hydronic in floor heat questions

[bmxer883]

I've been reading up on this I have recently built a 40x48x14 poll building for a garage and had 6in concrete with 1 in insulation and all PEX ran wish I would have done more insulation but to late now

So I'm debating on doing this system myself I am a industrial maintenance guy but haven't done a lot of plumbing stuff so I'm thinking of hiring someone but haven't really found anyone who does these systems all the time.

How hard would it be to do it myself could someone walk me through it or is there a drawing of the set up?

Boiler will be natural gas being that we have a gas well

 

[383 240z]

My buddy has his set up like this. Gas hot water tank, the thermostat is set at 60*F. He uses a taco pump to move the water. Instead of the thermostat controlling the flame, it runs the pump.

 

[whatuusay1]

It depends how handy you are... general concepts aren’t too difficult. And given you have a nat gas well you should be all set

Have you worked up btu requirements for the building?

 

[bmxer883]

I'm un sure on btu calculations I've done some but worried they aren't right would rather someone who does them more often tell me

 

[PWC Repair]

How many feet of tubing in the floor? Spacing? Ceiling installed or open span? What kind of doors and insulation?

 

[yeldogt]

With free gas the insulation is less important.

You still need a basic load done -- air leaking is a huge thing with any building. It can change the BTU's needed. you need that for the heat source as going bigger with a boiler is not better.

The tubing type -- length and spacing do come into play -- but, it's more about control.

Using a proper boiler is the way to go. Spend the extra 1k upfront and you can set them up with outdoor reset and be done with it.

If you google Viessmann application guide -- it has a lot of information on layouts and piping that fits many mod con boilers. Any boiler you buy will have some diagrams with it ...

Pumping away is an older book that changed they way people did piping ---

Typically near pipe is threaded black pipe and the rest is copper. Done correctly they operate efficiently for many years. One of my buildings is going on 25 years ... I'm sure you can put together some ******* and solder some pipe.

Water heaters-- tank or on-demand are not designed for radiant. Will they make heat and work for a while if properly sized (most tanks are way too small) ... sure. For 20 years ... not likely.

Same with mod con boilers without primary/ secondary as most want to be piped ... will they work for a while sure .. they will not like it long term. I have beed asked to look at quite a few 7 year old dead systems.

 

[meathooker]

Water heaters-- tank or on-demand are not designed for radiant. Will they make heat and work for a while if properly sized (most tanks are way too small) ... sure. For 20 years ... not likely.

Same with mod con boilers without primary/ secondary as most want to be piped ... will they work for a while sure .. they will not like it long term. I have beed asked to look at quite a few 7 year old dead systems.

What have you seen fail on hot water heaters?

There are guys around my area that have a 40k resin unit going for years and I haven’t heard of many failures ..... yet

 

[yeldogt]

What have you seen fail on hot water heaters?

There are guys around my area that have a 40k resin unit going for years and I haven’t heard of many failures ..... yet

Don't know that unit ... 40k BTU would indicate a bigger burner. They ones I have looked at are leaking or the burners are shot.

A typically 40gallon only has a 80% 26k burner ---

 

[Tduby]

I don’t understand where it started or why anyone would think a hot water heater would work good for a heating system they are either way to small 25k btu tanks or 100k+ tankless units that run too high. Since you aren’t to concerned about efficacy I would look into cast iron boiler and get a good boiler protection mixer and call it good the boiler will probably run for 50 years and hardly need any maintenance.

 

[jack stand]

FWIW I had my hydronic system designed for me, if I bought the materials from them they waived the design fees. Along the way I price "checked " them with local and big online vendors and they were right in line with each other. They provided me with working drawings for EVERYTHING allowing this carpenter to install it 100% and also understand my system completely, the varied pumps, valves, etc.- I'd be scratching my head like I was looking under the hood of a modern vehicle if I had not installed it.
To save space, I wanted to avoid a boiler and he specked out a Bock hwh, designed for dhw and provisions for a radiant loop that is isolated by a flat plate heat exchanger. So there are hwh's out there for radiant heating but if space is not an issue, you can't beat a boiler. I'm at the 10 year mark, BUT after the "shoulder seasons" I have a gasification wood boiler that is the workhorse.
I believe that several online suppliers will offer design services to get you going, and believe me it's not rocket science. They should size your pumps, flow rates, expansion tank, etc. That stuff matters bigly!
Supplyhouse.com is one of those companies.

 

[jack stand]

I had to supply the design people construction information like dimensions, insulation values of walls, windows and doors etc. and after that I believe on the designers end is just plugging in your info to get a heat load, then a computer radiant program will do the rest of the job.

 

[bmxer883]

Okay so I got a "professional" out here and they are supposed to give me a quote but they didn't ask for size of building or anything I have 6 runs and they said they will size it off of that. Also it would be walk mount type. they did ask type of insulation and I'll be doing spray foam walls and blow in ceiling.

I like the idea of someone design everything then me installing it so depending on price they give maybe I'll try supply house that was mentioned

 

[svtride]

I had my system sized and spec'd out by hydronic specialists and I worked with my GC to get insulation, PEX and manifold installed per design. I then built the pump manifold with air separator, expansion tank, gauges, isolation valves, etc and had my plumber neighbor (not a heating specialist) install a 90% eff A.O Smith 50 gal, 62.5k BTU gas water heater. That was back in 2008. System works great. I've yet to service anything on the system. Just turned on system last week again.

 

[yeldogt]

There is nothing special about radiant .... getting the heat load done is most important.

Heat load ..... BTU's per foot/

 

[johnnyradiant]

With free gas the insulation is less important.

You still need a basic load done -- air leaking is a huge thing with any building. It can change the BTU's needed. you need that for the heat source as going bigger with a boiler is not better.

The tubing type -- length and spacing do come into play -- but, it's more about control.

Using a proper boiler is the way to go. Spend the extra 1k upfront and you can set them up with outdoor reset and be done with it.

If you google Viessmann application guide -- it has a lot of information on layouts and piping that fits many mod con boilers. Any boiler you buy will have some diagrams with it ...

Pumping away is an older book that changed they way people did piping ---

Typically near pipe is threaded black pipe and the rest is copper. Done correctly they operate efficiently for many years. One of my buildings is going on 25 years ... I'm sure you can put together some ******* and solder some pipe.

Water heaters-- tank or on-demand are not designed for radiant. Will they make heat and work for a while if properly sized (most tanks are way too small) ... sure. For 20 years ... not likely.

Same with mod con boilers without primary/ secondary as most want to be piped ... will they work for a while sure .. they will not like it long term. I have beed asked to look at quite a few 7 year old dead systems.

Pumping Away gets a thumbs up and a double thumbs up to bigger is not better when it comes to picking the right size. I would rather have undersized than oversized, but we would all fall in the Goldilocks category of just right so sweat the details with a good calc.