What's the hot setup for in floor heating?

[tstaude]

I keep on reading about tankless setups being the best way vs boilers. I see there are a lot of options out there, what has anyone out there used to date in this category?

My dad has a very elaborate setup at his place with a boiler but my 1200 sf shop should be a lot more simple.
Also looking at using propane as a fuel source.

Also looking for tips on insulating a grade beam slab.

 

[Jackfre]

The Takagi tankless water heater is the only tankless that has had success in space heating applications. Regardless of what source you use it should be piped primary/secondary. With a boiler you have an assortment of sizes to choose from. Assuming decent construction and perimeter insulation you probably won‘t exceed 60kbtu. The tankless will be much larger. Yes it will modulate, but capacity that will never be used is not worth paying for. Your boiler will likely have an internal circ to handle the primary loop. It will also likely have an Outdoor Reset Program built in. The ODR is what can make these systems sing and save you money long term by closely controlling the firing rate. You want it. The boiler will be designed to handle system wiring connection in a straightforward manner. The tankless will cost less up front, but that is its only benefit compared to a modulating boiler.

 

[tstaude]

Thanks for the input!
With all that in mind what would be a good boiler in that size?
This is all new to me as the last setup I helped with is now 20 years old.

Does it get cold in norther CA ?

 

[Jackfre]

There are a lot of good wall hung boilers. Look up your local HVAC/P&H suppliers and see what they are carrying. If you have any relationship with anyone in the biz ask them what they like and why. If you end up with something that is just a whiz-bang piece of equipment but then get into a jam with it you may not have local support in either the knowledge or parts dept. If you are going to self install go and talk to the branch manager of the supply house. Most likely they will sell it to you and you get to know them. You become a customer. That is a good thing. As to picking a specific brand, I’ve been out of the biz for a few years now and things change so fast that picking a brand is probably not the best Thing to help.
As far as “cold here in N CA”, why a couple years ago it got all the way down to 18*. Now that is at 3000’ elev. If I want colder I go up the grade. Used to get a few multi-foot storms a year at 3000’. Not any more. Our issue is fear of fire. As well with the drought all water use is locked down. You can’t use it if you don’t have it. My three surrounding neighbors all lost their wells in the last drought, ‘12-‘17. I have the best well in the neighborhood but you don’t push it.

 

[slackdaddy1]

There are many great wall mounted elecrtic and gas mini boilers.
I used a Electro Industries EMB-S-5 - 4.5 kW - 15K BTU Electric boiler in my 720 sq ft shop.
I could not be happier. It is a total "set it and forget it" system. I installed it 4 years ago and set the T-stat at 55 deg and have never touched the system since then.Electric use is minimal

 

[Purplecam]

@Slack Daddy would you mind sharing your total cost of hydronic? I’m in PA, considering same Electro EMB-S-5 for a 660 sq ft Workshop. Did you run 3 1/2” pex loops with 2” XPS like commonly recommended? Any idea what the average or peak electrical costs are a month?

 

[PoorUB]

@Slack Daddy would you mind sharing your total cost of hydronic? I’m in PA, considering same Electro EMB-S-5 for a 660 sq ft Workshop. Did you run 3 1/2” pex loops with 2” XPS like commonly recommended? Any idea what the average or peak electrical costs are a month?

Slackdaddy hasn't been around since August of 2021 so don't hold your breath waiting for an answer!

 

[Purplecam]

Slackdaddy hasn't been around since August of 2021 so don't hold your breath waiting for an answer!

Good point, and I realized I tagged the wrong user should have been @slackdaddy1

 

[PoorUB]

Good point, and I realized I tagged the wrong user should have been @slackdaddy1

slackdaddy1 was who I was referring too! There isn't any other Slackdady in the thread!

 

[fitter30]

@Slack Daddy would you mind sharing your total cost of hydronic? I’m in PA, considering same Electro EMB-S-5 for a 660 sq ft Workshop. Did you run 3 1/2” pex loops with 2” XPS like commonly recommended? Any idea what the average or peak electrical costs are a month?

Most garages 10-12" loops except in really cold climates. Can't bend 1/2" pex no tighter than 6" . Use only oxygen barrier pex. Max loop length for 1/2" is 300' and with a design 20° temperature drop 35 btu's per foot. Underfloor insulation is just as important.

How much insulation under a radiant floor?

I am having a 24 x 36 accessory building [can't call it a garage as the city would then require that I put in a driveway] that will have radiant heat in the floating slab. For reference, it is in the Minneapolis Minnesota area. It is obviously cheaper to put the insulation in before the pour...

www.google.com

 

[Mr onetwo]

Viessmann Vitodens 100 model B1HE-85 is the only way to go IMHO. https://www.viessmann-us.com/en/products/vitodens/vitodens-100-b1he.html
Efficiency (AFUE) 95% turns down to 8,500 BTU

 

[road_king]

Viessmann Vitodens 100 model B1HE-85 is the only way to go IMHO. https://www.viessmann-us.com/en/products/vitodens/vitodens-100-b1he.html
Efficiency (AFUE) 95% turns down to 8,500 BTU

I couldn't agree more. Have had this model boiler in my 30X40 garage as radiant heat and DHW for the last 5 years and couldn't be happier with its performance.

 

[theoldwizard1]

Also looking at using propane as a fuel source.

More expensive to install, but cheaper to operate !

 

[yeldogt]

Viessmann boilers are are excellent. First - they are self regulating .. so the burner setup is very easy (none) Also: by all accounts they are the best with Propane (propane is a dirty fuel compared to NG and the quality can be inconsistent) -- the self correcting combustion again wins the day.

The 100 has all the basic stuff the 200 gives a bit more and also the ability to run two water temps both with outdoor reset curves (not going to be needed by most people)

Over the years e-bay has provided some interesting deals. I keep an igniter on hand that way you never need it. They also are not approved with PVC exhaust

 

[Mr onetwo]

Viessmann boilers are are excellent. First - they are self regulating .. so the burner setup is very easy (none) Also: by all accounts they are the best with Propane (propane is a dirty fuel compared to NG and the quality can be inconsistent) -- the self correcting combustion again wins the day.

The 100 has all the basic stuff the 200 gives a bit more and also the ability to run two water temps both with outdoor reset curves (not going to be needed by most people)

Over the years e-bay has provided some interesting deals. I keep an igniter on hand that way you never need it. They also are not approved with PVC exhaust

not true on the 100...combustion must be set with instruments.The 200 has Lambda but casts around $1100 more.The Vitodens 100 is a super solid reliable tank of a boiler.PP exhaust (Z-DENS,Innova,ect.) is not too expensive and easy to install.

 

[yeldogt]

not true on the 100...combustion must be set with instruments.The 200 has Lambda but casts around $1100 more.The Vitodens 100 is a super solid reliable tank of a boiler.PP exhaust (Z-DENS,Innova,ect.) is not too expensive and easy to install.

Maybe that was years ago ? My literature says it does ... from about a year ago. They could have different models. I know years ago they sort of positioned the 100 as an all in one solution with the add on domestic water heater heat exchanger. I have never used the 100 ....

The last two I got were NOS in the low 2k range .... Viessmann starts the warranty when you fire them up if you contact.

Viessmann tends to make some of the information complex when it does not have to be. I always used conventional Buderus boilers in all my projects using boilers -- switching to the wall units they made back in the 00's. I moved over to the Viessmann for two reasons. The overall Buderus setup using the mixing modules was crazy expensive and then Bosch bought them and I knew it would all change. Viessmann has a nice straight forward system --

 

[35k0]

I'm using the Electro Industries EZB-Eco - 10 kW - 34.1K BTU system for my 30x40. It's awesome and easy to install.

I went back and forth on Electric vs Propane
you really have to do the homework on KWH vs $/gallon cost of propane in your area.
This year, propane costs have been so high that is was pretty much a wash between the two in Northern MN.
An upside to electric is no exhaust, no yearly maintenance/cleaning.

 

[thammel]

I'm using the Electro Industries EZB-Eco - 10 kW - 34.1K BTU system for my 30x40. It's awesome and easy to install.

I went back and forth on Electric vs Propane
you really have to do the homework on KWH vs $/gallon cost of propane in your area.
This year, propane costs have been so high that is was pretty much a wash between the two in Northern MN.
An upside to electric is no exhaust, no yearly maintenance/cleaning.

Is your breaker then a 240v/50amp one?

 

[yeldogt]

I'm using the Electro Industries EZB-Eco - 10 kW - 34.1K BTU system for my 30x40. It's awesome and easy to install.

I went back and forth on Electric vs Propane
you really have to do the homework on KWH vs $/gallon cost of propane in your area.
This year, propane costs have been so high that is was pretty much a wash between the two in Northern MN.
An upside to electric is no exhaust, no yearly maintenance/cleaning.

It's all about the electric cost ..... using the 27 rule. At .10KW electric .... you need about $2.70 propane. Factor a bit more for the efficiency of the propane equipment. I was at $1.69 starting out to over $2 later this year. At .20KW for electric in our area --- no way close to my lower propane cost. Would need sub .10KW electric cost at my propane cost.

Where things change is using a heat pump --- with a cop of say 3 ... things change. Even at .20 -- now I'm at sub .07. That makes things very close .... case can be made for an air to water heat pump (if we can ever get many choices) for radiant.

 

[35k0]

Is your breaker then a 240v/50amp one?

I'll double check but I believe it is a 240 60 amp and a 20amp for the pump.

 

[Mr onetwo]

Viessmann boilers are are excellent. First - they are self regulating .. so the burner setup is very easy (none) Also: by all accounts they are the best with Propane (propane is a dirty fuel compared to NG and the quality can be inconsistent) -- the self correcting combustion again wins the day.

The 100 has all the basic stuff the 200 gives a bit more and also the ability to run two water temps both with outdoor reset curves (not going to be needed by most people)

Over the years e-bay has provided some interesting deals. I keep an igniter on hand that way you never need it. They also are not approved with PVC exhaust

Good catch on the 100 series.The B1HA/B1KA boilers must be set up.I have not installed a B1HE (the latest series) yet , but it is self regulating.You can't beat Viessman boilers IMHO. I am trying an NTI S20W wall hung indirect water heater...pretty exciting concept. https://ntiboilers.com/product/s20w I have moved off of Taco and Argo zone controls and really like Tekmar...used their stuff for many years. https://www.watts.com/products/hvac-hot-water-solutions/controls/zone-controls/306v/306v

 

[slackdaddy1]

@Slack Daddy would you mind sharing your total cost of hydronic? I’m in PA, considering same Electro EMB-S-5 for a 660 sq ft Workshop. Did you run 3 1/2” pex loops with 2” XPS like commonly recommended? Any idea what the average or peak electrical costs are a month?

Sorry for the long vacation
My shop is 22 deep x 32' wide,, slab is about 31 x 21 so roughly 600 sq ft.
1/2" X link PEX, 2 loops about 10" - 12" spacing (Spiral in, spiral back out.)
I got my design and piping from Radiantech,, they are good helpfull folks

 

[yeldogt]

Good catch on the 100 series.The B1HA/B1KA boilers must be set up.I have not installed a B1HE (the latest series) yet , but it is self regulating.You can't beat Viessman boilers IMHO. I am trying an NTI S20W wall hung indirect water heater...pretty exciting concept. https://ntiboilers.com/product/s20w I have moved off of Taco and Argo zone controls and really like Tekmar...used their stuff for many years. https://www.watts.com/products/hvac-hot-water-solutions/controls/zone-controls/306v/306v

With all manufacturers -- the products keep coming and changing. Viessmann makes a very nice boiler ... they make it look complex w/ all the literature they have with it! It's really a simple boiler and it does so much right out of the box .. the self regulating (especially with propane) is a real advantage.

Radiant slab is very forgiving .... pump heat into the slab and the slab with get hot. The devil is always in the details .... that's where the efficiencies come from. Most people here have small spaces and with the lower delta of a utility space -- not getting high efficiencies often is not even noticed -- especially with natural gas.

It does surprise me that so many buy the pre-made panels that don't match up to the instructions on the heat source. Pex size and loops are another ... there are things not to cut out if you want efficiencies

 

[tbody321]

my set up for 25x85 driveway and 28x60 garage. Very efficient for radiant

 

[yeldogt]

my set up for 25x85 driveway and 28x60 garage. Very efficient for radiant

NIce set up .... like the mount for the expansion tank. Assume the higher flow is out to the driveway ... using a low Loss header solves most of the math