Replies

1. 
   bigman | Feb 14, 2005 03:32am | #1

   ????? Rufus my  house is  2-1/2 years old, well insulated with wet blown cellulose in 2x6 walls, 3200 sq ft, with a mix of hydro-air(1/4) of house,  baseboard radiant (1/4) and radiant (1/2) the house. My heating bill from 10/7/03-10/25/04 was $1474.00 with LP Gas!!! monthly average off $122.00. And Rufus, I live in SE Conn, a cold-climate as far as heating days go. Oh yeah I forgot I also heat my water with the same setup using a Weil-Mclain GV4 HE Furnace.

   
   

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   Edited 2/13/2005 7:37 pm ET by BigMan

1. 
   badarse | Feb 14, 2005 07:41am | #2

   Thanks for the reply.. Doesn't sound too bad considering I live in a much warmer climate. What do you mean by hydro/air??

1. 
   bigman | Feb 14, 2005 04:44pm | #5

   Sorry, Hydro-air is using an airhandler for heating and cooling, the heating part is done with a hot water coil fed from a gas/oil fired boiler. It gives you the advantage of locating your airhandler without worrying about venting the exhaust gases.

2. 
   caseyr | Feb 14, 2005 08:47am | #3

   Unless you live in Yellowstone, Geyser, CA, or similar local over a pool of magma, I am guessing that the term "ground source" is closer to what you want to install than "geothermal".  There is a lot of info out there.  The following should get you started:

   http://hem.dis.anl.gov/eehem/96/961112.html

   http://hem.dis.anl.gov/eehem/94/940703.html

   http://www.igshpa.okstate.edu/

   http://www.eere.energy.gov/femp/technologies/eep_groundsource_heatpumps.cfm

1. 
   RBean | Feb 14, 2005 11:01am | #4

   The most perfectly efficient mechanical system is the one which never runs...which then means there is nothing efficient about a heating system - Any heating system. Zero. Zip. Notta.

   Real efficiency comes from reducing or eliminating the load and that begins with the building.  So if anyone hears about radiant systems consuming horrendous amount of energy it’s because the building it is trying to heat is inefficient and in most cases it’s because the slab was not insulated or the perimeter / header joist leak like a sieve. 

   As we say in the business - heat in - heat out...

   If a lot heat goes out - you have to put a lot of heat in.

    

    

    RBean

   http://www.healthyheating.com

   http://www.healthyheating.com/blog

    

    

1. 
   CloudHidden | Feb 14, 2005 05:26pm | #6

   I agree. Gotta check the loads and understand why they are what they are. Whether rfh or forced air or radiators or baseboard, you're just putting back btus being lost by the house. The form of heat delivery is more a matter of comfort and capital cost than anything else. The form of heat production--ground source (geothermal), air-to-air heat pump, electric boiler, gas boiler--is a function of local fuel prices and capital cost. Personally I like warm floors...went there and don't ever wanna go back. And personally I like my ground source heat pump be/c I didn't want a gas tank by the house and I already had a dead 800' well hole. But the choices for heat production and heat delivery throughout the house are largely separate choices made for their own reasons. It all starts with understanding your heat loads and utility costs in the area.

1. 
   DaveRicheson | Feb 15, 2005 07:44pm | #7

   Excellent post Cloud.

   RHF can be couple to a ground source heat pump. A good HVAC contractor should be able to do his load calculations and then offer systems installation cost and operations based on you list of choices.

    

   Dave

2. 
   timkline | Feb 15, 2005 10:51pm | #8

   not too familiar with ground source systems running on radiant.

   what kind of water temperatures do you run on a system like this ?

    carpenter in transition

1. 
   CloudHidden | Feb 15, 2005 10:54pm | #10

   The temp will depend on the house design, including things like floor coverings, zoning, etc. In our case, the set point for the GSHP is 105. We don't need high temps, for a variety of reasons. A GSHP will definitely not produce the temps that a boiler will.

2. 
   JohnT8 | Feb 15, 2005 10:52pm | #9

   Good links, Casey.  I realize there is a specific group of systems that make use of volcanic/etc heat, but around there geothermal/ground-source are interchangeable terms.

   Rufus, geothermal/ground-source is an excellent choice.  But as several people have mentioned, the final bill is going to depend much more on loads/insulation.

   I believe there is a combo hyrdo/air geothermal unit that can run either a radiant floor, or in summer an ac unit.  They can also ad a de-superheater that will utilize the heat removed in summer to heat your domestic hot water.jt8

   The reason so many people never get anywhere in life is because when opportunity knocks, they are out in the backyard looking for four-leaf clovers.    -- Walter Percy Chrysler

3. 
   djohan | Feb 16, 2005 12:37am | #11

   very good article in the Journal of Light Construction which came out early this month.  Good info on efficiency.