Radiantec and water heater for hydronics

[stealman]

I am looking for info about how to set up hydronic heat in my shop. I have been reading the Radiantec web sight and I really like their ideas about keeping it simple.

One thing they say is to use a high quality water heater {Polaris} as the heat source for the system. They say it is more efficiant. I have also read that water heaters are not good for running hydronics. I would like to here feed back on this.

Another thing that they say makes the system more efficiant is the use of small pumps on each loop instead of one pump. They say it costs about the same to do this and it is more efficiant to run because the only pumps running are the ones that call for heat and they dont use as much electricity.

They are also trying to sell Pex type tubing that is designed for the hydronic heat.

Has any one set up a system from this company? Are their ideas ligitamit?

 

[KenB]

I don't have direct experience with Radiantec, but I did research and purchase a radiant system for my wood pole barn, which I've been happy with for 2 years. The following are comments based on my experience.

A common problem with water heaters is that they have short "recovery times" -- the time it takes to reheat the large quantity of water in the tank. Because they are designed to heat moving water, tankless heaters and boilers have shorter recovery times and are better suited to cold areas where there is a large difference between supply and return temps. Takagi tankless heaters are popular in natural gas hydronic applications, and this is what I use in mine. Hydro-Shark boilers are popular in electric systems.

It seems to me that a one pump system is simpler than a multi-pump setup (requiring multiple thermostats), not to mention cheaper to install and maintain, which may offset possible savings from energy efficiency.

I found this site useful: http://www.healthyheating.com/Radiant_Design_Guide/Infloor_Radiant_Design_Guide.htm

Just some food for thought.

Ken

 

[jack stand]

I just dropped this link on KenB's thread. http://www.greenbuildingtalk.com/Forums/tabid/53/afv/topicsview/aff/12/Default.aspx
There are a bunch of smart folks over there. I used a guy (he has a radiant design co) that is active on there to design my radiant system and I am glad that I did. They sold me the parts and materials but it was not required and I DID shop them just so I could sleep at night. They have a program where the design fees come off of sales invoice$. Anyway my primary heat source is a woodboiler and I told him that I would like an oil HWH for backup and DHW in the summer. I don't have nat gas and I think propane is a scam, so I have a (BOCK) direct vent - reg. tank type DHW that is 90K or so btu and it seems pretty efficient (although the post burn purge time drives me nuts) Radiant seems to be very simple by nature but there are a lot of things involved with it's design that for a few bucks I really believe that I may have spent anyway "winging it" without this professional design and really nice drawings that enabled me to do ALL of the installation myself (another recoup on the design fees) check out that link (it's a forum) and ask away. I thought that I read somewhere that the "tankless" WH's were turning out to be not as much of an energy saver in some circumstances because that it takes tons on energy to make hot water that fast and that a modern efficient, well insulated HWH is apropriate for many situations. Keep doing your homework, it's worth it.

 

[BadgerBoilerMN]

Quality or not, water heaters may be appropriate depending on the size of the building being heated. We use water heaters all the time for small systems that will not justify a proper boiler.

Tankless water heaters lack proper controls like outdoor reset. This is true of the Polaris unit if not properly sized and controlled.

Beware the online vendor that has but one design.

http://www.badgerboilerservice.com/boilerchoice.html

 

[Displaced Hokie]

I'm curious about this myself. The house we just bought used to be heated by an oil fired boiler, and has hydronic heat in the great room (20x25 room) and radiators in the bedrooms. Since a heat pump and ducting was just put in and we are also adding a wood stove, we don't need the old system. I'd like to scrap the radiators and the massive boiler and tangle of water lines that come with it. Then, find a simple electric (or gas) way to use just the hydronic in the great room from time to time. What are the options?

 

[BadgerBoilerMN]

Depends on the fuel source and cost. A simple electric boiler may be in order.

 

[mnavarre60]

I have a system for Radiantec for my new garage but have not installed it as of yet, I am waiting for warmer weather to pore the concrete. I to was concerned about the heat source. besides a broiler and the Polaris tank they recommend a Bradford White hot water tank. they are spendy but they can heat both water for the floor and hot water for the house. the keep the water separate by way of a coil in the tank. the unit I need because my shop is 36X52 is about 2,500 whole sale

 

[rburke65]

$2,500 Wholesale for a water heater!? That sounds like enough to me.

 

[thejudges69]

Any updates on radiantec? I just got a quote from them for my 40 x 100 heat, almost 7k in materials including the boiler/water heater. I'm reading online tho. The heater they use, American brand, actually has very bad reviews and I was also floored by the cost of the heaters and pumps. I did take a minute to review the quote and it will go down substantially cause they zoned it which I don't want and also added some other stuff I see no need from. Most of all I'd like feedback on the company and materials.

Oh, I should add, tubing and manifolds were done by me, the 7k was just the boiler/heater, piping, pumps and some miscellaneous stuff.