mdbelanger
Almost broke my 3rd.....member
Get The Cheap Pump Then.
Radiant floor heat for the garage need help with mechanicals
- Thread starter bobs77vet
- Start date
bobs77vet
Well-known member
ok here is the concept and flow diagram, i figured this may be the easier way of doing it.
I am envisioning this will be controlled by an on/off switch (panel box circuit breaker) with no thermstatic control other then the lowest setting on the hot water heater or possibly an electric hot water timer. the water heater will be a $200 40-50 gallon electric unit from Home depot, it will be a closed loop system using a food grade polyglycol antifreeze at about a 25% soloution. there is approximaletly 180 linear feet of 1/2" pex running through the 512 square feet garage
A hot water tank hot water output to:
B on/off ball flow valve to:
c drain valve to:
d 1-2 gallon expansion tank with bladder mounted under pipe to:
e T pipe rising 12" up with air bleeder valve on it to:
f brass pump (i need to figure how to switch this) like was posted to:
e on/off flow valve to:
f input side of Pex loop running through concrete to:
g out put side of same pex loop running to:
h cold water input side of hot water tank.
thanks for taking the time to look at this, bob
I am envisioning this will be controlled by an on/off switch (panel box circuit breaker) with no thermstatic control other then the lowest setting on the hot water heater or possibly an electric hot water timer. the water heater will be a $200 40-50 gallon electric unit from Home depot, it will be a closed loop system using a food grade polyglycol antifreeze at about a 25% soloution. there is approximaletly 180 linear feet of 1/2" pex running through the 512 square feet garage
A hot water tank hot water output to:
B on/off ball flow valve to:
c drain valve to:
d 1-2 gallon expansion tank with bladder mounted under pipe to:
e T pipe rising 12" up with air bleeder valve on it to:
f brass pump (i need to figure how to switch this) like was posted to:
e on/off flow valve to:
f input side of Pex loop running through concrete to:
g out put side of same pex loop running to:
h cold water input side of hot water tank.
thanks for taking the time to look at this, bob
JPhil
Huh?
Michael,
Having never installed one these systems, I defer to your experience. However I have a couple questions/comments:
As a former plumber (ahem!), most all of the air bladder tanks I installed were on household domestic water heaters. They came from the factory with an air charge of 40 psi. This is just a factory set average and for the tank to work properly the water pressure in the system has to be checked (before installing the bladder tank) and the tank pumped up to equal it--typically 80 to 90 psi around here. This keeps the bladder membrane in a "neutral" position for longer life & allowing it to react equally to pressure drop or gain in the system.
Bladders for hot water heat systems (different in that they are built for higher temperature & anti-freeze) came pre-set at 12-15 psi, which is about typical operating pressure for that set up, so we left them at the factory setting (but always verified it--some had leaked down).
Since Bob will be running a basically non-pressurized system--only the pressure derived from the expansion of the fluid as it is heated to a lower temperature than either domestic or heating water--shouldn't he reduce the pressure in the bladder to, say, 3 to 5 psi?
And Bob, be sure to get a bladder tank for hot water heat system, not domestic/potable use! The tank can go anywhere in the system, but secure it well--when full, it will weigh at least 10-15 pounds or so and you don't want the pipe connections to be the only support.
The air bleeder should be at the highest point of the system.
Wouldn't a 30 gallon water heater be more than ample? (& cheaper as well?)
( & don't let that Home Depot salesman tell you to put a plug in the third bung on the water heater--that's where the t&p valve goes!)
Disconnect switch for water heater must by National Electric Code be within sight of water heater, but breaker in panel is OK if this meets that requirement.
Where is your filler? Is your "c) drain valve" (boiler drain?) going to double as a filler?
(Sorry if I sound like I'm speaking down to you--as a building inspector, I see some really moronic stuff done by smart people!)
John
Having never installed one these systems, I defer to your experience. However I have a couple questions/comments:
As a former plumber (ahem!), most all of the air bladder tanks I installed were on household domestic water heaters. They came from the factory with an air charge of 40 psi. This is just a factory set average and for the tank to work properly the water pressure in the system has to be checked (before installing the bladder tank) and the tank pumped up to equal it--typically 80 to 90 psi around here. This keeps the bladder membrane in a "neutral" position for longer life & allowing it to react equally to pressure drop or gain in the system.
Bladders for hot water heat systems (different in that they are built for higher temperature & anti-freeze) came pre-set at 12-15 psi, which is about typical operating pressure for that set up, so we left them at the factory setting (but always verified it--some had leaked down).
Since Bob will be running a basically non-pressurized system--only the pressure derived from the expansion of the fluid as it is heated to a lower temperature than either domestic or heating water--shouldn't he reduce the pressure in the bladder to, say, 3 to 5 psi?
And Bob, be sure to get a bladder tank for hot water heat system, not domestic/potable use! The tank can go anywhere in the system, but secure it well--when full, it will weigh at least 10-15 pounds or so and you don't want the pipe connections to be the only support.
The air bleeder should be at the highest point of the system.
Wouldn't a 30 gallon water heater be more than ample? (& cheaper as well?)
( & don't let that Home Depot salesman tell you to put a plug in the third bung on the water heater--that's where the t&p valve goes!)
Disconnect switch for water heater must by National Electric Code be within sight of water heater, but breaker in panel is OK if this meets that requirement.
Where is your filler? Is your "c) drain valve" (boiler drain?) going to double as a filler?
(Sorry if I sound like I'm speaking down to you--as a building inspector, I see some really moronic stuff done by smart people!)
John
Last edited:
bobs77vet
Well-known member
thanks for the info and you can't speak down to me since i am admittedly at the bottom of the knowledge curve on this one. what is a t&p valve? i do have a disconnect breaker like the one you use for working on a/c systems that i can use. thks bob
JPhil
Huh?
T&P valve is 'temperature & pressure' relief valve---it keeps the pressure vessel (water heater) from exploding from over-heating / over-pressuring. That's why old boilers blew up.
Be sure your disconnect is rated for or above the amperage of the water heater, they typically pull more than A/C. It will be listed on it somewhere.
Be sure your disconnect is rated for or above the amperage of the water heater, they typically pull more than A/C. It will be listed on it somewhere.
bobs77vet
Well-known member
thnaks i will check the amperage on the disconnect it has a bar that pulls out and disconnects everything.... i wonder how i quantify the water heater since i'm not looking to store any hot water i really just need to know the heating capacity of the heating elements and how quickly it will turn over the water, do they use a btu measurement for electric water heaters?
The heaters that Homey Depot sells now all come with the t&p valve, because of liabilities. Just be sure to plumb it to the outside of the building with 3/4" min. Code here.
WH are all measured in watts and probably around 4500 draw with a 30 amp circuit for the great majority of them. The specs should list a recovery time. The higher the wattage the faster recovery, but in reality it won't help you much, you're sort of stuck with what you get, especially at bargain prices.
Remember this isn't going to be an instant on type of heat. It will take hours and hours to preheat the slab to your level, but concrete retains heat fairly well too.
The Taco bronze/brass pump I use is a 220v and it's either draws 1/40 or 1/10 amp which is very small and it is wired to run whenever the a/c is on.
The unit came with an in line fuse (like for a car radio) in each power feed for the motor.
I would just wire it to the on/off switch of the water heater and have it circulate all the time the heater is switched on. The elements will take care of the temp control. This isn't your primary heat anyway, I think you said.
Too bad I just threw away 2 good pumps a couple months ago. Sorry
Probably set the system pressure for the most possible for optimum lifespan of parts. I'd hate to replace in slab plumbing.
WH are all measured in watts and probably around 4500 draw with a 30 amp circuit for the great majority of them. The specs should list a recovery time. The higher the wattage the faster recovery, but in reality it won't help you much, you're sort of stuck with what you get, especially at bargain prices.
Remember this isn't going to be an instant on type of heat. It will take hours and hours to preheat the slab to your level, but concrete retains heat fairly well too.
The Taco bronze/brass pump I use is a 220v and it's either draws 1/40 or 1/10 amp which is very small and it is wired to run whenever the a/c is on.
The unit came with an in line fuse (like for a car radio) in each power feed for the motor.
I would just wire it to the on/off switch of the water heater and have it circulate all the time the heater is switched on. The elements will take care of the temp control. This isn't your primary heat anyway, I think you said.
Too bad I just threw away 2 good pumps a couple months ago. Sorry
Probably set the system pressure for the most possible for optimum lifespan of parts. I'd hate to replace in slab plumbing.
bobs77vet
Well-known member
ok thanks, i just checked the disconnect i have is 30a/240 volts.... i think i will try and pressure check the pex this weekend to make sure i have no leaks before i spend any money on mechanicals