How to Choose the Most Efficient Boiler | This Old House

[Music] look at that baby now this looks a little bit different than a typical condensing boiler normally a condensate boil is a relatively small unit that would hang on a wall and directly vent to outside but some of the issues that arose with these smaller units you put them in you connect them to existing piping that were filled with sludge so here's a heat exchanger from a typical wall hung boiler the burner would sit right here you can see right here this is actually the heat exchanger where water goes through it it spirals around and water passes through it the burner sits here tries to drive through and exhausts to the back what can happen is it can clog in a couple of different places right here on the water side see the sludge that's right here and that'll affect transfer over time and clog it but also on the burner side you see these sections they're really close together and you can see impurities right here that can trip an error code no heat call homeowners are not happy that the super efficient boiler doesn't give him any heat so one way the manufacturers try to deal with the sludge issue is have a dedicated circulator pump to push water through this heat exchanger so nothing can clog and they also will do a dirt separator right here well this new unit addresses all that now here's the unit here but i brought a cutaway today it really helps to understand what's going on inside now there's a gas burner right here that looks a little different this is a stainless steel mesh gas will come in here and just this will glow like an orange orb heat will go into this combustion chamber right here now behind it really all around it is water and plenty of it look at the difference in terms of water quality so there's no real place for sludge to collect so now the burner comes on it drives downward not upward down through these heat exchanger sections right here these are cross hatch and they squeeze all the heat out and look at the difference there's plenty of water right here to take all that heat away and by the time it does by the time it gets to the bottom right here there's hardly any temperature left flue gas temperature down here might be 150 degrees where you might have been 700 800 1000 degrees up here but it squeezes down to nothing and the only thing left down here by the way in this little white thing is condensate water that's a byproduct of combustion and that'll go to a condensate neutralizer so flu will leave here at a low temperature now what do you do with it in the old days we always went into a chimney you can't go into a chimney because there's no flue gas temperature left so we have to use a special plastic vent now we thought about putting it right into the chimney right here but local codes just changed last year after so much snow they don't let you run the flu pipe this plastic pipe up through the chimney without letting it go another three feet above the top of the chimney which looked like a flagpole homers didn't want that so what we did instead was to run this through the building and up through the roof to make it look like an old conventional plumbing pipe all right kevin how do i help you here just hold her check the level aren't you okay there you go all right kevin that looks pretty good that way [Music] [Music] all right so that completes our vent with the polypropylene up through the roof that's great we still have combustion air to come in through this pvc line to right to the back of the boiler great job kevin thanks so now we've got plenty of work to do still here's our boiler here's our very smart control but now we've got to leave with the hydronic piping off the back of the boiler so we're going to have a supply and a return that's going to come over right here now we have to think about what we have to deliver to the building first there'll be a circulator pump right here and that'll go up to all the existing radiators or baseboard in the building now we've got a couple of different manifolds right here one for wood floors with radiant and one for tile floors on each of them we're going to have a separate mixing valve right here that'll have a control on it to put just the right water temperature for wood floors you'll have a really smart circulator pump right here that'll just change its speed according to what the load is into the building we'll have another mixing valve and pump right here and we'll also have power heads on the manifold right here with local thermostats that will come down and wired at this point right here the last thing for hydronic piping is we're going to come over here with another circulator pump and we're going to feed into a coil like this that sits inside the stainless steel tank to make hot water for the faucets so we end up here with a 96 efficient heating system doing everything in the building on this job where we're remodeling thanks for watching this whole house has got a video for just about every home improvement 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Channel: This Old House

Views: 108,399

Keywords: This Old House, Ask This Old House, DIY, Home Improvement, DIY Ideas, Renovation, Renovation Ideas, How To Fix, How To Install, How To Build, heating, boiler, plumbing, Richard Trethewey

Id: xhuGW-umeC8

Length: 5min 5sec (305 seconds)

Published: Mon Nov 02 2020