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The vent yes, but on a TRV the valve isolates the vent. That’s the whole point. So the radiator pressure will drop causing it to draw in steam once it closes during a heat cycle.

Actually...

My boss is going to let me build the boiler manifold for a Navien Combi connected to 3 zones of in slab radiant.

Using zone pumps. Radiant manifolds are cheap Bluefin type and are 3, 3, 4 loops...

I installed heat pumps when I added central air to my home with a steam boiler. I found a 2 ton HP held the downstairs at 69F, upstairs at 67F @ 40F OAT. Pretty good for a 3500swft brick Victorian...

This a X13 ECM motor. So each speed is a constant torque setting that preprogrammed for that air handler. With constant torque, the RPM will change as static increases or decreases so it...

The valve that most of the one pipe TRV’s come with is equal to about a Hoffman 40, which is between a 4 or 5 on the Gorton or Maid of Mist scale for venting rate. What specific vent was on there...

Not sure you even need to both with a load call. If it’s built to code, in your climate it will be under 2 tons cooling. Might need more than 24k heating, but not much. Might be worth the extra...

Is that 14 gauge? Bad enough its 1) hooked up wrong 2) not protected wit ha breaker or fuse but on top of that 3) even if it was protected its undersized unless it’s a 15A or smaller load.

that’s...

I’m also remembering that it takes a few days to a week to reach maximum output. It needs the water in a certain conductivity range. Too hard or too soft of water supply and output is reduced. ...

Is it on 240V service? Is the dip switch set for maximum output?

Does it run with the fan only, without a call for heat? I assume yes.

Otherwise you must have crazy air leaks. I have a 112...

I ended up moving to Michigan. Bought 2 homes there. Replaced 1 AC and furnace and downsized it in half. Super comfortable now. Then moved back 2 blocks away from my previous house. Now I have...

Focus on air leaks first, insulation second.

Replacement Windows have a horrible payback (100+ years) and some historic windows on older home are of high quality and can be nearly air tight when...

For what it's worth, cooler air being more dense, will allow the same fan to spin at a lower RPM to move the same CFM. May improve fan economy slightly. Not a big deal with a 30F delta T however.
...

I don't see any solution that won't clog up that would transfer any meaningful percentage of heat to get a payback. Plus a lot of the energy is latent heat, so you'll have a condensation and frost...

Lots of great info in the last couple posts. Thanks.

The Engineer of Record has made their final responses to the Commissioning Punchlist which includes my observations and effectively walked...

I used it in a compressed air dryer that had really dirty scummy tower water that was shared with a process equipment. It worked really well overall. Stuff wasn't cheap.

Little update:

It developed a leak at a vit coupling on the sink source side. There's no isolation valve on the buffer tank, so they have ot drain 1000+ gallons to fix it. They weren't able to...

I am a bit more passive aggressive. You blow me off... don't expect me to send more business your way in the future. I don't care if there's a 20 year relationship. The engineer I'm told pushed...

I added 40+ gallons total so far. Was busy resetting pumps and figuring out how to keep the heating loop pump running but keep the unit operating in cooling mode. I couldn't find a "cooling only"...

Sadly, there was a balance. What it needs is a proper controls system and tech that knows how to tune it. He clearly is chasing his tail and missing something.

... off the reset the hot water...

Some reference 25%, some 20%, some 30%. Depends where I look. the drum supplied by the mechanical say 25%.

It's not low temp, but it has vertical loops for a geo field and a fluid cooler that...

That's what I've asked them to do in summary. Get someone butt here and finish start-up/commissioning/tuning/programming/balancing.

Very good point. What I'm able to do it is limited to,...

... if the issues continue into the spring, I'll probably demand that the engineering firm complete a full design and set of drawings at no cost to install a 100 Ton replacement rotary chiller to...

I was thinking strainers could be an issue. If the pressure at the suction was really low, I wonder if they would cause the expansion tanks to effective become almost useless to control pressure...

.. also note the delta T's on the heating and chilled water loop and the amount of water being bypassed. At that moment I took the shot, it had just cycled off. Setpoint is 130F. Design delta T...

UPDATE; Still no decision from the engineers. They want to study the temperatures more. I'll let ya'll study this and tell me what you think. I'm curious what happens mid winter when the ground...

Great points. That's what I think I'm seeing. At times my delta T is low, then other times it right at design. I came in the other morning and 2 compressors were tripped on high pressure, so...

For a data point for noise, we have a quiet classroom spaces and with 6" think concrete floors, and double drywall for the walls in he mechancial room, spring isolation under the steel skid for the 3...

Anyone have any DCS-8500's out there for sale? I'm trying to limp along for 1 more year until a large $17MM capital outlay project replaces all the controls and central plants.

I may be forced...

It was my understanding that the low end is 20% when microbe growth takes off. You should be using inhibited glycol to resist growth as well. Unless it's a food grade application.

Even at 30%,...

+1. Better to get a small rotary that you can bring up in pieces. Multistack is multiple chillers anyway.

Get a good mechanical/systems engineer to design the pumps and system all together. ...

It's a hydronic, chiller staging hot mess. I watched hot water system this morning. With the bypass closed, heating loop pump at 60Hz, I had 110F SAT (achieving setpoint) discharge temp with the...

There are expansion tanks on all 3 loops. However, today on restart (after building power loss) I could see a significant swing in pressure as the temperatures changed. Probably about 1psi per 1...

I think simplest is to use DP to control pump speed on reverse return secondary loop and use 2 way valves and maybe just a passive bypass at the end at a certain maximum DP so you never deadhead the...

Could some doubt check my basic logic here. Just making sure I'm not crazy or off base. I'm getting resistance from the engineers, Trane & Multistack on this one. I suspect is a major part of some...

I would have rather put in a nice RTWD with 3 way valves, added some fin tube in 2 of the zones and be able to use 120F water. Much more efficient. Multistack is getting the water resets working to...

Just a followup. They are going to alter the piping. Though some engineer still wants to claim it will work OK this way. I in not so many words told him, to refund on on 20% of loss of loop and...

I've heard your a little short on capacity initially even if they pumped heat transfer mud into the bore holes. We have the ground very wet, the new sod they put down has been heavily watered. Most...

It's piped like my drawing. Fluid cooler returns to the suction on the geo pump. The suction for both the FC & Geo are on a common header, single outlet on the bottom of the tank. Yup.

I cant...

The controls vendor hasn't yet mapped out the points for the chiller status, so you can't see which modules are running, demand %, load %, status, alarms, etc. Chilled water setpoint is 45F, hot...

This is better.

http://i227.photobucket.com/albums/dd41/motoguy128/Capture%200825161431_zps6f2muunx.jpg

Note that the fluid cooler return is drawn incorrectly on this controls screen. It goes...

Case in point. Right now, the return temp off the geo loop is 87F, Fluid cooler is 86F, but return to the chiller is 92F. 100F leaving the chiller. 93F EWT to the fluid cooler. Hmmm, do you think...

Sorry for the hand writing. Hopefully you can follow it.

http://i227.photobucket.com/albums/dd41/motoguy128/IMG_20160825_141152675_zpszqbqzeel.jpg

Yes, ALL of those pumps are variable speed....

Let me see what I can come up with.

I need someone to give me a rationale for piping a buffer tank as described below. From what I can tell, the system will never buffer unless the sink/source is off, and the tank is better described...

Thank about what the US gets in return for having the strongest military in the world. It's a cost, but it's similar to a sakes and marketing expense or having a expensive downtown high-rise...

I like your premise. But Japan as a culture long before the war was highly driven and innovative... And an industrial might. Consider a relatively small island produced enough heavy metal to...

Yes. And those jobs pay a lot more. It raises your countries GDP which means everyone can afford more. Rising tide, raises all ships. So the unskilled workers sweeping floors also makes more...

All that plaster adds a LOT of mass. Depending on solar gain (shading), it makes a huge difference. I had a 3200sqft 1925 plaster & stucco home, no insulation with a ton of windows that maintain...

I very roughly estimate about a 6-8 year payback depending on if your labor rate and how long it takes the change it out. I figured a simple 100W savings. Could be more, but depends on what ECM,...

I've always respected this viewpoint as well. Why is an American unskilled worker more deserving of a high standard of living than a Mexican trying to earn a low to moderate standard? I think...