Question about Compressor

[nhoj]

If the AC compressor is going bad would you be using more electric?

I received my electric bill today and it was $175.00. I have my thermostat set at 75.
Back around July 4 I had a HVAC contractor come out and he told me that the compressor was getting bad.

I contacted Rheem and they told me that I have 1 year left on the warranty and told me to have the HVAC contractor get a new one so I did, This Friday will be two weeks, how long does it take to get a NEW COMPRESSOR?

My next question is will the new compressor ( 2016 ) be more energy efferent than the old one ( 2007)?

Is the compressor like a engine in a car? The mean item that runs the AC?

By putting a NEW COMPRESSOR in will it be worth it or would you be better to put a whole NEW AC UNIT in?

 

[Jadnashua]

A direct replacement compressor probably won't be any different than what it replaces...i.e., not more or less efficient.

While compressor design can make efficiency differences, the a/c system is just that, a system composed of evaporator, compressor, condenser and a few other bits. Then, each component is optimized for a specific type of refrigerant. Today's systems are required to be more efficient than those of old, but depending on the model, a super high efficiency model from your age, to the minimum of today, today's may or may not be more efficient, but if you go with the highest available efficiency, it will almost certainly be more efficient. All of the parts must be matched, and there are limits on what can work with each other. To maximize the efficiency, you may need to replace not only the outside compressor unit, but the evaporator coil in the ductwork.

 

[Sponsor]

 

[nhoj]

Can someone tell me what you would call the engine of the AC system if it is not the compressor?

By putting a new compressor in will I be able to see less usage of electric on my bill?
Is it a wast to put a new compressor in if it is not going to save me money?

 

[Jadnashua]

If the seals on the compressor are failing, it will run longer to try to provide the pressure to liquefy the refrigerant and, in the process, lose refrigerant. An old compressor might have bearing problems (but you'd likely hear that as a screeching). A good tech can check the pressures...if the compressor can't create the desired pressures and the refrigerant isn't too low or too high, you could probably see a new compressor save you some. Today's a/c systems are more efficient than the old ones. And, if you have a proper analysis done, you could probably end up with a smaller one and that will also save money and make the house more comfortable in the process.

 

[nhoj]

For the past 6 or 7 years when the AC shout off it makes a clinking noise so it is the compressor, the HVAC Contractor that put it in told us that it was the fan and he would wait tell it quick working. He never checked the compressor so we took his word and when talking to Rheem about 2 weeks ago they said that the motor was still under warranty back then. If he would have changed it out he would have saved us $300.00 + dollars. nice to know.

 

[DonL]

If your system uses R22 you may be better off installing a new one.

R22 is about $100 a pound now a days.

Normally if the compressor is going bad it will make strange noise when it builds up head pressure.

If it does not build pressure, It could have a leak and is low on refrigerant.

A amp probe is good for testing. Many add to much refrigerant, and never test for leaks. That is against the law now.

If they do change your compressor, Make sure they flush and pump down the system properly.

I wish my cooling cost was as low as yours. Mine is only $300. That is not bad in Texas Heat.

Good Luck.

 

[Dana]

The spring and early summer was on the mild side (with lower latent-loads/humidity too) for most of the north eastern quadrant of the US, but picked up considerably in July. It's highly likely that the increased power use was due to increased cooling load. Plug your ZIP code into this web-widget, set the base temp to 65F, and compare the monthly total CDD against your power bills. (In my ZIP code there were 3.5x as many CDD in July as there was in June, and it shows in the power bill.)

If you want to nail it down to the weather between exact meter reading dates, down load a daily +65F base temp cooling degree-day spreadsheet from a nearby weatherstation from this website.

 

[nhoj]

I am yet to hear anyone tell me to get a NEW AC unit.

I keep asking myself should I get a NEW AC UNIT or should I have them replace the compressor since it still has ONE year left on it before the compressor loses the warranty.

I want to be realistic about this and do the best thing.

 

[Jadnashua]

What is the SEER of the one you have verses the one you might purchase? If you do not want the maximum efficiency, you might be able to salvage the evaporator coil inside, but depending on the refrigerant used, that may limit your choices. A new compressor should last years, but then you have the fan(s) and controls (but they aren't all that expensive). A unit as old as yours might have a SEER of 6 or so. You can buy a new one with a SEER of around 20, or over 3x as efficient. Plus, it would give you the opportunity to 'right size' the unit, which may also save some money and almost certainly would improved the comfort levels. A new one would come with a new warranty. Your replacement compressor probably only has a 1-year warranty, and doesn't cover any other parts in the system.

The payback period might dictate your choice, but pair that with the comfort improvement if it is 'right sized', too. If your furnace is also that age, it might make things a bit easier (but not on your pocketbook initially!), because that would allow the interior parts to more easily be changed, and some utility companies give you a better rebate on a whole system verses just the a/c. You won't qualify for any rebate for just the compressor being replaced. Rebates are a local/state thing, so you'd have to look up to see what may be available in your area. Keep in mind, also, that sometimes, they have a budget for the year, and the longer you wait, you may find they don't have any more funds available, and on most, you can't apply next year for work done this year.

From an energy use standpoint, replacing with a new, high efficiency unit has merit. And, you might find the payback period (when coupled with rebates) means it's a good idea, but you'd have to run your numbers.

 

[nhoj]

I have a 13 seer right now and they say that is all we need here in Ohio, I feel that a 14 seer would be better.

 

[Dana]

A 14 SEER replacement for a 13 SEER is an almost infinitesimally small boost in performance.

If you're going to replace it, get a better handle on the true cooling load by measuring the duty cycle of your existing unit. Even replacing it with another 13 SEER unit that was right-sized would deliver a bigger improvement in both comfort and power use than bumping to 14 SEER at the same size, which is typically well above the optimal oversizing. In most houses in OH you'd have a cooling load to floor area ratio of about 1 ton per 1000-1500 square feet, but it's more typical to find installed equipment running a ton per 500-700'. It's easier on the equipment, more comfortable and more efficient if it runs long, nearly continuous duty cycles rather than having equipment oversized to the point that can bring the house from 95F to 75F in an hour, but cycles compressor cycles on/off more than once per hour when just maintaining temp.

 

[Jadnashua]

FWIW, some have a SEER of 19 and there may be some that are better, still. Eking out that extra performance comes with an upfront cost, though, although, if properly sized, that is likely the bigger contributor to comfort An x-ton unit, regardless of the efficiency, still will cool the same, just use less power doing it. Given maybe a 20-year life, that can make a big difference in operating costs...depends on your desire for a payback and how long you expect to live in the unit.

 

[Dana]

Most OH locations have fewer than 1000 CDD, and lower electricity pricing pretty close to the national average. It's hard to see much short term "payback" on the higher price in lower operating costs between between a 20 SEER unit vs. a code-min SEER 13, but maybe over it's lifecycle. However, a right sized and modulating (or even a simple 2-stager) would deliver a higher-comfort payback.

The biggest thing is to just get the sizing right, which takes either a very careful and aggressive Manual-J calculation, or simply measuring the duty cycle of the condenser on hotter days to get a close handle on the true cooling loads. A 2-stage or modulating air conditioner that is 2.5 x oversized never needs the higher stage, or never modulates, since even the best modulating split AC systems only have a 2.5:1 turn down ratio, never dropping below 40% of it's maximum output.