Heating system upgrade.

Discussion in 'HVAC Heating & Cooling' started by monz78, Jul 14, 2008.

  1. monz78

    monz78 New Member

    Jul 14, 2008
    I have a 1404 square foot home I currently heat with a forced hot air system with central air. Over the last few years I have spent so much on repairs I could have replaced the furnace already.
    So now is the time I need to up grade everything. I have had severaly contractors here and have gotten prices from $8500 to $15,000.
    The current system has flexable ducts connected to a big metal box in the center of the attic. The duct sizes are 6". I know this is not big enough for the central air part. Some of the guys said those ducts are fine. Then a few said they all need to be replaced.
    Now what I am looking at is a hybreed heat pump with propane backup.
    My current system runs on Keroseen. I have a 27x30 garage in the backyard with a 500 gallon propane tank so I can run the house off the same tank.

    So I guess my question is, is the heat pump hybreed the best way to go? And if so should it be propane or electric strips for the backup part.
    Currently electric is .12902 and propane is $3.79 a gallon but I have been told it will be around $5.00 a gallon by winter.

    So far I believe the best deal offered was by Sears. They priced out a hybreed with propane backup with all new ductwork. Using the formed fiberglass ductwork. There price was $12,000.
    Not the cheapest, but I always seem to get bad workmen ship when I go with the cheapest price.

    Now secondly in my garage I have radiant in floor heat. The hot water comes from a 60 gallon propane hot water heater. I'm also looking to save money here. Last year it cost me over $2000 to heat the garage.
    I have been told to change over to a Seisco SH-14 Electric Micro Boiler.
    Do you think it would be cheaper with this unit?
  2. Bob NH

    Bob NH In the Trades

    Oct 20, 2005
    New Hampshire
    If you have radiant floor heat in your garage you are probably using a lot of energy to heat the ground.

    I would abandon the radiant floor heat and connect the existing water heater to a hot-water unit heater, or put a through-wall vent or no-vent propane heater in the garage. Then operate the garage at a very low temperature (maybe just above freezing).

    An electric micro-boiler supplying the radiant floor heat would probably be the worst possible solution from a cost point of view. If you are going to use electricity for heat, just use an electric unit-heater or leave a lot of lights on.
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  4. jimbo

    jimbo Plumber

    Aug 31, 2004
    San Diego, CA
    If you live in a climate where you have to heat the garage! I don't suspect that a heat pump is a good idea. Typically, they stop working around 30º and you have to switch to backup. Also, heat pump forced air is not my favorite heat on forced air.....you always feel just a coolish breeze, not really hot air, coming out of the registers.

    Why not go with a propane fired forced air furnace, with A/C coil?
  5. monz78

    monz78 New Member

    Jul 14, 2008
    I can't use any kind of open flame propane unit in the garage area. I use my garage allot and I paint cars in it. So there are lots of fumes at times.
    I'm just trying to get away from propane because I really can't afford to pay $5.00 per gallon for it.
    I do have a forced hot air electric heater that will heat the garage. I used it in my old shop and it worked pretty good. The old shop was 12x27 and it cost about $40 a month in electric to keep it at 50 degrees. As I said my new shop is 27x30. I can't remember the BTU's of the heater but it was over sized for the old shop.

    If I stut down the radiant how would I drain all the water from it so it doesn't freeze?
    I also have high dllor show cars in my garage so I need to keep it at least 50 in there.

    My main consern is the house right now because the furnace in there is old. The olny reason I was thinking of a heat pump with the propane backup is to save some money.
    I have a friend with an 18 year old heat pump with electric strips for backup and it works very good for him. So I would think a modern day unit would be better.
    And I live in the great North East in New York so it does get cold here.
  6. Bill Arden

    Bill Arden Computer Programmer

    Sep 30, 2006
    computer programmer
    MN, USA
    Your most efficient option is a ground source heat pump, but I am guessing you would have to go with a more expensive "closed loop" system.

    I picked up a used heat pump and plan on connecting it up in parallel with my current oil furnace. I want to keep the oil furnace for when the power goes out. note: I am not exactly sure how the plenum will work in my case yet?

    As for the garage floor. I would keep the in floor heat as it makes it easier to work on cars. You could save a small amount of money though by adding "water to air" heat exchangers, but you would be better off spending the money on insulation around the building.

    My garage for example was built with 2 inches of foam under the slab and two inches coming up the outside of the 4 inch block. (it's a 2x6 wall)
    it also has 2 inch insulation going out 4 feet in all directions.

    1. Check to see if you can use a "pump-n-Dump" "open loop" heat pump system?

    2. What kind of insulation does your garage have?

    3. Watch out for how much heat the attic ducts loose. They need to be insulated just as much as the attic.
  7. monz78

    monz78 New Member

    Jul 14, 2008
    With a ground sourse heat pump is that with the tubes buried under the ground? I really which I would have considered all this two months ago. I just installed a new leach field in my back yard and the whole thing was dug up. It would have been the prefect time to do this.
    In my house after the furnace and central air was installed in 1992 the AC didn't work. The temps in my attic were over 200 degrees on hot days. So I added a layer of insulation in the whole attic running it over the duct work. That helped allot. The I added a rig vent. Vents in both eves and along the soffets on the front and back of the house. My attic is a much happier place now and the AC works great. But years of use have wore out the furnace. So it needs to be replaced.
    So I really think I'm going with a hybred heat pump with propane backup. As I said I live in the Northeast and it gets cold. But I believe the number of days it stays over 30 will save me some money.

    Now my garage is detached. It was built in 2001 and I designed it myself. It is very well insulated. So I know thats not the problem. It does'nt use a huge amount of propane. I saw on a few different forums about Seisco SH-14 Electric Micro Boiler. And have seen nothing but good things said about it.
    People with garages similar to mine are claiming $45 to 50 a month to operate it. If that number is true thats allot cheaper than I am paying in propane now.
  8. Furd

    Furd Engineer

    Jul 3, 2007
    Retired energy systems engineer
    Wet side of Washington State
    If you know the BTU per hour firing rate of your present boiler and the number of hours it fires in a "typical" month you can calculate the cost of burning propane and calculate the cost if you used an electric boiler. Any claims like "$45 to 50 a month to operate it" are meaningless without knowing ALL the details of the claimant's garage, their weather and their cost of electricity.
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