Replies

1. 
   BillHartmann | Jul 31, 2005 03:01am | #1

   Look at the ductless mini-slit systems instead of "central" air.

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   hurnik | Jul 31, 2005 03:16am | #2

   Thanks, but the expense of those is pretty high (plus they're electric). Around here, electric heat is a definite "no go".I need something to heat/cool 240 sq of full basement, 240 sq foot of 1st floor addition and heat/cool 450 sq feet of 2nd floor addition.I know Mitsubishi has a miniduct split unit that can do up to 3 rooms (in my case it's going to be about 4-5 rooms), and it's like $10,000 for a dual room unit. although I'm curious as to what's the diff. between a heat pump and a Central AC unit?

1. 
   BillHartmann | Jul 31, 2005 03:58am | #3

   "although I'm curious as to what's the diff. between a heat pump and a Central AC unit?"The basic difference is that there is valving to have the freon flow the "opposite direction" so that in additon to transfering heat from inside to the outside for air conditioning, it can also transfer heat from the outside to inside for heating.In general heat pumps are very, very cost effective for heating down to the balance point, where it can't supply enough heat to heat the house and supplimental heat is needed.The mini-splits are available in both AC and heat pumps.But I did not realise that you where going over 3 floors. That makes it difficult, difficult for a furnace also. I was thing more of single area or related areas and maybe a gas fireplace for heat.Here is a whole different way to go. Don't know how difficult that it would be and it would be more costly, but in the long run possible a much better system.Replace the existing system with a new one or even two. Zoned with one system for the first floor and basement. The 2nd for the 2nd floor. Will probably be more comfortable and less operating cost.

1. 
   hurnik | Jul 31, 2005 06:01am | #4

   Thanks for the information.Currently I've got a 2-ton Trane AC and a Lennox (I think 85,000 BTU) furnace which heats/cools the current house (basement and 1st and 2nd floors) just fine.It's the addition that will require a separate HVAC system.I'm trying to get a 2-zone setup. Generally speaking the basement portion won't need to be heated/cooled hardly at all (based upon how well insulated things are in the current basement). Current system I only have one duct open in the summer for AC (just to keep the humidity low). In the winter, I open a second duct to keep it fairly warm.We'll see what the HVAC contractor comes back with.

1. 
   RayMoore2G | Jul 31, 2005 08:56am | #5

   What you are looking for doesn't exist. You can find 1.5 tons from Lennox. There is a one ton ductless split from carrier but not at that SEER. Maybe something will come out soon but we've been trying to find that animal for years with no success. Let me know if you find something like that.

2. 
   hurnik | Aug 02, 2005 05:30am | #6

   Yeah, I kinda got the sinking feeling of that. 1.5 ton might be too big (again, I'm basing mine on the HVAC calculation after I input all the sizes of the rooms, insulation, etc.)The miniduct split units are WAY too expensive for me to justify, so I may be caught between a rock and a hard place.But we'll see.Hopefully I'll hear something in the next day or two from the HVAC guy.

2. 
   TRice | Aug 02, 2005 03:57pm | #7

   Friedrich makes a 3-zone unit, cooling only, with 3 35 ft line sets for about $5400. It has a single condensing unit, (2) 9,000 btuh (3/4 ton) evap/blower units and one 18,000. They also make a dual zone 1-1/2T, with (2) 9,000 buth inside units. Costs about $3150. They are rated at 11.0 SEER and 10.5 SEER, respectively. You provide wiring, installation, evacuation and refrigerant charge.

1. 
   hurnik | Aug 03, 2005 03:16am | #8

   Hmm, I will definitely check that out.Thanks!--Kevin