Results 1 to 8 of 8
  1. #1

    Need help with HVAC quote

    Looks like I'm not going to be getting the heat strips in the attic for the Heat Pump so I'm going with a furnace. Do to the fact that I would need to upgrade my breaker box. So the plan is to replace the 13 year old A/C with a Heat Pump and have a 80% furnace installed in the attic with a fresh air intake and exhaust pipe. The house was built in 2000 and is 1300 square feet and is in Austin Tx. 100+ summers with a couple of days a year at 32 degrees. So I need more cooling then heating.
    Does anyone know anything about this equipment. Is model FA3648, the fresh air and exhaust pipe, I can’t find anything about it on the net. I need the exhaust pushed out, because I’m having the attic spray foamed after the heat pump and everything is installed. So I need that taken care of, the installer also said that he would be installing a carbon monoxide detector. However I don’t see that on the bid I posted below.

    Model: FA3648, FAN INDUCED FRESH AIR 36-48 (4 FAN ASSEMBLY) Knockouts
    std,FHP Air
    Model: N8MSN0451408A, 80%, 45K, sgl-stg, MP, 2t clg
    Model: EDM4X24BA, Cased, 2t, MP
    Model: NXH524GKA, COND-HP 15S, 2t R410A GRD, 15 SEER ENTRY HP-R410A
    Model: P4741035, Digital, 5/2 Prog, 1H/1C (Sgl stage HP compatible), no auxil heat cont

    Thank you very must for your help.

  2. #2
    Join Date
    Jan 2009
    Location
    Keokuk, IA
    Posts
    5,520
    Why not just install a direct vent 95% furnace and not mess with having to bring in outside air? That's what I have in my attic. You can still get a 40 or 45k condensing furnace. For hte price of that fresh air kit and messing with B vent pipe, you are probably close the the upcharge for a condensing furnace and smaller PVC pipes. You can use a concentric vent and still have jsut a single roof penetration located anywhere in the attic you want. A 45k usually only needs 1-1/2" PVC for vents, 2" for longer runs.

    For controlling dual fuel, I'd look at a honeywell dual fuel capable theremostat. In your climate you probably don't need a outdoor sensor, jsut let it stage based on heating demand. For that size home with spray foam roof deck, you'll only use the furnace during setbacks or below about 30F based on my experience.

  3. #3
    Do you think the cost of a 95% furnace would be a good investment for my mild winters we have in Austin TX? I can count the number of nights the temperature drops to 35 on one hand. In the research I’ve done I don’t know it would be worth it. The sales person even stated the same, he didn’t even attempt to sale it to me.

    Do you know if the vent system in the first post, will work for the furnace they want to install. Does it bring in fresh air and remove the exhaust out the top of the roof line? Thanks for your help, your knowledge is very helpful.

  4. #4
    Join Date
    Jan 2009
    Location
    Keokuk, IA
    Posts
    5,520
    Return on energy savings....no. But a cleaner install because its direct vent yes. 80% furnace cannot vent on pvc. The flute gasses are to hot... Anna they are not sealed combustion...which is why you news make up air in a foamed attic for it.


    Sent from my DROID RAZR using Tapatalk 2

  5. #5
    Join Date
    Jul 2006
    Posts
    1,091
    My home is 30 degree north (same as Austin, TX) a couple of states to the east of you, I have a heat pump with no back up heat.... I have a #14 wire to my air handler where my gas furnace use to set. My thermostat is set at 65 (really it's off, but will turn it on if it gets below 65), it has not run this season.

  6. #6
    Join Date
    Aug 2012
    Location
    North Dakota
    Posts
    518
    I would concour w/ motoguy if you go w/ a furnace go 90+ as why would you want a air intake in a well insulated attic Id sure be more comfortable with sealed combustion up there the only issue that may come in is the drain though it likely wont be a problem as it wont freeze in your climate just would a place to run or pump it to

  7. #7
    Join Date
    Jan 2009
    Location
    Keokuk, IA
    Posts
    5,520
    That's a good point. I would think that you could manage just a minimal 5kw heat strips on your existing electrical service. Keep in mind the new 2 ton ac unit only uses a 20Amp breaker. You sold system probably used a 30amp breaker and the running amps of the unit are very low. KW consumption for a HE 2 ton unit are usually under 2.5kw.

  8. #8
    Just spoke with the sales person, and he stated that this furnace has a fresh air intake and an exhaust pipe that is going to remove the exhaust. So it looks like I don't need a 90% furnace. I did look into the 90% one but I must admit that it's way over my budget at this time. And living in such a warm winter place, I will not use it to the fullest.

    Thank you for your help everyone. If you have anything else to state. Talk away. I'm needing to learn as much as I can.

    Thanks again.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event