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  1. #1

    What size HP will work for me - general opinions

    As mentioned in another thread I am thinking about converting from my current oil fired boiler using basboard rads over to a HP solution. I originally started out looking for a solution to keep my existing system rads and use a air to water HP with my current boiler as back-up however I cannot find any local contractor in my location that seems to know of a system that will work well. Some say it just wont work, some say it might if I change all my rads to LT. This uncertainty is making me doubt wheather or not I am going down the right road with this conversion. Also, I have come to realize that changing the rads is going to be just as much trouble as running all new ductwork and going with a air to air HP.

    So based on the below what size ATA HP and accessories will I need to heat my home . Our house is 10 years old and is built well. It is 3600 sq ft (1800 1st level & 1800 in basement), walls insulated with regular bat insulation, attic blown in with R40 (to be topped up soon after 10 years settling). Basement finished with 2" high density foam on the outside with framed walls inside insulated with regular insulation as well. Windows are Jeld Wen single hung, not sure about the doors but they are of good quality.

    My location is Newfoundland Canada and in this area winter temps usually hover around 0 deg C but sometimes drop to as cold as -10 deg C......but this is rare. Inside temps we usually like to be around 22 deg C in main living spaces with it a little cooler in the bedrooms.

    I know it is recommended to get a heat load calc done but in my area this is pretty much unheard of. All I am lookinf for hear is as much information as I can get to educate myself so i know if a contractor is promoting a solution that will work. This is going to be a huge investment for us so I want a system that will work at a reasonable price. The current system I have works but it is expensive to run and heating oil seems to be going nowhere but up.

    Also, i would like recommendations on brands as well. The contractors around my area seem to promote Mitsubishi however I hear Diakin are good as well. I have done some reading on the Mitsubishi Zuba but it only comes in 3 tonne, i think it will be too small......thoughts.

    Anyway, sorry for being long winded but I am looking for some expert advise and it seems this forum has it.

    Thanks

  2. #2
    Join Date
    Jan 2004
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    Lancaster PA
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    Use the below to do your own load calc.

    http://www.hvaccomputer.com/gtarget1...FQ7NnAod6CcALw
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    How many times must one fix something before it is fixed?

  3. #3
    Quote Originally Posted by beenthere View Post
    Use the below to do your own load calc.

    http://www.hvaccomputer.com/gtarget1...FQ7NnAod6CcALw
    Software looks good however the trial dont generate many reports, guess they want money first. Wish i would have know this before taking an hour to enter all my data.

  4. #4
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    Sorry. But its worth the 49 bucks, to know what size you need, so you don't buy larger more expensive equipment then you need. Along with pay more for large duct work.
    Contractor locator map

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    How many times must one fix something before it is fixed?

  5. #5
    Quote Originally Posted by beenthere View Post
    Sorry. But its worth the 49 bucks, to know what size you need, so you don't buy larger more expensive equipment then you need. Along with pay more for large duct work.
    I'm sure it is worth the money but I have a contractor coming in a week, said he was going to do load calc so i will wait to see what he says first. If he seems amature I will do my own. Thanks for the link, like I said it looks really good and easy to use.

  6. #6
    The more i look at my basement the more I think that ductwork is just not going to work. Maybe it will have to be a ductless HP system. Do anyone have experience with the Mitsubishi S series ductless. It states it can have up to eight indoor units, that is appealing. The Mr slim has a max of 4 indoor units but I would like more.

  7. #7
    Join Date
    Nov 2006
    Location
    Athens, Ohio
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    1,694
    Mitsubishi makes a great heat pump. The M series multi-zone can have up to 8 heads but you may want to consider 2 4-head multis depending on lineset lengths and location of outdoor units. The multi-zone has very high efficiency - even better than a ducted system. Add to that the zoning and de-humidification and it is hard to beat.

  8. #8
    Join Date
    Jan 2004
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    Lancaster PA
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    Quote Originally Posted by Newfiestang50 View Post
    I'm sure it is worth the money but I have a contractor coming in a week, said he was going to do load calc so i will wait to see what he says first. If he seems amature I will do my own. Thanks for the link, like I said it looks really good and easy to use.
    Most contractors that will do a load calc won't give you a copy of the load calc, unless you pay them for it. many other say they will do one, but don't.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  9. #9
    Join Date
    Nov 2004
    Location
    SW FL
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    6,240

    Thumbs up Heat Loss Estimate

    Quote Originally Posted by Newfiestang50 View Post
    I'm sure it is worth the money
    but I have a contractor coming in a week, said he was going to do load calc so i will wait to see what he says first.
    If he seems amateur I will do my own.
    Thanks for the link, like I said it looks really good and easy to use.
    Heat Loss Estimate = 36,000 BTU/Hr at 7'F / -13'C
    in my opinion (basic calc) based on info you provided.

    See attached Balance Point Chart
    applicable to CARRIER GREENSPEED 3-ton or equal

    C.O.P. =~ 2.4 at 7'F / -14'C
    Attached Images Attached Images
    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. #10
    Quote Originally Posted by dan sw fl View Post
    Heat Loss Estimate = 36,000 BTU/Hr at 7'F / -13'C
    in my opinion (basic calc) based on info you provided.

    See attached Balance Point Chart
    applicable to CARRIER GREENSPEED 3-ton or equal

    C.O.P. =~ 2.4 at 7'F / -14'C
    Thanks Dan. Just wondering, is a basement included in your calc?

  11. #11
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,240

    Load Estimate - First floor and Basement

    Quote Originally Posted by Newfiestang50 View Post
    Thanks Dan. Just wondering, is a basement included in your calc?
    Yes.

    It is quite difficult to -envision- all your parameters, but
    knowing 1,800 Sq. Ft, 10 year old and location,
    I would guess 39,000 BTU/Hr total heat loss with ~1/3 for basement.

    Total window area and U-value was not provided,
    so 216 Square foot and 0.48 were used based on
    frequently encountered in Northern U.S.

    Infiltration should be < 0.5 air change per hour (A.C.H.) for 10-year old residence.
    Leaky ducts? _ Duct pressure test is now required in many states.

    Heat loss for ceiling and walls are known with fairly well defined degree of accuracy.

    See new attached file for calculation and details.
    Attached Images Attached Images
    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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