I could use some help with sizing of a pump and plate heat exchanger for my new E-classic. Here is a basic over view of the installation. I have an older farm house in the country with baseboard hot water heat. The current propane boiler is rated at 200,000 BTU input with approx 150,000 BTU output to the water system. My plan is to keep the current propane boiler system intact and use a plate heat exchanger. I am also planning on installing a side arm on the hot water heater. My E-classic will be approx 110 ft from the house and down a hill about 15ft. I am planning on using 1" Thermopex for the run between the E-classic and the house. My questions are as follows. How large of a heat exchanger do I need and what pump would be required for this long of a uphill run? The final install will also have the E-classic heating my shop of 40X70 via infloor heat, but for the time being need to get the house nice and warm. Thanks in advance.
Help with pump/exchanger sizing
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g900 - welcome to the Boiler Room. I know there are several E-classic owners here, and I am sure they will be more help to you than I. Lets start with the basics.
Wow- those are some serious heat loads. Have you discussed your setup with your CB dealer? They should be able to at least get you in the ballpark. Rather than using the propane furnace as a load indicator, do a heat loss calc on the house, and that will give you a better picture of the size of HX you need. Keys to remember are flow rate and fitting sizes. Larger fittings and more plates on the HX = less head loss through it, but also means more $$$. You are probably looking at an HX of 70 plates or more, unless your heat loss calcs show your propane unit to be grossly oversized.
That shop is huge! Are you really going to try and heat that much space with an E-classic? If so, I suspect you will be firing that puppy 24/7, and consuming a lot of wood. You may want to consider a seperate unit for a space that large.
As to house load pump, the above calcs will tell you what you need as far as pump sizing. The distance and the HX will determine the bulk of the head loss. The elevation is not an issue as far as head loss, as the return flow balances the supply flow (simplified). Given the elevation difference, you might also consider installing the HX closer to the wood furnace, but that may not be feasible with the CB.
Slantfin.com has a free heat loss estimater, and flatplate.com has a free HX sizing program.
Best of luck.
Wow- those are some serious heat loads. Have you discussed your setup with your CB dealer? They should be able to at least get you in the ballpark. Rather than using the propane furnace as a load indicator, do a heat loss calc on the house, and that will give you a better picture of the size of HX you need. Keys to remember are flow rate and fitting sizes. Larger fittings and more plates on the HX = less head loss through it, but also means more $$$. You are probably looking at an HX of 70 plates or more, unless your heat loss calcs show your propane unit to be grossly oversized.
That shop is huge! Are you really going to try and heat that much space with an E-classic? If so, I suspect you will be firing that puppy 24/7, and consuming a lot of wood. You may want to consider a seperate unit for a space that large.
As to house load pump, the above calcs will tell you what you need as far as pump sizing. The distance and the HX will determine the bulk of the head loss. The elevation is not an issue as far as head loss, as the return flow balances the supply flow (simplified). Given the elevation difference, you might also consider installing the HX closer to the wood furnace, but that may not be feasible with the CB.
Slantfin.com has a free heat loss estimater, and flatplate.com has a free HX sizing program.
Best of luck.
Jim
Thanks for the welcome. I believe that the propane boiler to be oversized by a bunch. We had some -40 below nights last month and it ran only about 1/2 the time. One of the online heat loss calculators came up with a heat loss of approx 65,000 BTU for the house. The shop will be well insulated and only at about 45-50 degrees with the doors not being opened very much. I have a near endless supply of wood, thankfully most of which is hardwood. In talking with Central Boiler they believed that the E-classic would be up to the task. My thinking is that by burning harder I should have less of the issues that come from idling.
Thanks for the welcome. I believe that the propane boiler to be oversized by a bunch. We had some -40 below nights last month and it ran only about 1/2 the time. One of the online heat loss calculators came up with a heat loss of approx 65,000 BTU for the house. The shop will be well insulated and only at about 45-50 degrees with the doors not being opened very much. I have a near endless supply of wood, thankfully most of which is hardwood. In talking with Central Boiler they believed that the E-classic would be up to the task. My thinking is that by burning harder I should have less of the issues that come from idling.
To keep pump costs down I know several people that put two pumps in series (like two 007s or two 15-58s) It is often less expensive than getting one larger pump and easier to get a replacement for. Even if you run 3/4" PEX to the plate HX, use larger ports for better flow. You could probably get by with a 50 plate with 1" ports, but use one of the calcs to be sure. These are expensive enough, you want to get it right the first time. Extra plates is ok, but too few and you won't get enough heat.
I would never run 1" underground again
! large heat load+ distance 1" will not transfer the BTU. Spend a little extra now and run a smaller pump will save you$$$ and problems in the future.
! large heat load+ distance 1" will not transfer the BTU. Spend a little extra now and run a smaller pump will save you$$$ and problems in the future.I would never run 1” underground again
Take some time this weekend and just run down the thread listing pages for this forum and read any posts on outside installations and underground tubing. You'll very quickly notice people echoing taxidermist's sentiment above. Seems like a lot of people have trouble getting large loads through 1" tubes. For lots of reasons.
I think a lot of OWB dealers try to minimize the overall cost of installations by recommending smaller tubing and bubblewrap insulation because they fear losing the sale of the boiler if the project seems too expensive.
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