The envelope

Discussion in 'Geothermal Heat Pump Testimonials' started by waterpirate, Dec 27, 2010.

  1. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    I seem to have perpetuated a really bad stereo-type by accident. Improvements to my 100 year old envelope move at a snails pace for a variety of reasons, most of them lead back to procrastination. The western exposure was stripped to the studs and insulated and re sheathed and shingled 3 years ago, the northern face is slated for this spring. The weather man had predicted baaad snow and wind for Cristmas, and he was right. We are snowed in now, state of emergancy, yada yada.
    Prior to the arrival of the front Mrs. Waterpirate convinced me to swing by Lowes and pick up some caulk to put a band-aid on the northern face prior to the front. Well I was cranky to say the least but I went. I purchased 4 tubes of goober at about 2.85 a tube, lets round up to 3 bucks each for a total investment of 12.00. I spent about 2 hours humoring the wife spreading it liberally in the cracks, gaps, and other places, including my ear on the north side.
    Now hear is the embarrassing part. The wind is blowing out of the west at about 35mph and gusting 45. We have 8 inches plus of snow. The wind chill is in the teens. I gained four degrees of capacity in my short tonnage downstairs unit!!:eek:
    I am estimating for every 3.00 tube of goober I gained a degree of capacity. Now the re siding and shingles are still going to happen in te spring, but the importance of envelope can not be overlooked here, or down played. Mrs. Waterpirate is just as smugg as she can be, all full of listen to me and I told you so, which I fully deserve and wear quite well. Oh well.
    Now the stereo- type. The house painter who has the peeling house paint. The mechanic who drives a pick up with a dead miss. The looper with the leaky house that was greatly improved by a 12.00 investment of goober.:D
  2. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    I am always looking to seal the conditioned space when possible. Great job, I hope Mrs. Waterpirate is good with your effort. Very important when you are snowed in.

    We are lucky that the snow missed DC. We are still grounded as the wind makes me nevous driving the motor home on the interstates through the mountains. I may try taking route 40 east to Morgantown.

    We will be back often as our daughter lives in DC and helps advise Public Transportation Systems. Next time it we are here and it is not snowing sideways at 45 MPH we will come inspect the caulking and bend elbows.

    Last edited: Dec 27, 2010
  3. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Sounds good Mark, my schedule went from crazy busy to deadstop thanx to the weather. Give me a shout next trip through.Eric
  4. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    Way to go Eric,

    you are a better man than I.

    When ever I give my wife has reason to gloat, I try not to tell anyone and I would surely never post it online for all the world to view. :D:D
  5. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Au contrair

    When confronted with hard evidence I ALWAYS admit fault early and unabashedly

    It confuses my adversary and paves the way for more mistakes.

    I've seen some online info lately suggesting that stopping infiltration is way more important than adding a bit more R-value, so I'm not suprised at WP's outcome
  6. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Yesterday I went out in the snow because the hvac tech told a home owner that his red light on the thermostat was on due to the well guys pump defficency???????:confused:

    After looking at the system and evaluating the water pump, go fish. It is a brand new modular two story, touted to be energy star rated. Short of the manual j being botched up I suspect improper sealing or no sealing in a portion of the assymbly. I.E. infiltration. The wind is going sideways at 45 mph at the home owners house, just like at mine.

  7. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Ahhh the "automechanics car" stereo type. Would that be like a geo guy with a gas furnace with jumped out safety controls short cycling in his attic 'til the new unit in his garage (since last winter) gets installed? All hypothetical, but my wife's gonna kill me if I don't get that thing installed.
  8. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    testing to face book
  9. Verdae

    Verdae Member

    Infiltration really is more important than more insulation. The infiltration will negate extra pink fluffy stuff every time. I suggest anyone who wants to understand how their envelope should be constructed or repaired should go to and get their book for your climate. Building science needs to be understood in order to really get a building to perform. It is all about applied physics. Think about this: for every cubic foot of cold dry air coming into the building a cubic foot of warm moist air has to leave, infiltration and exfiltration are linked. I have fixed many poor performing geothermal systems, where the loop or equipment is undersized, by improving the buildings performance. Lowering the load is the easiest way to improve the operational efficiency of the geothermal system. The building is a system and the geothermal HVAC is a sub system of the total system.
  10. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Here here!
    Nice post and totally agree
    I would only add what has been identified here previously that in most cases it is more cost effective to improve the envelope than up size the eqipment to meet a leaky load.
  11. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    System size and operating costs are more reasonable if the system has to just heat and cool the home, not the yard and neighborhood.

    I agree that way too much emphasis is sometimes placed on insulation rather than air sealing.

    R50 walls don't help much if there is leakage equivalent of a window being open 24/7
  12. Verdae

    Verdae Member

    Build it tight and ventilate it right. I start with the mandate that the building will require mechanical ventilation in the form of an ERV. I have one builder who reliably gets less than 500cfm/-50 blower door leakage test for his 3500+ sqft homes, 250cfm/-50 for more than one home.
    These homes get a two ton two stage geothermal unit with 500' foot loop in hard rock and I use water as the loop fluid. By reducing the load, the equipment is smalle, the efficiency stays high, the btu output stays high and the system cost is managed.
    The best part is the homes are extremely comfortable and durable with high indoor environmental quality. Asthma tends to diminish or disappear and general health improves.

    This is the least understood part of building tight and ventilating right. Comfort, durability and indoor environmental quality, all things people value and desire, are only truly obtainable when the envelope is super tight. Sealing 90% of the holes only yields a 50% reduction in infiltration due to the fact that the forces inducing infiltration are unchanged no matter how tight the building plus air is compressible and likes to move fast. The equation must be balanced so more air has to move through the small holes that are left. Only by sealing every hole and crack can the air flow be controlled and control is critical. The leaking outside air creates cold spots for moisture to condense. The dust mites and mold must have liquid water to grow and the air leaks create the small amount of water they need. It is all about physics and biology.

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