Got my bids....need some help making decisions - Page 3
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  1. #27
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    Nov 2004
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    Originally posted by jclancy
    really impacted by what this group on this forum is saying (NO ONE saying an 80% is the right move),Is there a higher profit margin on 80%'s or something? What am I missing here?

    I haven't rechecked ,but I think you mentioned that the cost of venting with the 80% came out to about the same as the 90%.
    (and the 90% was cheaper to vent...
    was i reading too fast,or am i on the wrong thread?)

    If that is correct,then there you go.

    Not oversizing your furnace is the most cost affective move you can make...after you have insulated,weatherized.

    I will have to re-read now,but in the meantime you might get a greater diversity of answers.

  2. #28
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    Nov 2004
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    Originally posted by jclancy
    UNLESS I opted to exhaust the furnace out via PVC pipe to the back or side yard (i.e. not use the chimney for exhausting the furnace, as we're doing now, and only have the gas hot water heater using the chimney). new lining _to me_, it's not an insignificant cost, and maybe not a necessary one?
    if you go that way,it will require a condensing furnace,ie:90+

    and I am only guessing that it would be cheaper and safer than using the old chimney

  3. #29
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    Sep 2005
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    35
    I think the chimney's going to get lined either way, to be honest....if I go with the 94%, only the HWH is venting out the chimney, and go a liner is needed. If I go with the 80%, it sounds like what you all are telling me, a liner's a good idea anyway with modern furnaces.

  4. #30
    Join Date
    Oct 2005
    Location
    South Jersey
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    jclancy - I too am in the market for a new heating and A/C system and I am weighing the advantages of an 80% vs. a 90+% heating system. Being in South Jersey (Philly Area), my winters will be slightly less severe than yours. I don't understand the math that the contractors are using when they say that a 94% will only be 5 to 10% more efficient than an 80% model. If both systems are installed properly, I believe that a 94% system would be 14% more efficient than an 80% system. What is their rationale for 5-10%?

    Therefore, based on a 2004 heating bill of $1500, if you stayed with your current system @ ~65%, and a natural gas price increase of 50%, your new 2005 heating bill would be $2250. If you bought an 80% system, your new bill would be 15% less, which would be $1912. If you installed a 94% system, your new bill would be 29% less or $1597. The difference per year between the 80% and 94% would be $315 as a minumum. That would give you a payback period of ~ 5 years. This assumes that the price of natural gas stays the same over the next five years which we all know won't happen. Don't forget the electricity savings for the higher efficiency A/C unit. I hope this helps.

  5. #31
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    Sep 2005
    Location
    Atlanta GA area
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    Hi Kcerce,

    THX for the analysis of costs for 90+ furnaces, you did a great job of figuring out the numbers for efficiency. Also thank you for posting your thoughts about energy costs. My personal opinion is similar to yours on this subject.

    I would like to go back to the topic of high efficiency vs standard efficiency equipment: I think I made mention a few posts back about a variable speed blower in the furnace. The variable speed blower furnaces use a different kind of motor, one that uses something like 1/2 or less current (read that as watts, what you get billed for on your electric bill). Now add to this the same variable speed blower will be saving you money all year, not just during the winter. Add a higher efficiency A/C system that can take advantage of the variable speed blower, and you will save $$$ all year long. Sooo: we have a furnace that saves $$$ heating, a furnace blower motor that saves $$$ all year long, and an A/C system that saves $$$ cooling. Could we be piling up savings from multiple sources already???

    Now lets remember that N/Gas is going up, and electricity is sometimes made with N/Gas (mostly with coal, and diesel fuel runs the trains that carry the coal to the power plants). No matter how one looks at it, the price of energy is going only one way: UP (and UP and UP and UP). It just seems to me that it would really be penny wise and pound foolish to not plan ahead for the cost of energy.

    Here is another thought: What about the comfort in your home? Variable speed blowers in the furnace tend to keep the temperature more balanced (it feels better) in the home winter and summer, and they tend to manage humidity in the summer a lot better than the less expensive alternative. Lastly (but probably not least), better equipment tends to last longer with less repairs. Many times, a high end system could last 20+ years or more. Wonder what the average cost of N/Gas and electricity will be over the next 20 years (or more)???

    I realize this final comment may be kinda bold, but I have personally learned the hard way to regret taking a 'bean counter' attitude on some purchases (look only at the $$$, and not look at the bigger picture). It is not that I am in the business and want to push the high end equipment (I am licensed in GA, I could not install it for most of the folks reading this anyhow). What I am trying to say is that most of the customers I have installed this high end equipment for have been thankful they chose it. I guess it is like having A/C in your car; or having power seats and/or power windows. We may think this is a wasteful luxury until we have it, and then we get really comfortable with it and wonder why we did not buy it sooner.

    Best to you on your decision.

    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  6. #32
    Join Date
    Jul 2005
    Location
    Cypress, Texas
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    why would anyone waste money on a HWH (hot water heater)? hot water is already heated, no need to heat it again and waste energy dollars.

    damn I'm a smart a** today

  7. #33
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    Nov 2004
    Location
    SW FL
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    Question Energy Bill$

    Originally posted by kcerce
    Therefore, based on a 2004 heating bill of $1500, if you stayed with your current system @ ~65%, and a natural gas price increase of 50%, your new 2005 heating bill would be $2250.

    If you installed a 94% system, your new bill would be 29% less or $1597.
    94% / 65% = 1.4462

    ... Sounds like an Efficiency Ratio Increase of 44.6%

    Re-calculate energy bill ...
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  8. #34
    Join Date
    Sep 2005
    Posts
    35
    Thanks for the numbers....is it really as straight as that? If I'm paying $100 a month using a 65% efficient furnace, I'll then pay $77 with an 80% and $54 with a 94%????? (let's pretend I have no other gas powered items and consistent use of the furnace)

    It can't be that simple, can it?

    When I heard the Contrator say that I'd only see a 5-10% reduction in gas bill compared to the 80%, I assumed that there was a point of diminishing returns with this stuff, like there is with a lot of things.


    [Edited by jclancy on 10-05-2005 at 06:58 AM]

  9. #35
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    Sep 2005
    Location
    Atlanta GA area
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    I want to apologize ahead of time for any toes I might step on with this thought:

    I have talked to some HVAC contractors that appear to just not like high efficiency equipment. Not sure why, but when 'talking shop' at industry gatherings, some of them seem they would almost rather go to the dentist than get involved in a high end installation.

    I realize each of us that runs a business needs to pick our market nitch and work in it, and I am by no means critizing anyone for it.

    Just think there is more out there than the 'status quo'.



    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  10. #36
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    Oct 2005
    Location
    South Jersey
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    2
    ga-hvac-tech,

    I agee completely with your comments about high efficiency heating. Unless jclancy plans to move in less than 5 years, the best choice is 90%+.

    Your comment about variable speed motors is interesting. I did not realize that the variable speed motors are much more efficient than multi-speed motors. Do all major manufacturers offer variable speed blowers? Will a special thermostat be required?

    A question about AC - what minimum SEER level do you recommend for an AC unit in the Philly area? I run my AC for most of June, July, August, and half of September for a total of 3 to 3.5 months.

    Thanks.

  11. #37
    Join Date
    Sep 2005
    Location
    Atlanta GA area
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    Mornin' Kcerce,

    THX for the reply. I really enjoy the internet, one gets to meet lots of folks and converse all over the country and world...

    Concerning your question about A/C: In the Manual J book (heat gain and heat loss, the code book load calculation theory comes from), there is something called 'design temperature'. This is an 'average' high and low temp for the area. Note that these are not actual extremes, but averages the industry uses for calculation. There is some 'interpolation' in deciding what size furnace or A/C (or H/P) to use in one's home. My approach to this comes from experience as well as properly selling the job (asking the right questions to find out what the customer wants/needs).

    "According to the book" (and we have all heard that one before...), the Atlanta area (my area) has a design temp of 92 D for the summer. The book also references 90 D for Philadelphia Penn. In Atlanta, we use A/C from around early/mid May to early/mid Cotober (today will get up into the low 80's, probably need a little A/C during the warmer part of the day).

    As I mentioned above, there is some 'interpolation' in this process. I guess the first questions I need to ask you is how long you plan to stay in your home, and the particulars about your home (size, windows, insulation, etc).

    You asked about the variable speed blowers: O K all you engineer types, time to put on your detail caps... Currently, most motors used in residential HVAC (blowers, fans, and compressors) are what is called a PSC motor (permanent split capacitor). This motor is wound for a particular speed, and relies on the phase of the current to run it. The armature is simply a chunck of steel to react with the changing magnetic field. The variable speed motor is actually a DC syncronous motor with a magnetized armature, and a module attached to the back. Within the module is a set of electronics that determines the speed. The motor also maintains constant torque, which allows some fine tuning of air-flow.

    The way a variable speed motor helps with humidity is to ramp up to speed in stages. Depending on the system (and make), it may stay at 60% or 70% for the first 5-8 minutes of cooling. During that time, the system is drawing down humidity faster. Then it ramps up to full speed. After the T-stat is satisfied for cooling, the condenser outside stops. The fan motor runs for a little while longer, and then ramps down slowly. This is only one of many 'cycles' the motor is programmed to do.

    And yes, some companies have a special T-stat to work with their applications of the motor.

    Note also that some companies have logic boards in the condenser (or H/P) to work with this motor, and the special T-stat.

    One can have whatever level of energy efficiency and comfort they want, as long as they are willing to spend the $$$ for it.

    An example of this (I hope I am not 'over bending' the rules here) is a new home I did the HVAC system for (new construction) last summer. Two systems, top of the line Trane equipment with IAQ (indoor air quality) extra's for a special needs child. Installation was close to $30K, about 10% of that was IAQ stuff. Builder lets me talk directly with the client (spec builder). Seems to work out well for all parties. What is interesting about this arrangement is that in a spoec home that is getting close to $1M, a lot of builders are tight on the HVAC. AMAZING to me... With that much money on the table, it only takes a little more to have a really comfortable house year round (and with proper maintenance, the system will last well into 20-something years). IMveryHO, that is real 'bang for the buck'!!!

    (Note: If I am bending the rules on price too much, please let me know, I will retract the post and not do so again).

    GA-HVAC-Tech

    Quality work at a fair price with excellent customer service!

    Romans Ch's 5-6-7-8

    2 Chronicles 7:14

  12. #38
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    Nov 2004
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    Originally posted by ga-hvac-tech
    Installation was close to $30K, about 10% of that was IAQ stuff.
    (Note: If I am bending the rules on price too much, please let me know, I will retract the post and not do so again).

    yea,that kinda low-balling is frowned on...

  13. #39
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    Nov 2004
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    but ,thanks for the informative post


    and welcome to h-talk.

    Sometimes there are compounding complexities of multiple variables that are not intuitively obvious

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