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jen11k

Advice on new construciton (x post)

jen11k
10 years ago

Hi - Our architect did not specify heating and cooling on the plans for tight budget 5500sf new const in NJ. one hvac bid i'm looking at is for 4 zone forced hot+a/c not including basement (full).
I want to price out some selective radiant or hydronic forced air but it's hard to compared mechanicals and cost. plumbing # goes up and hvac # goes down? what would you rec i do is the best way to explore my options?
Radiant is top on my list for any extra spending on the house but now i see i should maybe look at increasing the standard insulation r-19 walls we are spec'd. that is not costly right?

Comments (10)

  • mike_home
    10 years ago

    Does the 5500 sq. feet include the basement? If it does how much are the first and second floor areas?

    Do you have access to natural gas?

    The walls would have to be 2X6 framing in order to achieve R-19 insulation. This is fine for the NJ winters. I would put the money into better windows.

    Do you know what equipment your are getting? Has a load calculation been done?

  • jen11k
    Original Author
    10 years ago

    mike it does not include the basement. the first floor is 2850 and second floor is 2600sf. yes we heat using gas. we are looking at pella or anderson 400 windows.

    i don't have it with me but the bid that the gc gave us shows trane systems that think handle both heat/cooling. it shows details of tonnage, but should i ask for load calculations and check them? do they typically share this?

    if i want hydronic air, the hvac guys will only handle a/c?

  • mike_home
    10 years ago

    You want model numbers and sizes of all equipment. Get a copy of the load calculation and review it for obvious errors.

    My suggestion is to have a furnace and AC condenser for each floor. Each floor could then be split into two zones.

    I am not familiar with hydronic air systems? What is your interest in this type of system?

  • fsq4cw
    10 years ago

    I would suggest an all hydronic system for low water temperature in-floor radiant and hydronic cooling coupled to a geothermal Liquid-to-Water heat pump with a gas boiler backup. This configuration would ensure maximum comfort, lowest operating & maintenance cost, and longest life cycle. It can also be easily backed up in heating mode with a modest gas powered generator.

    DonâÂÂt over look an HRV for IAQ and fresh air exchange!

    Do not under estimate the operational, maintenance and life cycle costs of your HVAC system. This configuration will ALWAYS ensure the lowest cost regardless of where the cost of energy goes, which we know will be significantly higher in 10-years - or less. Your home will be large; so will your heating and cooling costs.

    Hire mechanical contractors that are experienced with these technologies as they relate to energy efficiency and advanced controls. YouâÂÂll be glad you did.

    IMPO

    SR

  • mike_home
    10 years ago

    fsq4cw,

    The OP is paying NJ gas and electric rates. What you are proposing is likely to cost more for heating. For cooling it will may cost a little less, but he is investing in above average insulation. The extra costs in geothermal will have a long pay back.

    I would be very interested in seeing all the numbers for a house in NJ.

  • PRO
    CJ Mechanical of North jersey llc.
    10 years ago

    Hi Jenn,
    I recommend that you get a few more Quotes.Radiant floor can be very exspensive to install And adding hydronic to a forced air cooling system is not complicated. Just add a water coil to the duct system and run the plumbing. They MUST have a manual J load calculation for the house. Do not procede with any co. with out them providing you with one. My co. is in Morris co. NJ if you want to discuss. CJ Mechanical of north jersey. cjmechanicalhvac.com

  • fsq4cw
    10 years ago

    Re: Mike_Home

    Irrespective of whatever the electric or gas rates may be now or in the future, the system I proposed will have the lowest operating cost, probably by far, for the foreseeable future unless the OP chooses to go âÂÂOff GridâÂÂ!

    Just to be clear, the geothermal heat pump would both heat and cool hydronically with the gas backup to simultaneously heat when required. Geothermal with a COP of about 4 and gas with an efficiency of about 95%, all designed around low temperature water (heating mode).

    I donâÂÂt see how that can be beat.

    If IâÂÂve forgotten something please let me know.

    IMPO

    SR

  • mike_home
    10 years ago

    Re: fswq4cw,

    There is no argument about how efficiently a geothermal heat pump can heat and cool a residential home. I only question the economics versus a conventional gas furnace and AC condenser.

    The labor to install a horizontal or vertical loop in NJ is very expensive. In addition the typical prices for electricity is 18 cents per KWH and 85 cents per therm for natural gas. The geothermal heat pump will save some money on cooling costs, and less on heating. I don't think the annual savings will not be enough to offset the higher initial installation costs, but I would still like to see a spreadsheet with all the numbers before coming to that conclusion. Show me the numbers and I can be converted!.

  • fsq4cw
    10 years ago

    The OP will have to crunch his own numbers to determine what they would like to do. My contention is that what I have proposed will be the least expensive way to space condition using active methods with the possible exception of perhaps going âÂÂOff GridâÂÂ.

    No question this would be the most expensive up front. Geothermal is almost always very expensive to do up front - anywhere, everywhere. The larger the house the faster the payback, 5500sf not including the basement is a pretty big house. IâÂÂd spend $100k or even more on the HVAC & DHW system in house this size but itâÂÂs not my house and itâÂÂs not my moneyâ¦


    IMPO

    SR

  • bakerboy63
    10 years ago

    For a "tight budget" 5,500 sqft house, I would not recommend geothermal, that would not be on a tight budget home, IMHO. Living in NJ myself, I am not sure why that size home would be built on a budget. How about a very well built and appointed home at 4,000sqft? My 2 cents

    If you are on a tight budget it's forced air heat with AC. If you want to go hydronic, it is 2x min of that. If you want to go radiant it is 3x of that or more.

    I know, I am doing it now in a Reno.