Sun Bandit solar water heater pricing?

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  • C_Heath
    Junior Member
    • Feb 2017
    • 32

    #46
    Originally posted by J.P.M.
    A couple thoughts:

    1.) The large temperature difference in the outlet temps from one set of bedrooms to the other is a clue to something. One something is that the heat pump seems to be putting out sufficient heat or cool. Another is that the ducting to the other rooms is not doing a good job of getting heat/cool to where it's wanted. Does any of the ducting run through the attic ? Is the ducting insulated ? Is it tight ?

    2.) Your home is brick. From a prior post, note that I wrote that brick is a lousy insulator. I believe I asked if your walls are insulated. If your couch is near an outside, uninsulated wall, that draft you feel may well be from a draft created by air as it's cooled by the uninsulated wall, dropping over the couch and your arm. Any uninsulated (or poorly insulated) walls will, among other things, create drafts. Uninsulated walls, because they are usually colder/warmer than desired, can well be a source of discomfort, not only from drafts but from thermal radiation heat transfer. If those brick walls are uninsulated, they will be a major source of heat loss/gain. For comfort, as Brian 53713 suggests I'd second his suggestion of covering bare skin.

    3.) One indication of a "tight enough" building envelope is to take note of how difficult it is to close or open a well hung and fitted door. A well sealed dwelling will have doors that often exhibit a slight and initial reluctance to movement aside from the resistance any door seals/weatherstripping may provide. Make sure all the building (kitchen/bath, etc.) vents are closed and otherwise well sealed.

    4. As a safety issue, make sure the wood stove you have/use is in proper working order AND remember that it does need a sufficient and (to be safe) at least a slight excess of air for proper combustion and operation. Sometimes, when tightening up a dwelling, folks living in such dwellings that have such combustion sources inside the dwelling forget to allow for the excess air needed for those combustion devices and get closer to an unsafe condition. DO NOT FORGET THIS. IT'S A BIG DEAL !
    walls are insulated. I removed an outlet and stuck a plastic zip tie up in it. Pulled out some and heard the paper. So that's good.

    Comment

    • J.P.M.
      Solar Fanatic
      • Aug 2013
      • 14925

      #47
      Originally posted by Mike90250

      And you will have to install an outside source of combustion air.
      Or the stove will either A) suck cold outdoor air in, heat it, and send it up the chimney B) can't get air in a sealed house and just smoke and smoulder. C) kill you with combustion byproducts (Co)
      Yea, that's the excess air for combustion and proper operation part.

      Comment

      • LucMan
        Solar Fanatic
        • Jul 2010
        • 624

        #48
        Welcome to the world of warm air heating! There is no way to make this type of system Draft free, especially with a heat pump. Register out let temperatures are in the neighborhood of 110 degrees and the air is moving when the system fan is on. A 3.5 ton HP with 1400 CFM of Air movement makes it feel drafty, nature of the beast. Radiant floor heating is popular today because of this reason very little air movement. I have also had excellent results with using the new style steel radiators with constant circulation, the radiators are always warm emitting a constant temperature corresponding to the outdoor temperature. Comfortable settings are in the 65-68 degree range with these systems.

        Comment

        • J.P.M.
          Solar Fanatic
          • Aug 2013
          • 14925

          #49
          Originally posted by lucman
          welcome to the world of warm air heating! There is no way to make this type of system draft free, especially with a heat pump. Register out let temperatures are in the neighborhood of 110 degrees and the air is moving when the system fan is on. A 3.5 ton hp with 1400 cfm of air movement makes it feel drafty, nature of the beast. Radiant floor heating is popular today because of this reason very little air movement. I have also had excellent results with using the new style steel radiators with constant circulation, the radiators are always warm emitting a constant temperature corresponding to the outdoor temperature. Comfortable settings are in the 65-68 degree range with these systems.
          fwiw, +1.

          Comment

          • bcroe
            Solar Fanatic
            • Jan 2012
            • 5198

            #50
            Originally posted by LucMan
            Radiant floor heating is popular today because of this reason very little air movement.
            OK, but when the ceiling fans are engaged, the draft is back anyway. Set to 73 deg here, 4 full sun days starting. Bruce Roe

            Comment

            • J.P.M.
              Solar Fanatic
              • Aug 2013
              • 14925

              #51
              Originally posted by bcroe

              OK, but when the ceiling fans are engaged, the draft is back anyway. Set to 73 deg here, 4 full sun days starting. Bruce Roe
              My experience, having lived and fooled with all 3, forced hot air, heat pump and radiant floor systems is that heat pump systems, as Lucman notes can produce the "feeling " of producing more drafts because, also as he notes, outlet temps are ~ 95F. - 110F. or so at the registers, but forced air systems usually produce higher temps. that don't feel as much like cold drafts as hair dryer blasts. Some of the effect of either air current is due to air velocity as well as air temp. A higher air velocity usually makes a cold breeze feel colder, and a hot breeze feel hotter. Blame convective heat transfer theory. Turn the fan down a bit.

              Comment

              • C_Heath
                Junior Member
                • Feb 2017
                • 32

                #52
                That all makes sense. You should see my gargantuan cold air return. It's on the floor. I'm in NC so we split right down the middle. 6 cold months, 6 warm. I believe That a lot of it is the return. I have made some progress for sure. This place before all this would drop a Degree in 15 minutes or so after the unit cut off. Now it's holding it much longer. I'm still working on it as a whole. Much thanks always to you guys for the help and support. And one day! ONE DAY! I will have my 9kw system. I have my eyes on the prize. Lol.

                Comment

                • J.P.M.
                  Solar Fanatic
                  • Aug 2013
                  • 14925

                  #53
                  Originally posted by C_Heath
                  That all makes sense. You should see my gargantuan cold air return. It's on the floor. I'm in NC so we split right down the middle. 6 cold months, 6 warm. I believe That a lot of it is the return. I have made some progress for sure. This place before all this would drop a Degree in 15 minutes or so after the unit cut off. Now it's holding it much longer. I'm still working on it as a whole. Much thanks always to you guys for the help and support. And one day! ONE DAY! I will have my 9kw system. I have my eyes on the prize. Lol.
                  Read up, do homework. fill in the knowledge gaps for what you can't get on your own here. Knowledge is power.

                  Comment

                  • LucMan
                    Solar Fanatic
                    • Jul 2010
                    • 624

                    #54
                    Originally posted by bcroe

                    OK, but when the ceiling fans are engaged, the draft is back anyway. Set to 73 deg here, 4 full sun days starting. Bruce Roe
                    Why use ceiling fans with radiant? The coldest air is near the ceiling and the warmest near the floor. Fans are not recommended.

                    Comment

                    • LucMan
                      Solar Fanatic
                      • Jul 2010
                      • 624

                      #55
                      Originally posted by C_Heath
                      That all makes sense. You should see my gargantuan cold air return. It's on the floor. I'm in NC so we split right down the middle. 6 cold months, 6 warm. I believe That a lot of it is the return. I have made some progress for sure. This place before all this would drop a Degree in 15 minutes or so after the unit cut off. Now it's holding it much longer. I'm still working on it as a whole. Much thanks always to you guys for the help and support. And one day! ONE DAY! I will have my 9kw system. I have my eyes on the prize. Lol.
                      Replacing a large return with several small capable of handling the same CFM will help some. A properly designed HP or hot air system has a return in every room preferably a high and a low to accomodate cooling and heating.
                      Hot air rises and cold air settles, we use physics to help us design a better system. Money usually gets in the way though. Installing more registers and duct work raises the cost of the job, so I'll give you a quess as to how many residential systems are designed and installed the way they should be.
                      In the very near future HP systems will all use inverter compressors, with that the fans will run almost continuously with a varying BTU output to keep the home at a constant temperature. No more off then on again after 15 minutes. The micro processors will make sure that just the right amount of BTU'S are supplied to meet the structure's heat loss or gain.
                      Last edited by LucMan; 02-17-2017, 07:31 PM.

                      Comment

                      • bcroe
                        Solar Fanatic
                        • Jan 2012
                        • 5198

                        #56
                        Originally posted by LucMan
                        A properly designed HP or hot air system has a return in every room preferably a high and a low
                        to accomodate cooling and heating. Hot air rises and cold air settles, we use physics to help us design a better system.

                        Money usually gets in the way though. Installing more registers and duct work raises the cost of the job, so I'll give you a
                        guess as to how many residential systems are designed and installed the way they should be.
                        Right, money interferes. In these parts the heat vents are at the floor, returns high up. Then we add air cond using
                        the same circulation.

                        Does radiant work OK for multi floors? I just thought if the air is circulated enough, the vent locations are less
                        important. Moving air doesn't bother me if the temp isn't unpleasant. Here the first reason for using fans is
                        to avoid turning on the air cond all together. Then there is the matter of heavy work outside in the heat (tree
                        was shadowing my PV). Walking in, a fan bumped up to high is far more effective cooling down than just
                        stationary cool air. Bruce Roe

                        Comment

                        • J.P.M.
                          Solar Fanatic
                          • Aug 2013
                          • 14925

                          #57
                          Originally posted by LucMan

                          Why use ceiling fans with radiant? The coldest air is near the ceiling and the warmest near the floor. Fans are not recommended.
                          I disagree to some extent. and probably mostly if the ceiling fans are used correctly.

                          The way I leaned it and found out by confirming on my own, with no ceiling fan, air will be heated by the floor and rise by natural convection. In the simple case of a rectangular room with no mechanical (fan/blower) ventilation, a natural convection cell will form with air being heated by floor, creating a buoyancy effect in the air that causes the heated air to rise, more so toward the center of the room and continuing that rise to the ceiling. Then, the air will travel across the ceiling in a radially outward direction and drop down the walls to the floor, losing its temperature to the colder walls while decreasing its density along the way and attaining its lowest temperature at the base of the walls. Then, with momentum carrying it across the floor and completing the convection cell, it gets reheated by the floor.

                          When the air rises it loses some, but not a lot of heat via thermal radiation to the walls/ceiling (and a very slight amount of heat energy through uncontrolled expansion), and collecting to some extent at a slightly to moderately higher bulk temp. and larger quantity of heat than the air near(er) the floor. Heated (and slightly less dense) air will collect and want to say at higher elevations until cooled or moved by the natural convection currents, just like a hot air balloon, including up stairwells or other elevation changes. Those convection cells will tend to decrease the thermal stratification but not eliminate it, particularly with high ceilings. Things will set up in such a way that a larger volume (heat quantity) of slightly warmer (heat quality) air will tend to be, and stay, at the higher elevations in a somewhat stubborn way until cooled or pushed along.

                          Ceiling fans can help reduce that temp. stratification, but not the way many/most folks use them. Often, folks use ceiling fans to blow hot air downward. That pattern works counter to the way the natural convection cells in such situations, and as described above, want to work.

                          In winter, the more effective way to operate a ceiling fan is to work WITH natural convection and operate the ceiling fan in reverse rotation with the air being directed upward against the ceiling, and also at a relatively low fan speed. That 'reversed' flow will eliminate local air velocity spikes directly below the fan blowing downward, and also aid the natural convection cell(s) by sending air in the same direction natural convection wants it to go - similar to (but not entirely) why solar thermal collectors have their inlets at the bottom.

                          With the ceiling fan blowing upward, the bulk ceiling air temp. will be cooler, the floor will likely see slightly warmer air from the walls, and there will usually be less of an opportunity for air velocities to get high enough to cause noticeable chills/discomfort. The overall effect will be a more uniform room air temp. that, if done correctly will result in at least no more, if not fewer drafts, with less heat (read less $$ spent) needed to maintain a particular air temp. at floor level.

                          Take what you want of the above. Scrap the rest.
                          Last edited by J.P.M.; 02-18-2017, 12:48 AM.

                          Comment

                          • Mike90250
                            Moderator
                            • May 2009
                            • 16020

                            #58
                            Originally posted by bcroe
                            ........Does radiant work OK for multi floors? ......
                            Mostly, We have radiant heat from the masonry heater, and easily keep the ground floor 68 - 69 F in the heating season, and very comfortable within view of the heater.
                            Even though we have a large hole ( 8' x 10') for the stairwell, the 2nd floor is about 10 degrees cooler, which is fine for sleeping in, not so fine for showers.

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                            Comment

                            • LucMan
                              Solar Fanatic
                              • Jul 2010
                              • 624

                              #59
                              Originally posted by bcroe

                              Right, money interferes. In these parts the heat vents are at the floor, returns high up. Then we add air cond using
                              the same circulation.

                              Does radiant work OK for multi floors? I just thought if the air is circulated enough, the vent locations are less
                              important. Moving air doesn't bother me if the temp isn't unpleasant. Here the first reason for using fans is
                              to avoid turning on the air cond all together. Then there is the matter of heavy work outside in the heat (tree
                              was shadowing my PV). Walking in, a fan bumped up to high is far more effective cooling down than just
                              stationary cool air. Bruce Roe
                              Originally posted by bcroe

                              Right, money interferes. In these parts the heat vents are at the floor, returns high up. Then we add air cond using
                              the same circulation.

                              Does radiant work OK for multi floors? I just thought if the air is circulated enough, the vent locations are less
                              important. Moving air doesn't bother me if the temp isn't unpleasant. Here the first reason for using fans is
                              to avoid turning on the air cond all together. Then there is the matter of heavy work outside in the heat (tree
                              was shadowing my PV). Walking in, a fan bumped up to high is far more effective cooling down than just
                              stationary cool air. Bruce Roe
                              People seem to learn to operate their HVAC systems to achieve maximum comfort from their individual system. None are perfect. In a perfect world A/C would come from the ceiling and heat from the floor. Depending on construction that's not always possible.

                              Radiant works fine in multiple floor configuration. With radiant floor heating its important to place insulation where you don't want the heat to go. The second floor requires the proper amount and location of insulation under the radiant tubing to keep the heat from radiating down from the cieling heating the room below from above.
                              Again in most situations you have the $ factor. The contractor uses the the old rule of thumb that the heat is still supplied to the building envelope why insulate the the ceiling. The first floor is now heated by the floor and the cieling not really how the system is supposed to work. A properly designed and operating radiant floor heating system will have a floor surface temp of 80 -85 degrees depending on the floor type, the temp at the ceiling should be 60 ish head level 70 degrees. This can easily be achieved by fine tuning the water temps to the radiant tubing or adjusting the outdoor reset control. Just a few degrees difference in water temps can make big difference in comfort level.
                              Just a word of caution certain flooring surfaces such as hard wood floors can be damaged by excessive temperatures, check with the flooring manufacturer for max temperature for the particular flooring.

                              Here is avery informative site on the subject
                              Last edited by LucMan; 02-18-2017, 11:03 AM.

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