Best way to pipe a system?

Constantin

> I am looking for advice on how to best pipe a <BR>
> system .The basement has infloor heating ,on the <BR>
> second floor is another infloor zoneand the <BR>
> remainder is old cast iron radiators.The heat <BR>
> source is a Burnham Spirit Boiler .A proper <BR>
> heatloss has been done ,Iam just trying to avoid <BR>
> flue gas condensation in the boiler being that it <BR>
> is non condensing.Any thoughts and in sights <BR>
> would be greatly appreciated. <BR>
<BR>

Adam Grant

PIPING A BOILER

I am looking for advice on how to best pipe a system .The basement has infloor heating ,on the second floor is another infloor zoneand the remainder is old cast iron radiators.The heat source is a Burnham Spirit Boiler .A proper heatloss has been done ,Iam just trying to avoid flue gas condensation in the boiler being that it is non condensing.Any thoughts and in sights would be greatly appreciated.

bigugh_4

Radiators need

180 degree water and floors need usually less than body temperture water since hot feet is not liked! has that been provided by the split system? I bet the whole system is on the cooler tenperture. It will require a tempering valve, and pipeing to accomadate the your set up. the boiler must run at 180 degrees or higher to prevent it from terminating itself early. (as you know)! If this was installed by others, you may have recourse to have it fixed, If by your self, then look and discover on the left of the wall and find a solution of diagram & how to pipe it correctly. Good luck! www.taco-hvac.com comes to mind

Steve Ebels_3

You need

You need to design the system with 2, possibly 3 temperature capability. The basement zone is a slab of concrete I would guess. Given the low heat loss typical of most basements you're probably looking at water temps of 95* or less. you didn't say what type of radiant the second floor is but just about anything you can put in there will require a little higher temp than the basement unless it too is a poured slab application. The rads obviously require higher temps yet so..........there's your three temps.

You are correct in saying that the boiler has to be protected from condensation so you're going to have to run it much higher than the floors need. Make your system temp high enough to protect the boiler and make that your primary loop. You can then feed the rads off from it. The radiant zones will require some sort of mixing or injection device to drop the temps going to the floors. Make sure whatever control you pick has the capability of shutting down the loop pump if the return temp gets to low. In scenario's where you have a load that will soak up gobs of btu's (slab type floor) you can easily run into return temps that are too low for the boiler. What this means is that you can't just pipe in a mixing valve to drop the temp and expect the boiler not to condense. Do some homework on the Tekmar site or look at the radiant mixing block available from Taco.

My first choice would be to use a boiler that is impervious to condensation problems. I'd also guess that in anything but design conditions, the rads will never need to be above 150-160*. Sure looks like a good application for a high efficiency boiler to me. Are you stuck with the Spirit?

hr

Start with

a couple sheets of paper! Define the loads and required temperature, btu, and delta t. Determine how many zones for the various temperature loads. How will you zone pumps, or ZV's.

Draw up a couple ideas, there are dozens of ways to actually pipe and control hydronics. End up with one that safely accomplishes all the goals and fits you price range.

Plenty of good design books available at the Books and More section here to get you thinking along the right lines. Most boiler manufactures have piping drawings included, or at their webpages. Draw up some ideas and post them here for input.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Constantin

... some random pre-coffee thoughts...

... I'm not a high end contractor like Steve, just a homeowner who has happened to have taken a couple of classes at Viessmann.

IMO, the number of zones will depend greatly on how well you have insulated your home and what emitter strategy you're looking to use. If you're after constant circulation, then 3 water temperatures are likely necessary. On the other hand, if you're content to let some zones lie dormant from time to time, then 2 temps may be enough. Allow me to elaborate.

The home I have renovated is blessed with a lot of insulation. So much so, that the above-floor radiant heating system can heat the home with a supply temperature range from 90°F to 100°F. As the basement area (which is heated by in-slab radiant) loses little heat and the supply temps for the in-house radiant are so low, we simply put the entire home on a single supply temperature (regulated by a motorized 4-way valve).

The only "high" temperature item my boiler has to contend with is the indirect water heater. Were it not for the IDWH, our heating system wouldn't even have a 4-way valve because of the boiler design. Were it not for the dirty oil and the limited boiler choices in NA, I would have purchased a condensing boiler. However, you seem to want to heat with gas, so you have far more equipment choices to chose from.

I second Steve in that you ought to look at more boilers than the Spirit. Burnham is a great company and they stand behind their product, but with such a low-temp emitter system, you would be better served by a modulating, condensing boiler like a Buderus GB142, HTP Munchkin, NTI Trinity, Triangle-Tube Prestige, Viessmann Vitodens, WM Ultra, etc.

If these options are out of your price range, I'd follow Steve's advice and pay a lot of attention to the boiler piping to ensure that the flue gases don't start condensing. You may discover that unless the Spirit is free that all the boiler protection may make the marginal cost of going with a modulating, condensing boiler is pretty low. Given where energy prices have been going I wouldn't install a non-condensing gas boiler in a home built like yours.

Unknown

Steve

I'm taking your comment regarding "being stuck with the Spirit" to task here! Although the Spirit may not be a condensing boiler, it is and has been a very affordable, dependable and simplistic boiler to operate and maintain for some years now. I will agree that a boiler that can deal with colder water internally such as the Revolution or Revolution II may have been a better choice here.

I would advise installing a boiler loop with pump and to tee off of that with the radiator zone in Primary/Secondary fashion. Install a secondary loop for the radiant and connect to that with primary/secondary for the underfloor circuits utilizing a mixing valve off of that loop for the concrete radiant circuits. Heat to the secondary loop will be via variable speed injection from the boiler loop. This will aide in keeping the cool return water from affecting the boiler. I have attached a graphic of the piping configuration below. Hope this helps.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Adam Grant

Spirit Boiler

Thanks Glen for the informative post I was begining to doubt my choice of boiler.

Unknown

You are welcome Adam!

As I stated, the Spirit is a real workhouse but with all of the low temperature possibilities you have with the radiant and radiators, the Revolution may have been a much better choice. It has buit-in bypass piping as well as variable speed primary/secondary injection to allow it to operate with return water as low as 55°F without condensing in the heat exchanger. With the Spirit you will need to add these provisions in the system piping. Either way you will be getting the protection you need for about the same investment overall. Hope this helps.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

hr

May I make 1 suggestion, Glenn

I would put the DHW indirect tank circulator before the boiler loop pump. As both will need flow checks, or Grundfos Super Brutes w check. You want to assure the DHW circ pulls from the boiler not backwards from the boiler loop. The control package would pritorize the DHW load, of course and stop the boiler loop pump during DHW call.

Some of the newer controls will time out the DHW priority so as not to allow the heat load to be "forgotten" with long teen ager showers, or a DHW malfunction.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Unknown

Good Advice

That drawing was one that our Radiant Dept. had sent to them from another company....Taco I believe. I had never noticed the location of that pump. Here is a drawing I did depicting two high temperature zones and two low temperature zones with mixing valves in a more simplistic manner but still with the added protection that a boiler loop offers.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

hr

I would still

add a check (Or grundfos downstream of the boiler loop circ. Or else the DHW circ could pull from either direction.

It's as simple as putting another of those small rectangular boxes with the slash through it, downstream of the boiler pump

Very nice drawings, by the way.

hot rod



To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Unknown

Hot Rod

I modified the drawing and reposted depicting the check valve. I usually advise keeping the loop pump and piping big enough to handle the full capacity of the boiler or system. In this case it will usually always be the largest capacity pump and should not be at risk of reverse flow if priority is utilized because it should be larger than the DHW pump. But I'll put it in future drawings anyway because things happen! Thanks.

Glenn Stanton

Manager of Training

Burnham Hydronics

U.S. Boiler Co., Inc.

Doug Oest

Hawkeye Hot Rod

Hey Hot Rod. Nice catch!