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Newly built house... A/C running all the time to keep cool??

Michael Little
6 years ago

We just finished our new home with spray foam throughout. It's a piling home with spray foam in the lower floor, roof and all walls. We live on the panhandle of FL and the last days have been nice (75-80 with mild humidity). We have 2 zones and I was keeping the lower level at 76 and the upper level at 76 as well but I feel like the A/C is running all the time. We have a lot of windows so I can imagine heat coming from there, but after the sun went down last night and it was 68 outside the A/C was STILL running to keep the upper level at 76. When I woke up this morning it was STILL running. Our second level has a loft that over looks a tall foyer.. so I imagine a lot of the heat is rising to the second level? But at some point it should be cooling the house and holding a temperature shouldn't it? The thermostats are both ecobee4 and have yet to connect them to the internet or with other room sensors yet. At night the other rooms are noticeably cooler than the loft, but I still find it crazy that we cannot keep the loft cool without running the A/C nonstop.

Comments (113)

  • Michael Little
    Original Author
    6 years ago

    And I remembered I had this in the home inspection report we had done:

    Energy Source: Electricity 240 Volt Power Supply

    System Type: Air Source Central Heat Pump System

    System Manufacturer:  #1 & #2 Carrier

    System Description: Model #CH14NB030Serial #1-3717X40564 Approximate Age (in

    years):,#1-New, Serial#2-3717X40574

    Temperature Drop Recorded: 19 Degrees

    Air Flow:  400 fpm avg

  • sofikbr
    6 years ago

    I am not an expert, but we live in Florida with 3,200sf home. Two story. AC is not running all time. But we have two units. 5 ton for downstairs and 3 ton for upstairs. Our first floor is 2,200 sf and second 1,000. Also if you will decide to update units to larger one eventually, your system might need to be updated for larger unit. From little that i know if unit is low, pipes going to unit and blades will freeze. Water coming out of pipes is dehumidifier working.

  • PRO
    Austin Air Companie
    6 years ago

    Marisha,

    The pictures are considerably different from what I was expecting. I suspect you are either in an area prone to flooding or maybe some requirement for hurricanes as to why the condensers are installed on that platform on exterior of home.

    That's going to make servicing these systems much more difficult.

    Anyway, the drain pipe appears to be secondary pipe, for simple reason it's not insulated. However, to be certain I need to see picture of indoor equipment that shows piping coming out of the air handler and I also want to see if the air handler is sitting in a drain pan.

    If you can get me pictures of that I can make a better determination. It should be noted why you have two drain pipes to the exterior. (You have two HVAC systems) Typically when drain pipes are run this high and terminate this high they are there to warn you of trouble. You should never see water dripping from them. (who would want to buy a house like that? Think eyesore.)

    If there is dripping inside the picture you posted what looks to be air return box, this dripping is probably coming from dripping caused by freezing coil. When a coil freezes it will block the path of the primary drain, in addition to that the primary drain pan can sweat. It's either that or the drain pan is cracked.

    Based on ecobee chart plots, the needle still points to refrigerant charge issues.

    There is no load on this house look at out door temps!

  • Michael Little
    Original Author
    6 years ago

    So the house is a piling home since we built on the water. Here are some pics of the HVAC and pipes. This is everything that I can see.. everything else are inside walls. The left pipe you can see below was not dripping but lightly streaming water out of it. Not sure which unit goes to what.. I'll have to turn one on and find out.

  • Michael Little
    Original Author
    6 years ago

    More pics...

  • Michael Little
    Original Author
    6 years ago

    And more..

  • PRO
    Austin Air Companie
    6 years ago
    last modified: 6 years ago

    How long I've been doing what I do, very little surprises me. But from what you show, surprises me.... mostly because this is a new build, and builders should know better.

    There's several concerns with this set up. As far as I can tell from what you show, the primary condensate lines run to the outside. This is really a bad idea, for several reasons above eyesore reasons. Given the climate of your location there will always be a wet spot out doors. This can cause all kinds of nuisances in the form of pests namely mosquitos which are known carriers of diseases, not to mention staining of the exterior if the water trickles off the exterior of the home.

    There is no condensate overflow protection, except for a cheesy float switch dongle at the base of the air handler. These condensate drain problems will only get worse as the home ages. I suspect that building codes in your area are considerable lax in terms of where condensate waste water can go.

    Depending on how they wired the float switch dongle this can lead to other problems given your climate and how humid it is. My location is similar to yours and it's not uncommon for an AC here to generate 5 gallons of water an hour in condensate waste. That is a lot of water. You have 2 systems if you follow me.

    Because your Air Handler is in a closet and vertical mounted the options tend to be quite few to deal with condensate waste water, but clearly it would be better to drain this waste water into your plumbing system rather than outdoors.

    To alleviate the problems with condensate waste water I would continue to pipe the drains to near ground level and install French drains for both AC condensate drain lines to run into. This is code for my area when other options aren't feasible. (But only for primary condensate line, not a secondary drain line.)

    As time goes on the drains could become slow draining this may take 10 years or more. Due to the float switch dongle set up and your humid climate the condensate drain gets over whelmed under heavy cooling and high humidity causing the poor float switch dongle to trip and in essence short cycles the ac system. Certainly you could be lucky and never experience this problem. I've seen it too many times to not comment about it. Condensate drains for humid climates are recipes for disaster if not dealt with properly. If the cheesy float switch dongle is removed or disconnected your house would flood due to no condensate over flow protection in the form of a secondary drain pan. So as time goes on be careful who you let work on this system.

    This is what I mean when I say builders build and move on to next build. The things they do are often end result of problems you incur as your home ages.

    The condensate waste water problem is above and beyond the cooling problems you are having. Hopefully you can get the builder to correct this.

  • Michael Little
    Original Author
    6 years ago

    Thanks Austin.. is there any way to determine whether or not this was calculated properly? This calculation was done before we decided to go with spray foam. Either way I noticed at least one difference. The windows he listed are .27 SHGC but what's installed is .29. Can anyone take a look at this and see if it's accurate of what equipment I have and that it was done correctly? Mainly I'm interested in the BTU/hr as it confuses me. On the document it says 45.4 for cooling systems. Is that what I have, or what's required? And is that per system considering it's a dual zone?


  • Michael Little
    Original Author
    6 years ago

    Anyone have insight on the Code Calc?

  • deegw
    6 years ago

    Marisha, if you don't trust your current HVAC company or builder, you should talk to your friends or real estate agent and get the name of a respected HVAC contractor in your area to come out and go through your space.

    Diagnosing HVAC issues via the internet is dicey at best.

  • sktn77a
    6 years ago
    last modified: 6 years ago

    The 45-46 kbtu/hr is consistent with the 1350 cfm listed also. This is a bit strange(?)

    2 x 2.5 tons should be about right in a new build like yours, although as someone else has pointed out, you need to beef up your ceiling insulation.

    How are the systems performing after the additional refrigerant was added?

  • mike_home
    6 years ago

    The document you posted is not the output of a Manual J load calculation. The calculation which show all the data of sizes and insulation values, and the resulting heating and cooling loads. This seems to be a summary of the house's energy performance features. It does not indicate if the equipment is properly sized.

  • Michael Little
    Original Author
    6 years ago

    Well the county says this is all they have...builder gives me nothing...hvac says they don't have it. Gulf power was just here and said the hvac company would have accomplished it. How would they not have it?? Was it never done??

  • mike_home
    6 years ago

    If it is not required for a building permit then good chance a load calculation was not done.

  • Michael Little
    Original Author
    6 years ago

    its required

  • PRO
    Austin Air Companie
    6 years ago
    last modified: 6 years ago

    If you can't get the heat load from the HVAC contractor, the only true way would be to hire a HVAC contractor to come out and perform it. It might cost you $500 or more depending on size of structure.

    It's best to have someone go to location, take measurements to perform calculation.

    Don't try to do this in the summer or heavy demand time (hot outside), you will probably get shunned... and you may get shunned anyway because the home is new and already built.

  • opaone
    6 years ago

    My first thought was frozen coils. Second was charge. That charging was required at all is concerning. When the system was installed they should have provided you with a document stating the charge in both systems. When the tech came back out they should also have provided you with another document stating current charge and where they left it.

    Does Florida require all ducting to be within the insulation envelope so that leaks in ducting are not major issues? If not and if OP's are not then checking for duct leaks would be a good idea even if the system seems to be performing correctly.

    Outside units are on west side? Full sun all afternoon is good for some plants, not so good for A/C systems. Would some shading help?

    Get an IR thermometer from Thermoworks and measure your ceiling temps. There had been some problems with builders in some parts of Florida, namely Collier County, not allowing proper attic ventilation so ceilings would be like hot plates making houses nearly impossible to cool.

    0.29 SHGC seems high for Florida?

    What was the ACH50 on your house?

    Someone above mentioned insulated drapes. These or blinds can make a room more comfortable but they do nothing to lower the heat load of the house. The heat is already inside. Shading like this must be done outside (and is a very good idea).

  • Michael Little
    Original Author
    6 years ago

    The attic is a conditioned space. I'll have to measure temps of the ceilings when I find the temp gun..hope fully today. When I look at the soffit around the house there are NO visible vents. Does that mean there is no venting? Should there be venting with a spray foam roof? The last 2 days we have set the A/C at 78 and it has not run at all. However this requires opening windows. I did notice that when I open windows in the morning (50 degrees 40% humidity) the temperature in the house drops as does the humidity. Woke up at about 55+% and opening the windows caused the temp to drop from 73 to 60 and humidity to 35%. Is this a venting issue??

  • Michael Little
    Original Author
    6 years ago

    Anyone have any more thoughts on this? I have not run the A/C for a few days now. Outside temps at about 70. Opening the windows all day makes the temp drop as well as humidity. Got home last night and closed the windows after the sun went down. Temp rose from 73 to 77 and humidity increased as well.. How is that possible? Is the heat not able (or supposed to) escape?

  • opaone
    6 years ago

    You can do an unvented roof w/ spray foam directly underneath the sheathing. I'd never do it, but people do. There are two issues you have to be concerned about; heat and condensation (and ice dams in northern climates).

    Roofs are like giant heatsinks. The sun's rays heat up the roof surface and everything underneath. Also keep in mind that heat rises, and often with great force. Every bit of heat in the structure rises and finds it's way in to the roof structure. It takes an enormous amount of insulation to protect from that amount of heat. Some people tried PERSIST construction without venting and even those with 14" of XPS (R-70) were finding increased cooling loads vs having an air vent.

    When warm humid air encounters a cold surface the result is condensation. When this happens within a wall or roof structure then mold develops. Building structures s/b designed to prevent this.

    More: https://buildingscience.com


  • opaone
    6 years ago

    Your house s/b well sealed so that when you close doors and windows that it will not get a lot of air exchanges. Your builder should have provided you with a blower door test report to tell you what the ACH50 value (air infiltration) is. The lower the better.

    The best ventilation is always open windows whenever outside temps and humidity allow. This costs less, wastes less energy and is much healthier. The latter is particularly important for the first couple of years of new construction when materials are still off-gasing.

    However, when you do close everything up your A/C should always be able to keep the inside comfortably cool and dry. A bit of a bump up in temp is not unusual when you first close all the windows but it shouldn't last more than about 15 - 20 minutes.

    If you've had windows open with somewhat high humidity then it will take longer to cool down than the same temp with low humidity, but it should still cool down fairly quickly. An exception might be extremely high humidity that will cause the A/C system to moderate itself to prevent icing the coils.

    In any case, your system does not sound like it's working properly, regardless of house structure and should be looked at by a third party not associated with your builder or their HVAC folks.

  • mike_home
    6 years ago

    If the attic is sealed then it would be counter productive to punch holes in the soffits. It sounds like your house is very tight and the moisture in the house has no way to escape unless you open the windows. Your AC is not working properly so it is not helping to lower the humidity.

    A ventilation system would help. Once the AC is fixed it may get the humidity down to an acceptable level. If not then a dehumidifier may be required.

    There is a lot going on in your house between HVAC and construction. You need someone who knows what they are doing and you trust to make the correct recommendations.

  • Michael Little
    Original Author
    6 years ago

    opaone.. you have to understand.. my builder left things unpainted, unfinished and is the most unprofessional person I have ever come across. He provided me with nothing. Is the blower door test required by code?

  • Michael Little
    Original Author
    6 years ago

    He actually text me back.. said blower test was not required so was not accomplished

  • opaone
    6 years ago
    last modified: 6 years ago

    As of 1 July 2017 a blower door test is required of all new homes.

    http://www.floridabuilding.org/fbc/commission/fbc_0817/Energy_TAC/Blower_Door_Testing_Guide_for_BASF_for_TAC.pdf

    @mike_home, agree that vents would be counter-productive at this point.

  • Michael Little
    Original Author
    6 years ago

    So even though we commenced April 2017 and completed Jan 2018 it would be required?

  • opaone
    6 years ago

    I think that's up to your local building inspector. Some are telling builders that it's been known for a couple of years so no CO after 1 July without it. Yours may be applying it only to those permitted after 1 July.

  • energy_rater_la
    6 years ago

    although blower door and duct test are now code, here in La.

    builders & ac folks do their own testing. which means a large

    percentage of results are in favor of their work.

    hire an energy rater with experience in building envelope.

    blower door test house, then test attic to make sure

    that foam insulation has created a sealed unvented attic.

    have the rater mark leakage areas on foam insulation

    with spray paint.

    in my years of testing homes I find that many unvented

    attics are not truly unvented. usually the soffit area is not

    completely sealed.

    invest in an unbiased testing and diagnostic of your home.

    its to your advantage. you'll learn a lot about your home.

    and keep the windows closed, and never run fan in on position

    all the time. set to auto. with fan on the moisture removed

    is redistributed throughout your home.



    best of luck.

  • opaone
    6 years ago

    "with fan on the moisture removed is redistributed throughout your home."

    ??

  • PRO
    Austin Air Companie
    6 years ago

    Anyone have any more thoughts on this? I have not run the A/C for a few days now. Outside temps at about 70. Opening the windows all day makes the temp drop as well as humidity. Got home last night and closed the windows after the sun went down. Temp rose from 73 to 77 and humidity increased as well.. How is that possible? Is the heat not able (or supposed to) escape?

    This is only a suspicion (guess)... you have spray foam attic and the attic is conditioned right?

    When you open windows this acts as a vent and allows heat to escape, when you close the windows this keeps heat in and relies on your air conditioner to get rid of the heat. If the air conditioner is not working properly, it will not remove the heat.

    If the indoor coils are icing up (on a new home), this is typically due to improperly charged AC system, defective or clogged up metering devices, refrigerant leaks, low / improper air flow across indoor coil or poor or improper duct system. It could be one of these issues or a combination of them.

    Indoor coils do not freeze on a properly charged system with proper air flow / clean filters, no refrigerant leaks etc. Typically the indoor Evaporator coil runs between 40 - 50 degrees Fahrenheit under normal operation.

    If an evaporator coil is freezing there is always a reason.

  • udarrell
    6 years ago

    Problem can be an undersized duct system with filter too small with excessive velocity & pressure-drops causing very low performance...

    I need Techs to check new clean RA filter fpm velocities, starting with a popularly used 16X25 filter of various types so we can divide the velocity in fpm into the CFM flow volume to get the filters Ak (open air area).. Example; 800-CFM / 250-fpm = 3.2-Ak. Most filter areas are way undersized as is a lot of duct systems leading to very poor performance in both heating & cooling modes... Publish the results here, this is very important...! Thank you, Darrell AKA ' udarrell '

  • energy_rater_la
    6 years ago





    opaone

    moisture removed from air collects on coil.

    leaving the fan in the on position means that after

    the a/c shuts off, the fan continues to run.

    as the fan runs after the a/c stops the moisture that

    has collected on the coil is re-distributed throughout the house.

    this undoes all the humidity removal as you are taking it out

    of the house...then putting it back into the house.

    in hot/humid climates fan should be set to auto, not on positon,

  • opaone
    6 years ago
    last modified: 6 years ago

    How much moisture remains on the coils after the compressor turns off?

    The bulk of the moisture should drain off during each cycle unless the HVAC folks installed too large of a system that results in extremely short cycles (or the fan speed is set too high during a cool cycle). The IAQ and other benefits of a continuously running fan would seem to outweigh the minimal amount of moisture.

  • weedmeister
    6 years ago

    "How much moisture remains on the coils after the compressor turns off?"

    A lot. My folks had a system that stayed on 30 sec after the compressor turned off. You could feel the humidity level rising at the end of each cycle.

  • opaone
    6 years ago

    The only way I can imagine that being possible is if their coil was icing (or a flat coil (vs A) was laid too flat to drain off properly). Otherwise there should not be that much moisture remaining at the end of a cycle.

  • Michael Little
    Original Author
    6 years ago

    We have yet to run the A/C really since I last posted... there are still a number of issues. We have a leaky roof done by an unlicensed roofer the GC used, numerous cosmetic defects, light switches that don't work.. but honestly what does it matter? Seems there is no recourse whatsoever and the so called warranty that's provided is a complete crock. Not enforceable at any level.

  • klem1
    6 years ago

    Jerry Reed might say,"The GC got the gold mine and gave you the shaft".

  • suzyq53
    6 years ago

    Hire a lawyer. The GC has to be insured.

  • opaone
    6 years ago

    What is your GC saying about the roof, light switches, AC and other problems? I think that no matter how good of a builder there will be problems, building a house is a complicated project with a gob of things going on, but a reliable and honest builder will correct them.

    As above, it may be time to talk to an attorney.


  • Michael Little
    Original Author
    6 years ago

    The GC doesn't say anything about anything. Doesn't return phone calls, texts... nothing. We have everything tied up in this house thinking we were building our dream house. Don't have the money for an attorney.

  • latifolia
    6 years ago

    Marisha, feel so sorry for you. It must be incredibly frustrating. Building a home is a dream for so many people. Reading your woes may help folks to understand how stressful it can be, and that one doesn’t always get exactly what one hoped for.

  • suzyq53
    6 years ago

    Some lawyers will take cases on a contingency basis, meaning if they think its a good case they will work for a percentage of the recovery, not an hourly fee, with minimal upfront cost to you. You could make some inquiries to see if that is available in your case. Or you might consult with an attorney, meaning pay for an hour or two for contract review and advise on your options. The GC should be insured, so any failure to honor warranty claims, would be made through the insurance company.

  • opaone
    6 years ago
    last modified: 6 years ago

    If your builder is not responding then it sounds like time for a good attorney. Are you in a well planned community like Rosemary Beach? If so then they will often help you to put pressure on your builder as they don't want shoddy work in their communities.

  • Michael Little
    Original Author
    6 years ago

    Our community is called lighthouse pointe in Gulfbreeze FL. they have a HOA but nothing super strict.

  • opaone
    6 years ago

    An HOA will likely not be of much help. Find a good attorney.

  • suzyq53
    6 years ago

    Has your builder built other homes in that HOA? How many lots are left to be built-out?

  • Michael Little
    Original Author
    6 years ago

    No..he most likely won't build here. It's really barely a HOA. As far as an attorney, I looked around previously. Didnt ask about the % of the judgement thing.. but they are about $275 an hour. I'll call around to see if there are any willing but we simply can't afford to pay that.

  • deegw
    6 years ago
    last modified: 6 years ago

    I mentioned way up thread that you should talk to friends or your real estate agent and ask for the name of an a/c company that they trust. Explain your situation and have them come out and do an inspection. It could be a very simple fix, like a duct tear. You are more likely to get someone to come out now when it is slow than in the dead of summer.

    Don't go into a long complicated explanation. Just say you feel like the a/c is not working properly, the builder is ignoring calls, will you come out and do inspection?

    If the a/c inspection finds a more complicated issue then take some photos and you will have ammo against the builder.

  • Michael Little
    Original Author
    6 years ago

    Thank you Suzyq.. I'll contact these guys this week. I hear them on the radio and thought they were only injury lawyers. I'll have to look at the contract but I do know it didn't specify mediation or rule out litigation.