Solar DHW Up and Running With New Controller...

[WES999]

Some of you may have seen my solar system I build last year. You can see the write up and pics here:

http://www.builditsolar.com/Projects/WaterHeating/Metal1K/Metal1K.htm

The first version had a simple temp controller that would turn the pump on when the collector reached a set temp, no differential control.

I wanted something better, after looking at several different controllers I purchased one of these:

http://www.mydtcstore.com/index.html

I have the DTC deluxe, it seemed to be a pretty good value, It had a lot of features for a reasonable price, I really like the data logging feature. I have it set to log every 5 min.

The controller is connected to a computer by a 25' serial cable, I can check the status and review the logs from upstairs easily.

Today was the first day I had it running with nice sunny weather, no clouds.

So far it is working quite well, the one 4' X 8' collector raised the temp of 100gl of water from 91 °F to 117 °F over the course of about 7 hr.

The next upgrade is to add another collector, I think this should be a good improvement.

Here is a portion of the log.

T1 is the collector
T2 is tank 1
T4 is tank2
R1 us pump relay

Display Logs :

DAY:HH:MM TICK T1 T2 T3 T4 T5 T6 T7 T8 R1 R2
001:09:07 0001 118 91 55 90 -13 -13 -13 -13 ON OFF
001:09:12 0002 118 91 55 91 -13 -13 -13 -13 ON OFF
001:09:17 0003 118 91 54 91 -13 -13 -13 -13 ON OFF
001:09:22 0004 119 93 55 92 -13 -13 -13 -13 ON OFF
001:09:27 0005 118 92 53 91 -13 -13 -13 -13 ON OFF
001:09:32 0006 120 92 54 92 -13 -13 -13 -13 ON OFF
001:09:37 0007 122 93 54 92 -13 -13 -13 -13 ON OFF
001:09:42 0008 123 93 55 93 -13 -13 -13 -13 ON OFF
001:09:47 0009 123 93 54 93 -13 -13 -13 -13 ON OFF
001:09:52 0010 125 94 53 92 -13 -13 -13 -13 ON OFF
001:09:57 0011 125 95 55 93 -13 -13 -13 -13 ON OFF
001:10:02 0012 126 95 55 95 -13 -13 -13 -13 ON OFF
001:10:07 0013 127 95 54 93 -13 -13 -13 -13 ON OFF
001:10:12 0014 128 96 55 95 -13 -13 -13 -13 ON OFF
001:10:17 0015 129 96 54 95 -13 -13 -13 -13 ON OFF
001:10:22 0016 130 97 54 95 -13 -13 -13 -13 ON OFF
001:10:27 0017 131 97 54 95 -13 -13 -13 -13 ON OFF
001:10:32 0018 132 97 55 97 -13 -13 -13 -13 ON OFF
001:10:37 0019 133 98 54 97 -13 -13 -13 -13 ON OFF
001:10:42 0020 133 98 54 97 -13 -13 -13 -13 ON OFF
001:10:47 0021 133 99 54 98 -13 -13 -13 -13 ON OFF
001:10:52 0022 134 101 55 100 -13 -13 -13 -13 ON OFF
001:10:57 0023 135 101 55 99 -13 -13 -13 -13 ON OFF
001:11:02 0024 133 101 54 100 -13 -13 -13 -13 ON OFF
001:11:07 0025 135 102 54 100 -13 -13 -13 -13 ON OFF
001:11:12 0026 136 102 54 100 -13 -13 -13 -13 ON OFF
001:11:17 0027 136 102 54 102 -13 -13 -13 -13 ON OFF
001:11:22 0028 136 103 54 102 -13 -13 -13 -13 ON OFF
001:11:27 0029 135 104 55 103 -13 -13 -13 -13 ON OFF
001:11:32 0030 138 104 55 104 -13 -13 -13 -13 ON OFF
001:11:37 0031 138 104 55 104 -13 -13 -13 -13 ON OFF
001:11:42 0032 135 104 54 104 -13 -13 -13 -13 ON OFF
001:11:47 0033 138 104 54 104 -13 -13 -13 -13 ON OFF
001:11:52 0034 138 106 55 105 -13 -13 -13 -13 ON OFF
001:11:57 0035 139 106 55 105 -13 -13 -13 -13 ON OFF
001:12:02 0036 138 106 54 105 -13 -13 -13 -13 ON OFF
001:12:07 0037 139 106 55 106 -13 -13 -13 -13 ON OFF
001:12:12 0038 138 107 54 106 -13 -13 -13 -13 ON OFF
001:12:17 0039 139 107 55 106 -13 -13 -13 -13 ON OFF
001:12:22 0040 139 107 54 107 -13 -13 -13 -13 ON OFF
001:12:27 0041 139 108 55 108 -13 -13 -13 -13 ON OFF
001:12:32 0042 139 109 55 108 -13 -13 -13 -13 ON OFF
001:12:37 0043 139 109 55 108 -13 -13 -13 -13 ON OFF
001:12:42 0044 139 109 55 109 -13 -13 -13 -13 ON OFF
001:12:47 0045 138 110 55 109 -13 -13 -13 -13 ON OFF
001:12:52 0046 139 110 55 109 -13 -13 -13 -13 ON OFF
001:12:57 0047 138 111 55 110 -13 -13 -13 -13 ON OFF
001:13:02 0048 139 110 55 110 -13 -13 -13 -13 ON OFF
001:13:07 0049 139 111 55 110 -13 -13 -13 -13 ON OFF
001:13:12 0050 136 112 55 111 -13 -13 -13 -13 ON OFF
001:13:17 0051 139 112 55 112 -13 -13 -13 -13 ON OFF
001:13:22 0052 138 113 55 112 -13 -13 -13 -13 ON OFF
001:13:27 0053 139 113 55 112 -13 -13 -13 -13 ON OFF
001:13:32 0054 139 113 55 112 -13 -13 -13 -13 ON OFF
001:13:37 0055 139 114 55 114 -13 -13 -13 -13 ON OFF
001:13:42 0056 138 114 55 114 -13 -13 -13 -13 ON OFF
001:13:47 0057 138 114 55 114 -13 -13 -13 -13 ON OFF
001:13:52 0058 138 114 54 114 -13 -13 -13 -13 ON OFF
001:13:57 0059 136 115 54 114 -13 -13 -13 -13 ON OFF
001:14:02 0060 136 115 55 115 -13 -13 -13 -13 ON OFF
001:14:07 0061 136 115 55 116 -13 -13 -13 -13 ON OFF
001:14:12 0062 135 116 54 116 -13 -13 -13 -13 ON OFF
001:14:17 0063 135 116 55 116 -13 -13 -13 -13 ON OFF
001:14:22 0064 136 116 53 116 -13 -13 -13 -13 ON OFF
001:14:27 0065 135 117 55 116 -13 -13 -13 -13 ON OFF
001:14:32 0066 135 116 55 116 -13 -13 -13 -13 ON OFF
001:14:37 0067 135 117 55 117 -13 -13 -13 -13 ON OFF
001:14:42 0068 134 117 55 117 -13 -13 -13 -13 ON OFF
001:14:47 0069 134 117 55 117 -13 -13 -13 -13 ON OFF
001:14:52 0070 132 117 55 117 -13 -13 -13 -13 ON OFF
001:14:57 0071 133 117 55 118 -13 -13 -13 -13 ON OFF
001:15:02 0072 132 117 53 117 -13 -13 -13 -13 ON OFF
001:15:07 0073 131 118 55 118 -13 -13 -13 -13 ON OFF
001:15:12 0074 131 118 55 118 -13 -13 -13 -13 ON OFF
001:15:17 0075 131 118 55 118 -13 -13 -13 -13 ON OFF
001:15:22 0076 129 118 55 118 -13 -13 -13 -13 ON OFF
001:15:27 0077 129 118 55 118 -13 -13 -13 -13 ON OFF
001:15:32 0078 129 118 54 118 -13 -13 -13 -13 ON OFF
001:15:37 0079 127 118 55 118 -13 -13 -13 -13 ON OFF
001:15:42 0080 126 118 55 118 -13 -13 -13 -13 ON OFF
001:15:47 0081 124 118 55 118 -13 -13 -13 -13 ON OFF
001:15:52 0082 118 117 55 118 -13 -13 -13 -13 OFF OFF

 

[afblue]

Good info I am looking for a DIY package that gives the best bang for the buck. This would be a perfect controller to run my plans of 100sq ft of collector charging a 900gal unpressurized tank in the "off heating season" and give the boiler a break.

 

[markmudd]

afblue

My 2 cents! 100 sq ft of collector for 900 gallons of storage is too much storage for sq ft of collector. I have 64 sq ft home made pex alum collector draindown system that will heat 450 gallons unpressurized storage above 110 dgrees only when temps are in mid 80' and above. We had 2 straight weeks with temps in high 90's to low 100's and sunny and highest tank temp recorded was 130. average temp this summer has been around 110-112, which is marginal for DHW. A copper collector would do better I'm sure. I am in process of adding 120' more of flat panel copper collector area with 3 additional 4x10 panels and changing solar system to a smaller (250 gal) tank, in hopes of getting hotter water and maybe some heating in winter months.