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Intellihot?

dlud
dlud Member Posts: 6
Warning: Muli question post.
#1 FNG here, so thank you all for your input ahead of time.

#2: Anyone here have any experience with Intellihot combi boilers?
Background:
I have a very ancient gas boiler heating my 2000sqft home with baseboard hot water radiators. Currently its vented through the chimney, i would like to replace it with a direct vent unit out the side of the house so i can demo and roof over the chimney. Im in the Denver area, so cold winters and warm summers. I would like a combination boiler-DHW as either tankless or boiler with indirect. Im not married to high efficiency but rather durable, cost effective, and does what it should - provide hot water when needed. Would not want to worry about showering during laundry, etc.

So far Ive got bids for Navien ncb-210 and Intellihot combi (both tankless obviously). Although I like the advertised efficiency of a mod-con Im a little worried about the practicality of tankless. That said the Navien bid includes a buffer tank. I like that both units are "smart" and performance can be monitored with a smartphone app. Navien reviews across the web seem to be poor. Very little information about Intellihot, but the contractor speaks highly of his home unit.

#3: Should I consider a different setup? Boiler w/indirect DHW heat? If so, suggested brand/model?

Thanks!

Comments

  • Zman
    Zman Member Posts: 7,611
    I like the boiler with indirect. It is much easier to match the loads and optimize efficiency.
    Have you performed a heat loss? What are your DHW needs.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    dlud
  • dlud
    dlud Member Posts: 6
    I have performed a heat loss using a basic calculator from US Boiler. For a 80 deg temp diff (assuming the very coldest night of -10F and 70F inside temp) my heat loss is 140,072 BTU. DHW needs are fairly minimal. We have 2.5 baths. It would be nice to take 2 showers simultaneously and not worry about someone turning on the washing machine or something in the middle. Normally the max draw would be one shower and hot water from another faucet (just two of us for now but we have family stay regularly).

    For those that recommend indirect, what kind of boiler is best suited for that setup? What size buffer tank?

    Thanks!
  • Jack
    Jack Member Posts: 1,049
    140k for 2000 sq ft?
    Canucker
  • dlud
    dlud Member Posts: 6
    edited June 2017
    Yeah. Is that a lot or a little?
    I tried another basic heat loss calculator (supplyhouse.com), and that came up with 127k. House is actually 2570 sqft according to my plat survey. Double pane windows, we had r40 insulation put in the attic, but everything else is low insulation 50s construction, especially walls.
  • KC_Jones
    KC_Jones Member Posts: 5,840
    supplyhouse doesn't have a heat loss calculator...well not a proper one. You need to do a room by room heat loss, there is no way given what you said that your heat loss is that high. The numbers you are getting are higher than my house with 1900 construction single pane windows and no insulation.

    If I had to take a WAG I would say you are half or less than the numbers you are quoting.

    Slant fin has a decent heat loss program, you should try that one.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • intellitech
    intellitech Member Posts: 3
    I am lead tech support for Intellihot. 1500-2000 sq ft house is perfect for our i251x
  • dlud
    dlud Member Posts: 6

    I am lead tech support for Intellihot. 1500-2000 sq ft house is perfect for our i251x

    So for 2560 sqft, the i251x would be a bit under powered, correct?
  • dlud
    dlud Member Posts: 6
    KC_Jones said:

    supplyhouse doesn't have a heat loss calculator...well not a proper one. You need to do a room by room heat loss, there is no way given what you said that your heat loss is that high. The numbers you are getting are higher than my house with 1900 construction single pane windows and no insulation.

    If I had to take a WAG I would say you are half or less than the numbers you are quoting.

    Slant fin has a decent heat loss program, you should try that one.

    Thanks. Being new to this I have no idea whats high or low. The slan fin program looks pretty thorough. I might have to wait for the weekend to dive into that.
  • Canucker
    Canucker Member Posts: 722
    Your current heat loss calculation works out to 54 btuh per sq ft. That seems really high unless you don't have doors and windows installed. ;)
    You can have it good, fast or cheap. Pick two
    kcopp
  • kcopp
    kcopp Member Posts: 4,472

    I am lead tech support for Intellihot. 1500-2000 sq ft house is perfect for our i251x

    I am curious about what the heat exchanger design is on the Intellihot....
  • dlud
    dlud Member Posts: 6
    Canucker said:

    Your current heat loss calculation works out to 54 btuh per sq ft. That seems really high unless you don't have doors and windows installed. ;)

    As others pointed out, the heat loss calculator i used is not reliable. I'd still be interested to hear from anyone thats had and used an intellihot system.
  • bob eck
    bob eck Member Posts: 930
    Take a look at the Lochinvar Noble combi boiler with SS fire tube heat exchanger. Three sizes with 199,000 BTU input the largest and it delivers 4.8 GPM domestic hot water at a 70 deg temp rise. If you install two good 1.5 GPM shower heads you will be able to take two showers at one time. On the heating side of this boiler once you determine the correct heat loss you can reduce the heating BTU input and the boiler will still go to 199,000 BTU input for the domestic hot water needs.
    Check this boiler out at the Lochinvar web site.