Manual J software.

Discussion in 'General Discussions' started by Kogashuko, Mar 18, 2013.

  1. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Design is what it is all about. I have used that program for 20 years and never had an un-happy customer. Coupled with Bell & Gossett's system sizer and Burnham's Hydronic Helper I go anywhere and design heating and cooling system using water instead of duct work.

    I got started in this with the help of and it's owner Dan H.

    I am surprised you did not ask for the load fudge. It may depend on what version you found.

    Last edited: Mar 21, 2013
  2. TowPro

    TowPro Member

    I thought about it, but I didn't want to push my luck about those type secrets :) since I am just the DIY guy around here; just soaking up knowledge :).
    Even if it has no fudge factor the results are right in the ball park for me and the 2 ton 30 digital I am planning on installing.
    I still have a balance point before AUX comes into play at around 9-11 deg
    Its Hydronic Explorer version 2.
    None of the links for "check for updates" work so I think its an older version.
  3. I didn't go back over the entire thread to find out where you are, but we have a home in NoHIo that has "super insulation" spray foam, that didn't need any back up (aux) heat this winter.

    BTW, it's a cold partition. When we take the time to explain, please give the jargon back correctly.
  4. Kogashuko

    Kogashuko Member

    I wish I could afford to do the water instead of ductwork option. Unfortunately, everywhere I have looked has air handlers for at least a grand on top of the four grand for the water to water heat pump. I would just go radiant only if it wasnt for the damn warm season here. I suspect that even with dehumidification a chilled floor would get condensation. Good news is my house is already setup for forced air and I have done several improvements on it over the last couple of years.

    Ran geodesigner tonight and got my new loop length. Mark I looked at your pex loop posts from a few years back and I think I might use pex for the loops. I am also going to still consider a design that can use the well also.

    If I spelled partition wrong I am sorry, I always misspell stuff and my smart phone auto predict doesnt help.
    Last edited: Mar 22, 2013
  5. It wasn't the spelling, but the definition. Yes you will need cooling and ductwork. You can put a chilled water coil into an air handler and use the wwhp to cool.
  6. Kogashuko

    Kogashuko Member

    After playing with the software for the last two weeks this is exactly what I am going to do. Making a few changes here and there drastically changes heat loss and gain. With making a few simple and inexpensive changes I think I can quite easily make the envelope tighter and work the whole house on the existing air source system. I talked with the wife and she agrees that it makes sense to completely finish envelope improvements before sizing the HVAC system.

    I am going to not only cellulose the addition but invest in one of those spray foam kits to do a "flash and batt" type setup with a inch of closed cell for air/moisture sealing followed by 8 inches of cellulose in the walls. I am also going to install foil faced rigid foam under the roof trusses (to allow for the air to flow behind the roof from the soffit to the ridge vent) and seal all the cracks with spray foam. Yes the foam is going to be a bit more expensive but it should make things drastically better. I am also going to do the existing attic in a similar manner where all my second floor duct work is.

    As for the existing house I have to rip up carpet in 3 rooms on the second floor and install the bamboo that I have just sitting right now. I am considering, depending on how well I can do drywall in the addition, banging out the couple of exterior walls and adding about an inch of foam as an air barrier with a minimum of R15 insulation on top.

    If I can get the existing system to work properly I can probably go with a 3 ton water source unit and drastically reduce the loop field size compared to a 5 ton. I think I can save the amount of money invested in the envelope improvements just in rental time of excavation equipment. I will also have the advantage of having the thing sized right after the envelope improvements and vice versa. Worst case scenario I have to cool the addition with a window unit until I put in the geo unit.

    I have already begun documenting the whole project right wrong or indifferent with video that I want to post on youtube when done.
  7. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    If we go to help Geochallenged we will stop by and take a look.

  8. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Consider hiring a pro for the "flash" - Yield from professional spray rigs is said to be much higher than DIY kits and you can skip the learning curve and Hazmat perils of two part sprayfoam

    Consider investing in fog or infrared testing of the foam to insure it is as airtight as possible.

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