Guaranteed Performance - Page 4
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  1. #40
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    Apr 2004
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    The post has indeed switched gears.

    Somehow we went from gaurenteed reduction of utility bills to merely gaurenteing the capacity and efficiency to be per the equipment specs + or - 10%.

    Your right Norm, this is easy to do and not an unrealistic expectation. However, lower bills is misleading in many cases. For instance, if there is a room in the home that was poorly heated or cooled, and the contractor address that issue, he in effect has increased the amount of heating or cooling needed to satisfy the load based on the expectation. How do you show that as an energy savings? If the new system has a dehumidification cycle, how does that save money? It doesnt, its comfot related and comfort costs money.

    The problem is that comfort and efficiency need to be seperated when it comes to operating costs. I suspect after reading the OP last post that comfort is paramount and money is not the issue but this contrasts the original post where he wanted his bills lower. That said, a good high efficiency system with comfort features, properly installed is what he needs, but by throwing promised savings into the mix it comes down to the contractor not addressing the comfort issue with the same level as the cost savings. The OP handicaps the contractor before he even starts.

  2. #41
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    Feb 2005
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    MA
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    Frown

    Originally posted by reddog4
    I am a homeowner looking to buy a new furnace and air conditioner. I have read many stories on this site from homeowners that stated they did not see any savings. In some cases their bills actually increased. On the other hand I have read information on this site and others that the actual performance of a furnace and air conditioner can be measured and documented.I was wondering if any contractor here or anywhere guarantees that the eqipment that they install will perform and deliver the heating and cooling btu's and efficiency within 10% of the equipment rating plate? If not can I hold back payment until this is accomplished?
    Read the above carefully and then the OP's other posts (minus the snarky remarks). He is not asking for anything unreasonable - although I don't know how you'd arrange the holdback or final payment. Some have replied they would do this for an added fee - and this exposes a point I think most have missed.

    Seems to me, the OP wants a quality job and some proof. Most have dismissed him as a potential POA customer because they have stereotyped him as cheap or possessing enough knowledge to be dangerous (much worse). Others would take the job and accept this risk - for extra. I think what this thread and some of the posts is revealing is the overall dissatisfaction with the industry in general.

    While there will always be the POA customers, the cheap ones, etc - an (assumedly) honest, no BS customer is just trying to figure a way to get what he paid for! If you read between the lines, how many of us can say we wouldn't want the same end result.

  3. #42
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    Again, how would you even think about proving SEER in a system installed in a home? This type of testing is done in pyschrometric chambers with exact conditions. For instance, unless you could verify airflow of the system to be exact, arrange for outdoor conditions to be exactly right along with indoor conditions to be exact and steady. On top of that you would need all tools and insturments with precise readings.

    "The SEER of a system is determined by multiplying the steady state energy efficiency ratio (EER) measured at conditions of 82F outdoor temperature, 80F dB and 67F wB indoor entering air temperature by the Part Load Factor (PLF) of the system. (The PLF is supplied by the government.)"

    If you can do that in an installed system so be it.

    Capacity is not a problem

  4. #43
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    Doc - I think a reasonable customer can be informed (by the installer) enough to understand that the SEER or AFUE or whatever efficiency rating they choose are only for equipment comparison and have no real meaning in the real world. A competent and knowledgeable installer should be able to perform tests and gather enough real data to "prove" the installation is as promised. What tests, data?
    This could be a topic for another thread - what are the determinants (that can be documented) that best qualify a system (or individual component) as generally operating at its "optimum" capabilities.

  5. #44
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    May 2005
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    7
    Originally posted by ps
    Doc - I think a reasonable customer can be informed (by the installer) enough to understand that the SEER or AFUE or whatever efficiency rating they choose are only for equipment comparison and have no real meaning in the real world. A competent and knowledgeable installer should be able to perform tests and gather enough real data to "prove" the installation is as promised. What tests, data?
    This could be a topic for another thread - what are the determinants (that can be documented) that best qualify a system (or individual component) as generally operating at its "optimum" capabilities.
    First I would like to say I had no intention of holding back any money from my contractor.But more importantly how many trips back to my house would a contractor make until I was satisfied? Moving forward. According to most of the answers I have gotten so far is that you recommend all this high efficiency equipment and yet you will not guarantee it acually performs within some reasonable expectations. All-Tech says there is no way to check equipment (not system) performance without going though a lot of expense? It can be possible that when I buy new high efficiency equipment that my utility bills could actualy increase? As long as I am comfortable,utility bills have little or no bearing,although I said nothing about energy savings in the first place.Why would anyone think that someone asking this question would be interested in a LOW bid. My problem is that the HIGH bid would not guarantee anything? I have found a contractor that does guarantee the performance of their equipment and provides measurements and documentation. His equipment and prices are not the highest yet the work he is performing exceeds every other bid. It is unfortunate that most consumers are gullible enough to believe the BS I have read from some so called Professionals

  6. #45
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    Office and warehouse in both Crystal River & New Port Richey ,FL
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    I agree with your position and it's great you found a contractor willing and capable of doing the job.

  7. #46
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    Apr 2005
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    to redddog 4,

    Probably everyone is happy that you found a contractor who will do everything you request. I work for a large outfit in NY and have known of only several requests such as yours. In my opinion, your requests should be standard. But often a great deal of time is spent by the contractor and too few consumers end up going with our prices. Most of the responses have either been we are too expensive or we may NOT fully be able to guarantee 100% satisfaction. Subjective variables throw out guarantees. A good contractor, good product, proper installation and MAINTENANCE..........you will be satisfied.
    meanwhile, back at the ranch.....

  8. #47
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    reddog4,
    Congratulations on finding a contractor who performance test his systems & meets your expectations.
    I would be interested in hearing how you come out at the completion of your project.
    Did your contractor show you & put it in writing how they would be performing the various test on your system to verify it is working properly?
    Have you set up a Google alert for Carbon Monoxide yet?
    Click here to find out how.

  9. #48
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    SW FL
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    Measures

    Originally posted by davidr
    contractor who performance test his systems & meets your expectations.

    Did your contractor show you & put it in writing how they would be performing the various test on your system to verify it is working properly?
    K I S S : Measure only a few parameters
    as a Standard A/C Start-up Procedure

    1. Total Air flow
    2. Supply Static Pressure
    3. Return Static Pressure
    4. Fan amps
    5. Delta T

    6. Compressor Suction Pressure
    7. Compressor Discharge Pressure
    8. Compressor Amps

    9. Verify overflow switch works

    10. ________

    11. ________
    12. ________

    Can only " Guarantee " total air flow + Delta T within 12% of NOMINAL Rating @ ~90'F outside temperature.
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  10. #49
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    SW FL
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    Exclamation 2.5 Ton Example

    Example: 2.5 Ton x 400 CFM / ton .. 1000 CFM
    Guarantee > 880 CFM
    ...... or > ____ CFM

    30,000 Total BTUh, 22,200 Sensible BTUh

    Delta T =
    22,200 /(1,000 * 1.08 ) * 0.88 = > 18'F Delta T

    30000 * 0.74 = 22200 / 1000 = 22.2 /1.08 = 20.555
    * 0.88 = 18.088

    Are YOU willing to Guarantee
    ... 1. > 18' F dT
    ... 2. > 17' F dT
    ... 3. > 16' F dT
    ... 4. > 15' F dT
    ... 5. None
    ...... or all of the above ?
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  11. #50
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    Central Kentucky
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    Re: Measures

    Originally posted by dan sw fl
    Originally posted by davidr
    contractor who performance test his systems & meets your expectations.

    Did your contractor show you & put it in writing how they would be performing the various test on your system to verify it is working properly?
    K I S S : Measure only a few parameters
    as a Standard A/C Start-up Procedure

    1. Total Air flow
    2. Supply Static Pressure
    3. Return Static Pressure
    4. Fan amps
    5. Delta T

    6. Compressor Suction Pressure
    7. Compressor Discharge Pressure
    8. Compressor Amps

    9. Verify overflow switch works

    10. ________

    11. ________
    12. ________

    Can only " Guarantee " total air flow + Delta T within 12% of NOMINAL Rating @ ~90'F outside temperature.
    Dan,while all the measurements you mention are important we take our performance testing just a little further than this.
    With Manual J loads on the building we adjust supply & return airflow values into each room to +/- 10% with an airflow hood.
    This helps to keep individual rooms under a neutral pressure when doors are closed.
    Then the total,sensible & latent BTU's of the "system"
    not just the equipment are measured & compared to Manual J loads on a room by room & total building envelope basis.
    This helps us to insure proper BTU delivery to each room is within +/- 10% of design.
    In addition to this we figure how much capacity is lost through the supply & return ductwork,it should be less than 15% or a temperature change of 3 degrees through the ductwork.
    The duct leakage is verified to be within 10% of the fans capacity.
    If the equipment is gas then a combustion analysis is added to these procedures to insure we are getting all available BTU's from the fuel & that the firing rate for the equipment is properly set up for field conditions.
    Then a CSER/HSER procedure is figured to compare equipment rated BTU delivery versus the systems actual BTU delivery.
    After all this is completed the customer now has proof in writing that their system is operating as designed.
    If I told you 100% of our customers took this opportunity I would be lying,but the majority of retrofits we do this is incorporated into the proposal along with educating the customer as to why it is needed.
    In new construction all installs are figured this way it is not bid as an option.
    In the end it is a win-win situation for all.
    Have you set up a Google alert for Carbon Monoxide yet?
    Click here to find out how.

  12. #51
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    Apr 2004
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    Originally posted by reddog4
    ...I was wondering if any contractor here or anywhere guarantees that the eqipment that they install will perform and deliver the heating and cooling btu's and efficiency within 10% of the equipment rating plate? If not can I hold back payment until this is accomplished?
    Ok, maybe I misunderstood. It looked to me as though you were insisting on efficiency proof. And yes, if you are replacing a substandard system (and by system I am referring primarily to the distribution system) and replace it all in an effort to overcome the poor performance, the added performance can cost ultimately in utility bills because it would be doing more work. The right amount but more none the less.

    Take for instance a cape cod that has a second floor that stays 8 degrees warmer in summer than the main floor. This is a ducting issue. If contractorX comes in, improves the ductwork to overcome the difference. I would expect the coling bill to increase because of the added btuh's required to satisfy that additonal load. Sure you could increase efficiency but in some cases not enough to overcome that gap resulting in higher bills.

    How about installing a properly sized system in replacement of an oversized unit that satisified the sensible load quickly but didnt do any latent work? ContractorX installs a system for comfort resulting in proper run times?

    You did indeed want to hold back payment based on performance and efficiency. Hey, if it doesnt work or the actual output of the machine is that far off, I wouldnt pay either frankly but thats a performance issue, not an efficiency issue. The Efficiency of the furnace is simple enough to prove and that can be documented. But again, if the amount of heat needed to overcome cold spots or rooms is higher than the difference in combustion efficiency your bill can also go up.

    In all these cases, the comfort level is increased significantly and as stated, the capacity is simple to document. The load calculation and balancing are easy to document and simple to compare to the design. The output Btuh's is also easy to document. Any competent contractor can and should give you this data. Combustion efficency can be also proven simple enough but SEER cannot. The problem is that if the bill doesnt drop by X%, you will likely make the claim you are getting ripped off.

    If, on the other hand your exsisitng system is well desinged, then I would have no problem showing the energy savings.

    [Edited by docholiday on 05-28-2005 at 10:17 AM]

  13. #52
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    Nov 2004
    Location
    SW FL
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    Re: Re: Measures

    [QUOTE]Originally posted by davidr
    If I told you 100% of our customers took this opportunity I would be lying, but the majority of retrofits we do this is incorporated into the proposal along with educating the customer as to why it is needed.

    In New construction all installs are figured this way it is not bid as an option.
    ...
    .... the Man-Hours to perform testing and documentation
    on 3 systems with 40 diffusers and 8 returns would be ___
    ( Typical residence for me).

    ... ( speculate ? )
    ___ % of builders in ____ ( ? your area) would select this IF Bid as an option on new construction.

    I appreciate a COMPLETE Install / Test but
    Would even the Florida ' Quality ' builders elect to pay?
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

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