I Need a New HVAC System
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  1. #1
    Join Date
    Jun 2012
    Posts
    10

    I Need a New HVAC System

    Hello All,


    I have a 16 year old York HVAC system that I am going to replace. It is the original system installed when the house was built back in 1996. It appears the evaporator coil drain pan is leaking plus there is a freon leak causing me to have the A/C system charged at the beginning of each summer for the past 4 years. 4lbs. of freon were added this month. The water puddling up at the bottom of the furnace reduced greatly after freon was added as the coil may have been icing up. Now there are trace amount of water around the furnace. The condensation line has been checked and it is open and draining. I figure replacing just the A/C system after water has been dripping on the 16 year old furnace is probably not smart. Right?

    The current upflow gas furnace is 80% - 100,000 btu input and 80,000 output with a 1/2hp blower motor which I have read is a 4 ton blower. External A/C condenser is a 3.5 unit. Evaporator coil is rated for 4 tons. This system serves the 1st floor and basement of the house. 1st floor is about 1735sq. ft and 9ft. ceilings and basement is 1247sq. ft. with 7ft ceilings. Combined it is about 3000 sq ft. without factoring in ceiling height. I have a separate attic HVAC system for the 2nd floor - 1136sq. ft. which I already replaced the coil drain pan 3 years ago.

    Questions:

    I have had 4 different companies, including my gas company give me estimates for a replacement system. Since I plan to be here at most another 5 years, they all are steering me towards another 80% furnace with a 13 seer A/C due to cost recovery time. When pushed, they will discuss higher efficiency systems but venting to the outside seems to be an issue as the most accessible area to install a new intake & exhaust vent outside is located next to a corner and 24" from a window and will only be 12" above ground. It will have to be located right next to my sump discharge line. It is possible, but very infrequent that we receive more than 12" of snow being in Maryland, near Washington, DC. Mind you only the gas company contractor pointed this out and said he will not install anything higher than a 80% due to intake and exhaust venting. He also pointed out that going to a high efficiency furnace will require sleeving the existing flue to reduce it's size so that the existing gas water heater continues to vent correctly. I understand the issues with venting the furnace but have not found enough documentation to determine if it would be code compliant or not. As for the orphaned water heater, I have done some reading but wasn't able to determine if I need to sleeve the flue. Currently both the furnace and the water heater vent to a flue that is roughly 6.75" in diameter, up from the basement, thru the 1st and 2nd floors to the unconditioned attic and out thru the roof. I need help understanding the 7x rule.

    None of the companies has conducted a Manual J and when asked, they tell me that the existing system was correctly sized by engineers prior to the building of my house and is correct based on square footage. Again, the 1st floor has 9ft ceilings and the family room 15ft cathedral ceilings. The basement was finished 10 years ago but no area was added to the house. Only some additional ductwork. None have measured the house or asked me for dimensions. From reading tips on this and other forums, a Manual J should be done, right? I can tell you that the family room built on a slab with 15ft cathedral ceilings is 4-6 degree colder in the winter than the rest of 1st floor and I have various drafts that I can not determine their source.

    I like the idea of a high efficiency furnace with a multiple or variable speed blower such as the one found in the below Goodman. The price between a 80% and a 90-95% furnace seems little compared to energy cost saving. I am assuming I am going to save money by going to a 13 seer A/C vs. my existing 8-10 seer A/C so...

    Systems under consideration:

    Goodman - GMH950904CX furnace, GSX130421 A/C, CAPF3642C6 Coil

    Payne - PG9MAB048100 Furnace, PA13NA048 A/C and CNPVP4821ATA

    Carrier Systems with a rebate until 6/30/12.

    If I have to drop to a 80%, the Payne units have gotten very good reviews from what I have read.

    2 out of 4 companies are quoting Carrier. The gas company contractor explained the reason they sell Carrier is because it is the brand most commonly stocked by local distributors. One quoted Payne saying that it is the same as the lower level Carrier, just a different color and cheaper. The 4th quoted Fridgidaire. None really like Goodman which I had recently had installed in a rental house by a contractor who won't service the area my house is in.

    Thoughts?

    Sorry for the length but I figure the more info I provide the more helpful info I'll get.

    Pictures @: http://s210.photobucket.com/albums/b...IMG_0001-1.jpg


    Thanks...

    Neil

  2. #2
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,604
    The gas comany contractor appears to be looking out for the gas company by not wanting to put in a 90 or 95% furnace ,are you on propane or natural gas .keep calling till you get the correct contractor.

  3. #3
    Join Date
    Feb 2011
    Location
    North East Ohio
    Posts
    765
    Quote Originally Posted by catmanacman View Post
    The gas comany contractor appears to be looking out for the gas company by not wanting to put in a 90 or 95% furnace ,are you on propane or natural gas .keep calling till you get the correct contractor.
    I agree. Putting in an 80% these days seems a bit crazy to me (Unless you're in FL) Find a contractor whom will do a manual J to verify your sized right. Call the local building dept. about the flue liner.

  4. #4
    Join Date
    Jun 2012
    Posts
    10

    Natural Gas

    Sorry for the omission.

    Furnace and hot water heater are natural gas. I have called many contractors for price quotes.

    I'll call some more and ask if they perform a manual j for estimates. I called the permits office about the flue liner. They referred me to the gas company.

    Thanks for the info.

  5. #5
    Join Date
    Mar 2006
    Location
    The South
    Posts
    2,126
    Neil

    What is your location?

    I would want to see in writing a load calculation for both heating and cooling this zone.

    Keep in mind, basements at or partially below grade have small heating and cooling loads.

    And unless there are Bldg obstacles concerning venting, I would want a two stg var speed 95+% eff furnace.

    IMO

  6. #6
    Join Date
    Jan 2004
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    Lancaster PA
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    67,616
    cindyandwade, this is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise here. Please apply to the AOPC today, thank you.

    You can find the rules for posting and qualifications here.


    Further infractions may result in loss of posting privileges.
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  7. #7
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    ewitte, this is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise here. Please apply to the AOPC today, thank you.

    You can find the rules for posting and qualifications here.


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  8. #8
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    ewitte you are not allowed to post advise, links, or comments in other peoples threads, in the AOP forums.

    Please read this link.

    An excerpt from it: THE ONLY PEOPLE allowed to REPLY in the Owner Assistance Forums will be a Pro Member with a * by their user title and the one who started the thread. No others may post a reply.
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  9. #9
    Join Date
    Jun 2012
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    Location

    I am located in Bowie, MD.

  10. #10
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    Jan 2004
    Location
    Lancaster PA
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    Code generally requires the vent and intake of a 90% or better furnace to be 12" above normal snow accumulation level.
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  11. #11
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    Jun 2012
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    Height

    If an intake and exhaust or rather, concentric vent was installed adjacent to the sump discharge line, it would be 12" from the ground. I assume there is no such thing as a concentric elbow to raise it further from the ground?

    According the the gas company contractor, the real issue is the corner. True or false?

  12. #12
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    Corners are really a problem. depending on the corner. if ran as 2 separate pipes, they can be elled up to get the clearance from the ground/snow level.
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  13. #13
    Join Date
    Jun 2012
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    Quote Originally Posted by beenthere View Post
    Corners are really a problem. depending on the corner. if ran as 2 separate pipes, they can be elled up to get the clearance from the ground/snow level.

    Well it is a year later and we made it through the winter fine with our old system. As it is warming up here, I plan to have the system replaced within the next 20 days or so by a HVAC firend I trust. He has given me the green light to buy whatever equipment I want and he'll install it for me. He has looked at the install and is against vent outside as it will require boring through my sill plate near a corner (picture of the wall with the yardstick). He also has serious concerns about venting near the windows and corners and relining the existing flue to draft the natural gas water heater correctly. As such he is also steering me towards the 80%. Everyone is.

    Since my installer is staying the same, how would you rank the below basic 80% 100,000 btu in, 80,000 out, single stage natural gas, 3.5 ton 13 seer with coil system all priced fairly close?

    Goodman
    Payne - 110k but in 89k btu out
    Rheem
    York - not LX furnace

    And would you spend a little extra for a 2 stage gas valve, multi speed blower (not variable) 80%? The variable speed 80% are very hard to come by and expensive. I did find a decent deal on a Comfortmaker though.

    Thanks...

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