I'm doing my (first and hopefully only, since I'm the homeowner) WELServer install and I couldn't decide whether to start a new thread or not (there seem to be 2 older WELServer threads in this forum), so I have a few questions about planning my WELServer install. My GSHP system design seems to be a little different than many of those I've read about here and on WELServer.com. I'm having 2 4-ton Waterfurnace systems put in. One is an all-in-one in the basement serving the 1st floor (2 zones). The other one is a split (in the basement) with an air handler in the attic serving the 2nd floor (2 zones). My auxiliary heat will be a natural gas boiler (Prestige Solo 175) which will also supplement my hot water through an indirect hot water heater and might be used to heat the basement during the winter at a later point. Here are my challenges:

1. -What's the best way to monitor my electrical usage? I will have 3 circuits for the GSHP (1st floor all-in-one unit, 230V, Full load 31A; 2nd floor split unit, 230V, full load 27A; Attic air handle, 230V, full load 9A) and I presume another circuit for the circulation pumps. I get the sense that I will need 3-4 sensors or do I get this all put in a subpanel and monitor the whole subpanel? I presume getting individual sensors won't work because there aren't enough inputs available on the WEL. Would either the WattNode or the 100A amp sensor work equally as well?
2. -What's the best way to monitor the natural gas usage? From what I've read here, my understanding is that I will need to submeter the gas line (with a pulser compatible submeter). A submeter sounds like a little bit of overkill. Is there any other way to measure the gas flow?
3. -What are the real world 1-wire limitations? Is the wire that comes with the WELServer better or worse than using cat5? From researching, it seems like there's a 100 ft limit on the length of the wire and if you use any stars, it sounds like that distance would be further reduced. What I'd like to do is have 3 stars: 1)in the mechanical room where the GSHPs will be located along with the WELServer and 1-wire hub, probably with a total of about 12 sensors over about 25ft of cable, 2)outdoor temp sensor will have a straight run (with no other sensors) of about 20 ft back to the 1-wire hub, 3)attic will have a temp/humidity sensor, an air handler supply temp, and an air handler return temp and will be about 35ft back to the 1-wire hub. Will I bump up against the abilities of a 1-wire network? I would be willing to forgo the attic sensors if necessary.
4. -What thermostat signals should I be capturing if I only have 1 combo-box with 8 connections? I've read here I should capture 1st, 2nd, aux, fan and reversing valve (A/C), but that is 5 signals and since I have 2 systems that would require 10 connections. If I would prioritize, what signals should I capture or should I get a 2nd combo box? Also, any connectivity (connecting the wires in serial or parallel with the GSHP) concerns I should be aware of?
5. -Is anyone measuring hot water usage? Would the best way to do that be by putting a water flow meter on the line out of the hot water tank? If so, any recommendations? During the time when we're not using the boiler for auxiliary heat (just for supplemental hot water), I would be able to measure cost per gallon of hot water which might be useful when my kids become teenagers;-).

Any other insight would be appreciated.

We have about 15 WELs installed and display it on our webpage.

1) I would go with the Amp sensor, the wattsnode is much more expensive and does not add much once you calibrated the sensor. Each WEL can monitor (2) 0-5 volt signals, so you are maxed out with (2) Amp sensors per WEL. But you could contact Phil Malone and ask him if he could build you a combo module with a couple more 0-5V inputs.

2) No idea on how to monitor gas flow. See if youcan geta counter which gives you a pulse. But you could calculate it with the WEL but counting the amount of time your thermostat calls for Aux heat. Since the BTUs used by your furnace per hour is a constant, you should get very close numbers that way.
3) The newer are not as sensitive to line losses so the bus wire so the WELs can go much longer. Again, Phil Malone would know much better.
4) I don't see much sense in the Fan monitoring, so I would monitor 2x4 signals.
5) I monitor hot water indirectly via an amp meter and an on/off amp-meter. Some of our system run the hot water tank as a zone, so I againmonitor a 24V signal via the combo module.

Posted By geek on 25 Jul 2012 10:40 AM
I'm doing my (first and hopefully only, since I'm the homeowner) WELServer install and I couldn't decide whether to start a new thread or not (there seem to be 2 older WELServer threads in this forum), so I have a few questions about planning my WELServer install. My GSHP system design seems to be a little different than many of those I've read about here and on WELServer.com. I'm having 2 4-ton Waterfurnace systems put in. One is an all-in-one in the basement serving the 1st floor (2 zones). The other one is a split (in the basement) with an air handler in the attic serving the 2nd floor (2 zones). My auxiliary heat will be a natural gas boiler (Prestige Solo 175) which will also supplement my hot water through an indirect hot water heater and might be used to heat the basement during the winter at a later point. Here are my challenges:

1. -What's the best way to monitor my electrical usage? I will have 3 circuits for the GSHP (1st floor all-in-one unit, 230V, Full load 31A; 2nd floor split unit, 230V, full load 27A; Attic air handle, 230V, full load 9A) and I presume another circuit for the circulation pumps. I get the sense that I will need 3-4 sensors or do I get this all put in a subpanel and monitor the whole subpanel? I presume getting individual sensors won't work because there aren't enough inputs available on the WEL. Would either the WattNode or the 100A amp sensor work equally as well?
2. -What's the best way to monitor the natural gas usage? From what I've read here, my understanding is that I will need to submeter the gas line (with a pulser compatible submeter). A submeter sounds like a little bit of overkill. Is there any other way to measure the gas flow?
3. -What are the real world 1-wire limitations? Is the wire that comes with the WELServer better or worse than using cat5? From researching, it seems like there's a 100 ft limit on the length of the wire and if you use any stars, it sounds like that distance would be further reduced. What I'd like to do is have 3 stars: 1)in the mechanical room where the GSHPs will be located along with the WELServer and 1-wire hub, probably with a total of about 12 sensors over about 25ft of cable, 2)outdoor temp sensor will have a straight run (with no other sensors) of about 20 ft back to the 1-wire hub, 3)attic will have a temp/humidity sensor, an air handler supply temp, and an air handler return temp and will be about 35ft back to the 1-wire hub. Will I bump up against the abilities of a 1-wire network? I would be willing to forgo the attic sensors if necessary.
4. -What thermostat signals should I be capturing if I only have 1 combo-box with 8 connections? I've read here I should capture 1st, 2nd, aux, fan and reversing valve (A/C), but that is 5 signals and since I have 2 systems that would require 10 connections. If I would prioritize, what signals should I capture or should I get a 2nd combo box? Also, any connectivity (connecting the wires in serial or parallel with the GSHP) concerns I should be aware of?
5. -Is anyone measuring hot water usage? Would the best way to do that be by putting a water flow meter on the line out of the hot water tank? If so, any recommendations? During the time when we're not using the boiler for auxiliary heat (just for supplemental hot water), I would be able to measure cost per gallon of hot water which might be useful when my kids become teenagers;-).

Any other insight would be appreciated.

A new thread is probably best!

My overall recommendation is that you reverse the thinking process.  Layout the subjects you're really interested in, figure out what you want to illustrate with your (up to) 8 charts, and then design your WEL implementation.  You'll save a lot of time and expense.

Having done both residential and commercial WEL implementations, I have learned the design process is very incremental.  Start small/basic, learn from what you have, and then adjust.

Here's an example of 'coming down the learning curve:' you may initially think you need a NG submeter to measure BTU usage by your furance or HWH.  But, after some time, you end up figuring out that it's a constant flow, and thus if you instead simply measure run-time in some manner, you can then compute BTU useage using some reasonable assumptions.

I'd take a look at various WEL implementations to get ideas.  Mine are at WEL0043 and WEL0343.  In fact, I have 2 GSHP units, like you, and thus you're welcome to copy/use my system diagram (no credit required, either).

Doc's WEL implementations are well documented on his web site.  And Phil Malone has means where you can look at every WEL implementation that's currently online (from his http://www.welserver.com web site).

Specfic to your questions:

1.) You're going to get different recommendations from various implementers.  I happen to be very favorable on WattNode units.  At 300 Hz, you've got a very accurate resolution all the way down to 4 watts just at a 200 Amp service entrance.  And the resolution further gets finer with branch circuit monitoring with appropriately sized CTs.

In your case I'd start with a WattNode on the overall service to the house.  You'll learn a lot just from all of this information, enabling you to implement power reduction and savings actions.

And I'd put in another WattNode for all GSHPS equipment, total.  You can run the 3 branch circuit wires through one CT (on each side of the 220 V circuit) to monitoring everything.  At this beginning stage, I would not make investment into monitoring per GSHP, per compressor, per aux heat, per loop pumps, etc.  It's all detail information that, while interesting initially, will quickly prove to be more than you need/want.  You'll have plenty of information just from one overall HVAC power monitor, that you may end up concluding is sufficient.  (This is what happened with me - I still only have one WattNode for all of my HVAC: 2 GSHPs + 3 loop water pumps).

2.) Don't know of any way to directly monitor NG usage other than to purchase a submeter with pulse output.  Not difficult to do if you have plumbing skills.

But you can indirectly monitor NG usage.  For example, I measure NG usage for my HWH by measuring the flu temperature.  When the HWH's burner first turns on, the temp goes way up.  Then, when the HWH's burner turns off, temp drops.  By setting up some calculations internal to the WEL, and using the labeled BTU/hr number on the HWH, you can measure HWH NG usage with simply a temp sensor (see this chart: WEL0043 HWH NG usage chart).

I would think this would apply to your boiler, assuming you have some means to measure runtime. Thus I don't think you need NG submeters unless you have something that using variable amounts of NG (i.e. a cook top stove).

3.) With a WEL your practical 1-wire network limit is over 1000 feet.  The WEL uses the best available 1-wire transceiver on the market today, very tolerant of network conditions.  Fundamental to getting good, long length, reliable 1-wire network performance is two things: absolutely a 'linear topology,' and use at least CAT5 cable (or CAT5E or CAT6).  If you've got a long network, avoid 'star' subsections.  If your network is short, don't worry about topology.  WRT to connecting sensors to the network cable, I use wirenuts to ensure absolute mechanical connection.

4.) I would only directly connect the combo unito to monitor 1st stage, 2nd stage, and Mode (Heat/Cool via reversing valve).  Everything else you're going to be able to see via power measurement, and you can put in forumulas to detect things.  That's 6 total for one combo unit, giving you 2 more inputs if needed.  I've got 2 GSHPs and it's these 6 that I am connected to.

5.) I wish I had a water flow sensor on the hot water side of the HWH, but, so far, I haven't proceeded.  It's not difficult to do, just something I haven't gotten to yet.  Meanwhile, I use the monitor on the HWH that I talked about above.  In fact, I've got an alarm set in the WEL such that if HWH usage (burner on/off time) gets to be much over 2 hours in a day, I start chatting with our kids on what's going on!  They know that the HWH usage chart is out there, and it's helped a lot these days with them being more frugal with there long hot showers.

Hope all of this helps.

Good luck!

Best regards,

Bill