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Re: Removing plumber’s epoxy
PC7060 maybe so, I’m no pro but what do you recommend for a lowly DIYer who can only afford $40 Harbor Freight tools?
Either learn to solder or sharkbites. It'll likely be fine as long as it's in a place that's accessible.
You need to do something and I'd try to get as much of that copper replaced as possible.
For what it's worth I consider my self pretty good at sweating pipe and I've found Uponor brass fittings to be less than easy to solder for whatever reason. I got the work done, and they were quality joints, but it wasn't as easy as normal fittings.
ChrisJ
2
Re: optimum thickness of radiant heat slab?
Consider a radiant ceiling
3/8 pex in plates, 6” on center. That would be a quick responding system
The Roth radiant panels would add sone R value also
with a slab you beed to get all the mass warmed before you feel the heat.
3/8 pex in plates, 6” on center. That would be a quick responding system
The Roth radiant panels would add sone R value also
with a slab you beed to get all the mass warmed before you feel the heat.
hot_rod
3
Re: Thermal Imaging Camera Recommendation
I'm looking too. My TG165 took a dump. No matter the brand, I'd probably look at the user manual and make sure the battery is (easily) replaceable. Mine wasn't.
Re: Combining baseboard and in-floor temperature issue
Hi @Alan (California Radiant) Forbes. Thanks for your diagram. Good to see yet another support for the piping system that has come to be the consensus best practice for how it should be done. Yes it is so disappointing I got the crap shoot of plumbers when I chose this company.
Hi @edtheheaterman. Not sure what a bull head is. And I don't see the difference between what you drew and AlanCRF's diagram. My expansion tank is on the primary loop I believe.
Hi @hotrod. Is the header where the boiler manifold connects to the copper pipe?
Hi @edtheheaterman. Not sure what a bull head is. And I don't see the difference between what you drew and AlanCRF's diagram. My expansion tank is on the primary loop I believe.
Hi @hotrod. Is the header where the boiler manifold connects to the copper pipe?
Re: Evacuated tube failure
there is not a lot of additional energy available from tubes compared to flat plate
cold ambient, below 20F, is about where tubes start to have some advantage
The formula takes into account ambient and collector inlet temperature, divided by solar radiation
with the heat pipe style evac tubes you have two vacuums to maintain. The tube itself, and there is vacuum pulled inside those copper heat pipe bulbs. That allows the water alcohol mix inside to boil around 110F
It flashes to steam and that is how the copper bulb can get to 300F plus temperature
It is hard to know when the vacuum in the copper heat pipe is gone.
cold ambient, below 20F, is about where tubes start to have some advantage
The formula takes into account ambient and collector inlet temperature, divided by solar radiation
with the heat pipe style evac tubes you have two vacuums to maintain. The tube itself, and there is vacuum pulled inside those copper heat pipe bulbs. That allows the water alcohol mix inside to boil around 110F
It flashes to steam and that is how the copper bulb can get to 300F plus temperature
It is hard to know when the vacuum in the copper heat pipe is gone.
Looking at the array with an infrared camera will show the tubes that have gone bad. Without getting on the roof or removing the tubes from the header.
hot_rod
1
Re: Small boiler recommendation
Why does it have to go? Does your Mom agree ? Just a bit curious 🤔The chamber is pretty broken up, the outer jacket has areas rusted away at the bottom, and there are areas inside that long brushes and saws just can't seem to get to (pin boiler) from the top or side access plates. I also can't get it much over 7% CO2 without it smoking and the stack temp is over 600F gross. The AF is also some 30 plus years old (I didn't install that burner and don't even know if the head is even a correct match for that boiler), and the old Honeywell controls are archaic (the Honeywell aquastat board burned a hole through it and I had to rebuild that a couple of years ago). I also think that when I have to sell the house in a few years that big ugly chunk will be a big liability and will flag a house inspection.
Mom doesn't care and pretty much defers repairs to me and my brothers. As long as there's heat, mom is happy.
MaxMercy
4
Re: Combustion analysis startup calibration question
Outside, always calibrate the unit outside, and not right next to your running vehicle, generator, equipment etc.
GGross
3
Re: Combustion analysis startup calibration question
I am more concerned with my safety than a bogus combustion efficiency calculation. If your analyzer zeroes out the CO during calibration then it needs to be turned on outside, 30 degree in temperature affects the efficiency 1%. Not enough difference to sacrifice safety. Some people should not be teaching when they are teaching how to endanger yourself.
Re: Is the heat loss calculation linear --at all?
If you are sizing conventional fired systems, using the design temperature is what to do. This usually will cover 98% of the heating season. However, if using heat a heat pump, its much more complicated. The problem is that as you drop below design temperature, the heating capacity of the heat pump is steadily dropping I.E. ....Here in Chicago, the design temperature is about 0F, However, we have hit -25F as records. A fired system that is designed right on will be able to keep a building warm at 70F when it is 0F outside with let's say 100,000 btu/hr, so for the most part it will be able to maintain the building at 45F if it is -20F outdoors ( more or less, depending on ground contact tempering for example), also needing 100,000 btu/hr. However, with a heat pump, when you're below design temperature (0F) the heat pump capacity is now lower, so you can no longer producing 100,000 btu/hr so you can no longer maintain a 70F differential between the outdoors and indoors. The interior temperature will now drop lower than the 70F differential. This issue seems to currently be ignored in design calculations. As an example, we have a client that had a Heat Pump system installed to heat a large space. They could heat to 70F when it was 0F outdoor. However, when we had some extreme extreme outdoor temperatures ( -10 to -12F) a year or two ago, and they could not get the building above 40F. I have not been able to find what the COP is for a heat pump at 0F versus -25F, but I bet it is quite significant in a percentage or reduced heating capacity.The design day temperature he used, was a modestly cold number but nowhere near the record. I recalculated it based on the record outdoor low temperature but used a linear relationship to the delta T.
A bit surprising perhaps, but you should not use the absolute coldest temperature. You use the design temp.
Re: Wiring old hydronic gas boiler as backup for new heat pump
@litedesign you'll need your heat loss. Usually 32F is picked by contractors because it's when water freezes, not because it's a relevant balance point. Basically, you first plot your heat loss. It's a linear function of outdoor temp, as it gets colder it increases consistently. Then you plot your heat pumps operating envelope, which works in reverse - as it gets colder, it outputs less. It's usually not linear though. Idronics describes it better than I can.
If you're interested, you can probably find your Bosch's on the internet. Where the heat loss = heat pump max output, that temp is the balance point. You can try trial and error - lock out the boiler and see at which temp the heat pump can't maintain the thermostat. There's another topic called the "economic balance point", which is the point when the heat sources are equal in cost. That's much harder to find and often isn't worth the effort since gas prices changes frequently and efficiencies vary by temperature.
https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf
If you're interested, you can probably find your Bosch's on the internet. Where the heat loss = heat pump max output, that temp is the balance point. You can try trial and error - lock out the boiler and see at which temp the heat pump can't maintain the thermostat. There's another topic called the "economic balance point", which is the point when the heat sources are equal in cost. That's much harder to find and often isn't worth the effort since gas prices changes frequently and efficiencies vary by temperature.
https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf
