Z-Wave Pool Thermostat with Water Temperature Sensor

Hi Richard,

You can use an Oregon Scientific water temp sensor THWR288. The Homeseer xAP plug-in supports this type of sensor already and the ACRF2 plug-in will support it in the near future. To receive the Oregon sensors you need an RFXCOM 433.92MHz receiver.

RFXCOM has USB connected receivers and using the newest Ethernet connected receivers you can put your Home Automation receivers and transmitter now on the optimum location for receiving all sensors in your property. No longer problems with RF noise radiated by the PC. Simply put the receiver at a larger distance from the PC with a LAN or WLAN connection and it makes the receiver now more sensitive.

If the Ethernet interface is connected to the Internet it enables you to add remote locations to your Home Automation system. Connect your holiday home to receive the security sensors, temperature and humidity and switch X10 or control Harrison curtains or even control and check the home of your grandmother.

All existing Home Automation software that runs on a Windows platform and has interfacing software for the W800RF receiver or the RFXCOM receiver can use the RFXCOM Ethernet interface without any modification in the HA software thanks to the CPR (COM Port Redirector) software. This CPR software emulates a standard COM port in Windows.

On other platforms like Mac and Linux, the communication protocol is via TCP/IP with the receivers and transmitter. Of course, TCP/IP communication is also possible on the Windows platforms.

All RFXCOM receivers have a W800RF compatible receiving mode and the RFXCOM receiver translates all received non-X10 RF packets (like Visonic, SecureLinc, KlikOn-KlikOff, Domia Lite) to an equivalent X10 packet. This makes it possible to process those non-X10 sensors and remotes by all X10 oriented Home Automation software without any modification in this Home Automation software.

There are 4 different types of RFXCOM Ethernet interfaces.

1. LAN with 1 COM port and connections for 1 or 2 receivers OR 1 transmitter,
2. WLAN with 2 COM ports and connections for 1 or 2 receivers AND 1 transmitter,
3. LAN with 2 COM ports and connections for 1 or 2 receivers AND 1 transmitter,
4. WLAN+LAN with 2 COM ports and connections for 1 or 2 receivers AND

Thanks... it looks like that would work as a standalone thermometer.

What I am looking for though is a thermostat, not just a thermometer. I would like this thermostat to sense the temperature in my pool and then control my pool heater. Any idea how I can do that?

Let me understand this - a manufacturer of a Z-Wave thermostat has told you this is not a good application and you still to use Z-Wave for this? While you may find greedy dealers who neither know nor care about suitability, you should give a lot of credence when a manufacturer indicates you should look elsewhere.

In general, Z-Wave and all other FCC-compliant RF devices have limited range (although, outdoors with no obstructions is "best case"). Z-Wave and some other mesh networks overcome this by using multiple units to relay the signals but Z-Wave has a maximum number of hops (4 in the standard setup) which limits the maximum distance even with multiple units. There are also some issues with feedback from Z-Wave devices and Z-Wave devices relay the signal sequentially so there are delays proportional to the number of hops.

I would not recommend RF as the heart of the system for this application.

There are numerous companies that specialize in automated pool controls. Google using "pool automation" and you will be overwhelmed with choices.

Yes and no. They NO LONGER manufacture z-wave thermostats. Granted, maybe that means it didn't work well.

But the distance involved here is no more than for any other devices in my house. Is distance the only concern?

Yes and no. Jandy's system for example is apparently proprietary and cannot be operated over the Interernet except with some major hacking. And Intermatic uses z-wave technology on a dedicated pool automation system - so why does it work there?

What "official" or dedicated pool automation system which doesn't use z-wave can be operated via the Internet?

RCS is correct. If you do not plan to use other Z-Wave components such as light switches or dimmers and the pool sensor is to be mounted far from your master controls, Z-Wave is probably not the best choice. The advantage of a mesh network like Z-Wave is that each dimmer or other module acts as a repeater. This allows low power RF devices to effectively cover a very large area. As RCS has rightly pointed out, mesh networks don't offer any benefit if all you need is one or two points of control.

I'm not sure. I'll check with some of our manufacturers and get back to you. If you plan to use Z-Wave for lights and other things in the home or at least in the pool area, that may still be worth investigating. If not, you should consider other protocols. The simplest approach might be to just run a wire. Is this still possible or has the building been closed up already?

RCS is correct. If you do not plan to use other Z-Wave components such as light switches or dimmers and the pool sensor is to be mounted far from your master controls, Z-Wave is probably not the best choice. The advantage of a mesh network like Z-Wave is that each dimmer or other module acts as a repeater. This allows low power RF devices to effectively cover a very large area. As RCS has rightly pointed out, mesh networks don't offer any benefit if all you need is one or two points of control.

I'm not sure. I'll check with some of our manufacturers and get back to you. If you plan to use Z-Wave for lights and other things in the home or at least in the pool area, that may still be worth investigating. If not, you should consider other protocols. The simplest approach might be to just run a wire. Is this still possible or has the building been closed up already?

Running a wire from the thermostat to the pool is no problem - in fact that is what I planned to do as I understand the remote probe is hard-wired.

My reason for z-wave is to be able to then have my computer control the thermostat on my computer network such as with the HomeSeer Air and Heat plug-in. Is z-wave not reliable for that purpose? How would I do this with a wire instead?

On 2007-09-24 11:17:25 -0400, "Robert L Bass" said:

Such as?

I like the idea that I can connect a thermostat to my computer without having to deal with the major installation effort of a fixed box such as one of the Intermatic controls systems or the ELK-M1G which I think is overkill for me. I thought the idea of a z-wave thermostat plus HomeSeer software seems quite simple to implement. Other ideas?

Followup: I checked with ELK Products and they were not aware of an alternative Z-Wave compatible temperature sensor for use in the swimming pool. However, as mentioned below, there are hard-wired probes which will do the job quite well. ELK Products makes a ELK-M1ZTSR temperature sensor and remote probe kit. There are other manufacturers producing similar products. Since I sell ELK Products I'll use this one in my own application.

There's a brief thread on the ELK web forum where one user describes how he monitors and controls his swimming pool system using the ELK-M1G controller. You may find it interesting, regardless what controller you decide to use. If you want to read it, call my office and I'll get you a user name and password from the manufacturers.

looks very interesting - thanks. I will look at that in detail.

Does this require operating a computer full-time for the pool heating system to operate?

If yes then I think that's a risk - maybe not in Florida but definitely in Pennsylvania for a year-round pool.

If it can work independent of a computer then yes, I'd be interested.

OK some follow-up:

(1) It looks to me as if this system has a hardwired probe and then an X-10 connection to other devices. Why is that more reliable than x-wave?

(2) The manual is very lmited in terms of web capabilities - maybe this is very new?

(3) The company's website prominently invites customers to click and see a demo of their web interface. But the link is broken. Not very impressive.

Has anyone had experience with this company?

I'm not acquainted with the details and, since I have no direct interest, will not spend time doing your homework.

I did not look at the details but it looks to me like it uses UPB rather than X10. UPB costs more but most reports here are that it is more reliable than X10.

I have, in the past, exchanged email with them and can attest that they are quite knowledgeable and always looking to improve reliability.

I couldn't c>>

I just called them... Their demo is down today. As for their hardware, it is all in a transition from X10 to UPB. They don't recommend anyone buy their system today for purposes of connecting to the Internet "but it will be available soon."

In other words... it looks like terrific vaporware... oh well.

They've been around awhile and, AFAIK, have a good track record so it may be available faster than you think. If their system can work without the web connection and can offer the control you need, it may be worthwhile to go with them anyway and add the web connection once available. It does look like it runs without the need of a PC while some of the other things you've investigated need a PC. You've already seen that they are honest and upfront about the system. You may not get that elsewhere.

I've been around the block way too long to buy an incomplete product.

Besides - controlling pool temperature remotely (i.e. by web) is a fundamental point of my project.

In any event, I think I found another option to consider. Does anyone have any experience with HAI? They offer a professional-level pool control system and Homeseer has a Plug-in which can interface with their thermostats (thus resulting in web access). Here is their info:

Are you familiar with the HAI Omnistat series? I did some searching today and it appears they have new models RC-90BZ and RC-100BZ thermostats which are part of their "Omnistat-Z" series with Z-wave transceivers.

Would these work?