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[ST98]

Hello all, I've recently purchased an OWB and have to put most of the plumbing together myself.  I was looking for some assistance in sizing the heat exchangers.  The house is 1300 square feet with an oil furnace and it is 170' from the OWB.  The pole barn is about 35 feet from the OWB and 40 x 48 with 16 foot of clear space and then open rafters.  They are both insulated.  The house has hot water baseboard and the barn will have hot water baseboard in a 300 square foot insulated office.  The rest of the barn will have a hot air blower. 

I've done all the plumbing in all of the building but am a little inexperienced in the heat exchanger realm. 

Who offers the best bang for the buck for heat exchangers?  They seem to be pretty far spaced in price when looking online.

Living in Northeast Pa.

Thanks in advance and this probably won't be my last questions.

[Scott7m]

Z supply is where I get my plates and prices are great even on retail but it's a dealer only company. 

There are some out there that aren't real good or are to restrictive. 

Based on the size of your home I would probably go with a 60 plate heat exchanger on that and a 80-100 on the barn, that open space up and above more than doubles the actual square footage.  Sooo it's gonna require a lot.  You may be able to heat the home with let's say a 40-50, but I like them a but on the large side for flow as well.

As far as shop heaters for the forced air part, once again those are all over the board, Ive sold the same brand for years and for example they start at a 50kbtu unit and they retail for around $329.  They go on up from there depending on the size you may need

Just shop around, there are inferior products out there in regards to this stuff, avoiding it is a must. 

[ST98]

So the Btu of the exchanger doesn't have much bearing?  The plates are what makes it happen?  I was looking at flate plate exchanger and the btu rating on a 70 plate is higher than the furnace output.  A couple of my friends have flat plate and seem to be happy. Not sure if they are quality or not?

Any answers would be greatly appreciated.

Thanks

[willieG]

basically the more plates the more heat transfer..the more plates the longer your cold and hot water have to mix. so if your plate exchanger was long enough to have enough plates your  OWB water returning to the OWB would be the same temp as the water  on the domestic side of the exchanger and also i think the wider the exchanger the less friction (head pressure) it would create (i think i read that somewhere but the pros that are here can verify or squash that statement)

[Scott7m]

Keep in mind the ratings are basically bs!! 

Do they know how hot your water is?  Do they know how many gallons per minute your flowing???  Nope... 

A some point in time they were tested and designs copied but my advise was based on just experience rather than the charts..

[ST98]

Thanks All.  Great information and should make getting the right one easier.

Do I need to calculate the friction loss from the house to the OWB for a pump? The elevation difference is roughly 5 feet up but then you take out the height of the pump on the OWB it is 2 feet so 1 psi loss.

[RSI]

The elevation makes very little difference. What matters is the size and length of the pipe and number of elbows mostly.