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So I've got an issue I'm helping a friend with.
He needs to get me more information but here's what I've got so far.
Large room with large windows and in floor radiant under a wooden floor. I think it's also got carpet.
The issue is, the system ends up overheating the room once the sun comes out and then shuts down for too long so the room ends up too cold.
What info do I need to get to solve this issue?
Can an ODR be added to a normal boiler or does it come with a boiler as a system and would it solve this problem?
Apparently the system has no issue keeping up with the actual load, just the control is failing to work correctly.
Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
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Comments
What do they have for A/C?
Shades and awnings probably won't cut it, they like the view.
Or maybe constant circulation with something like this:
https://www.caleffi.com/usa/en-us/catalogue/hydromixertm-injection-pump-mixing-unit-165600a
Our house up in the Mountains in Winter Park, CO had an atmospheric boiler connected to infloor pex tubing in concrete for the walkout lower level, & Gyp on the main floor. It grossly overshot temps was an understatement. With help & information from this site, I repiped with a Buffer to make the boiler happy & Injection with constant circulation to make us Happy. It works like a charm. The individual room stats become high limits. The south facing great room has a bunch of windows & solar gain, its way better, but it still overshoots for a few hours in the morning.
Tim
Outdoor and indoor feed back would help. Also limiting solar gain, automatically if possible.
Lots of big glass homes in the mountains suffer from this issue.
Jeffery from Steamboat was here recently asking about radiation sensors, I suspect for the same reason, to handle over-shooting issues.
High mass radiant are not a great mix for rapid response, or areas with wide temperature swings. Carpet and pad adds to the problem as they generally run high SWT.
Put a wood panel system over it if it is a slab, like the Viega, Roth or Uponor system
trainer for Caleffi NA
The magic is in hydronics, and hydronics is in me
Amen to the flywheel effect, but the outdoor reset/constant circ helped a bunch. It works very well in the rooms that don't have the big windows facing south. The solar is just too strong at altitude, I've even tried turning the t-stat off for the great room the night before, it still overshoots, no joy, but cracking the slider from 9 to 10 am helps a bunch.
Tim
Right now I know it's a wood floor, no concrete.
And he said the temperature is something like 130F if that's even possible?!
trainer for Caleffi NA
The magic is in hydronics, and hydronics is in me
Can get complex with controls...…
D
Staple up, if it's done right (back loss prevention) (low R value padding and carpet) (done with PEX) should be great. Your problem is solar gain, I think.
If you have a single pump pushing all your zones, I might try this.
Put a Taco sentry zone valve or a diverter valve on that part of the circuit input if it is part of other heat emitters and maybe a check valve on the return to prevent ghost flow. I don't know what your circuit layout is. I might put that valve on a timer that shuts that circuit down an hour before the solar gain heats up and turns on that circuit an hour before you loose the solar gain. It all depends on circuit layout as to how I might do it. Make sure you don't have a ghost flow now when that circuit is off that's providing extra heat to that room.
Basically, you need to control the flow and timing to that room. Maybe put the thermostat in the hottest part of the room in direct sunlight.
Thermal inertia is the biggest downside I have experienced with my heated concrete slab. I have ODR and run low water temps (80-82) most of the winter, but if the slab is warm enough to heat the building when it is 30 outside with no sun, it is way to warm for the building when the sun is out and it warms to 45 outside during the morning. You just can’t make the heat in the slab magically stop being emitted.
Albert Einstein
I solved a similar problem using two outdoor temperature sensors - one in the shade and one in the sun. The solar sensor picks up that the sun us shining and shuts off the heat early. The shade sensor does its usual thing. Both sensors are connected to a tekmar 152 which controls the heat demand. Works great.
Solar sensor inside a white PVC pipe exposed to the sun may read 12 degrees higher than shade sensor on a sunny day and responds much faster. Grey PVC pipe would would increase response.
Doug
To the original question. Outdoor reset can be added to any boiler. If it a non condensing boiler, condensate protection need to be addressed.
Albert Einstein
> This post is highly speculative until the OP returns to the job to get more detail. Could be almost any type of system.
> To the original question. Outdoor reset can be added to any boiler. If it a non condensing boiler, condensate protection need to be addressed.
Agreed.
I'm still waiting to get all of the info. I just wanted to get an idea about odr and other options. Aside from "rip it all out".
What I find interesting is the lag once the room cools down, which from the sounds of it, is the primary complaint. Assuming it's controlled by a t-stat, where is the t-stat located? Is it working properly? If the zones are controlled by zone valves, is the end switch for that zone working?
I am waiting for Chris to now add his bologna comment to your post also. LOL.
He never said anything even similar to "It is likely impossible to completely solve this problem without turning on AC or opening windows. It is simple physics."
I can admit if I was wrong......and it's looking like I may have been wrong and owe @Voyager an apology.
I'm curious, why run A\C and not just bring in fresh air?
I didn't know anyone ran their heat when it's 70 degrees out? Mine gets locked out at 65 because it's about where my house breaks even and will maintain it self on most days. Actual, 62-63.
Saying that it is likely that not much can be done vita the heating system, means you need to use something else like a cooling system or opening the windows, which is exactly what I said.
However, if there is large thermal mass, high solar gain and the OAT is close to the IAT, then you may need the power that only AC can provide.
It all depends on the circumstances. That is why I asked all of the questions earlier, you really need to know things like the temperature differences, the area of the windows as a percent of the total wall area, the thickness of the floor to estimate thermal mass, the R value of the wall and windows to know how much heat is being lost compared to what is being added to the room, etc.
Still no real progress on this.
Except....................can anyone tell me if a slab sensor can be used with a Honeywell Prestige and the EIM? I can't imagine it not being possible, yet I didn't see it in any of my documentation. It's got 4 inputs, but I only see duct temp sensors as a listing.
Also, how does a slab sensor actually work?
Does it effect anticipation? What's the objective in such a setup?
Some people mentioned ducted air conditioning and ventilation. That is not the only option. Another option can be a ceiling with a combo of both radiant heating and cooling. Just put a new Messana radiant cooling ceiling up over the existing ceiling. It might be easier than jamming in some ducts.
Hydronics Designer
Hydronics is the most comfortable and energy efficient HVAC system.
AI and more sensors may be helpful, but you simply can’t ignore physics. If the solar heat gain exceeds the room’s heat loss, the temp is going to rise. Even if the heat is completely off and has been for hours, the temp may rise to uncomfortable levels from solar gain alone. I simply don’t think you can solve this problem by focusing on the heating system and its controls.
The heat loss needs to be calculated and then the solar heat gain estimated. If the gain exceeds the room losses, then you have to have some cooling option available if temp is to be controlled.