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General => Vacation & Rental => Topic started by: aecchalet on April 08, 2012, 12:28:22 pm

Title: Schedule Hot Water Recirculation Pump?
Post by: aecchalet on April 08, 2012, 12:28:22 pm
My vacation home has a hot water recirculation pump.  When it is not running, it takes about 2 minutes to get hot water to the taps in the master bedroom, which many find annoying.  Wasting the very expensive water is also not good.  However running the recirc pump cost about $90/mo in electricity charges there.  I tried a mechanical timer on a zwave controlled wall outlet.  It seemed like a good idea, except I realized that when I shut off the outlet when no one is there that the timing is off when I energize the outlet again.
I would like to be able to create a scene that checks my virtual state to see if the house is occupied or not.  If occupied it would energize the outlet on the following schedule:
5 AM-8 AM On
8 AM - 5 PM Off
5 PM - 8 PM On
8 PM - 5 AM Off
With UI5, I can't seem to figure out how to do this.
Any suggestions?
Thanks
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: aecchalet on April 09, 2012, 12:11:17 am
After I thought about it a while, here is what I decided to try.
I made on scene to run every day at 5 AM and 5 PM and first run Luup code to determine if the virtual state device indicated that the home was occupied. If not occupied it stops the scene.  If occupied, it turns on on th outlet where I have my recirculation pump plugged in.
I made another scene to run every day at 9 AM and 9 PM.  This doesn't check the virtual state device.  It simply shuts the outlet off at each of these times.
Although it is a simple approach, I hope that it works.
Any other suggestions?
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: Les F on April 09, 2012, 07:08:33 am

Curious about your "virtual state to see if the house is occupied or not".  How is that being set?  Motion?,  Off a rental calendar?,  As a scene that you set to fire per guest?

Thanks!

 Les
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: aecchalet on April 09, 2012, 08:12:01 am
I installed the "Virtual On/Off Switch" plugin from http://apps.mios.com.

I have "Occupied" and "Unoccupied" scenes, which run from a "schedule" that I enter containing each guest's  date/time  of arrival and departure, respectively.
In the "Actions" tab, the "Occupied" scene uses a "settarget" command for my virtual switch to set a "newtargetvalue" to "1".  The "Unoccupied" scene sets the "newtargetvalue" to "0".

I use luup code in other scenes that I want to run depending upon the occupied status.
I use the following Luup code in scenes that I only want to run if the home is unoccupied:

--[[OCCDevice is virtual state device,  OCC = Occupied, True if unoccupied]]
local OCCDevice = 45
local OCCStatus = luup.variable_get("urn:upnp-org:serviceId:VSwitch1", "Status", OCCDevice) or "0"
if (OCCStatus == "0") then
    return true
else
    return false
end

For scenes that I want to run if occupied, I make the first return "false" and 2nd return "true".

I hope to replace the virtual switch device with the Google Calendar plugin device.  To use the google Calendar device, first one enters the guest's reservation as a "event" with a keyword such as "booked" in the calendar.  In scenes that run depending upon the occupied or booked status, they enter Luup code similar to the above (except with a different device identifier) to query or get the status of the Google Calendar plugin device.  If the calendar has an active event containing the specified key word such as "booked", the "status" is set to "1".  If unoccupied, the "status" is set to "0".  I had some trouble with my Google Calendar last week so I have to see if that is straightened out first.

I enter my reservation dates in MyVRZone.com, which creates and synchs my reservation Google calendar with my other reservation calendars on VRBO, Homeaway, FlipKey, etc.  If I get the Google plugin working, I will only have to enter my reservation dates in MyVRZone.com and it will synch all of my online calendars and avoid the necessity of me to having to enter the dates into my occupied and unoccupied scenes.
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: Les F on April 09, 2012, 08:42:51 am

Yeah... I have scenes to pre heat/cool the cabin (as well as make sure things are off after checkout time).  Right now manuall setting scenes to fire on dates/times but really need to tie it back to something like that google calendar plug in.

Title: Re: Schedule Hot Water Recirculation Pump?
Post by: Ap15e on April 09, 2012, 09:18:13 am
My solution:

Title: Re: Schedule Hot Water Recirculation Pump?
Post by: aecchalet on April 09, 2012, 12:34:57 pm
Ap15e's solution is very nice. It is clean and will work for many.
I have to turn on my AC for at least 1 hr prior to my guest's arrival.  My unoccupied scene activates my camera and arms my motion detectors and door/window sensors, which notify me if tripped.  I have to be concerned about unauthorized entry in my vacation home.
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: Les F on April 09, 2012, 08:02:44 pm

Just discovered my rental software ( VacationRentPro ) can export bookings to google calendar in a roundabout way.  Will play around with that and the google calendar plug in.  One less thing to poke in manually when I book a rental
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: aecchalet on April 09, 2012, 08:32:38 pm
The multiple rental calendar synch function of MyVRZone.com is available on their free subscription level and works very well!
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: dnarba on April 10, 2012, 04:38:38 am
My solution for the recirc pump control is a hot water demand sensor.    I have a recirc pump and a tankless heater.    I hooked a high impedance coil relay to the 90V burner solenoid of the tankless heater.   When someone opens a hot water tap and the heater burner fires my relay triggers.   The relay opens the contact on a HRDS1 sensor.    Once the HRD1 shows the hot water use it triggers a scene to run the recirc pump for 30 minutes.   That ensures the house gets hot water for a while.   Each time someone requests some hot water the cycle starts over.   I'm monitoring this and I see I have about a 20-25% recirc pump duty cycle and a 5-10% burner on duty cycle when the house is occupied.   It depends on how many people are there.   When the house it empty it automatically does not run.

One more thing:   I power my HRDS1 with a 5V wall wart which came from a USB2.0 port expander.    It has a switching regulated 5V output and consumes <0.1Watt.   Since my electricity is $0.60 / KWH I appreciated the low power consumption.
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: Les F on April 10, 2012, 06:38:46 am

@aecchalet, Thanks for that info on MyVRZone.com , I had no idea there was a reservation/booking package that outright says it integrates with vera (for temperature control).  That along with all the other features looks pretty good.  I may give them a test drive.  I remember seeing something about MyVRZone.com several years ago but for some reason did not follow up on it.

Thanks again..
Les
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: HakanSoderbom on January 20, 2013, 06:27:23 pm
I just added a simple scene that runs the recirculation pump for 10 minutes, then I added triggers from two bathroom light switches and the kitchen sink light switch. I.e. anytime one of these designated lights are turned on the pump will run for 10 minutes.

I found it easier to teach people to take 5-10 minutes before they jump into the shower (brush teeth, select clothes, use lavatory...) than trying to predict when someone wants hot water during the day.
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: RichardTSchaefer on January 20, 2013, 08:18:04 pm
You need to use the Countdown Timer or Program Logic Event Generator (PLEG) or Program Logic Timer Switch (PLTS) plugins and use separate On and Off scenes.

If Vera Reboots in the middle of your 10 minute scene .. the pump will stay on until the scene is triggered again. The above plugins do not have that problem. Never count on the Scene's scheduled commands to execute ... the longer the schedule ... the more likely you will get caught.

I use the PLTS to turn on my circulating pump when any of the bathroom, kitchen, or utility room lights are turned on .. It runs for 10 minutes after an it was triggered.
I have separate ones for each of the bathrooms ... that also turns off the lights and fans 30 minutes any are turned on.

Title: Re: Schedule Hot Water Recirculation Pump?
Post by: aecchalet on January 21, 2013, 04:46:29 pm
The PLTS plugin looks powerful but the instructions are rather cryptic.
If possible, I would like to do the following with it:
Use any of the light/fan switches in the shower/tub areas of my 3 bathrooms as trigger.
If triggered, PLTS would run recirc pump for 5 min.
30 min after trigger, PLTS woud turn off light/fan switch (in case it was left on).
60 min after trigger, PLTS would reset and start waiting for trigger again.
I would like to schedule this to run from 5-8 AM and 5-8 PM and then possibly expand the hrs depending upon use.

Can the PLTS plugin do this?
Thanks
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: RichardTSchaefer on January 23, 2013, 01:16:01 am
I use the following setup to run my bathroom lights, .... one for each bathroom!

http://rts-services.com/Vera/Plugin/PLTS/TurnOffTheLights/

I use the Program Logic Timer Switch where the Status changes to On trigger from each bathroom, the kitchen counter lights, and utility room to trigger a PLTS timer for the recirculate pump.

You need a PUMP On and PUMP off scene with the appropriate trigger from the Recirculate PLTS.

If you do not mind to use LUUP code you can do this with one scene and two triggers.
     Recirculate On trigger
          Trigger Luup:
                Target = 1
                return true
      Recirculate Off trigger
          Trigger Luup:
                Target = 0
                return true
And for the Scene LUUP code:
     SwPwrSvs = "urn:upnp-org:serviceId:SwitchPower1"
     dev = 43
     luup.call_action(SwPwrSvs, "SetTarget", {newTargetValue=Target}, dev)


Where 43 is my device to control the pump moter.
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: tvipond on April 22, 2013, 01:11:23 pm
To Add to the already great conversation...I did this exact thing in my house...not a vacation house, but I stepped it up a little.

Instead of simply turning the circ pump on and off, I added a thermocouple on the circ loop piping as well. I actually turn on and off the hot water tank on predefined schedules or if the "On Holidays" virtual switch is triggered. This saves energy not having to maintain the water temp when not needed. I feed my tank with pre-heated hot water from a Geothermal so if my tank was ice cold when the tank electricity comes back on, it only takes about 1/2 hour to get to usuable temp. I just ensure that I enable restore the "On Holidays" switch via my cell phone when I am at the airport waiting for my flight home. For the recirc pump, place a thermocouple on the piping so you can actually get a variable speed pump or better yet, just turn the pump on and off if the temp in the circ loop is sufficient. I think the waste of energy from running the pump pales in comparison to the waste of energy because of heat loss in the water that is in the loop. Most loops are not insulated so therefore, you are heating the house with the loop, which causes your hot water tank to be running excessively. It is not the most efficient for heating your house. Let your high efficiency furnace do that and not your hot water tank.

Just my 2 cents.
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: RichardTSchaefer on April 22, 2013, 04:51:42 pm
I have instant Hot Water ... not as efficient ... but since I do not use it often ... I do not waste energy trying to keep water warm in a storage tank.

Actually I do have a storage tank (Small 20 Gal How Water tank that is NOT turned on) as the input to the Instant On Hot Water. If I do circulate water ... the excess hot water pre-heats the water in this tank. If the stored water gets too cold ... then I circulate the water just to preheat the water in the 20 Gal tank. If I did not want the option to pre-heat the water ... then the thermostat would be the better option.

My heat loss in the lines is pretty low ... since all of my hot water lines ... including the return line ... are insulated.

For me the power is cheap ... the waste of water is a big problem.  We have been in a severe drought. I do mot want to waste water and let the water go down the drain while people wait for hot water.

Title: Re: Schedule Hot Water Recirculation Pump?
Post by: tvipond on April 23, 2013, 01:38:19 am
I think it is brilliant to only circ the pump when lights or motion is triggered. I did try a primitive trial of that when I started but with the size of my house, the number of bathrooms and the distance of pipe between the main bathroom or kitchen and the hot water tank, it takes over a minute for the hot water to reach. The wife nagged me to submission and i added the thermocouple instead to at least turn off the pump Intermittantly. Your concept of only turning it on when needed is the best but for me I would need to investigate a small secondary tank to hold and reheat water. It might definitely pay off for me though.

Cheers.
Title: Re: Schedule Hot Water Recirculation Pump?
Post by: Pseudomizer on December 18, 2015, 03:09:44 pm
However running the recirc pump cost about $90/mo in electricity charges there. 

Seriously? I got one installed at my home where we live (not a vacation home) and my bill didn't go up that much. I will try to figure out how much that thing consumes but that high of a number seems unrealistic.