Airtap - any users here?

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  • TheBackRoads
    TheBackRoads Solar Expert Posts: 274 ✭✭
    Re: Airtap - any users here?

    off topic but whats "cheap natural gas" cost?
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?
    off topic but whats "cheap natural gas" cost?

    Not sure, since I don't have gas. I know a few people who have gas water heaters and they say it's really cheap compared to electric water heaters..

    This is page is about Heat Pump Water Heaters.
    http://www.mge.com/business/saving/BEA/_escrc_0013000000DP22YAAT-2_BEA1_PA_PA_WaterHeating_PA-26.html


    Since I'm paying 16.33 cents per kWh, this chart it telling me bad news.. Simple Payback is Never!
    _files_esource_images_PA-26_2T.gif

    But, during the last 6 days, the A7 has done very well. Using just under 6 kWh.
    If it stayed this warm, :p that would come out to only $59.60 per year.. (at $0.1633/kWh).
    But, since it's going to get colder.. We'll have to wait and see how it performs.

    During the last 12 months, we've been burning up $2 a day in fuel oil. $730 for the year. :(
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Airtap - any users here?

    We pay around $1.25 per therm. Or $12.5 Mbtu.
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    The A7 Airtap works okay in cold basements

    Here's my status report. http://ecorenovator.org/forum/geothermal-heat-pumps/2286-a7-airtap-install-ashp-hot-water-heater-25.html#post28463

    Re: The Solar Boost
    I've got 800w of PV connected to lower heating element in the GE water heater. Good sun gives us 500-800w.
    It's for an experiment I'm doing, to see if a small PV array can help with the cost of hotwater.
    So far, I've found out the PV easily makes enough BTUhs to over-come the thermal heat losses of the water heater.
    When the weather gets better, I hope to be able to see how much help 800w can be.
    Due to the very erratic hot water use of two old people, this is going to be a longish project.. :p
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Airtap - any users here?

    Had an interesting convo with one of the guys I know at a building supply cntr re water heaters with the heat pump on top. They're getting lots of complaints re them making the basements very cold. Problem is serious enough that they're bringing in a special vent system that will bring in outside air to the heat pump, then exhaust the cold air outdoors.
    I knew they would cool whatever room they were installed in, but had no idea it would be such a problem.
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Airtap - any users here?
    I knew they would cool whatever room they were installed in, but had no idea it would be such a problem.
    You have to get used to thinking about heat pumps in general. All of the heat that goes into the water tank (with the exception of what is provided directly by the AC input watts) has to be pulled from the room air.
    Think of a mini-split AC which draws that same amount of power as the Airtap, and it should be less of a surprise.
    SMA SB 3000, old BP panels.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Airtap - any users here?

    Hmmm cheap beer cooling eh?
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?

    It's not a big problem with our system, since we don't heat the basement anyway.
    Since we stopped using the oil burner, we don't even get the benefit of heating boiler heat losses in the basement.

    The heat loss via the floor(between upstairs and the basement),
    from the heated spaces upstairs provides much of the basement's heat.
    The second heat source is the basement floor slab. It gives up a little geothermal heat.

    We use mini-split systems upstairs for all our heating (and cooling), and the floor on the unfinished
    side of the basement is where the A7 is located..
    Here's a video.. th_basementSmall_zps53faf5f3.jpg


    When I scan the concrete walls in the basement, they are warmer down near the floor,
    but very cold up near the top of the wall(other side is in the open air, outside).
    Depending on outdoor temps, they can be down around 25 deg F. That's a LOT of heat leaking out!

    So the floor near the A7 can get colder than 44F while it's running, but an hour later the area is back to normal.
    It' the same temperature as the floor 40 feet away in finished basement areas. Must be the geothermal.
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?
    westbranch wrote: »
    Hmmm cheap beer cooling eh?

    Beer and wine.. :)
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?
    Problem is serious enough that they're bringing in a special vent system that will bring in outside air to the heat pump, then exhaust the cold air outdoors.
    .

    If it's really cold outside, you might not be able to get much hot water.. I know the A7 works pretty well down to 44 degrees F.
    But, I've not tested it at lower temperature. My guess is, it will work poorly down in the teens.
    So, venting 18 deg F air into the basement isn't likely to work very well..

    And of course you can't just vent the cold air outdoors.. Since that would cause outdoor air to be sucked indoors.
    It would work like a clothes dryer, sucking the winter air indoors!


    When I was working in my shop, I found that a 1200w space heater would keep the area from getting overly cold.
    I did not notice any change in A7 run time, but the room temperature didn't have to recover much when the A7 shut off.

    Experiment # 63718B:
    I rigged up an automatic switch to turn on the 1200w space heater whenever the A7 ran.
    Put the heater up where it would blow hot air right into the A7 input.
    It worked fine. The room didn't cool off as much, but the power use of the A7 seemed about the same..
    So, the kWh used by the space heater was kinda, wasted money..
    Ended Experiment # 63718B after about 2 days. Marked as Failed :p
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Airtap - any users here?
    XRinger wrote: »


    So the floor near the A7 can get colder than 44F while it's running, but an hour later the area is back to normal.
    It' the same temperature as the floor 40 feet away in finished basement areas. Must be the geothermal.

    ...
    When I scan the concrete walls in the basement, they are warmer down near the floor,
    but very cold up near the top of the wall(other side is in the open air, outside).
    Depending on outdoor temps, they can be down around 25 deg F. That's a LOT of heat leaking out!

    Properly called a ground source heat leak, I think, since nobody is pumping and you are not going down to the really active heat supplies further down in the crust. :-)

    Yes, once you get down below the frost line in the ground outside, the earth is a lot warmer than the outside air. It may or may not be a lot of heat leaking out, since the basement air will not necessarily transfer heat to the walls really well. And depending on whether you are using the basement for anything and how well insulated the basement ceiling/main floor is, you may not be losing a lot of heat from the occupied part of your house. But some insulation on the walls (either inside or else outside to the point where the soil is reasonably warm) may be a good idea. Just do not let moisture condense on the cold walls and cause mold.
    SMA SB 3000, old BP panels.
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?
    inetdog wrote: »
    Properly called a ground source heat leak, I think, since nobody is pumping and you are not going down to the really active heat supplies further down in the crust. :-)

    Yes, once you get down below the frost line in the ground outside, the earth is a lot warmer than the outside air. It may or may not be a lot of heat leaking out, since the basement air will not necessarily transfer heat to the walls really well. And depending on whether you are using the basement for anything and how well insulated the basement ceiling/main floor is, you may not be losing a lot of heat from the occupied part of your house. But some insulation on the walls (either inside or else outside to the point where the soil is reasonably warm) may be a good idea. Just do not let moisture condense on the cold walls and cause mold.

    Okay
    No results found for "ground source heat leak".

    I guess it's just me, but I like to call heat coming up out of the ground, "Geothermal", since I think it sounds so cool. Well warm actually.. :roll:

    When people tell me that I'm crazy for using those (cheap) ASHP systems, instead of the much better (very costly) GSHP systems,
    I tell them that I am using some GS heat, because, early in the morning when the air is very cold,
    it's not the heat from Star light that's keeping me from freezing, it's the warm Earth, giving up it's heat.. :)
    Even if the sun hasn't been out for weeks, at 5AM, mother earth is keeping my Sanyos fully supplied...
    With... Wait for it... Geothermal heat!!! 8)
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Airtap - any users here?
    XRinger wrote: »
    I guess it's just me, but I like to call heat coming up out of the ground, "Geothermal", since I think it sounds so cool. Well warm actually.. :roll:

    But, pause for effect, would you call heat going back into the ground geothermal air conditioning?
    To a heat pump, it is a reversible heat path. And even without a heat pump, you will get geothermal cooling of your basement in the summer. But that does not sound cool either. :roll:
    SMA SB 3000, old BP panels.
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?
    inetdog wrote: »
    But, pause for effect, would you call heat going back into the ground geothermal air conditioning?
    To a heat pump, it is a reversible heat path. And even without a heat pump, you will get geothermal cooling of your basement in the summer. But that does not sound cool either. :roll:

    Back in BS (Before Sanyo), I used to like to head down to the basement during the summer and cool off..

    But, even if it's not a lot of heat, there is some still heat coming up from the slab.. It's just feels cool to the touch.
    Maybe some heat energy is being forced into the slab from above during the summer,
    but that's not going to stop the normal upflow of heat from the earth.
    It's just going to add to the overall heat of the slab and surrounding matter.

    On the left, I'm scanning the bottom(~2ft down) of covered sump hole. On the right is the floor a few inches from the sump hole.
    As you can see, it's warmer down under the slab. I know there is some thorium decaying down there, since it's causing Radon gas.. :grr

    Attachment not found.
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Airtap - any users here?
    XRinger wrote: »
    Back in BS (Before Sanyo), I used to like to head down to the basement during the summer and cool off..

    But, even if it's not a lot of heat, there is some still heat coming up from the slab.. It's just feels cool to the touch.
    Maybe some heat energy is being forced into the slab from above during the summer,
    but that's not going to stop the normal upflow of heat from the earth.
    It's just going to add to the overall heat of the slab and surrounding matter.

    On the left, I'm scanning the bottom(~2ft down) of covered sump hole. On the right is the floor a few inches from the sump hole.
    As you can see, it's warmer down under the slab. I know there is some thorium decaying down there, since it's causing Radon gas.. :grr
    My exact experience before I got my minisplit. Had to sleep in the basement when the heat got unbearable on the ground floor. And yes, if I was away in winter, there was enough warmth coming up through the ground, even through the insulated basement floor, to keep my extremely well insulated place from freezing. And yes, I too have radon problems, the basement is dredged out of ledge rock. :cry:
    When I first tested for radon, it was during summer, in the basement, with no air flow in the basement due to temperature stratification. Did that deliberately to see if there was any radon at all. Results came back over 800! WOW! Since them the air exchanger is never turned off and last year results were 400 in the upstairs living space. Since them I've plugged the drain holes in the basement floor and am now waiting my latest long term (3 month) test kit's arrival and hoping for the best. Health Canada recommends nothing higher than 200, but the lower the better.
    Just wondering how a thread on water heaters can turn into a radon discussion? Sorry guys. :D
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?

    Because, it's the radon that's heating your basement?? :p
    http://ecorenovator.org/forum/other-improvements/1927-radon-reduction-thread.html

    "From Lutgens & Tarbuck there is an estimate that the top 6 feet of soil from an average acre of land contains
    about 50 lbs of uranium. This corresponds to about 2 to 3 parts per million. "


    There is only one sump hole (it's new) that is spewing out radon.. It's the one with the cover over it..

    I monitor it 24/7, just in case it kicks up (higher water table, earthquake etc).
    http://i46.photobucket.com/albums/f147/Xringer/Green%20slot/1st48.jpg
  • LucMan
    LucMan Solar Expert Posts: 223 ✭✭✭
    Re: Airtap - any users here?
    My exact experience before I got my minisplit. Had to sleep in the basement when the heat got unbearable on the ground floor. And yes, if I was away in winter, there was enough warmth coming up through the ground, even through the insulated basement floor, to keep my extremely well insulated place from freezing. And yes, I too have radon problems, the basement is dredged out of ledge rock. :cry:
    When I first tested for radon, it was during summer, in the basement, with no air flow in the basement due to temperature stratification. Did that deliberately to see if there was any radon at all. Results came back over 800! WOW! Since them the air exchanger is never turned off and last year results were 400 in the upstairs living space. Since them I've plugged the drain holes in the basement floor and am now waiting my latest long term (3 month) test kit's arrival and hoping for the best. Health Canada recommends nothing higher than 200, but the lower the better.
    Just wondering how a thread on water heaters can turn into a radon discussion? Sorry guys. :D

    To continue the side step in this thread.
    Try one of these http://www.safehomeproducts.com/shp2/showcategories.aspx?source=adwords&category=1260&gclid=CNKm99vV0bUCFVGf4AodVgQA3g
    They give short term & long term readouts and has an alarm when the radon level becomes unsafe.
    With these you can see how much the radon level varies when the ground is frozen or wet, great product and you don't have to send away to get the radon levels checked.
    I have had mine for over 5 years and it's still working great.
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?
    LucMan wrote: »
    To continue the side step in this thread.
    Try one of these http://www.safehomeproducts.com/shp2/showcategories.aspx?source=adwords&category=1260&gclid=CNKm99vV0bUCFVGf4AodVgQA3g
    They give short term & long term readouts and has an alarm when the radon level becomes unsafe.
    With these you can see how much the radon level varies when the ground is frozen or wet, great product and you don't have to send away to get the radon levels checked.
    I have had mine for over 5 years and it's still working great.

    Yeah, I got my second one at Amazon. I posted a pic link above.. http://i46.photobucket.com/albums/f147/Xringer/Green%20slot/1st48.jpg
    They work very well and I've been using one for well over 5 years.. It's readings are consistent with the newer model..
  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    Re: Airtap - any users here?

    New version AirTap units for sale on Ebay.. www.ebay.com/itm/251265921294
    These use R410A. I know a couple of guys have purchased them, but no one has installed one yet.
    They look about the same as mine, should work about the same, and the price is pretty low.