connecting OWB to second location

[gregk]

I am looking for suggestions on hooking up my central boiler to a second small house on my property.currently it is only heating my 24x40 garage,and is doing a awesome job.I had to pay a contractor to switch over my heating in my garage,and he charged a arm and leg and all my copper pipes are crooked.
I do not want to pay this contractor to do this small house if i do not have to.currently i am heating this small house with 1 30,000btu ventless heater.I do not have any kind of furnace inside.I know i need to install 2 brazed plate heat exchangers.1 for my domestic hot water,and 1 for my other heat.I was going to install hot water baseboard to heat the house with,but not sure if i need like a propane boiler inside to go through first,or can i just hook up a brazed plate heat exchanger,and a circulating pump that will kick on to heat the house when the new thermostat would call for heat.
If anyone out there could help me with laying something out for this small house,I would greatly appreciate it.
I will have a 2nd house to hook up to this boiler after i get this small house hooked up.my boiler has 3 connections for 3 pumps,and i want to eventually heat all 3 buildings.
Thanks in advance for any help.any further questions about anything please ask.

 

[NateB]

What kind of heat do you want to have? (forced air, radiant...)

 

[gregk]

I am going to install hot water baseboard units.slant fins.I planned on running pex up to the slant fin units.I believe that i need a brazed plate exchanger at my hot water tank,then off that to my 2nd brazed plate heat exchanger for the baseboard heat.I am not sure where i will put my circulating pump,and whatever else i need after the second plate exchanger.I am looking for some drawing or detailed direction.I am able to do all my own plumbing,just dont quiet understand the heating part with bleeders,thermostat controls,and etc.

 

[maple1]

You should be able to find some fundamentals in the sticky threads. Not sure anyone could or would get too detailed in replies - a lot of the finer details is down to the situational specifics, some of which might get overlooked from here. If doing baseboard you should size to your heat loss - one fundamental. Although oversizing is not a bad thing by any means. But your basic idea of DHW HX then heating HX sounds decent.

Do you have a heating supply place around there? Some of those give good help to DIYers if you're buying stuff there.

Basic control idea is thermostat to operate a relay on call for heat. The other side of the relay would start & stop your circulator. If you want to zone (more than one heating loop), you'd use a thermostat for each zone. And maybe zone valves. Which in the control scheme of things would fit in between the thermostat & the circulator - stat opens zone valve, the switch built into the zone valve starts the circ by operating the relay. There is also more than one way to skin this cat too...

 

[E Yoder]

If you don't intend to tie into a propane boiler (pressurized) then I see no need for the second flat plate. I would normally pump a continuous loop to the DHW flat plate, then on the return place two close tees with a ball valve between. First tee is supply for the baseboard loop, second tee is return. Ball valve between is to help purge. Pump for baseboard loop would be pull water out of the supply tee when the thermostat calls for heat, dumping back in the return tee.
You'll most likely need a spring check vlave in the loop to prevent ghost flow (from pressure drop at the tees).
There's definitely more than one way to do it though.

 

[E Yoder]

Here's a picture, not finished supporting or insulating but it has the components.
Air vents back to the OWB.

 

[gregk]

Here's a picture, not finished supporting or insulating but it has the components.
Air vents back to the OWB.

Thanks for the great info.Now i am going to have a circulating pump at the wood boiler to circulate the water through the plate exchanger at the hot water tank.you are saying come off the return of the plate exchanger I would install 2 Tee's with a ball valve between them.where would i put the 2nd circulating pump?
Next,Where will i wire my thermostat to?will i need a zone valve?not quite sure where the thermostat will connect to.
Any way I could get a closer picture of the picture you sent me?
Also will i need a drain,like a bib drain or something to get the air out of my baseboard run?
Thank you for all your help.very much appreciated.

 

[E Yoder]

The goal here is to be able to pump continuously through the flat plate to provide domestic hot water, but start and stop flow through the baseboard, signaled by the thermostat. A 3 way zone valve could do the same thing as what I'm describing.
The second pump in the picture is pulling from the supply tee, pushing around the loop, going through a check valve, then returning in the second tee. I don't have a closer picture. In that picture the return line is going downhill to go back out to the outdoor furnace, so the upper tee gets the first chance at the water flowing by.
The thermostat would be powered by a transformer, which would send 24 v. AC to a relay, which powers the pump during calls for heat.
To purge air on an open system I would merely close the valve between the tees, this puts both pumps in series and typically purges all the air back to the vent pipe on the outdoor furnace quickly. A boiler drain/hose bib would work if it's lower than the top of the outdoor furnace, it'll suck air in if it's higher. Open systems are different than a pressurized boiler.

 

[E Yoder]

A drawing

 

[gregk]

A drawing

Thank You so much for the awesome drawing.now off the plate exchanger,I will be feeding into the cold water side of my elec.hot water tank correct?also I am going to want to install some pressure/temperature guages in a couple different locations so I know what temps.I am getting at different locations of the loop.Is that a good idea?
Am I going to have to worry about pressure since it will be a open loop system?

 

[gregk]

EYODER,
are there any purge valves,and check valves that you would recommend off of supply house.com?also i was thinking for my circulating pump for my baseboard heaters,I will only need a small 3 speed grundfos pump for this small house.Does that sound correct?

 

[E Yoder]

Yes. Cold water side of water heater.
It's an open loop, do no pressure other than a few psi the pump makes. Temp guages are nice.
The valves I normally use a regular pex ball valves, even the purge valve between the tees. I purge air back to outdoor furnace which vents there.
The check valve is a spring loaded check.
A 15-58 Grundfos should work well for a normal baseboard loop. Depending on the distance from the outdoor furnace it might work on the main loop too.

 

[maple1]

Thank You so much for the awesome drawing.now off the plate exchanger,I will be feeding into the cold water side of my elec.hot water tank correct?also I am going to want to install some pressure/temperature guages in a couple different locations so I know what temps.I am getting at different locations of the loop.Is that a good idea?
Am I going to have to worry about pressure since it will be a open loop system?

All your loops aren't open ones. So need to be careful on the communications aspect with this stuff.

 

[gregk]

All your loops aren't open ones. So need to be careful on the communications aspect with this stuff.

Could you make a little more clear for me to understand what you are saying?is my hot water baseboard slant fin units a closed loop?
I am guessing that i am not the only person that has ever tried to connect something like this from scratch.

 

[maple1]

Could you make a little more clear for me to understand what you are saying?is my hot water baseboard slant fin units a closed loop?
I am guessing that i am not the only person that has ever tried to connect something like this from scratch.

It should be.

 

[E Yoder]

What I was describing was leaving the baseboard part of the unpressurized open system.

 

[gregk]

EYoder,So what you are saying is that the whole thing will be a open loop system?Or should the baseboard part be a closed loop system?

 

[E Yoder]

What I drew was a completely open system. But it could be separated with a heat exchanger, which is what I do if there's a indoor boiler that is being tied into.
There are reasons to pressurize the inside. Air removal, etc. But I've done it without with good results.