Best Of
Re: Water too hot in condo unit
Since all this started, I gather, when the new boiler was installed — along with, I expect, a fair amount of plumbing rearranging in the boiler room — that's where I would go looking. Not in the individual units.
One thing — it is unlikely (unless something was done incorrectly — that the recirculation pump could add any pressure. At least, it shouldn't. What it can do, however, in the absence of check valves, is take hot water from one set of lines and run it into the cold water lines of another set, when there is demand on those lines and hence lower pressure on those lines. Which it shouldn't be able to do, if there are check valves where needed.
In any event — back down to the boiler room and figure out how each unit gets its hot an cold water, where each unit's recirculation lines go, and so on. Don't assume that ANYTHING was done right until it is veriried.
Re: Could my envelope really be this good? And how bad is it to oversize a modcon?
This winter I had the chance to do a reality check on the calculations that I had done on my house using gas consumption and manual J. I was able to monitor the boiler for a couple of hours when the outside temperature was close to the heating design day temperature. The house stayed at 72 degrees inside when it was -10 outside and the cast iron boiler was only on for about 50 percent of the time. That validated the calculations and my suspicion that the boiler was significantly oversized after all the energy improvements I've made to the house.
Re: Question about Erie zone valve
Disconnect the zone valve wires and test the system with a hot water call. If it still gets hot it has to be the zone valve. One thing to note if you have power stealing thermostats A1 should go to your R terminal on the thermostat subbase. Polarity is important and can affect the manager. Also if there is no common wire used it can create ghost calls with just enough voltage thru the manager to give you this problem .
You can dm me if you need further help
Robertw
Re: AC mini booster
Seriously guys. Why the attitude? Obviously, the company long known for redneck mobile climate control solutions has expanded into commercial equipment. Don't be jealous!
Seriously, as far as Ed's post, I'd bet a beer that the thing is powered by an extension cord inside the make-up unit connected to one leg of the three phase on the load side of the contactor. Since there's probably no neutral up there, I'd guess they are using the equipment ground for a neutral. I'd also guess that the filter has been removed - although I suppose it doesn't really matter in this particular application.
Re: Weil McLain Lgb 6-23 battery backup
I don't have the manual either — but if it's more or less typical and on a 15 amp fused circuit, I'd make a quick guess — probably close enough — that it draws somewhere between 500 and 1000 watts running, and around 1.5 kW starting (briefly).
Two things to consider on the battery "generator". First, check the surge output capability. It must be at least 1.5 kW. The second, though, is this: either unit you mention, if they have the surge capacity, should be able to run the boiler. For a while. Remember that unlike a fuel fired real generator, these things are really batteries with an inverter — and when the battery goes flat, that's it. You can't just pour in more gas and off you go. With the larger unit you mention, and the smaller draw I estimate, you'd have no more than 4 hours of operation — and going the other way, you're down to one hour (powering nothing else). Is that long enough to cover your needs?
Edit: I notice that the Jackery web site cheerfully notes that when the battery goes down you can recharge it from solar (with the sun out and a good big array) or a USB port (but what is powering that?) or plug it in (to what????)
Re: Pressure Valve
That gauge could be bad. When they go they usually indicate temperature ok but the pressure is wrong .
Either way I would put a pressure gauge on a drain valve so you can figure it out.
Re: Cutting a concrete radiant slab
The closer spacing give you more consistent slab temperature, good for baths to use 6". You feel a wide temperature spread wit 12" min bare feet.
It also gives you higher btu/ ft output, quickens response and allows for lowest supply temperature. I run an A2WHP so low temperatures drive the HP efficiency up.
The depth of the tube matters also. I had thought I did a better job getting the tube 2" below by raising the mesh on foam blocks. You really need to use continuous bar chairs every 2' to assure the mesh stays up into the pour. That adds a lot of steel cost.
Tube 6" OC and into the slab can drop your supply 10 degrees or more. See below charts.
For my own slabs I always do 6" oc. It can be done with 1/2" pex if you light bulb the ends.
This slab as poured several years ago.
hot_rod
Re: Cutting a concrete radiant slab
I like these Viega PureFlow couplings for non-PEX A tubing. (Thank you @kcopp.)
Cutting a concrete radiant slab
I'm adding a bath to the read of my shop space to create an ADU.
Unfortunately I needed to cut a utility trench through a slab that is only a few years old.
I do want to retain the radiant heat so I came up with a method to re-attach the cut loops.
The loops are 6" OC so it required a number of couplings, and some concrete sawing.
These 12" electric hand concrete saws work amazingly well. I used a gas powered walk behind sam for them long cuts. The hand saw was just as fast to cut, actually.
I used the wet saw to cut parallel to the loops first. Then a cut across the tube about 1-1-2" deep. The piece came out easily with a chisel. Luckily concrete doesn't stick to pex, so the tube was undamaged to reconnect. This provided just enough room to get a crimp tool around the tube.
I can slide some insulation below the tubes, some rebar to keep the pour stable.
hot_rod