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urbanriot
Premium
join:2004-10-18
Canada
kudos:3
Reviews:
·Cogeco Cable

New central air vs. my old central air unit - better or same

Click for full size
We've had an aged central air unit on the side of our house which was old when we moved in. The image attached is not mine but similar, a big rectangular thing that blows air an intense amount of air. When I bought the house the home inspector told me the unit was ancient and probably on its last legs but fast forward a number of years and its still trucking along just fine. A few hands-on folks that are friends of mine told me the old ones are just fine.

... except the cost to run it is pretty high, basically around $5 to $6 a day to run it on a very hot day which seems high here in Ontario, Canada but I don't have a means for comparison. Yesterday was 32+ degrees C (around 90 or so degrees F), so it was cranking away all day and night, so I'd expect it would be a higher cost day.

So, my question is, since 'newer stuff' is generally most energy efficient than older stuff, would I stand to save a lot of money on electricity costs by having this big thing swapped out with something newer? Enough money to make it worth swapping out?


dandelion
Premium,MVM
join:2003-04-29
Germantown, TN
kudos:5

I am only guessing but figure you would save money to swap it out but we are talking years... *shrugs* I'd run it as long as it works.



Lurch77
Premium
join:2001-11-22
Oconto, WI
kudos:4
reply to urbanriot

Have you had a check and tune up on it anytime recently? AC systems are energy hogs, especially the older models. But there are many things that can cause them to run even less efficient. Things that a reputable contractor can address during a regular check.



urbanriot
Premium
join:2004-10-18
Canada
kudos:3
Reviews:
·Cogeco Cable

said by Lurch77:

Have you had a check and tune up on it anytime recently? AC systems are energy hogs, especially the older models. But there are many things that can cause them to run even less efficient. Things that a reputable contractor can address during a regular check.

No, I hadn't had anyone look at it but that's probably not a bad idea.


pende_tim
Premium
join:2004-01-04
Andover, NJ
kudos:1
Reviews:
·Comcast
reply to urbanriot

Yes newer ones are more efficient, but costly to purchase.

Before investing all that money, get a pro in to evaluate the system: are coils clean? is the blower clean and moving the proper amount of air? is the ductwork tight and not leaking? Is the system charge correct?

Any patio doors? is the glass in good shape?
etc...
--
The difference between genius and stupidity is that genius has its limits.



urbanriot
Premium
join:2004-10-18
Canada
kudos:3
Reviews:
·Cogeco Cable

said by pende_tim:

Any patio doors? is the glass in good shape?
etc...

The house is excellent with climate retention. I basically have the AC unit on until I sleep and then turn it off, when I get up the temperature's gone up maybe one degree celsius. Newish windows and all that.


Lurch77
Premium
join:2001-11-22
Oconto, WI
kudos:4
reply to pende_tim

said by pende_tim:

Before investing all that money, get a pro in to evaluate the system....

This is where I would start. Tell the contractor you have no desire to replace the system at this time, that you only want to make sure your current system is running at its peak.

Body Count

join:2010-09-11
Columbus, OH
reply to urbanriot

That AC unit looks just like mine. Is it a Rheem?

Mine costs a lot to run as well and yes in Ohio it runs constantly and jacks up my electric bill big time. Especially this week during this heat wave the midwest is having.

Get it checked out by a heating and cooling company. They will check the fins and make sure air is passing through them. Plus they will check the coolant levels to make sure it's where it should be. If you want to be cheap the least you can do is turn the fuse breaker off and then take off the metal casing and see if the fins are being blocked. Sometimes mowing the lawn will shoot grass in the vents and that will clog up he air which lowers your efficiency.

Also if you're not in the house for periods of time every day (like if everyone is working or in school), then it will help if you get a programmable thermostat. I got one a couple years ago and saw my bill drop by at least 20% (summer and winter months with my gas bill too). Of course it depends on how many hours no one is in your house. For me no one is in my house from 8AM to 5PM on weekdays so I have my thermostat set to 80F in the summer during that time. At 4:30 PM my thermostat drops down to 73F which it roughly takes a half hour to hour for my house to cool back down which is perfect timing for when I get home from work.



urbanriot
Premium
join:2004-10-18
Canada
kudos:3
Reviews:
·Cogeco Cable

Yea, great tip re: thermostat, I also have one and I've optimized the four allowed periods around my habits and our time-of-use hydro billing periods (after 7:00 on week days and weekends, electricity is cheaper). I basically set it to default to the upper limit of comfortability and when I'm home, set it a bit lower.



djrobx
Premium
join:2000-05-31
Valencia, CA
kudos:2
Reviews:
·Time Warner Cable
·VOIPO

1 edit
reply to urbanriot

Wow, I didn't know the Dharma Initiative was also producing air conditioners.

You need to look at your energy bills in the summer vs. months when it's not running to determine how much it's costing. I replaced my 15 year old beast, and difference in energy usage is pretty significant. It seems to be using less than half of the amount of energy. But because I have cheap power thanks to solar, I stand to maybe save $250 per year. I probably won't recoup the cost in its lifetime. The other one needed to go though, LOL, so I'm happy I did the changeout anyway!

--
AT&T U-Hearse - RIP Unlimited Internet 1995-2011
Rethink Billable.



shdesigns
Powered By Infinite Improbabilty Drive
Premium
join:2000-12-01
Stone Mountain, GA
Reviews:
·EarthLink
·Comcast
·Atlantic Nexus
reply to urbanriot

I had the same unit, probably about 10 SEER (maybe even 9.)

A newer 13-SEER of the same size should reduce your cooling costs by about 25%
A 16 SEER would reduce it by 37%.

You'll have to see how much more your power bill is in the summer than when not running A/C or heat. The savings would be the the percentage calculated above of the difference. Then see how long the cost is regained.

I had the old one checked and it worked fine but could not keep up. Turned out the idiot who installed it had the fan set to low in A/C mode (and two techs never noticed it.) It developed a leak and I retired it rather than fix it.

Have it checked to see if it can be cleaned and maybe improved a bit. That may be a short term solution as that looks like a late-80s/early '90s unit and probably will need replacing anyway soon.
--
Scott Henion

Embedded Systems Consultant,
SHDesigns home - DIY Welder



djrobx
Premium
join:2000-05-31
Valencia, CA
kudos:2
Reviews:
·Time Warner Cable
·VOIPO
reply to Lurch77

This is where I would start. Tell the contractor you have no desire to replace the system at this time, that you only want to make sure your current system is running at its peak.

Just be sure to get a quote on how much it's going to cost. Two years ago I had my clunker inspected by a reputable pro. It was low on refrigerant so they topped it off. What I wasn't expecting was the $300 bill - my system had a leak somewhere they couldn't identify, and R22 has become expensive. That's a pretty good chunk of money towards a newer unit....
--
AT&T U-Hearse - RIP Unlimited Internet 1995-2011
Rethink Billable.


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to urbanriot

It all depends on how much it is being used.
Sure it may cost $5-6 a day for few weeks a year. What is the total for the season? If you reduce that cost by 30-40%, how long would it take to break even with the $3000-4000 of a new system?



workablob

join:2004-06-09
Houston, TX
kudos:3
reply to urbanriot

$5 OR$6 ON A HOT DAY?

Stick with it until it dies as you'll never recoup the cost of replacing it.

I pay 20 bux on a hot day here.

Blob
--
I may have been born yesterday. But it wasn't at night.



jester121
Premium
join:2003-08-09
Lake Zurich, IL
reply to urbanriot

I've heard from our physical plant guys here at work that a lot of the new residential units are junky and have frequent parts failures under warranty even in the first couple years, unlike the 20 year old models that just ran and ran. They advised me to ride mine into the ground rather than preemptively replace it.


garys_2k
Premium
join:2004-05-07
Farmington, MI
Reviews:
·Callcentric
·callwithus
reply to urbanriot

Run it until it dies, but in the meantime get some PM service done (make it clear to the tech. that you intend to keep it) and do consider a smart thermostat. It's extremely unlikely you'd ever get enough savings from replacing the unit itself to pay for the total replacement.


agtle

join:2013-03-09
reply to urbanriot

If you do decide to replace it, make sure you get equipment that is eligible for the OPA rebates! (seer 14.5 or better). Watch out, and run from, any contractors that try and charge you a fee to process the paperwork.

»saveonenergy.ca/consumer/program···tes.aspx



davidg
Good Bye My Friend
Premium,MVM
join:2002-06-15
none
reply to urbanriot

can a new one pay for itself quickly, yes. BUT only if the old one is really sucking up the electric. When we bought our house the HVAC system(3 ton AC and electric furnace) for the front half was nearing 30 years old. during peak usage in summer/winter my electric bill was 700.00 a month! i decided to replace the system with a new heat pump and started shopping around. Ended up getting a 3 ton Trane XL14i and saw immediate savings of 300.00 a month on the cooling costs!

not all of the savings was from the new system's better efficiency, there were leaking ducts found during the replacement and a few other minor issues. So my advice would be to have it checked by a reputable pro, and run it until it is apparent it must be replaced. BTW, one of our HVAC systems at our office is over 30 years old and home owner grade not commercial grade. It ran 7 days a week up until about 5 years ago when i installed set back stats on all the units. the only issue it has ever had is the blower motor in the air handler is belt driven and the belt breaks about every 9-10 years. It still can freeze you out the office if turned down during high summer, and burn you out if turned up in cold winter.
--
Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!



Hall
Premium,MVM
join:2000-04-28
Germantown, OH
kudos:2
reply to Lurch77

said by Lurch77:

This is where I would start. Tell the contractor you have no desire to replace the system at this time...

Even better, tell them "I can't afford a new system right now". Just nip in the bud any sales pitch. It often depends on the technician too - some are just out to do the job they're given (not saying that in a negative way) while others look at helping the company by maybe getting a sale.

Just curious, is it common for a technician to maybe get a "bonus" if they up-sell a customer from a (major) repair to a replacement unit ?


urbanriot
Premium
join:2004-10-18
Canada
kudos:3
Reviews:
·Cogeco Cable
reply to djrobx

said by djrobx:

You need to look at your energy bills in the summer vs. months when it's not running to determine how much it's costing.

Well I already know as I have access to see hourly costs with my provider. I turn it off for an hour and turn it on, then the next day I can see how much it cost that hour. I've also done that for entire days to have a comparison from one day to the next as on average most days in a week that are the same temperature have the same cost and the days when the AC unit are off, the costs are significantly different... and it gets hot in the house!

said by jester121:

I've heard from our physical plant guys here at work that a lot of the new residential units are junky and have frequent parts failures under warranty even in the first couple years, unlike the 20 year old models that just ran and ran. They advised me to ride mine into the ground rather than preemptively replace it.

Well I heard the same thing from a mechanic friend of mine that does a lot of AC work, that the old units are reliable and something about them that they don't do any more, it makes them more effective. I don't know if that's simply a "they don't make them like they used to" default idea or there's some truth to it.


djrobx
Premium
join:2000-05-31
Valencia, CA
kudos:2
Reviews:
·Time Warner Cable
·VOIPO

Well I already know as I have access to see hourly costs with my provider. I turn it off for an hour and turn it on, then the next day I can see how much it cost that hour. I've also done that for entire days to have a comparison from one day to the next as on average most days in a week that are the same temperature have the same cost and the days when the AC unit are off, the costs are significantly different... and it gets hot in the house!

That one data point is not enough. We know ACs are energy hogs. We not only need to know how much energy it consumes while spinning, but how often it's spinning over the course of the summer. On the hottest day this year, my new efficient AC added around 40kwh to a day, but that's nowhere near typical usage for July (average was closer to 20).

So, you have to look at your whole summer season, and subtract your baseline usage (pick a non-AC month) to determine how much per year your current AC is costing you. You can use what data you have to forecast if you don't have over a year's worth of usage. Once you figure that amount out, you can determine how much a more efficient AC will save you on a yearly basis.
--
AT&T U-Hearse - RIP Unlimited Internet 1995-2011
Rethink Billable.


runnoft
Premium
join:2003-10-14
Nags Head, NC
kudos:1
reply to urbanriot

said by cowboyro:

It all depends on how much it is being used.
Sure it may cost $5-6 a day for few weeks a year. What is the total for the season? If you reduce that cost by 30-40%, how long would it take to break even with the $3000-4000 of a new system?

This. In Canada it would take a long time to pay off the upgrade costs because the cooling season is short. (Houston's a different situation entirely--then it might make more sense.) If it were mine, I'd leave it be until the compressor needed to be replaced or it needed other very expensive repair or unavailable part. Also keep in mind that the savings from upgrading things like this are rarely on the real world utility bills what they're advertised to be.


hm

@videotron.ca
reply to urbanriot

Not worth swapping out. Keep it till it dies.

I have an old one as well when I bought the house, think it's about 15-18-yrs old. With what we pay in electricity (you pay a tiny bit more in ON due to TOU), it just isn't worth upgrading.

Have you done the math on a new install + new machine + apparent electrical savings on a new machine?

How many years down the road will you start to see a savings?

Just not worth it.



Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2

Electricity in Quebec is a fraction of what it is in Ontario...
--
The talented hawk speaks French.



Inssomniak
The Glitch
Premium
join:2005-04-06
Cayuga, ON
kudos:2

1 recommendation

reply to urbanriot

My house had a 35 year old unit, costs $15 to just think about turning it on..and it didn't work that great, was noisy as all hell..
It eventually leaked out. A couple years ago.
I bought a new one, and now it's quiet, cheap to run, and turns my house into a fridge even during this Ontario heat wave.
--
OptionsDSL Wireless Internet
»www.optionsdsl.ca



KrK
Heavy Artillery For The Little Guy
Premium
join:2000-01-17
Tulsa, OK
reply to urbanriot

I'm not convinced the newer units are the same robust quality. While they are more energy efficient, you have to wonder how long they will operate before a major and expensive repair. I have a gigantic Rheem unit that looks much like that one but 3 times the size. Inside it looks in fairly pristine condition and continues to operate reliably. I do keep it maintained and clean.
--
"Fascism should more properly be called corporatism because it is the merger of state and corporate power." -- Benito Mussolini



urbanriot
Premium
join:2004-10-18
Canada
kudos:3
Reviews:
·Cogeco Cable
reply to urbanriot

Thanks for the feedback guys! I'll take the advice to have it serviced since I haven't had it serviced while I've lived here and I have no idea of its history. In all honesty I was surprised when it started up years ago because it looks ancient... and was even more surprised when it seemed to work well.

As runnoft said, the air conditioning season is short here in Canada. We strangely needed it a couple days in April, a few in May and a lot of nights in June, which isn't a big deal since we pay 40% less for hydro in the evening), but mid July - mid September is pretty much an every day situation.



Derwood
Wherever you go, there you are
Premium
join:2003-01-21
Dayton, OH
Reviews:
·Dish Network
·Time Warner Cable
reply to urbanriot

I just had my old AC unit replaced a couple of months ago.
The old unit was 21 years old and about 8 seer. It was replaced with a 14 seer unit.
The heatwave this week really put it to the test. If the old unit had been in place, it would not have been able to keep up. The temp would have been 5-6 degrees higher in the house until midnight. The new one worked flawlessly this week. Never saw the temp go above 73 once.
This is the first time it's really been hot enough to really test it since it was installed, so I'm not sure yet how it will affect the electricity bill. If the old unit had run all day, my bill would be in the $350-375 range for the month.

Here in Ohio, summers are much warmer, and theres usually a lot of humidity. So, the cost of getting the replacement was worth it to me.


slyphoxj

join:2002-06-23
Brook Park, OH
Reviews:
·ObiVoice
·WOW Internet and..
·magicjack.com
·Callcentric
reply to urbanriot

I've got an older (made in June 1994) Rheem unit that sort of looks like the OP's, but is smaller (I think it's only a 2-ton?). It has a "Scroll Inside" (or something like that) decal in the middle of the fan area. It's definitely low on refrigerant. It's behind my house, but I'd like to move it to the side if my city won't give me any grief about doing so... or just replace it considering what the cost of moving and adding refrigerant would be? I vaguely remember my neighbor (or someone) telling me that, about 20 years ago, my city required that central A/C unit be placed behind the house instead of beside.

I have a 4 bedroom, 2 bath, 1131 square foot bungalow with full basement built in 1956... I wonder if a 2 ton unit is just simply too small? It hardly cools my upstairs... I have a 5,000 BTU/h window unit to keep me cool in my upstairs bedroom at night.

My furnace is a newer (about 5 years old) Weather King gas unit. It looks like they used the old evaporator coils with the new furnace... I wonder if the coils and outside unit can be replaced and used with the existing furnace?


gordom

join:2006-06-14
Antelope, CA

1 recommendation

reply to urbanriot

another option is check if there is enough insulation in the attic to keep the cold in.