Please look over this proposal

Discussion in 'General Discussions' started by sunnyflies, Oct 21, 2009.

  1. sunnyflies

    sunnyflies Member Forum Leader

    Well, one of my potential installers just self selected himself out of consideration. He emailed to tell me he was about to send over a proposal - but he hasn't measured my house. :roll:

    I do have what sounds like an interesting proposal from someone else who did measure my two story house very carefully. When the addition is finished the house will be 4,200 sq ft .

    The proposal's for a six ton WF Envision, a desuperheater and a buffer tank, a 20K electric back up strip and 1040' of vertical closed loops. It is to have three zones, an Intellizone damper panel, three thermostats, an aprilaire 600 humidifier, a merve11 air cleaner and a UV-Aire Ultra Violet Germicidal light, if I want it at an extra cost. (Should I want it?)

    It says the six ton unit is rated at 74,400Bthu cooling and 55,5000Bthu heating. It is planned for a range of temps from 7º to 92º. However, the proposal also tells me that my cooling needs are 3.35 tons on the first floor and 2.87 on the second, which is a total of 6.22 tons. My heating needs would be 53,682 on the first floor and 43,879 Bthu on the second which is a total of 95,761Bthu. I have read that it is better to go a bit smaller with a geo system than larger, so perhaps the cooling is alright. But, what about the heating?

    I will be talking to the installer tomorrow. I would appreciate any input and advice. I am wondering if the loops ought to be longer as when he had given me a proposal before I planned the addition, it was for 1,200' of loops for a 2400 Sq ft house. With a bigger house it is now only 1040'. I don't want to be short looped. I do plan to ask him about it. Maybe, someone just transposed the numbers and meant to type 1400. Ground water temperature here is a steady 55º with a one foot a day ground water flow. The loops will be sunk in moist sand and gravel.

    I like this installer better than any I have spoken to, he is very experienced and seems to be honorable. All his references check out.
     
  2. gabby

    gabby Member Industry Professional Forum Leader

    I’m no expert for designs in Conn. There are always tradeoffs when you do geo for summer and winter operation in a cold zone, thus a 6.22 ton cooling load versus an almost 8 ton heating load. The 20K electric heat is suppose to meet this offset of one season to the other.
    Aren’t your electric rates very high like $.14-.$.22/KWH? How many days in a winter do you have in the single digits to below zero on average per year?

    What is the design temperature for winter, 68 degrees?
    What is the design temperature for summer operation, 73 degrees?

    I agree the tubing looks short for an 8 ton load, but more reasonable for a 6 ton load (96K-20K= 76K), 173.3 feet/ton. Now depending on your soil and what is normal per ton for your area I don’t know, but I sure would find out why the difference of 1200’ for 2400 sqft and 1040 for 4200 sqft. Moist soil makes a big difference in heat transfer than dry clay. You had an estimate of 4.5 tons for 1200 sqft or 268’/ton. Maybe one figured a dry soil and one figured a wet sand, or one figured a horizontal loop and one a vertical loop…..don’t know.

    Rather than go with a single system, why didn’t you decide on two systems to more evenly distribute the load from the new to the old, and from summer to winter?

    I personally don't like damper zones. You rob Peter to pay Paul, which is okay if Peter is on vacation, but makes for friction if both wish to be warm or cool at the same time. The home dynamics generally dictate what options are available and maybe that was the best solution due to many reasons. It is futile to design with one's eyes closed...or over the internet with a general description.
     
  3. sunnyflies

    sunnyflies Member Forum Leader

    Thanks for replying Gabby.

    The reason for only one unit was the $20,000 difference for installing two units. Using two units, a 4 ton and a 3 ton - which I realize would probably be better, would cost about $70,000 versus $52,000 for the six ton unit. Both quotes include loops, unit, desuperheater, buffer tank, intellizone, thermostats, humidifier and merve filter.

    Electric is .21 and we have 5406 degree days where I live, which is on Long Island. We are a bit milder in climate than Conn. due to the ocean's thermal effects. When it gets snow, we often get rain even though we are about 15 miles south of it on our north shore.

    The design temp. for winter is 70º at 7º outside with 15 mph wind
    The design temp. for summer is 74º degrees at 92º outside

    Loops in both quotes were for vertical loops through saturated sand and gravel by the same installer.

    Interesting about damper zones, but makes sense. If I understand correctly, it means that all's well when the entire house isn't calling for the same amount of heating or cooling; but, might not be if it is.

    Rats. I wish these systems were less expensive in my area. But, they're not. I'm in a high rent district and everything costs more. It does get frustrating to see posts by people in other areas who get the same system I want, same size, same vertical loops, same extras, etc, for about half the price. Lucky things! I had been keeping track of their quotes in the notebook I use to write down information about geo systems as I thought they might be useful when it came time to get proposals myself. Silly me.
     
  4. sunnyflies

    sunnyflies Member Forum Leader

    With what you said about zones in mind, I wonder if I should ask if he could reconfigure the zones to the way I will actually be using the house, both now and in the future. Perhaps I could go with two units, one to go in now and the other when the addition is finished. That might be more do-able financially.

    Would it do any harm to have all the loops I will need put in now? Is there a down side to over looping?

    I need a new heating system in the existing house as soon as possible, but haven't started on the addition which will wrap around two sides of the existing house. I plan to have the foundation put in and shell the addition - framing, roofing, siding, windows and doors, then finish it as finances permit.
     
  5. gabby

    gabby Member Industry Professional Forum Leader

    Yes....if all areas want the same cooling/heating the zone dampers should be balanced to deliver such. Let's call that reference zero. If you decide you want it warmer in the addition, the zone dampers will shift in unison from reference zero to accommodate the new loading, thus reducing the loads going to zone 2 and 3 and increasing the flow to zone 1. Only you know if that's acceptable. If zone 2 were bedrooms and no one is sleeping then no harm, no foul. If zone 3 were the dining room and foyer, again no harm no foul, if you are in the living room (great room). How and when you use different rooms determines how well you like the zone concept. What I have found is that over a few years the zone dampers are left in a particular arrangement, the same as if there were mechanical manual dampers. There are always exceptions...parties with 15-20 people in one location, empty nesters, and a myriad of other things.
    I have no clue how the zones are distributed, that’s a determination you and the designer have to agree upon.

    These are the questions, additional units/loops, two stage building process instead of one install, and valuing extra loops for a second install, that you and the person who sees the problems are better at answering than some geek on a keyboard. Almost anything is possible with the right amount of cash, except maybe lowering your taxes on Long Island, or New York.
     
  6. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    I question your design temps.

    My Elite RHVac shows design temps for Central Islip (NY town on LI) to be 15 winter and 85 summer. That is quite different from the 7 / 92 you posted above.

    The 92 summer design temp you posted is what drove me to crank up Elite. I'm in North Florida and use 92-94 for summer design temps, and I'm quite certain LI New York is much milder in summer than Florida.

    Same applies to winter. Single digit temps make sense for inland southern New England, but LI, surrounded by water, must be much milder.

    7-8 degree differences in design temp are substantial, particularly for summer cooling, so it is important to use the right values for load calculations.
     
  7. sunnyflies

    sunnyflies Member Forum Leader

    Thank you for responding, Engineer. Although the ocean and off shore breezes do cool us off somewhat in the summer, mid-80's are more normal for us. We do get stretches of sweltering 90's. The day I had my son - admittedly a while ago - it was 104º, after having been in the 90's for weeks. But, heat waves like that are unusual. We often have heavy humidity, though not as heavy as in Louisiana.

    "Single digit temps make sense for inland southern New England, but LI, surrounded by water, must be much milder." You are absolutely right. The ocean stays at about 45º during the winter which has a warming effect on us, and Long Island Sound, the large body of water between us and Conn., stays open. The bay between our north and south fork does sometimes freeze over. I know in the old days the LI Sound did too, but not recently.

    7º does seem a bit low as an average - would that be an average? -as we don't often get those - thankfully, but we do get zero's sometimes and even below. It seems to me that we are more in the 20's and low 30's, but I will try to look into it today. Interesting that you found 15º as a design temp. It might be correct if it was an average.

    Could it be that he is trying to take into account that part of the structure will be an antique house that will leak air more than a newly built house?

    This man seems to be the most professional of any of the installers I have met, and has done the most installs. I've checked his references and everyone was pleased with their systems. Even those he'd put in years ago. Several had recommended him to friends and relatives who has also used him. The only complaint I heard came from one woman who said his crew was a bit messy, but his work was excellent. I can live with that as I, too, am messy.

    He measured the house with great care and noted the sizes of all the windows and their exposure, which the others did not. He seems to know his business and does quite a bit of fixing other people's bad installs. He's a bit gruff, but I like that better than some of the slick salesmen I've run into.

    My other two proposals haven't come in, but will be based on a bit of surmise. Neither bothered, nor wanted, to measure the existing house, preferring to base their manual J's on the architect's square footage jotted onto the additions plans, which I told them I believe may be too large, based on the outside dimensions of the rectangular building. And, neither measured ceiling heights - our upstairs height is lower than down. The addition plans do not include drawings of the existing house, it's measurements or its windows, so they can't get them from it. I am disappointed as they had seemed among the best of the dozen or so firms I have met in the past six months. One came highly recommended - twice - by my local power company as doing a large number of geo installs this past year. Am I wrong to be disappointed? Shouldn't a house be measured for volume? I know windows play a big part in manual J's.

    Does a six ton system sound right for a 4,200 sq ft two story house? I had been concerned that the loops he proposed might be too short at 1040', but he told me he considers 160' per ton to be good for the area. Our soil is saturated sand and gravel, and the water table is about 30' down. I know the ground water flow here is about a foot a day, so the water the loops will be in will always stay at 55º.
     
  8. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    I will share a contractor's perspective.

    I have to admit, that when I know a client is price-shopping I find it is hard to find the time to invest a few hours in to a sizing calculation. I generally won't be the cheapest. There are easy ways to be cheapest around here (single speed units, interior PEX, and so forth).

    On the other hand, a client such as yourself, that is getting educated changes that. I know I will have time to show you I know what I'm talking about, and that as long as we're in the financial ballpark, we have a chance at getting the job. I'm more than happy to answer questions and spend the time in that case.

    We also know our area quite well, and can generally size equipment and quote without measuring everything. If we get the go ahead, we then measure and design. We explain that we never install without designing and that we will always re-visit the contract with the home owner if our initial estimate is off base.
     
  9. gabby

    gabby Member Industry Professional Forum Leader

    <<I generally won't be the cheapest. >>

    That is a fair assessment of a solid business. You don't want to be the most expensive, and you don't want to be the cheapest worrying about a job putting you out of business. The reputation one achieves by past action, brings a comparable "value added" that is justified by eating ones mistakes and delivering a professional installation. You have paid your dues and gained the knowledge of what it takes to deliver expectations. One can not do that at lower bids without cutting corners that the customer will have to bare.
    As Holmes would say, "Make it right the first time."

    As engineer stated your design parameters will oversize the optimum design needed to meet your needs of 95% of the time. If you are like me, a design temperature of 75 degrees cooling is too high, then you have little choice but go bigger or reduce the size of the home. Your input of lower cooling and higher heating comes at a cost, and as long as you understand that then so be it.
     
  10. sunnyflies

    sunnyflies Member Forum Leader

    Urthboy, we could certainly use people like you here on Long Island. I have wasted a lot of time with people who I now realize didn't know much about geothermal systems, but were sure eager to sell them.

    <<I generally won't be the cheapest. >> The people I've narrowed it down to won't be either. To get a top of the line closed loop system here, for the square footage I will have, will cost at least $45,000.

    "As engineer stated your design parameters will oversize the optimum design needed to meet your needs of 95% of the time. If you are like me, a design temperature of 75 degrees cooling is too high, then you have little choice but go bigger or reduce the size of the home. Your input of lower cooling and higher heating comes at a cost, and as long as you understand that then so be it."

    Help me understand, please. I'm blonde, we're a bit slow on the uptake :)

    I know a geo system should be designed to meet 95% of a building's heating and cooling needs, not 100%. Does this mean the system will be straining to meet the temperatures it's designed to meet? That to meet them it should be bigger? I wish I were a :geek:

    Here's what the proposal says:

    1st floor: 3.35 tons, Clg. 53,682 BTUH Htg.
    2nd floor: 2.87 tons, Clg. 43,879 BTUH, Htg

    "... based on maintaining 75 D.B.,& 50% RH inside at 92 degrees outside with 74 W.B. for cooling, and 70 degrees inside at 7 degrees outside with 15 mph winds, for heating. Air changes have been figured in at .4 in the summer and .8 in the winter."
     
  11. gabby

    gabby Member Industry Professional Forum Leader

    As engineer stated, the design temperature for your area is not 7 degrees but closer to 30. Your design temperature for LI is 85 degrees cooling, not 92.
    If you lower the heating requirement by 20 degrees and raise the cooling max by 7 degrees you add capacity that 90+ percent of the time you will never need.

    Go to your local weather site and find the average winter and summer temperatures for LI. You will probably see the record highs and lows at the same site.

    Within a certain tolerance your design cooling and heating criteria should be around these averages. If nothing else you can see what a design of 7 degrees does in comparison...20 degrees lower, 15 degrees lower---and the same for summer temperatures. If you have 5 days or 10 days out of every winter/summer season that the highs and lows exceed these averages is it worth over-sizing and paying the price monthly for those few days?

    It is no different than a blond buying a station wagon to accommodate one, two week vacation where she takes 3 suitcases, coolers, picnic baskets, and pool toys. The rest of the year (50 weeks), you pay for driving a gas hog where a compact car would meet her needs. We all make those kind of blond decisions, when wants/desires supersede rational judgment.
     
  12. jrh

    jrh Member

    I have westhampton design temps at 10'F winter and 83'F for summer
     
  13. gabby

    gabby Member Industry Professional Forum Leader

    Re: LI weather

    Long Island City Weather---
    http://countrystudies.us/united-states/ ... d-city.htm




    NEW YORK, New York, February 18, 2009 (ENS) - As a low-lying coastal city, New York will face higher temperatures and more rapidly rising sea levels, as well as more frequent and intense extreme weather events - like heat waves, heavy rainstorms, and coastal flooding - over the course of the century as a result of global warming, according to a new report released Tuesday by Mayor Michael Bloomberg.
    The climate change projections specific to New York City were developed by the New York City Panel on Climate Change, made up climate change scientists, academics, and private sector practitioners convened by the mayor and funded by a $350,000 grant from the Rockefeller Foundation.


    Using global climate models and local information, the New York City Panel on Climate Change projects that by the end of the century New York City's mean annual temperatures projected to increase by 4 to 7.5 degrees Fahrenheit.
    The total number of days with a maximum temperature over 90 or 100 degrees Fahrenheit, is expected to increase as the 21st century progresses. The frequency and duration of heat waves, defined as three or more consecutive days with maximum temperatures above 90 degrees Fahrenheit, are also expected to increase. In contrast, the number of days per year with minimum temperature below 32 degrees Fahrenheit, are expected to become rarer.
    Full article:
    http://www.ens-newswire.com/ens/feb2009 ... 18-092.asp
     
  14. jrh

    jrh Member

    climate change Yet another reason to undersize geo
    Long Island city is no where near the hamptons
     
  15. sunnyflies

    sunnyflies Member Forum Leader

    I understand what you mean, now. I did know that oversizing is not a good idea, but you'd be surprised by how many people have told me that "going over a bit is fine" and pooh poohed me when I tried to suggest otherwise.

    I am not a pro, so it's hard to know what's right. I was told this 6 ton system would be a bit small for my house, and that two units, a 4 and a 3, would be better. They cost $20,000 more which I simply can not swing, so I've been hoping the six ton would just be able to do the job. Would five tons be better for 4,200 sq ft - and more efficient?

    Of all the installers and engineers I have spoken with, this guy seems to have the most experience, is the least salesman like, and every reference checks out. I called a bunch from the six pages worth he gave me and spoke to some very contented people, many of whom had referred him to friends who had also used him with success.

    Should I ask to have the numbers run again with more average temps? Probably. I don't think I specifically asked for the range given, but I did wonder aloud what would happen when it got very hot or very cold, so perhaps I am responsible. Maybe that would change the sizing.

    jhr- You're right, gritty and urban LI City is a long way from here in many ways, but I did like Gabby's article. My husband deals with global warming matters as part of his job, so I try to keep up with the subject. I figure my place will be waterfront property in 50 years :D Thank you for the design range temperatures: "I have westhampton design temps at 10'F winter and 83'F for summer".

    Thank you also, Engineer, for yours: " My Elite RHVac shows design temps for Central Islip (NY town on LI) to be 15 winter and 85 summer." I will talk to the proposal's author about both sets of them to see whether I did inadvertently ask for such a wide range.
     
  16. gabby

    gabby Member Industry Professional Forum Leader

    <<"going over a bit is fine" >>

    True.

    Definition of a bit over:
    To the nearest ton
    1/2 ton increase, not 2, 2.5 ton increase.
    Simply ask what design temperatures he used for customers in your area, and why the extremes for your place. If it is to offset less than adequate insulation in the main house, old single pane windows, or poor construction (deteriorated with time), this may be very reasonable. You are trying to heat/cool the outside.
     
  17. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    We can still

    Do Long Island.

    Sunny, It feels to me you are getting closer to what you think you want.

    Mark
     
  18. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    You've devoted many hours here.

    Consider buying the $50 60 day license to Don Sleeth's HVAC-CALC and performing your very own load calculation. That would backstop the load calculations you've received, expose you to the ins and outs of heat gain and loss (maybe there are window, door, wall, or other house features worthy of improvement that could get your loads down at modest cost), and empower you to more precise discussions with potential contractors.
     
  19. sunnyflies

    sunnyflies Member Forum Leader

    "If it is to offset less than adequate insulation in the main house, old single pane windows, or poor construction (deteriorated with time), this may be very reasonable."

    This may be the real reason for the wider parameters. I'll ask when I talk to him. The house is 170 years old, but it is not deteriorated ... well, I don't think so. We'd moved it years ago, put it on a new foundation and did our best to improve its insulation - it already had rockwool in its walls. I was kind of disappointed to find it didn't have dry seaweed in the walls as some even older houses in the area did - I wonder what "R" factor that gave them?

    I will be adding another layer of insulation over everything in the attic after the new ducts are put in and recaulking everything. I am hoping that will help along with building the addition which will wrap around the north and east sides.

    I'd like to have a propane furnace, if I can afford it, as a back up system because our power goes off randomly courtesy of our local utility company. While usually the outages are fairly short, longer ones during the winter can cause the house to get quite cold. I understand that I would be able to run it with a home generator whereas a geo system would need a lot more power to get going and run.

    "Consider buying the $50 60 day license to Don Sleeth's HVAC-CALC and performing your very own load calculation. That would backstop the load calculations you've received, expose you to the ins and outs of heat gain and loss (maybe there are window, door, wall, or other house features worthy of improvement that could get your loads down at modest cost), and empower you to more precise discussions with potential contractors." Hmmm, I will look into this. Thanks!
     
  20. gabby

    gabby Member Industry Professional Forum Leader

    Do you have propane now? If so that may be a good alternative, even though expensive for the short duration...but remember, furnaces need electric to operate the control valve, thermostat, and blower. They don't heat very much with the control valve closed, no call for heat from a thermostat, or something to blow the air from the plenum.
     

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