Results 1 to 11 of 11
  1. #1
    Join Date
    Jul 2007
    Posts
    5

    About Old Heat Reocvery line

    My contractor says that he will NOT reconnect heat recovery line (from a 15 year old unit) while he is replacing this to a newer 14 seer veriable speed carrier (model 24abr348a003
    and fk4dnf005000).

    Reason he states that, with newer systems like this, heat recovery line is not of much advantage and doesn't save in electricity cost.

    Is he right? or he just cutting corners?

    Please answer as soon as possible as I've not signed the contract yet.

    Thanks.

  2. #2
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,736
    was it something used to heat water??


    i would not hook up ANYTHING 15 yrs old into the refrigeration system of one of my installs.

  3. #3
    Join Date
    Jul 2007
    Posts
    5

    Yes.

    It probably is supposed to save energy by re-using heat in AC to get warm water.

    I wonder this will take away some of energy consumption benefit of installing new AC?

    Though I live in South Florida, but we still use warm water.

  4. #4
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,736
    i have heard of them but in 30 yrs have never seen one.

    energy saved would not be worth the risk of contaminating new system in my opinion.

    could also cause problems in operation of new system as refrigerant charges are more critical on the higher efficiency units.

  5. #5
    Join Date
    Feb 2006
    Location
    FL
    Posts
    565
    I dont like them either. We don't hook them back up and that requires opening up and cutting into a perfectly good system. Is your water heater the same age, if so maybe best to upgrade that.

  6. #6
    Join Date
    Jan 2002
    Location
    Ft.Worth,Tx
    Posts
    4,584

    Thumbs down Don't recommend it>

    Quote Originally Posted by sipak View Post
    My contractor says that he will NOT reconnect heat recovery line (from a 15 year old unit) while he is replacing this to a newer 14 seer veriable speed carrier (model 24abr348a003
    and fk4dnf005000).

    Reason he states that, with newer systems like this, heat recovery line is not of much advantage and doesn't save in electricity cost.

    Is he right? or he just cutting corners?

    Please answer as soon as possible as I've not signed the contract yet.

    Thanks.
    The older heat recovery systems used lines that were piped inside other line -set and to DWH with pump on recovery unit either outside or next to DWH tank. I installed a few of them in 1975-1980 on Coleman Heat Pumps and they worked ok. But, I don't know if I would use the same line set if it was that old on new Carrier with Puron which has high operating pressures.
    "Everyday above ground, is a good day".
    "But everyday that you have made a difference in someones life, may insure you stay above ground a little longer".<aircooled>

  7. #7
    Join Date
    Jul 2007
    Posts
    5

    What is your recomendation?

    Can old heat recovery line be reconnected with new Trane 14 seers with R410A?

    How you can confirm that your contractor is really using R410 with Trane?

  8. #8
    Join Date
    May 2004
    Location
    Austin, TX
    Posts
    1,733
    I would not use one of the old heat recovery systems with any new a/c
    systems above 10seer. I have disconnected so many of them. They
    did not work that good anyway.

    To find out if a 410a system is being used, just check the mfg., labels
    on the new equipment and make sure it lists 410a. Check labels before
    equipment is set in place.

  9. #9
    Join Date
    Jun 2007
    Location
    Round Rock
    Posts
    3,548
    Carrier will void the warranty if they find one of those things hooked up to their units. Chances are they will never find out, but there is always the chance of you using another service company for whatever reason or if you ever have serious issues with your system that require extensive work and warranties are involved, they might send a rep out. Far fetched, but stranger things have happened. We only hook them back up for extra $$$ on top of unit replacement. We recommend against it, but its your buck.

  10. #10
    Join Date
    Nov 2005
    Posts
    1,350
    Quote Originally Posted by sipak View Post
    Can old heat recovery line be reconnected with new Trane 14 seers with R410A?

    How you can confirm that your contractor is really using R410 with Trane?
    If the gear is already installed, look for big pink stickers on the indoor coil and on the outdoor unit by the service ports.
    I STARTED WITH NOTHING, AND I STILL HAVE MOST OF IT!

  11. #11
    Join Date
    Nov 2004
    Location
    Naples, Fla.
    Posts
    1,403

    1/2 right

    1st you should understand that heat recovery is very old school technology - very PROVEN technology - very stable technology

    Your contractor was only 1/2 right in NOT hooking up your old heat recovery.

    He was correct in not hooking it up because the OLD HRU's (heat recovery units) won't handle the higher pressures of the new refrigerants.

    He was very wrong in that it won't save you $. *****

    There is a gross misconception that newer units won't work or won't heat hot water. They are misinformed. It is very true that older units w/ recip compressors did heat water better (heat of compression) but bottom line - HEAT IS HEAT, if you are rejecting 36,000 BTU from the home - put it in your water heater.

    **** the new refrigerants require a heavy duty wall strength, and cost is slightly higher

    **** good contractors are correct in declining to hook up old HRU's - they are not trustworthy and can be a source of contamination.


    For the record, manufactures look for any reason to bail on warranty IE: installation of a HRU... particularly if it's not lining their pockets.. you can bet if they SOLD one with that was branded - that would get the thumbs up.

    Obviously the longer your running hours (the further south you are) the more ROI. Also the larger your family - the quicker your ROI.


    Florida Power is contemplating bringing BACK the HRU rebate in 2008



    I've attached a reprint from USF & FPL


    Water Heating and Heat Recovery1
    Florida Power Corporation2
    ENERGY-EFFICIENT WATER HEATING: IT'S THE EASIEST WAY TO SAVE ENERGY DOLLARS
    Anywhere from 10% to 25% of the money you spend on home energy each year is consumed by your water heater.
    Seem high? Not when you think about all the uses you have for hot water. Taking showers and baths, washing clothes and dishes, shaving, preparing food and just general cleaning - it all adds up.
    The good news is, it's easy to save money through efficient water heating. And you can begin saving energy - and money - almost immediately. The following suggestions will help you save energy dollars - month after month.

    PART 2: HEAT RECOVERY UNITS
    Heat Recovery Units Turn Hot Air Into Hot Water
    Your air conditioner or heat pump works hard during hot weather. It pulls heat out of the air inside your home and discharges it into the air outside your home Meanwhile, your water heater is toiling away generating heat for your showers, dishwashing and laundry. Why not recover some of that unused heat energy discharged by your air conditioner or heat pump and use it to heat your water? That's exactly what a heat recovery unit does.
    How Does a Heat Recovery Unit Work?
    This simple device was developed by the people at Florida Power as an economical, energy- efficient means of heating water.
    The heat recovery unit is installed in the hot line of your air conditioner or heat pump's refrigerant circuit. The hot vapor flows through a heat exchanger. The heat from the vapor is then absorbed by the water, which is circulated through the heat exchanger by a small pump. This gives you inexpensive hot water. Controls keep everything operating properly.
    In the summer, the heat recovery unit captures some of the heat discharged by your air conditioner, essentially giving you free hot water. You can even turn your regular water heater off - just remember to turn it back on when you're not using your air-conditioner. If the heat recovery unit is installed on a heat pump, low-cost heating for your water during the winter months is also possible.
    How Much Does It Cost?
    It varies according to individual installation requirements. Purchase and installation costs usually range from $2600 (new construction) to $4550. But, since the heat recovery unit could cut your water heating bills in half, it could pay for itself in approximately five –ten years.
    How Much Will I Save?
    Using a heat recovery unit, an average family can save up to 50% on water heating costs annually. The amount of energy and money your family saves will depend on factors such as: the size of your family, your water use habits and your air conditioning usage. Table 1 can help you estimate the annual savings you can expect with a heat recovery unit.
    What's The Best Unit To Buy?
    Look for a heat recovery unit with temperature and modulation controls. These features control the temperature and flow of water through the heat recovery unit into your water tank. Also, to minimize heat loss, select the smallest water lines possible for the recovery unit (preferably 3/8" diameter). And keep in mind that the closer your water heater is to your air conditioner or heat pump, the better. A distance of fifty feet or less is best for keeping heat loss to a minimum.
    Who Installs Heat Recovery Units?
    Call a qualified air conditioning contractor for information on how to have a heat recovery unit installed in your home. The unit should be installed according to instructions and recommendations from your heat pump or air conditioning manufacturer.
    Also, check to see if installation of a heat recovery unit will affect the warranty terms of your cooling system. A properly installed heat recovery unit will not adversely affect the operation of your heat pump or air conditioner.
    Remember, whether you're building a new home or trying to reduce energy costs in your present home, a heat recovery unit can be a very practical investment.
    Careful Energy Consumption Always Brings You Savings
    Electric energy contributes greatly to the high quality of life found in Florida. Use it to your best advantage. This brochure offers lots of proven methods for increasing energy efficiency and stretching energy dollars. If you have additional questions, please call your nearest Florida Power office. We're always available to help you get the most out of electric energy.
    NUMBER OF PERSONS HOT WATER USAGE
    Low Medium High
    1 $ 52 $ 58 $ 64
    2 77 86 95
    3 104 115 127
    4 130 144 159
    5 156 173 190
    Footnotes
    1. This document is PID 113 (488), from the Florida Power Corporation.
    2. Florida Power Corporation, General Office: 3201 Thirty-fourth Street South, P.O. Box 14042, St. Petersburg, Florida 33733, (813) 866-5151.

    The Institute of Food and Agricultural Sciences (IFAS) is an Equal Employment Opportunity - Affirmative Action Employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences / University of Florida / Larry R. Arrington, Interim Dean Copyright Information

    This document is copyrighted by the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all conventions, but permits free reproduction by all agents and offices of the Cooperative Extension Service and the people of the State of Florida. Permission is granted to others to use these materials in part or in full for educational purposes, provided that full credit is given to the UF/IFAS, citing the publication, its source, and date of publication.

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