Setback for hot water tank?
- Thread starter KenN
- Start date
tmbrown97
Senior Member
That could make for some fun ideas! I'd like to learn more too.
My house is plumbed with PEX and an distribution panel in the garage so I have individual control of every water line in the house - it could be fun to learn a way to meter and control that when my kids get older!
My house is plumbed with PEX and an distribution panel in the garage so I have individual control of every water line in the house - it could be fun to learn a way to meter and control that when my kids get older!
PEX is great, and having a central hub for water lines gives you unlimited control ;-) We have copper pipes and my plumber installed a hot water meter with reed pulse output (purchased it from this site: www.jerman.com/dljhotwatermeters.html) between the mixing valve and the faucet, so it measures total water flown. Since I have HAI controller, I have to use my old Stargate controller to count the pulses, but ELK can do it on a fast zone. He also installed electronic shut-off valve, it is controlled by relays from OP2. I am not sure if you would need a special valve for the PEX, but one example would be the valves used in radiant heating system.
dgage - it may be difficult to do such setup on the existing shower, but still possible if you have access to the water pipes. Another way would be to install a whole house meter and have an alternative way to detect people in the shower. It is not going to be 100% accurate, but will give you a reasonable feedback. You can even shut the water off for the whole house temporarily and yell at your kids through the speakers to get out of the shower
dgage - it may be difficult to do such setup on the existing shower, but still possible if you have access to the water pipes. Another way would be to install a whole house meter and have an alternative way to detect people in the shower. It is not going to be 100% accurate, but will give you a reasonable feedback. You can even shut the water off for the whole house temporarily and yell at your kids through the speakers to get out of the shower
KenN
Member
Lou Apo said:
One thing you can do is to put a mixing valve right at the outlet of the tank. Keep the tank set at 140F/60C and deliver through the house at 120F/49C (or even a bit less). Lower temperature in the lines is not considered a problem as they are frequently getting flushed.
http://www.wattscanada.ca/pages/learnAbout/temperingValves.asp?catId=1159
I have a large shower with body sprays and was told I would need two regular gas heaters or a large one so paid the extra for a condensing gas water heater, 130k BTU (standard is about 40 - 50 k BTU I think). It can be vented with PVC pipe as it extracts more heat from the flue gas making it cooler (and water will condense out, hence the "condensing" type). It cost about $2700 about 8 years ago.
I also installed a GFX heat recovery drain pipe device. It is just a brass section of drain pipe with coils around it that goes in a vertical drain stack. As the shower drain water goes through it the heat is transferred to the water going into the heater. They claim about 60% heat recovery. I just know it works very well and no moving parts. I think it was about $350 but that was about the same time and before copper prices shot up.
I think trying to change the temp of the tank at different times of day is going to give little, if any, savings. You could probably look at other things that have a faster payback.
We heat a 4000 sq. ft. house in the midwest and heat the garage a bit (50 degrees) as well and have budget billing of $45/month for gas - space heating, stove, grill, and hot water.
The sensing of shower with flow meters and such is interesting. I looked at taping into the water softener flow meter but it was total water flow (hot and cold) so I took a simpler approach. I just put a push button by the shower and hit it as I am getting ready. It triggers a circulation pump to run for 30 seconds and fill the pipes with hot water. What I haven't done yet is interlock the hydronic floor heat that also uses the same heater (through a heat exchanger so the floor loops are isolated). The floor heat will pull the tank temp down so I want to disable floor heat for about 45 minutes when the button is pushed. Being off that long will never be noticed for the floor heat.
I also installed a GFX heat recovery drain pipe device. It is just a brass section of drain pipe with coils around it that goes in a vertical drain stack. As the shower drain water goes through it the heat is transferred to the water going into the heater. They claim about 60% heat recovery. I just know it works very well and no moving parts. I think it was about $350 but that was about the same time and before copper prices shot up.
I think trying to change the temp of the tank at different times of day is going to give little, if any, savings. You could probably look at other things that have a faster payback.
We heat a 4000 sq. ft. house in the midwest and heat the garage a bit (50 degrees) as well and have budget billing of $45/month for gas - space heating, stove, grill, and hot water.
The sensing of shower with flow meters and such is interesting. I looked at taping into the water softener flow meter but it was total water flow (hot and cold) so I took a simpler approach. I just put a push button by the shower and hit it as I am getting ready. It triggers a circulation pump to run for 30 seconds and fill the pipes with hot water. What I haven't done yet is interlock the hydronic floor heat that also uses the same heater (through a heat exchanger so the floor loops are isolated). The floor heat will pull the tank temp down so I want to disable floor heat for about 45 minutes when the button is pushed. Being off that long will never be noticed for the floor heat.
Work2play, That's a huge cooling bill. Hard to know what to suggest without more details such as - what is the electric rate, what sort of cooling equipment do you have, insulation levels and sun exposure/shading. Lots of south and west facing windows? Maybe start a new thread as this is pretty far OT.
HelenAndRussell
New Member
Choose the water heater temp based on other factors.
tmbrown97
Senior Member
sda has it right - this is one area I wish the lawmakers would fix. After a very low baseline where my rates are about $.12/kwh, they quickly jump up to about $.32, then $.42/kwh. I use <2500kWh in my peak months but still pay these obscene rates.
Not to derail the topic... but it's a pretty sore subject, that's for sure!
Not to derail the topic... but it's a pretty sore subject, that's for sure!
apostolakisl
Senior Member
Work2Play said:
HAHAHA. Fat chance of that. Given the chance, I bet the CA legislatures would make it even worse. The only folks who will be left in CA pretty soon are the super rich and the very poor.
