Could I use ????

shar

I just want to install  infloor heating the  in the kitchen area, using pex piping between the joist.We just put in tile and it's pretty cold on the feet. The room is 20'by 25'. can I some how use my hot water unit, it is 60 gals and use just domestic house use. I did read some where, that you could use one tank without a separate loop to do both, but can't find that info any more.

RobbieDo

Potable Water

It isn't really good to use potable water. There are different ways to do this. What is heating your house now?

shar

what to use

I'm using natural gas furnace to heat home. I would like to put radiant heat under tiles. what would you see that would work better? Also have piping already.

RobbieDo

There is a way

To do what you want to do but it's expensive, hot water heaters aren't efficient either. You said the area is 20' x 25'? Did you or anyone do a heat loss calculation? In some areas, like where I live it isn't legal to use a domestic water heater for a heat source.

shar

heat loss

my main furnace will still heating the  home and this area, just want warm floors in this area, not worried about heat loss.

RobbieDo

Here is a way

I don't recommend this and isn't legal where I'm from. Here is a drawing the I took from the internet and this is how you would do it, but I don't recommend this. Too bad floor is down you could have used electric Radiant heating under the floors, it works very well and if electric is reasonable in your area it's worth it for a smaller area. Is your Pex that you say you have oxygen barrier type?? There is another way to do this.

shar

oxypex

the piping is oxypex and it has the oxygen barrier. The drawing i did see a while back came with a water heater that a friend had just installed into his new house. If I remember right it use a check valve on the cold return line and connected to the main line from the tank. You say there is another way? 

RobbieDo

Several Ways

There are several ways to pipe this type of setup. Does your DHWH have taps on the side along with the top?? What about a small electric boiler, what are your electric prices per KWH. I'm also a licensed electrician and have installed several of these and work great.

shar

2 lines

It has just hot and cold coming from the top of the tank. The rates here are going up about 30 % in the next couple of years. Not the way to go here, I wish I could remember which heater company it was that had that design in.

RobbieDo

Well

If you have just hot and cold taps on top, I recommend doing it the way the diagram states. The other way is going to cost you a lot more. if the area is small and well insulated electric boiler is a great way to go. What are you electric costs per KWH? What is your cost per therm for gas? This will help determine which way to go.

shar

ok that's it

thanks rob     where can I get that diagram from ?  That one is really hard to see, when i try to enlarge it.

RobbieDo

......

radaintfloorcompany.com

RobbieDo

Pumps

You do understand this isn't a good way to do this. The water will have oxygen in it and cause the pump or pumps to wear out fast and any other items in the system that are subject to rust.

Ironman

Caution!

That's a legionela special your concocting there! That's why it's illegal.

shar

I better not

I'll have to look at getting some thing else i guess !

thanks for help.

RobbieDo

Oh I know

Some people Bob want the cheap way out. I see a lot of it, as I'm sure a lot of us do. I understand the cost issue but there are better ways to do things. There are small, efficient electric boilers that will do the job just fine. That is what I was asking the cost of electric per KWH and cost of your gas per Therm. Tell me that and I can figure out some better options.

Ironman

I Know...

Robbie,

 And it would have been nice if they had approached this before the floor went down.



Another option is Taco's X Pump Block or even using a separate water heater that's setup with hydronic accessories, though this is not approved.



I'd look at the X Pump Block.

RobbieDo

That would work too

Yes, I was thinking about plate heat exchanger, Laing electric boiler but I guess it would have been nice to know before the floor went down. Electric radiant is also nice too. Many options I think that are better than DHWH for heating. Just my opinion.

Mark Eatherton

I'm confused Robbie

You said "I don't recommend this and isn't legal where I'm from. Here is a drawing the I took from the internet and this is how you would do it, but I don't recommend this. Too bad floor is down you could have used electric Radiant heating under the floors, it works very well and if electric is reasonable in your area it's worth it for a smaller area. Is your Pex that you say you have oxygen barrier type?? There is another way to do this."



So, if you know it isn't a good way of doing it, then why did you show the consumer, who knows no better, this design?



What you've shown her is a known Legionella Generator. Just because you found information and a drawing on the web doesn't make it any better.



If you are going to offer advice to the unwary, unknowing consumer, at least offer GOOD advice, and not something that you DON'T agree with.



Anyone that thinks this is a good design needs to have their head examined by an MD, because they have probably already contracted Legionaires Disease. Maybe THAT is why they think it's such a good idea.



Please think before you post. The consumers are here looking for expert advice.



Respectfully.



ME

RobbieDo

MARK

I just posted a diagram that is from the internet. Radiant floor company in Vermont is the one where I got the diagram from. As I said I don't recommend this, where I'm from this isn't legal, but on the other hand in some places it might be legal?? There are many towns/counties in the country that don't have codes or inspections. ALL of my work is inspected, I run my own business, licensed Electrician and HVAC. This does not mean I'm perfect as no one is, everyone makes mistakes, and for that I'm sorry. I told them it isn't recommended as I stated several times. You can lead a horse to water, but you can't make them drink. I will think more when I answer questions, but something should be left to professionals such as HVAC work. Take care

Mark Eatherton

Thanks for understanding...

Dave Yates and I made an attempt to get this type of system made illegal, but were fighting an uphill battle against some very powerful lobbying groups (HBA) water heater manufacturers and internet pedalers.



You can lead a horse to water, and you can't make him drink, true, but if you show him contaminated water, when he does eventually get thirsty, he MIGHT go a head and drink the contaminated water, and get sick or worse.



To Shar, use a Taco X block or equal to keep the potable water from becoming non potable water. Water heaters in general are terribly inefficient. I know because at one point in time, I actually had exactly as you are proposing. It did little more than knock the chill off the floor, and the water heater seemed to run FOREVER...



Consider setting a true boiler type of heat source, and let it also do your DHW heating through an indirect or reverse indirect. I am a master plumber by trade, and am charged with protecting the health of my customers, and I would NEVER recommend doing what you are proposing.



Go to www.contractormag.com and enter legionella into their site search engine and educate yourself. Once educated, I think you will see why these systems are potentially so deadly.



Done right (heat transfer plates, insulation etc) radiant floor heating can be the most comfortable system in the world. Done wrong, it can make you sick, or worse and waste your time and money.



Please, feel free to ask more questions. We're here to help.



ME

shar

which is best for ?

After doing lots of reading and  what you guys says that this is not the way to go,you have convinced me . I need a unit that will heat water for whole house use and the separite unit for the infloor heating. I'll look for unit that will do both jobs and not cost a arm and leg. Which unit would all you guys use and trust to last the longest, with little or no problem to maint over the life of the system ? I live in centeral B.C , Canada. We get pretty cold winters and they stay for 4 months and in good years 5 months.

Mark Eatherton

What are your energy costs?

That's a place to start.



Give us your local fuel costs for electricity, and natural gas and LP if you have access to them.



The problem with doing it right is that it does entail costs, and it is not inexpensive. It is also limited by the availability of power within your home. If you have cheap electricity, then we can help you design a fairly simple, inexpensive system that will serve your needs well. If all you have is gas, then it can get more expensive, and then it is limited by the existing flue pipes ability to handle additional input.



Internet pedlars would be more than glad to sell you a "system", and when it doesn't work as promised, it becomes YOUR problem to figure it out.



If possible, you wold be wise to contact a local contractor who is willing to allow you to do the grunt work under their supervision to help hold the cost down, and leave the technical stuff to the pros. Hydronic heating is not a simple as some entities would like you to believe, and you are dealing with things that can cause water damage, fire damage, explosions and carbon monoxide, not to mention legionaires disease.



Not trying to disuade you from going with radiant floors, but you need to be aware of all that is involved. It's not rocket science, but done wrong, it can and will create more hate and discontent than comfort.



The very first thing that needs to be done is a heat loss calculation, which you can find online.



ME

shar

Do I need to ?

the whole house is been heated with force air furance [gas] do I really need to do heat loss ?

Mark Eatherton

It depends upon what your final wishes, wants, needs and goals are...

If all you are doing is looking to knock the chill off of the floor, then probably not. But if you want it to maintain good human comfort, even when it is REALLY cold outside, then probably so.



If you want to use the new boiler to do the rest of your home AND the radiant floor AND the DHW, then absolutely, it is a must.



But you are driving the bus, so you can decide whether it is necessary or not.



ME

shar

want it right

What I want will be heating the kitchen floor area and suppy hot water to the rest of the house . The furance will heat the other rooms up stairs and the basement. I would think the heat loss was done for the house when the furance was put in back 12 years ago. Where would one look, for a simple way to calulate loss for that small area ?

Mark Eatherton

Google FREE HEAT LOSS CALCULATION PROGRAM

and see what pops up. If you have questions, we can try and help you out, but much of the needed information (insulation thickness and type) will have to be discovered on your own.



ME

shar

ok

I better get to it then, I'll post what I come out with

thanks     me