Boiler Setup for Radiant Heat

Piercy

Hello All,

I'm new to this forum/blog and looking for some advice/guidance on how to setup my new heating system. I'm currently renovating my entire house, and I'm at the boiler setup point. I have installed (3) 8 Zone Uponor manifolds to heat the basement, 1st Floor, 2nd Floor, and 3rd Floor (Total heating space 2900 sqft).
I have attached an conceptual design of what i believe is correct, but not 100% sure. The one thing that I'm kinda stuck on is the 3-way or 4-way mixing valve location. If anyone can share some knowledge I'd greatly appreciate it.

CMadatMe

Only time you would use a 4-way mixing valve is if you were using a cast iron boiler. Its used to provide boiler protection from thermal shock, low return water temp. With condensing you need not worry about that. You want the coldest water you can get to return back to the boiler.

Boiler needs to be piped primary/secondary and the DHW should be piped in on the primary/Boiler side not the system side but don't know whose boiler your installing.

If the boiler is providing only radiant heat then I wouldn't use a fancy mixing valve, just a thermostatic and use it more as a high limit. Set the boiler heating curve correctly and your boiler becomes the modulating mixing valve. Set the thermostatic for the design water temp under full conditions. Will protect the floor from spikes of hotter water after a domestic call or if the boiler ran to high limit for some reason.

Lastly, I wouldn't zone with pumps. Would use Zone Sentry Zone Valves and a variable speed pump such as a Grundofs Alpha or Taco 00e Series Varible speed pump dependent on flow and head requirements.

Rich_49

4 way mixer can be used for many things besides boiler protection Chris . 4 way valves allow for higher Cv when such things may be important .

http://www.taco-hvac.com/uploads/FileLibrary/102-145.pdf

Be careful where you tell folks to place things within a system . For instance , if this was a Utica SSc or Dunkirk Helix the indirect should be on the secondary side as the boiler pump never ceases to operate while the boiler is on . The indirect circ need only be sized for the head loss and GPM of the indirect , the 2 circs will work together . Not all mod cons must be piped pri / sec anymore also as can be found in so many manuals .

If you read his post more closely you would have seen that he has 3 manifolds heating 4 floors . What will not get heat when one of the 3 zone valves is off ? It is quite possible that a circ per manifold is exactly what should be done . We have no idea of the head and or flow rates that are present or required .

http://mechanical-hub.com/langans

Your advice is usually quite sound , maybe a few questions were in order before commenting .

Piercy ,

What boiler is to be used ?

Why do you need a mixing valve at all ?

How is this to be zoned ?

How many SWTs do you believe you require ?

Why are you not storing high in the indirect and mixing your DHW ? You could use a smaller tank with very similar results .

Did you size the boiler to the heat loss or to make hot water ?

GW

Very neat work, wow

Just curious why you pointed the manifolds down.

I'm pretty sure your upper floors need more temp than your basement, yes, no?

I've always been a constant circ man, I've been brain washed into thinking it's the best way to handle large mass. I like a clean brain

Your plumbing for the water heater is off, the cold enters from the top right?

I like the primary loop method, and taking your higher temps off 1st with close space tees, them your lower temp stuff last. This makes for sone large Delta t, smaller pump and piping to do the same work

Zman

I am assuming the boiler is a mod/con with domestic priority.
The mixing valve in this case does not need to be there at all.
The circs would need check valves.
Some means of purging will need to be figured in.

Gordy

Hmm I see no information on what the emitters are. So would assume since mention of a miximg valve........

Please answer questions Rich asked to better advise you.

Piercy

Thanks for the quick response guys.

What boiler is to be used ?

I'm currently in the market looking for one, but I have been looking at a wall mount Utica Boiler. To be fully honest I not sure whats a good brand / quality for radiant heating.......

Why do you need a mixing valve at all ?

I don't know.......

How is this to be zoned ?

Well there are 24 loops and 12 Zones

How many SWTs do you believe you require ?

Well I'm not quite sure. I would just say one. but there are two zones that I would like to increase due to the locations and heat losses (Foyer & Dining Rm, patio door is located)

Why are you not storing high in the indirect and mixing your DHW ? You could use a smaller tank with very similar results .

I will be using an indirect (Hotline HL80) and the only reason I'm using it is because I got it for free.

Did you size the boiler to the heat loss or to make hot water ?

The boiler will be used to as heating and domestic water heating. I had some one someone analyze the heating requirements and suggested 110,00 BTU. (Attached Heat Loss Report)

Rich_49

Did this gentleman by any chance send you the Design Summary - Manifold view ? If so please attach , if not please request that and post

Piercy

No, he did not. They just offer a free heat loss analysis of your house.

Rich_49

While performing the heat loss analysis on Uponor's ADS software this design manifold summary is a default report . Maybe you could request that so we may see if he added S & R piping lengths and sizes to the manifolds . If he did not do this your head losses that are state dare incorrect ., All the information must be entered for an entire circuit for you or anyone to have the slightest chance of getting it right .

Here is a sample

Zman

It looks like Richthomkins is a manufactures rep that does free designs for their customers. Normally the customer would buy the equipment package from them in exchange for the "free" services.
They likely have a complete design done that they would provide once the order is placed.
How does the OP fit into the mix?

As for the design, with a modulating condensing boiler you do not need the mixing valve. The boiler will adjust the temp based on the outdoor reset.
Given that you have so many zones, you will need to be careful of boiler short cycling. A buffer tank and/or a boiler with a high turndown ratio will be needed.

Gordy

Is,this all the same type of radiant heat in all zones?

What type of radiant install?

Piercy

Gordy,

Uponor radiant tubing. 5 loops for the basement are in the concrete, and all the other loops are mounted in uponor joist trac.

Piercy

Zman,

You are probably correct. The only reason that it didn't purchase from them was because of the pricing, which was ridiculous high compared to other suppliers.

I apologies for my ignorance, I'm trying tp get use to the acronyms on here but whats "OP"?

Gordy

Original poster of the topic.

CMadatMe

I'd still use a thermostatic more as a high limit then a mixing device. Get the boiler curve to run the radiant. Mixing valve will just open full bore when the water temp gets below the temp it's set at. Its more for a piece of mind protection in case the boiler runs away to its adj or fixed high limit then anything else. Rich , I also asked what boiler he was using and for this application.