HVAC question on used parts

[Richard]

I've got a heat pump. I do not know the size, only that it seems one of them (house has 2 systems) seems to be dying. The repairman was out Friday and said the compressor pump is dead.

He's going to see if he can find the parts I need so I can compare that price verses an entirely new system (compressor and air handler)

Current system is 10/11 years old and we have had nothing but troubles with it from the day it was installed. Anything from a circuit board frying on me, leak in the compressor, leak in the handler... just always something coming to bite me...fortunately, I (for once in my life) bought their 10 year extended warranty which is now over.

I might replace entire thing just because this has always been an annual headache and it might be time to simply buy a new one rather than play patch up ever year.

Ok... so...if I DO replace it with a new one, I'm sure they'll take the old parts away (or at least I hope so)

Thrust of my question: Any parts worth saving and trying to find a creative use for, or perhaps reselling?

Example, the compressor outside has a 220v motor on it. Works fine, might be of use to someone?

The entire air handler, although I don't know of the condition of the coils, might they have a scrap value? Would the (working) unit itself have any value to someone if nothing else, than to help push air?

I guess I'm realizing with today's economy... I would usually say "away with the old and any value you scrap out of it is more power to you"

Now I'm thinking... is it worth the headache to remove some of the parts and maybe put them up for sale or use them myself? (though I've got no idea what I'd need a 220v electric motor for)

Any thoughts on me trying to salvage some parts/value or just let them take the entire mess away?

 

[PAGUY]

Junk it. Anything you save will be in your way for years to come before you end up paying somebody to haul it away for you.

Smart move to invest in a new one. They are more energy efficient now a days. My only suggestion is that you make sure you get it sized right for your place. Did the old unit do the job correctly or did it struggle to keep the temperature comfortable. Under and oversizing are the two biggest headaches with heat pumps. Premature failure from overworking or the irritating starting and stopping from an oversize unit wasting electricity. It takes more electricity to start a motor than a motor in motion uses.

 

[Richard]

I don't know enough about them to say with any authority that it was over/under or proper sized. I'm aware that you want the right size, I just don't know enough about it to know.

I asked the repair guy if he'd also replace the other unit (smaller unit for upstairs and 'problem' unit is for main floor and finished basement)

He said he viewed it like buying a car... if I was planning on buying a car AND making a trip across the country... he'd just hop in the car and start driving... if the car made it to California then power to me, if it died in Kansas City then buy the new car when the existing car dies.

Evidently my smaller unit is operating fine so his opinion is, don't do anything.

I think I like this guy!

 

[orezok]

Under and oversizing are the two biggest headaches with heat pumps.

PAGUY is right about getting the right size. Most people think that oversizing is good, but in your neck of the woods, humidity is a big problem and is ONLY removed while the unit is running. If you oversize, the unit cools too quick and the humidity in the house remains high.

It may be cool, but it will not be comfortable.

 

[Richard]

Is the size calculated on square footage or cubic footage? My brain says cubic footage would make more sense although I know there is a basic correlation with sq footage.

We've 9' ceilings throughout the basement & first floor. The upstairs has vaulted ceilings, probably 12' and the new kitchen addition (back on the first floor) has a ceiling that is about 19'. Yes, nineteen, it's only for that one room though.

This is why I'm asking is cubic feet a better measure than square feet.

?

 

[Sigarms]

Most people think that oversizing is good, but in your neck of the woods, humidity is a big problem and is ONLY removed while the unit is running. If you oversize, the unit cools too quick and the humidity in the house remains high.

More mositure is removed from the air if the air movment over over the coil is reduced. With a standard PSE motor in the air handler, very hard to do. Shorty cycling the unit however does cause more "wear and tear" on the unit and can actually use more power (I sometimes do use the car analogy, going 55 MPH on the highway compared to starting and stopping in the city, you get better gas mileage on the highway)

However, oversizing you AC can actually cause you mositure issues.

Is the size calculated on square footage or cubic footage? My brain says cubic footage would make more sense although I know there is a basic correlation with sq footage.

Size is based on numerous variables, and hard to belive, but the size of the house house is not your biggest variable. Yes, size does play a factor, however, insulation is one of your biggest variables. Same size house, different value of insulation (along with the size and type of windows) can result in an enormous difference. Then you also have to consider your ductwork.

Any good HVAC guy will do a load calculation on your home before they quote you a system. Doing this also can save themselves a headache.

He's going to see if he can find the parts I need

Being that the system is 10 years or so old, shouldn't be hard to do. Although if the compressor is really dead, added to the problems you've mentioned on having, probably better to replace the system.

Any thoughts on me trying to salvage some parts/value or just let them take the entire mess away?

Junk it, unless it's a Lennox Pulse furnace and I'll buy the parts off you

Standard shelf parts come with a one year warranty. The biggest things of value on your outdoor unit are the compressor and coil, and any decent HVAC guy wouldn't try to sell these used parts to even their mother in law (unless you live in W.V, I've seen some strange things there ). Copper was at one of the lowest prices I've seen in years a month or so ago, and although it's slowly raising in cost, may cover your gas on a long drive to the scrap yard.

 

[Birdhunter1]

The only thing worth keeping would be the squirrel cage blower out of the air handler, they make dandy little fans in the garage or a wet basement, have your HVAC man set up a plug on the end of it so it can be plugged into a wall (if it's 110 volt). If it is a 220 volt have him put a plug on it to fit whatever 220 outlets you have around.

As for replacing the compressor, I don't know that I would go with a used one in a 10 year old unit (or any unit for that matter) because when it is all said and done you have a unit that is 10-12 years old. It would help the value of your house, your utility bills and would make more sense to just replace it all. Chances are a used compressor isn't in that great of shape anyway, now a whole outside unit that was used and you are replacing your current unit with that wouldn't be bad (maybe). I have taken alot of units out that were not all that old and in great shape for reasons such as they were adding onto teh house and the current unit wouldn't have been big enough or they went from an air-air system to a geothermal system.

 

[tallyho8]

You describe that unit as not being any good from the beginning so it is past time to scrap the complete unit and start over with a higher efficiency unit. That unit is R22 which is expensive and getting harder to get each year.

Make sure that they change the evaporator and condensor and all the line tubing as it will be full of contaminants and may be where your leak is. I've seen some a/c men save $20 worth of copper lines and ruin a new $3000 system.

You can probably get $15 for the copper and aluminum in the old unit if you want to spend an hour or two taking it apart and then hauling it to the scrapyard.

 

[kenmac]

Like sigrams said ... Have them do a load calc. on your home ..& show you their results.. Don't just replace it with the same sized unit.. That unit could be too small or too large.. You can do your on load calc. here if you so choose ...HVAC Load Calculations...HVAC Software, HVAC-Calc for HVAC Load Calculations.... Also insist on a R410 system & replacing your R22 refrigerant lines.Or,, doing a very good flush on your existing lines... If the lines are easy to replace.. I replace... If hard ( impossible ) to replace I do a good flush... Most systems now have a 10 yr parts warranty if you replace matching evap coil with condenser... I can't see replacing a new 13-14 seer condenser on an old evap coil

 

[2manyrocks]

Some HVAC guys take a rough guess at the proper unit size based on square foot of your home and cooling tons of the unit. The correct way to size the unit is do what sigarms and kenmac have suggested: calculate the heat load of your house and then size the unit to your heat load. The basic idea is that there is an outdoor heat load based on expected temperatures in your location that is constantly trying to get inside your house via your windows, doors, and exposed walls. How fast it gets inside your house depends on the relative R insulation factor of whatever the heat is passing through. The HVAC system has to cool the interior space and keep it cool depending on the heat load that is put on it.

 

[ScottAR]

In my somewhat limited experience, it's about $200-$300 difference between a new outside unit vs replacing just the compressor. By the time one figures in all the extra
labor to disassemble the outside unit it works out to nearly the same.

It would be higher to change the coil as well, but recommended. If they flush and reuse
the lines insist on seeing a dryer or "catch can" on the line into the outside unit.

I'm unsure on the new r410 but like it or not, it's coming. The production of r22
is stopping in 2010. It's a brave new world indeed.

 

[Richard]

Thanks all!

It's a log house... I hope that works to my benefit on size (cost)

 

[Sigarms]

I'm unsure on the new r410 but like it or not, it's coming.

R410A has been out since the 90's, first introduced by Carrier as "Puron".

Most contractors who are not familiar with it are usually afraid of two things.

1. Change
2. Operating pressure of R410A which is much higher than R22 (guys back in the 90's thought R410A would blow up). You also need some new tools for 410.

The one thing that you have to be very careful about with installing R410A is mositure. Guys who ran a vacuum pump for a half hour and felt it was fine with a R-22 unit will have nothing but problems if they have the same habits with a R410A system (habits can be hard to break). Bottom line, R410A will not let guys get away with sloppy install habits.

Long story short, R22 and R410A use different oils wich are not compatible with each other, on reason to replace the lineset as well.

Back in the 90's the cost of a jug R410A was about ten times the cost of a jug of R22. Guess what, they are now about equal in price. Next year (or perhaps this summer), I have no dobut that R22 will exceed R410A in price, which means higher service bills for R22 units.

 

[kenmac]

.

Back in the 90's the cost of a jug R410A was about ten times the cost of a jug of R22. Guess what, they are now about equal in price. Next year (or perhaps this summer), I have no dobut that R22 will exceed R410A in price,

Actually, right now.. I can buy 410 cheaper than than R22..The only thing load calc, don't take into account ( that may or may not) be a problem .. Is when you have alot of people over say for ,,, a party.. People give off heat... opening outside doors alot also allows heat / cold in... A load calc...isn't perfect,,,,but, it's close

 

[440roadrunner]

The only thing worth keeping would be the squirrel cage blower out of the air handler, they make dandy little fans in the garage or a wet basement, .

This can be a bad idea. Typical modern fans--if it's not the new variable speed, electronic controlled--are direct drive, and when the air restriction of the system is removed, IE, running in "free air" they will "overamp." You may well burn up the motor or cause a fire.

So far as replacing the unit, make SURE it is designed around the ductwork and otherwise properly sized. Back when we were doing local retrofits --removing electric, converting to NG--I ran into a number of "underducted" heat pumps. One guy had lost a couple of compressors in 10-15 years. At that rate there's certainly no savings in a heat pump.

Also make sure that the brand/ installer is WELL supported for maintenance, and find yourself a GOOD man to do yearly or at least bi-yearly checks.

The single most important thing you can do with a heat pump is NOT restrict the airflow--change filters, don't close down supply ducts

 

[Richard]

Long story short, R22 and R410A use different oils wich are not compatible with each other, on reason to replace the lineset as well.

Ok, this is probably the first thing I've read that has me nervous.

By lineset, do you mean the copper tubing connecting the air handler to the compressor outside?

I'm asking because the guy that was out on Friday said if the new stuff was put in, it was critical that it was VERY airtight (special tool to measure the vacume, compared to old system) and they would also purge/wash the connecting lines because if you mixed the two "freons" they would turn into some kind of GOO inside the line.

Your statement above is suggestive of this same thing... one bad reality... my connecting lines run through flooring AND walls for a portion of their run and I don't know that it could be easily replaced without a major major issue inside.

Hopefully you infer something different than the pipelines connecting the two? (my eyes are closed and I'm chanting "please say you are, please say you are...")

 

[2manyrocks]

Lineset means the refrigerant lines between the outdoor unit and the indoor coil.

 

[MarkV]

I know Sigarms and Kenmac are HVAC pro's so am I correct that as of next year you can no longer buy new R22 systems, EPA thing? Also when switching freon types don't you also have to change the air handler unit to be compatible?

Richard there are some government rebates currently available, up to $1500, for new energy efficient units with the newer type of freon. If parts are unavailable for your unit now and it has been an on going problem is it worth putting more money in it and possibly missing the rebate program?

MarkV

 

[dmccarty]

...
Your statement above is suggestive of this same thing... one bad reality... my connecting lines run through flooring AND walls for a portion of their run and I don't know that it could be easily replaced without a major major issue inside.

Hopefully you infer something different than the pipelines connecting the two? (my eyes are closed and I'm chanting "please say you are, please say you are...")

Ra Row. I am chanting as well. Our outside unit is on the north side of the house. The inside unit is in the attic on the south side of the house. The copper goes from the outside unit, through the brick veneer, up the outside wall and into the attic. From there its a 60-70 foot run to the south. The HVAC was installed in 2004 but it sounds their might be a chance that Rxxxx it uses might be unmixable when the system has to be replaced.

Later,
Dan

 

[tallyho8]

Ok, this is probably the first thing I've read that has me nervous.

By lineset, do you mean the copper tubing connecting the air handler to the compressor outside?

I'm asking because the guy that was out on Friday said if the new stuff was put in, it was critical that it was VERY airtight (special tool to measure the vacume, compared to old system) and they would also purge/wash the connecting lines because if you mixed the two "freons" they would turn into some kind of GOO inside the line.

Your statement above is suggestive of this same thing... one bad reality... my connecting lines run through flooring AND walls for a portion of their run and I don't know that it could be easily replaced without a major major issue inside.

Hopefully you infer something different than the pipelines connecting the two? (my eyes are closed and I'm chanting "please say you are, please say you are...")

It may be easier to run the new lines than you think. They may be able to be re-routed a different way. Besides having to clean the old lines extremely well, there is the possibility that they are leaking or that they are not the recommended size for your new unit with the new refrigerant but that the installer will go ahead and use them anyway.

Get the rebate money while you can.

PS. I only did air conditioning work for 38 years.