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Wow, that uses a lot more energy then I thought!

JakeCK
JakeCK Member Posts: 688
Finally turned the basement dehumidifier back on for the year. First time it has been on since before I've been able to see my energy usage in real time. I'll admit, I'm taken aback a bit by just how much energy it takes to keep my basement at ~%50RH. It is using about 10Kwh of energy a day, or a little over 300Kwh a month. And it isn't even really humid outside yet. My HPWH isn't even going to make a dent in that. It runs maybe 3-4 hours day. And it's sad that I spend more than 3x the energy just to keep my basement dry than I use to produce hot water for a family of four. So that begs the question, what can I do to eliminate that or significantly reduce it? My plan for this summer is/was to insulate and seal the foundation walls with 2" of polyiso bringing it up to r13 continuous insulation. And spray foaming the rim joists with dow's 2 part froth pak spray foam. Thoughts?

Anyone have personal experience doing anything like this? Have seen personally what kind of effect it has on humidity in the basement? How it affects infiltration and heating/cooling? The math and science says it will work and make a difference but I curious about anyone's personal experience.

You can see exactly when I turned it on Friday night around 8:30pm.



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Comments

  • Jamie Hall
    Jamie Hall Member Posts: 18,924
    Nice little lesson there in the physics of latent heat, eh? It's the same physics which makes steam heating systems work so well...

    But yes, reducing infiltration will help (but check and make sure you still have enough air changes per hour!). When you are doing insulation down there, however, make sure that you also do -- or have -- a continuous (like: be a fanatic) impermeable vapour barrier between the foundation and the interior space. heavy polyethylene sheet, well sealed around any interruptions, for instance, which extends to the top of the foundation walls and goes across the entire floor. Paint won't do it... exterior foundation drainage if it's working well will help a lot.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    JakeCK
  • JakeCK
    JakeCK Member Posts: 688
    So when I bought the house it had an office down there. The previous owner was a WW2 vet, a lawyer, and a factory worker at Ford. He paid for his education at Case while working at Ford. He was one of the few who didn't blow all their money drinking and gambling. Even after getting his law degree and passing the Bar he continued to work at Ford and got most of his legal work from coworkers. Wish I could have met him. He was in a nursing home with dementia by the time I bought the house.

    Anyways, my hope is to refinish it. He had his office and a bathroom down their for over 50 years before it started to have a moisture issue. I gutted it about a year after I moved in and it has been left as just a basement with a partially finished bathroom since then. I see no reason why I can't resolve these issues and rebuild a sanctuary from the kids down there for my self. The issue I believe is a combination of the failed sewer lateral(which is getting repaired late this spring, deposit is already paid), it is completely collapsed, water vapor migrating through the terracotta foundation, I can see the efflorescence on the foundation. And air infiltration from outside. The lake Erie shoreline is pretty humid all summer.

    This is what I'm using as a guide for insulating and sealing it:https://buildingscience.com/documents/enclosures-that-work/high-r-value-wall-assemblies/high-r-foundation-9-polyisocyanurate-insulation-2x4-framing-with-cellulose

    All of that sans the slab insulation because replacing the floor isn't an option, and I'll probably use rock wool insulation instead of cellulose. Now I wasn't going to do anything with the floor really, I even thought about looking into polishing the concrete floor and leaving it bare, and than just use area rugs. Yes I'll still get moisture migration through that but I'll at least eliminate what is coming though the walls.
  • Zman
    Zman Member Posts: 7,330
    I would suggest experimenting a bit to determine where the moisture is coming from. My guess is that it is wicking through the concrete walls or floors if you duct tape a ~2'x2' piece of plastic the floor and walls in suspect areas, the moisture forming on the backside will show you where it is coming from. This exercise will also reinforce why you want to be careful about where you install a vapor barrier. You want to be very careful not to trap moisture in the wall assembly. If the plastic sheets are relatively dry on the backside, you may just be condensing moisture ladened air on the cooler concrete surfaces.

    How is your exterior grading and drainage? Do you have gutters with downspouts that kick the water away? Is there a positive slope away from the building?

    I have solved similar issues by installing gutters and setting the dehumidifier to more like 60%
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    MikeAmannSTEVEusaPA
  • Dave Carpentier
    Dave Carpentier Member Posts: 172
    I know a couple of people who solved persistent moisture issues by grading and drainage, but you may end up having to also dig around the basement on the outside, reseal it, and improve weeping tile (if there is any). Speaking of weeping tile, is the sump pit covered and sealed tight ?
    30+ yrs in telecom outside plant.
    Currently in building maintenance.
  • Larry Weingarten
    Larry Weingarten Member Posts: 2,545
    Hi @JakeCK , How about testing by taping down about a foot square of clear plastic. Leave it for a day or so. See what moisture happens under it. If it’s wet, that’s a major source of water. See if you can find a glue to put down vinyl sheet goods.. or maybe tile. That could have a big impact.

    Yours, Larry
  • JakeCK
    JakeCK Member Posts: 688

    I know a couple of people who solved persistent moisture issues by grading and drainage, but you may end up having to also dig around the basement on the outside, reseal it, and improve weeping tile (if there is any). Speaking of weeping tile, is the sump pit covered and sealed tight ?

    No sump, just a floor drain. It does have weeping tile at the footer, and separate drainage tiles for the downspouts. Both are functioning until the water hits the collapsed storm lateral. At which point it saturates the ground and infiltrates into the sanitary. Things are still OK at the point, as long as the roots haven't yet backed up the sanitary lateral in the tree lawn. That is a bi-yearly maintenance item that I just have to call the city for. Don't ask me how I discovered that issue...
  • JakeCK
    JakeCK Member Posts: 688
    edited April 25
    Zman said:

    I would suggest experimenting a bit to determine where the moisture is coming from. My guess is that it is wicking through the concrete walls or floors if you duct tape a ~2'x2' piece of plastic the floor and walls in suspect areas, the moisture forming on the backside will show you where it is coming from. This exercise will also reinforce why you want to be careful about where you install a vapor barrier. You want to be very careful not to trap moisture in the wall assembly. If the plastic sheets are relatively dry on the backside, you may just be condensing moisture ladened air on the cooler concrete surfaces.

    How is your exterior grading and drainage? Do you have gutters with downspouts that kick the water away? Is there a positive slope away from the building?

    I have solved similar issues by installing gutters and setting the dehumidifier to more like 60%

    I just set it to 60% a little while ago. Lets see how it does. I don't like going much over that though.

    Yard is graded well. Downspouts are disconnected from storm sewer now since the city changed the ordinances. They are ran out away from the house.

    According BSC and Greenbuildingadvisor, I needn't worry about moisture trapped behind the polyiso. By sealing it all the way around one is essentially moving the building envelope further inward where both sides of the foundation are now considered outside of it. Mold growing on either side of the foundation is of no concern. Now of course the framed wall assembly must stay dry which is why the polyiso needs to have all of its seams taped and the top and bottom sealed well. https://greenbuildingadvisor.com/article/how-to-insulate-a-basement-wall#ixzz4MDszRDtJ&i
  • JakeCK
    JakeCK Member Posts: 688

    Hi @JakeCK , How about testing by taping down about a foot square of clear plastic. Leave it for a day or so. See what moisture happens under it. If it’s wet, that’s a major source of water. See if you can find a glue to put down vinyl sheet goods.. or maybe tile. That could have a big impact.

    Yours, Larry

    Vinyl flooring is an option...
  • mattmia2
    mattmia2 Member Posts: 5,512
    Maybe the code allows it but I can't see how moisture pooling on the surface of the foundation behind the wall (or floor) is going to end well.
  • mattmia2
    mattmia2 Member Posts: 5,512
    Oh, and are you sure the dehumidifier is functioning properly? So far I have a graveyard of 3 ~$250 dehumidifiers all of which have had the refrigerant escape.
    bucksnort
  • JakeCK
    JakeCK Member Posts: 688
    The dehumidifier is less than a year old. My previous one was just over 10 years old and had a foul smell when I started it up in the spring. For a full week I thought one of my cats decided to use my whole basement as a litter box. lol
  • ChrisJ
    ChrisJ Member Posts: 12,832
    edited April 25
    Mine runs 24/7 from April-October and the last time I did the math I think it was $40 a month.

    Due to the stone foundation and dirt floors there's not much I can do easily.

    But the way I see it is $40 a month is cheaper than renting a storage unit for all of my tools and such.  As far as the house and structure it doesn't seem to care one way or another.

    For more modern structures I'm not sure what I would do.  Sealing things up sounds like a good plan as long as it doesn't trap moisture in places.  To me. I would think sealing the outside is where to start.

    But I bet when you're done it's going to cost a lot more than running a dehu.

    Please let us know what you do and how it works out.  It's always nice to learn new ideas etc


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,992
    Controlling air temperature is easy.

    Controlling humidity is very difficult.

    Humidity will travel through any crack or opening.

    We had a temperature and humidity-controlled room (like a lab). The specs were 50% RH and 70-72 temp. The temperature was fine the humidity was not.

    We had completely rebuilt the three air handlers in this space, and we had a brand-new Carrier 100 ton chiller.

    We had 3 "engineers" running around the space trying to figure out what was wrong. We were running the chilled water temp at 44-54 which is typical CW temp.

    I sat in the corner and kept my mouth shut studying the Psyc chart which I wasn't that familiar with at the time.

    Afte a while I figured out we needed to keep the cw coils at below a 50 deg dew point which they were not with 54 deg return water. Only about 1/2 the coil was at 50 or below. We weren't "sweating" the whole coil.

    I ran upstairs to the chiller room and looked in the Carrier manual. It said we could run 38 degree water without glycol,

    I cranked the chiller down to 38-48 on the water temp and went back downstairs to find the room was now under control. I was up in the chiller room for 45 min at the most.


    It's all about dew point and the rate the humidity is coming into the space.

    In our case the room could have been sealed better

    Humidity transfer is almost instantaneous.
    JakeCKSolid_Fuel_Man
  • JakeCK
    JakeCK Member Posts: 688
    $40/month for 7 months of the year is $280/yr. If it were to cost one say $2K to purchase the insulation themselves and their own time to install it correctly. The payback would be less than 7 years. And that is straight line, without taking into account inflation, or the savings from not having so much heat escape though the foundation. I suspect we are all going to be hurting with in the next year or so when it comes to energy costs so I bet that $40/mo is going to become $60 or more soon enough.
  • JakeCK
    JakeCK Member Posts: 688
    @EBEBRATT-Ed Wouldn't insulating the basement walls help with staying above the dew point by keeping the basement temperature closer to the rest of the house?
  • ChrisJ
    ChrisJ Member Posts: 12,832
    edited April 25
    JakeCK said:
    $40/month for 7 months of the year is $280/yr. If it were to cost one say $2K to purchase the insulation themselves and their own time to install it correctly. The payback would be less than 7 years. And that is straight line, without taking into account inflation, or the savings from not having so much heat escape though the foundation. I suspect we are all going to be hurting with in the next year or so when it comes to energy costs so I bet that $40/mo is going to become $60 or more soon enough.
    That's true.

    But I was thinking digging up the foundation and sealing the outside etc.  

    Is trapping moisture in concrete block or a poured concrete foundation safe?  @Jamie Hall.    I have no idea.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 12,832
    edited April 25
    Controlling humidity can be difficult but I'm betting any improvement could be beneficial.  Slowing down how fast it comes in would likely be good if possible
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • hot_rod
    hot_rod Member Posts: 16,288
    You could also seal the concrete floors. Plenty of DIY options or have one of the garage floor coating companies come in.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Jamie Hall
    Jamie Hall Member Posts: 18,924
    No problem with trapping the moisture in a concrete wall, always assuming that there is a barrier between the foundation and the sills. The real trick is making the barrier really a seal.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • JakeCK
    JakeCK Member Posts: 688
    ChrisJ said:


    That's true.

    But I was thinking digging up the foundation and sealing the outside etc.  

    Is trapping moisture in concrete block or a poured concrete foundation safe?  @Jamie Hall.    I have no idea.
    Oh yea, I'm not digging around the entire foundation wall to waterproof it unless water is pouring in, which it isn't. There is no payback on something like that.

  • JakeCK
    JakeCK Member Posts: 688
    edited April 25

    No problem with trapping the moisture in a concrete wall, always assuming that there is a barrier between the foundation and the sills. The real trick is making the barrier really a seal.

    That barrier between the foundation and sill is one issue with this plan. This almost 100 year old house does not have that. That said I've read that as long as there is sufficient distance between grade and the sillplate and the foundation isn't covered with plantings and such so the sun and air can actually get to it, it should be ok.

    Now as far as reallying sealing it, if I use the closed cell spray foam around the rim joists and make sure it laps over the polyiso the top should be sealed well. Then by the cove joint I leave the foam board up an inch and seal that with the canned foam. And of course I would need to make sure all of the joints are taped. Penetrations such as where the gas line comes in are the only things I need to really worry about. again spray foam would work here.

    My biggest issue is the stairs. I might have to rebuild them because they are right against the foundation. But I was going to do that anyways because half the treads are split, and the bottom of the stringers are not in the best of condition.
  • mattmia2
    mattmia2 Member Posts: 5,512
    Remember if you are putting cyanide on the walls you need to cover it with a fire barrier.
  • The Steam Whisperer
    The Steam Whisperer Member Posts: 923
    How about a sump pit or two to drain the water from under the floor? The boiler room floor at my church used to be soaking wet all the time until we dropped a pump into the old sump where the underfloor drain tiles tied together ( the line to the sewers was plugged). Now the dehumidifier barely runs in that space. I also installed a new sump pit at my home where we would get water running across the floor after multiple heavy rains. Now, no water on the floor and you can hear the pump running occasionally to pump out the water.
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • JakeCK
    JakeCK Member Posts: 688
    edited April 25
    mattmia2 said:

    Remember if you are putting cyanide on the walls you need to cover it with a fire barrier.

    Cyanide? lol That's a little misleading.

    But yes, I'm aware it needs to be covered with a fire barrier such as drywall, unless of course one buys the polyiso that is rated to be left exposed. I will admit it has gotten very hard to find the the stuff that can be left exposed. And the increased costs(almost double) makes drywall much more affordable.
  • mattmia2
    mattmia2 Member Posts: 5,512
    It is polyisocyanurate. It releases cyanide when it burns. I don't want to know what sort of mental contortions they went to to get a rating for it to be exposed if such a thing exists.
  • JakeCK
    JakeCK Member Posts: 688
    Yes that is true when it burns. But lets talk about all the other synthetic materials in houses today and the crap they off gas even without burning.

    https://www.jm.com/en/building-insulation/residential/foam-board---sheathing/ci-max-foam-sheathing/
  • mattmia2
    mattmia2 Member Posts: 5,512
    The stuff they give off won't bind with the hemoglobin in your blood in place of oxygen and poison you in a similar way to carbon monoxide.
  • JakeCK
    JakeCK Member Posts: 688
    edited April 25

    No problem with trapping the moisture in a concrete wall, always assuming that there is a barrier between the foundation and the sills. The real trick is making the barrier really a seal.

    Oh and the flip side of that coin is if there is no dampproofing, and eventually even if there is, the foundation will always be damp. The soil provides a near infinite source of moisture that can and will wick through the wall. Unless of course you live somewhere like Arizona. In which case you can even insulate vaulted ceilings and attics with fluffy insulation with no ill effect.
  • JakeCK
    JakeCK Member Posts: 688
    mattmia2 said:

    The stuff they give off won't bind with the hemoglobin in your blood in place of oxygen and poison you in a similar way to carbon monoxide.

    No but they sure do mess with the endocrine system causing all sort of issues including epigenetic changes. The chemicals we've been dumping into the environment is causing animals to undergo spontaneous gender changes.

    And if we're all concerned with that maybe that is a good reason to get rid of appliances that produce CO and kill people regularly?
  • Jamie Hall
    Jamie Hall Member Posts: 18,924
    edited April 25
    JakeCK said:

    mattmia2 said:

    The stuff they give off won't bind with the hemoglobin in your blood in place of oxygen and poison you in a similar way to carbon monoxide.

    No but they sure do mess with the endocrine system causing all sort of issues including epigenetic changes. The chemicals we've been dumping into the environment is causing animals to undergo spontaneous gender changes.

    And if we're all concerned with that maybe that is a good reason to get rid of appliances that produce CO and kill people regularly?
    When you get to be my age, the only real regret you have is that you didn't raise a little more H__l and live a bit closer to the edge. I still regret selling my muscle car, but a friend lets me drive his 'vette and his Harley now and then. I vape instead of smoking now (used to be two packs a day of Camels, unfiltered) and I gave up the booze, but the only reason I don't fly any more is that I can't pass the vision test (used to b 20/10 -- where'd that go?). Wimps...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    bucksnortdelcrossv
  • mattmia2
    mattmia2 Member Posts: 5,512
    Of course a structure fire produced CO as well. Not sure about the volumes or if the cyanide has other issues like it may combine with and contaminate other things whereas the CO will dissipate.
  • ChrisJ
    ChrisJ Member Posts: 12,832
    The stuff they give off won't bind with the hemoglobin in your blood in place of oxygen and poison you in a similar way to carbon monoxide.
    No but they sure do mess with the endocrine system causing all sort of issues including epigenetic changes. The chemicals we've been dumping into the environment is causing animals to undergo spontaneous gender changes. And if we're all concerned with that maybe that is a good reason to get rid of appliances that produce CO and kill people regularly?
    When you get to be my age, the only real regret you have is that you didn't raise a little more H__l and live a bit closer to the edge. I still regret selling my muscle car, but a friend lets me drive his 'vette and his Harley now and then. I vape instead of smoking now (used to be two packs a day of Camels, unfiltered) and I gave up the booze, but the only reason I don't fly any more is that I can't pass the vision test (used to b 20/10 -- where'd that go?). Wimps...
    And yet someone mentions an unvented natural gas fire place and you throw your hands up.


    Interesting.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • bucksnort
    bucksnort Member Posts: 160
    JakeCK said:

    No but they sure do mess with the endocrine system causing all sort of issues including epigenetic changes. The chemicals we've been dumping into the environment is causing animals to undergo spontaneous gender changes.



    I blame it on Disney
    JakeCKMikeAmannJUGHNESolid_Fuel_Man
  • ratio
    ratio Member Posts: 3,174
    The good news is that once we've switched everything over to heat pumps all these problems will go away.
    pecmsgdelcrossvSolid_Fuel_Man
  • SlamDunk
    SlamDunk Member Posts: 1,283
    JakeCK said:

    The dehumidifier is less than a year old. My previous one was just over 10 years old and had a foul smell when I started it up in the spring. For a full week I thought one of my cats decided to use my whole basement as a litter box. lol

    So THAT is what made my basement smell like that! It took longer than a week to go away for me. I thought it was the PVC I laid in the crawl space.
    JakeCK
  • pecmsg
    pecmsg Member Posts: 2,881
    ratio said:
    The good news is that once we've switched everything over to heat pumps all these problems will go away.
    I wouldn’t bet on that!
    JakeCKdelcrossvSolid_Fuel_Man
  • JakeCK
    JakeCK Member Posts: 688
    edited April 25
    SlamDunk said:
    The dehumidifier is less than a year old. My previous one was just over 10 years old and had a foul smell when I started it up in the spring. For a full week I thought one of my cats decided to use my whole basement as a litter box. lol
    So THAT is what made my basement smell like that! It took longer than a week to go away for me. I thought it was the PVC I laid in the crawl space.
    Lol Maybe. I couldn't figure it out, I kept sniffing around the basement but it was so powerful I couldn't localize it. I even crawled my a** up into my crawl space thinking the sewer line for the back bathroom broke or something... It truly was pungent. 
  • JakeCK
    JakeCK Member Posts: 688
    pecmsg said:
    ratio said:
    The good news is that once we've switched everything over to heat pumps all these problems will go away.
    I wouldn’t bet on that!
    Not with out some serious envelope upgrade anyways.
  • CLamb
    CLamb Member Posts: 114
    A pity the waste heat from the dehumidifier is just dumped into the air instead of used to help heat the hot water. If only there was a way to do this easily.
    Zman
  • Jamie Hall
    Jamie Hall Member Posts: 18,924
    ChrisJ said:



    JakeCK said:

    mattmia2 said:

    The stuff they give off won't bind with the hemoglobin in your blood in place of oxygen and poison you in a similar way to carbon monoxide.

    No but they sure do mess with the endocrine system causing all sort of issues including epigenetic changes. The chemicals we've been dumping into the environment is causing animals to undergo spontaneous gender changes.

    And if we're all concerned with that maybe that is a good reason to get rid of appliances that produce CO and kill people regularly?
    When you get to be my age, the only real regret you have is that you didn't raise a little more H__l and live a bit closer to the edge. I still regret selling my muscle car, but a friend lets me drive his 'vette and his Harley now and then. I vape instead of smoking now (used to be two packs a day of Camels, unfiltered) and I gave up the booze, but the only reason I don't fly any more is that I can't pass the vision test (used to b 20/10 -- where'd that go?). Wimps...

    And yet someone mentions an unvented natural gas fire place and you throw your hands up.


    Interesting.

    Thing is, @ChrisJ , with very few exceptions (which I have regretted) I've never done things which put others at risk, or at the very worst at risks which they had not also understood and accepted. And once I became an at least vaguely responsible family man, I tried to lower my risk tolerance a lot. But yeah, in some ways I'm kind of an odd dude...
    CLamb said:

    A pity the waste heat from the dehumidifier is just dumped into the air instead of used to help heat the hot water. If only there was a way to do this easily.

    Problem with that is that the heat isn't wasted. The whole way in which dehumidification works is that the air is cooled to the dewpoint corresponding to the relative humidity at the desired air temperature, and then reheated back to the desired temperature.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England