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  1. Replies
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    20%, even 30%, seems much too low, that RH level...

    20%, even 30%, seems much too low, that RH level can cause dry skin, sinus irritation, dry eyes, and a big uptick in static electricity.
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    @Tekjunkie - I assume you know that humid air...

    @Tekjunkie - I assume you know that humid air rises, right?

    An ERV seems essential for you and yes an ERV will certainly raise the humidity since even the best ones remove only 75% of the delta...
  3. Thread: Water Temps?

    by terawatt
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    Try a Tee fitting and a directly inserted...

    Try a Tee fitting and a directly inserted PT100.[/U] This method of temp measurement is much more accurate and faster than any sensor affixed to the outside of a pipe and can be used when speed and...
  4. Chiltrix has had its R32 heat pumps in the USA...

    Chiltrix has had its R32 heat pumps in the USA market for >1 year, and those units hold AHRI efficiency records. They are air to water type, so all of the refrigerant stays outdoors and insulated PEX...
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    I can't speak much to repairs but we have been...

    I can't speak much to repairs but we have been involved in several recent projects where we see faulty geo being abandoned rather than repaired. And for a lot of new builds especially green-oriented,...
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    We recently did a calculation on this exact...

    We recently did a calculation on this exact question. In the example we had to work with, the annual savings of a geo unit, compared to a very high-efficency ATW heat pump (in this case, Chiltrix),...
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    Not enough info. Your contractor should be able...

    Not enough info. Your contractor should be able to calculate it.
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    The system uses a desuperheater for heat recovery...

    The system uses a desuperheater for heat recovery water heating. As such, in cooling mode, it is only recovering waste heat that would be otherwise thrown away. There is no "energy cost" for this...
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    Multiaqua is a good product but actually those...

    Multiaqua is a good product but actually those units are also air source, not geo - similar to chiltrix but lower efficiency.
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    I don't think there is any such product as a...

    I don't think there is any such product as a mini-split geothermal unit. Unless something has changed recently, the Aqua products units are sold as a "geothermal alternative" but they are air source...
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    MikePo, please see this page...

    MikePo, please see this page http://www.solarpanelsplus.com/products/solar-thermal-controls/
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    I have used the SPP iSolar Plus and SPP iSolar BX...

    I have used the SPP iSolar Plus and SPP iSolar BX for this. Either will work, the BX has a lot of extra relays in case you have a complex requirement.
  13. A vibration absorber is basically what you just...

    A vibration absorber is basically what you just described, they are made by Parker and others for this exact purpose.
  14. One more thing… without knowing your water usage...

    One more thing… without knowing your water usage and temperature numbers, even so, it’s appears that your payback would be really fast, under 2 years. According to www.dsireusa.org, in Tennessee you...
  15. If you use a 5 ton heat pump to chill some or all...

    If you use a 5 ton heat pump to chill some or all of the water the cooling costs should be about the same as currently. And for every BTU removed from the water you will have ~1.25 BTU available for...
  16. I agree evacuated tube solar collectors are...

    I agree evacuated tube solar collectors are excellent for making free hot water, I have some on my roof ;-) About heat recovery, you have a couple possible opportunities but you are now at the point...
  17. Desuperheaters are installed between the...

    Desuperheaters are installed between the compressor discharge and the reversing valve, so heat can be recovered in either mode. Basically what you are building is called a "heat recovery water...
  18. No tubes or compressor issues at all. There may...

    No tubes or compressor issues at all. There may already be connections for a desuperheater sometimes on certain water source heat pumps. If not, it’s still easy, just cut the compressor discharge...
  19. Great idea! As you mentioned, sufficient pre-heat...

    Great idea! As you mentioned, sufficient pre-heat storage will be key however it can require a lot of storage and a high hot water demand to make it work out.
    To look at some numbers we can guess...
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    There's a good write up on several different...

    There's a good write up on several different types of solar air conditioners here
    www.hotspotenergy.com/compare-solar-air-conditioners/
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    Thanks to everyone who replied, I am glad I...

    Thanks to everyone who replied, I am glad I posted my question. This forum and it's members are awesome.
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    Thanks JP, this confirms one of the methods I...

    Thanks JP, this confirms one of the methods I have used before, but I had never seen it explained by any doc before. Excellent resource.

    Question - when all you know is the coil tube OD and length...
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    The purpose is to calculate the size of a needed...

    The purpose is to calculate the size of a needed receiver. The system uses a heat recovery valve to switch between normal and water cooled condensers. The head pressure is a little high on the water...
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    Hey thanks for the reply. I'm not sure where I...

    Hey thanks for the reply. I'm not sure where I got that term, my work crosses over many areas so I probably borrowed it from somewhere. And maybe it isn't even a good term. My ultimate goal here is...
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    Calculating Trane Condenser Volume

    Does anyone know a resource for determining the flooded refrigerant volume of Trane condenser coils? I have asked Trane support a few times for a simple piece of information - "what is the flooded...
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    Actually these so-called "solar hybrid thermal...

    Actually these so-called "solar hybrid thermal AC" systems use a solar collector (usually an upside-down high temp evacuated tube type) that is connected on the compressor discharge line, not on the...
  27. Actually, using the pool as a heat sink should...

    Actually, using the pool as a heat sink should work out pretty well for the first 300,000-600,000 btu of heat rejection per day, depending on the the size, shade conditions, etc. of the pool. Make...
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    The current platform is 5/8, but ultimately I...

    The current platform is 5/8, but ultimately I need 1/2, 5/8, and 7/8.

    Seems odd that after all this time that r410a has been in play, there are still so many r22 valves that have no r410a...
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    Hey thanks. Unfortunately these normally open...

    Hey thanks. Unfortunately these normally open valves are not rated for r410a. Anyhow, they require a pressure differential. It may be that no such valve as I need exists due to rare demand. If anyone...
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    Need help finding special solenoid valves

    Hello, hoping someone can help. I have been searching suppliers without any luck. I am working on a heat recovery application, need to find direct acting, fully bidirectional, normally open solenoid...
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    >use their pool in the winter as part of their...

    >use their pool in the winter as part of their geothermal heat pump to help cut way down on their energy bills

    As others have indicated this will not work because of the limited BTUs available in...
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    Poll: >The new inverter units have much better heating...

    >The new inverter units have much better heating capacities without much penalty for overcapacity in cooling. Look at those

    Totally agree. Variable capacity system is the best solution, much...
  33. Actually, a 36000 BTU unit will have to reject at...

    Actually, a 36000 BTU unit will have to reject at least 15000BTU per ton or total 45000BTU/h for 3 tons including superheat etc. So in a 8 hour day of running AC you would get somewhere around...
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    Formula for how long will it take? Water weighs...

    Formula for how long will it take? Water weighs ~8.33 lbs. per gallon. A BTU is the energy needed to change the temp. of 1 lb. of water by one degree F.

    You can back into your answer roughly by...
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    @SkyHeating Great comparison. Just to clarify,...

    @SkyHeating

    Great comparison. Just to clarify, I wasn’t considering if geo is the right choice, I think that’s a given whenever there is a free ground loop in place ;-)

    My point about propane...
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    The reason the prices you were given seem so low...

    The reason the prices you were given seem so low is probably because the existing ground loop is still in good shape and is planned for re-use.Installing a complete new geo system from scratch could...
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    I don't think I have heard anyone say that. I...

    I don't think I have heard anyone say that. I don't think it is possible that it would be worse performance. Most heat recovery is really just a desuperheater, this is a well established principal....
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    Heat recovery systems are like solar, wind etc....

    Heat recovery systems are like solar, wind etc. as far as economics-they are a way of generating free energy, but have an upfront cost that must be recovered.

    Heat recovery can salvage wasted...
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    >please point out some of the specific problems...

    >please point out some of the specific problems as you understand them?

    There are no real technical issues working against heat recovery for water heating, probably the best case against it is...
  40. One issue with using your sewage system as a heat...

    One issue with using your sewage system as a heat source - removing too much heat could lead to an increase in viscosity of the sewage, interfering with flow and ultimately making it easier for the...
  41. >once the hot water faucet is opened in the...

    >once the hot water faucet is opened in the house, the line pressure forces water thru the Pex Coil

    Ok so if the water heater tank is operating, a demand will bring already-hot water from the top...
  42. Some ideas for going green could include products...

    Some ideas for going green could include products like adding heat recovery to new or existing systems. And I see there are companies like hotspot energy that build air-source heat pumps with hot...
  43. So how does this work without a pump?

    So how does this work without a pump?
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    The "500" comes from the weight of 1 gal water...

    The "500" comes from the weight of 1 gal water (8.33 pounds) x 60 minutes in an hour multiplied by specific heat, which is 1.0 for water. So if you know the specific heat of your glycol mix, just...
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    You could store some heat in the ground but the...

    You could store some heat in the ground but the losses will be very high. Better to store the heat in water in a well insulated tank. If it needs to be underground, it is possible to have below...
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    Nitrogen charge for air freight

    Probably not too many normal people use air freight for air conditioners, but for various reasons I do it frequently. It's not legal to air ship a pre-charged unit from or within the US by air. We...
  47. >There are way too many variables to consider, in...

    >There are way too many variables to consider, in my opinion

    I completely agree. It's a bad idea. But bad ideas seem to get executed on all the time. I am not promoting the idea. Just curious if...
  48. Thanks for confirming that this is not a popular...

    Thanks for confirming that this is not a popular idea, I didn't expect it would be. If I worked in the industry as a technician I think I would resent any suggestion that a book could tell me (or my...
  49. Chilton's Air Conditioning and Heating Labor Guide

    Hello, I believe the Chiltons guide only applies to automotive AC work but I was wondering if there is a similar guide for the commercial and/or residential AC repair business. I was really looking...
  50. Thanks for that. What about other brands of AC...

    Thanks for that. What about other brands of AC besides Trane? Also, lots of time the units are not AC, but are for freezers, coolers etc.

    I was hoping that somewhere there would be a central...
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