Heating Help

electric boiler reset

@ October 29, 2011 11:32 AM in electric boiler reset

I'm considering an EH- 20 electric boiler; now slant fin offers a unit with outdoor reset (M3 model)
I'm questioning reset on an electric boiler of minimal volume with no flue sucking out heat and longer run times on the circulator.
If this control a real benefit or a market sell up?

changing the resistance of the sensor

@ October 29, 2011 11:26 AM in Low-tech ways to adjust outdoor temp sensor based on wind

Since most (??) sensors used for outdoor reset have the resistance inversely proportional to the temp - temp drops and resistance goes up. Then a simple potentiometer, hooked to a vertical hanging wind paddle. wired in series with the outdoor sensor should increase the resistance when the wind blows - effectively lowering the temp the sensor reads.

I'm not sure why the BB is not working if its

@ January 19, 2011 8:10 AM in Expansion Tank

plumbed like a normal cast rad. However
on a similar gravity 2 pipe system I added a radiant floor where they didn't want a cast rad occupying space in the kitchen.
I took it off the take=offs that normally fed the old cast rad. I added a circulator and a strap on aquastat (near the boiler) so when things got hot the pump automatically started. It works great - to an extent - in that there is no t'stat for the kitchen and the rest of the large cast rads respond very differently. However they are satisfied, the floor is clearly warm.

yes, this is an old cast sectional column rad.

@ January 19, 2011 8:02 AM in cast rad with left hand thread

I'm not dealing with the LH-RH nipples used to pull the sections together. In the last section, the one with feet, there are 2 - 1 1/2" female fittings side by side at the bottom; both appear to be left hand. Now maybe it wasn't a good day, and I didn't have any 1 1/2 mipt fittings to try it; but just tracing the threads seem that they're LH. Next time I'm at the site I'll really take note. Until I get back there, Is this a possibility?

did you mean

@ January 18, 2011 8:46 PM in Expansion Tank

baseboard, fin or cast, or a radiant floor. Tell me which and I'll tell you what I did to a similar system that works great.

left hand thread

@ January 18, 2011 8:39 PM in cast rad with left hand thread

I don't understand what you mean. What ever goes in this pipe thread, bush, nipple, tightens counter clockwise.

left hand thread

@ January 18, 2011 8:39 PM in cast rad with left hand thread

I don't understand what you mean. What ever goes in this pipe thread, bush, nipple, tightens counter clockwise.

cast rad with left hand thread

@ January 18, 2011 6:09 PM in cast rad with left hand thread

I need a source of left hand bushings for a cast rad.

no tank

@ December 11, 2010 11:27 AM in setting the difference setpoint controller

no tank between collector and heat loops - directly into slab. However there is a 2nd circ which pumps to an indirect - this diverts flow to the tank based on the temperature of the supply line from the collector, etc.(the two circulators never operate at the same time). Otherwise it always goes to the slab. To answer your question - the 2nd sensor is in the tank, no sensor in the slab. The slab will never over heat. When the heating season is over a switch will divert all flow to the tank.
The tank will be kept at some minimum temp during the heating season - say 42F, after that all heat will go to the slab. This is not a temperature controlled space - it is an equipment shed for a dairy farm; the purpose to minimize condensation on equipment.
Thanks for the suggestion, I will datalog cycling. Then maybe I can fine tune.

setting the difference setpoint controller

@ December 10, 2010 10:09 PM in setting the difference setpoint controller

I'm pumping from 8 flat plates into a 1500 sq ft slab - no heat exchanger (there is diversion to an indirect should the temp go to high). I'd like suggestions on setting the delta t target to start pumping considering the massive size of the "heat exchanger" (tubing to concrete)

we got the elevation angle wrong

@ December 2, 2010 6:24 PM in we got the elevation angle wrong

We were headed for 60 degrees because we're heating a slab and want to reduce output during the summer.
We ordered the wrong tilt up which gives us only 49 degrees. We could modify things by
extending the legs. Is it worth it? How much gain would we get during the winter?

shocking a concrete slab

@ December 1, 2010 3:59 PM in shocking a concrete slab

I have Wirsboro hePex in this slab. What is the highest temperature that the slab can take (not the hePex Max temp) before thermal stress could cause damage to the slab? I guess it depends on the delta T between slab temperature and tubing temp. Any ideas about what is considered safe?.

Raupex will work with a Q&E expander??

@ November 29, 2010 8:45 PM in rehau to wirsboro

It's a dhw line.
Are you saying that a wirsboro quick and easy fitting, using the expander tool, will fit the raupex?

rehau to wirsboro

@ November 29, 2010 7:39 PM in rehau to wirsboro

This question was asked but never answered.
I came across 1" Rehau Raupex that I have to hook onto. I've never use it so have no tools. I use Q&E wirsboro fittings. Any suggestions for getting some fitting (insert?) that will be permanent onto the Raupex without their tool.

thanks

@ September 7, 2010 11:52 AM in thermal shock in a slab

good warning. Yes there will be diversion to an indirect.

As long as I stay within pex specs I'm OK.

My concern is with doing damage to the slab? Any ideas on those numbers

thermal shock in a slab

@ September 7, 2010 10:11 AM in thermal shock in a slab

I'd like this solar fired concrete slab to have no temperature protection. That is, coming directly from collectors to slab without any sort of mixing.
The only protection for the slab would be diverting glycol to an indirect tank during the summer or when the glycol temperature get too high.
My question: what is a reasonable maximum temperature difference between glycol and slab that can safely do no damage to the slab.

there are 2 boilers,

@ August 21, 2010 12:17 PM in spirovent or other

each with its own circ. The boilers and their respective circs never operate at the same time. Each circulator, when active, is also the system circulator.

I could use 2 spirovents, or course, but want to get away with one.

So which is more important for its effectiveness, low pressure, or hot water?

spirovent or other

@ August 20, 2010 5:22 PM in spirovent or other

Because of piping considerations I can only used a Spirovent at the circ outlet (hottest water but highest pressure); or before the circ and before the boiler (lowest pressure but lowest water temp)
Which would you go for?

thanks
Marty

Monoflo tees with Wirsboro Pex fittings

@ August 4, 2010 9:08 PM in Monoflo tees with Wirsboro Pex fittings

Anyone know of Monoflo tees that come with Pex fittings?