Denton Was Right!
Last week I posted a question about my high gas bills. My DH and I hooked up our radiant heat and indirect water heater to the existing boiler, thinking that we were slowly building our Brownstone Temple of Great Efficiency. What we got was $165 gas bills in the middle of summer. We thought we…
Last week I posted a question about my high gas bills.
My DH and I hooked up our radiant heat and indirect water heater to the existing boiler, thinking that we were slowly building our Brownstone Temple of Great Efficiency.
What we got was $165 gas bills in the middle of summer.
We thought we had hooked something up wrong. We used a plumber, but he was not a boiler expert, and had never worked with radiant heat before, and was a friend. It was all very DIY and seat-of-pants.
We hung our heads in shame, figuring that there were issues with how we set it up. We thought the pumps were pumping too hard. That the flow was backwards. Or something.
The good news is that we did a good job hooking everything up.
The bad news is that we didn’t do something simple and wrong. We just need a new boiler.
For all you baby-steps people who are renovating a little bit at a time like us:
Do not hook up your mad efficient new system to your inefficient boiler! Your old boiler doesn’t modulate the flame, so every time your water heater is like three degrees too cold, you’ll be blasting out 110,000 BTUs.
Listen to cmu.
VBP, with all due respect, your post is all over the place.
84% efficiency is VERY good.
And it may just be your terminology (I hope it’s not your plumber’s), but I’m sure you don’t have an “open system” and any boiler is going to need to pull in cool air to work properly.
Anyway, it sounds like you’re working it out.
There’s more here than meets the eye. I was thinking 60% (like our original coal-to-oil converted boiler) when you said “less efficient”…84% is pretty darn good.
The BEST you can hope for is 94-95%, which would reduce your current bill by a grand $19. And while modulating will increase efficiency, most of don’t have such, and your comment about “boiler blast all its BTUs a couple of times. For one shower” is exactly what’s normal. If you’re spending $165 for hot water alone, you’re taking 40 min showers or have a leak or something.
‘Stoners working together to help each other. That’s what it’s all about. Good stuff, Denton and vanburenproud!
I don’t have the radiant heat on yet, it’s been so mild! I’ll be sure to post a good gloat about it when I finally have it on.
Left Hook: thanks for the vote of support. This is about the relationship between the boiler and the H20 tank–the heat hasn’t been on, and when it was on last year briefly you are right, the bill was not a gagger, but it wasn’t efficient either, it was like the bill was with our old inefficient hot water radiators along the baseboards.
The plumber explained to me thusly:
My current boiler, first of all is like 84% efficient, so that’s a good loss right off the top.
Add to that the fact that the flame doesn’t modulate, so for a puny little water tank and a few degrees, I am seeing the boiler blast all its BTUs a couple of times. For one shower.
This is just how the boiler works. It goes on and off.
It’s also an open system, I don’t know whether this is a function of the larger efficiency percentage or not, but the bottom line is that fifty-degree air is coming in to the bottom of the boiler all the time.
I’ll look for this range thing. I see your point.
One more thought. The thermostat that is on your indirect water heater should have a high/low temperature range, i.e. if you set it at 130 degrees and give it a 25 degree range, your water heater should not call for heat unless it drops below 105 degrees. This will prevent your furnace from firing up all the time and an inefficient system.
Yes, radiant heat will be more efficient with a more efficient boiler, but it should still be at least as efficient as when you had radiators hooked up. I don’t think there is anything wrong with doing things one step at a time and getting a more efficient boiler when you have the money. The best radiant heat boilers are very expensive. Do you have a mixer on your system so that the water running through the tubes stays below 120 degrees?
Denton is ALWAYS right 🙂
Why thank you, VBP!
Yeah, I think you have to treat the entire heating system as a holistic whole in order to make things work right.
I’m jealous about your radiant heat tho!