story.

And as one of our goals here should be to encourage our European Luddite friends to use AC, it’s ok to use window AC. A quick and easy solution to the ridiculously hot summers you have been having. Your American visitors will be very appreciative. As will you.

Well thank you for attempting to help Frosty. You are a rare breed of DLer who is actually able to admit they may not know everything.

Perhaps you haven’t been here long enough to learn you are supposed to deny the truth repeatedly and argue your clearly incorrect view for days - and ultimately just resort to calling the other person a piece of shit asshole. I am shocked by your seeming sanity.

More for Frosty:

R42, you are wrong, Sir! I have been here since 1992, or something, and blah blah blah, you piece of shit asshole!

I kid.

I looked at a Tudor-style cottage that had central air and window units. The owners said that they had upgraded to central but left the window units so that drive-by property tax assessors would not be aware of the upgrade.

Thank you, R43, I have seen that.

I left “the biz”, to the extent that I was ever in it, in the early 1980s. I will ask my brother when I see him, as to what he knows. He worked there until a few years ago. My Dad, who built it, is gone now and not responsive.

R45, well, that certainly reads as a shady explanation.

Frosty, what do you think about mini-split systems? I'm considering the purchase of a 3 BR, 1200 sf row home that currently has window units---one downstairs and three upstairs (one in each bedroom). I toured the property on a fairly warm day and the four window units were doing a pretty good job of keeping the all the rooms cool. The only reason I would make a change is because I find window units to be unsightly, both inside and outside.......and they can be loud. Anyway, I got a bid for a mini-split system for $13k. Yikes. Not sure if the investment is worth it.

Oh, and the reason I'm considering a mini-split system instead of central air is because the house has baseboard heat. It was built in 1965.

Electric baseboard heat? If so, and not hot water or steam, you can save a lot of money in annual energy expense by buying the mini splits that are heat pumps, i.e., both cool and heat as needed.

I know nothing about split systems, R48. I think they were invented after my Dad passed the business to his heirs. Sorry.

R49, heat is HWBB.

Never mind then.

That may just be a newish name, “split system”. We might have actually had one, but I’m not really an expert on them.

We had a central A/C system with two thermostats, so it was split, in that sense. Ditto for the heat. And we closed the vents, occasionally, but rarely, haha.

I am well experienced with window A/Cs though, OP. I’d still like to see a picture. I think I can help there. Do you need help posting a picture?

I have a mini split and it cools my entire first floor because of where we put it, it open into pretty much all of the space. It cost $7500. It does not have a heat function. Some do.

I have 3 (small) upstairs bedrooms and they would have to each have their own unit. When I priced it about 8 years ago I was told $9,000. My husband said no.

I priced it through Home Depot this year and they said $12-15,000.

I said no.

I can cool the rooms with window ACs for about $500.

LOL R55, and THAT is why window a/c's are still around. They are cheap AF and get the job done, if not in a glamorous way.

Nowadays, many window units can operate with 110V so no 230V wiring required.

And if you take care of them (i.e., perform annual maintenance), window units can last for a very long time. I still rely on an old General Electric 8,000 BTU window AC that I bought 20 years ago. Works great.

Yes, the wiring is a big deal.

I use the largest unit I can find which still uses regular 110V electricity, so that I don’t need an electrician and all that fuss. It works fine. In a better world, I’d move up one size for the hottest days. In a perfect world, I’d spring for central air. But what I have works fine, so I let it be.

A friend of mine installed one of those motel units in his bedroom, the kind that sit under the front window and have the little pushbuttons, and it works like a champ. It's all he runs at night, and since it has both heat and air he keeps his furnace and central air down low all year. He said it wasn't all that expensive, and because it's a commercial grade unit it's built like a tank.

I lived in Washington, DC, in an apartment building that had central AC & central heating. Very nice and quiet. I don't know why you would not want central air.

r60 Because central air is much more expensive than window units, especially if a new duct system is required.

r59 My brother used one of those in his bonus room above their garage. It's called a PTAC unit. Pronounced "pee-tack.

Look what I found on Amazon - a 12k BTU split system/heat pump for only $748/free ship! Get one of these and head over to YouTube for vids on how to install yourself!

Try getting some one to install it and the manufacturer to guarantee it.

The PTAC units (image in R59) still require venting to the outside.

PTAC units look like a mini split.

If you can install it yourself, you're lucky.

The PTAC's are desgned to slide out easily. I had one die in a motel I was staying at, and when they said they were going to fix it I got ready for a major inconvenience, but one guy showed up with a new one on a little cart and swapped it out with my old one. I was back in business in under 5 minutes.

The other advantage to a PTAC is that they have both heat and air.

Cheap too!

Who knew a thread on AC could turn into such a lively - and informative - thread. Nice change from Connor Jessup (I still don’t need know who he is) and Pose/trans issues.

We use window units. They are cheap AF but I also swear they're not as cold as they used to be. Is it my imagination?

Not your imagination, R69. The new units no longer use Freon and the replacement refrigerants aren't as efficient. You lose about 10% in cooling efficiency,, but they try to make it up by blowing more air. (You really feel it in automobile systems.)

Small price to pay for Earth having an ozone layer though.

Consider combining your a/c system with a good quality dehumidifier. They're cheap as Hell, and once you get the moisture out of the air it'll feel a lot more comfortable even if they temp is a bit higher.