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Re: Viessmann Vitocal AWHP for hydronic baseboards or retrofit floor heating?
First step is to figure out your starting point. How many liner feet of baseboard you have and how much oil did you burn through last winter. Winter energy used in Therms*42 is about your heat loss. For more accurate number run the math here:
https://www.greenbuildingadvisor.com/article/replacing-a-furnace-or-boiler
AWHP likes to run at around 115F max, you can then see how much of the house heat your existing baseboards can supply at lower temp.
From there, you need to add extra emitters to make up for the shortfall. The easiest is oversized low temperature panel rads to replace sections of baseboard and a bit of floor heat where easier to get to without major demo.
Kaos
Re: Air Vent at boiler. Necessary with Air Sep?
That will depend on the type of compression tank you're using. (expansion tank). If you have a tank that has some type of membrane that separates the air from the water side of the system, then of course you should have an automatic air vent somewhere.
If however you have the older technology steel compression tank where the air and the water are in contact with each other, then you may want to make sure that the tank is equipped with the AirTrol® tank fitting, and use the top of the air scoop to vent air into the compression tank.
Can you explain the reason you feel you need the air separator? Are you experiencing air problems?
Re: Why purge valve above boiler? Pumping Away.
It makes a neater job and simple to purge the system , one hose .
Always makes me think of Dan's story of launching torpedos , Back in my Rite Fuel days, how many year . I am still launching them :)
Big Ed_4
Re: Why purge valve above boiler? Pumping Away.
I don’t have any experience with that fill valve
If it is working, may as well keep it.
If it fails, consider the 573.
I do work for Caleffi, so….
hot_rod
Re: Why purge valve above boiler? Pumping Away.
Very simply...its the last spot before the unwanted air gets out in to the system. Mad Dog
Re: Steam device to be identified
it is all the same yet all different. Everything is the same controls we have on US boilers but it is all a different design and manufacturer. It looks like the low water cutout is a Mcdonnell Miller low water cut out that we use in the US.
Unless there is something special about European boilers that can separate the steam and water, the near boiler piping is very wrong.
I assume that this is a 2 pipe steam system, each radiator has a supply and a return, not a single pipe where steam enters and condensate exits through the same pipe at the bottom of the radiator.
I think that is some sort of "boiler return trap". If the pressure in the steam supply main gets too high in comparison to the return for the water to be able to return to the boiler, it allows some steam in to the condensate return to equalize the pressure and allow the water to return to the boiler.
You would have to find the European @DanHolohan to figure out exactly what that device is.
mattmia2
Re: Piping from scratch
Scrap the system and run new panel radiators . I would run a home run system (3/8" works here).
Big Ed_4
Re: Cheap, Easy, And Invisible DIY Solar Thermal?
The first thing I thought of when I read your original idea is "Too Hot? Just purge some of that heat". If there is a High Limit temperature for that tubing, you can have a ventilation system operate to dump some of that "overheating" even if it just a damper motor that will allow thermal air flow to reduce the roof temperature.
Set the solar roof to the best angle for winter collection and open the dampers in the very hot months to keep the roof from getting 100% of the solar temperature by venting ambient air under the metal roof component. You could also pump cooler water thru the PEX when you are not collecting heat in the summer by dumping that heat into a closed loop geothermal well or field to cool off the tubing
The damper can be a single rod extended thru the roof joists with a pulley or linkage arm at one end, then attach sheetmetal dampers on that rod to fit between the roof joist spaces. One damper motor can move both linkages to open and close the dampers at the top and the bottom of all the joist spaces with PEX tubing
Re: Cheap, Easy, And Invisible DIY Solar Thermal?
There are also thermal actuators (wax motors) for dampers for overheat made for greenhouses and stock barns which have severe overheating problems. Might look into those. No wires, no power required.
Re: Antifreeze
If you use it I think it is fine but do not trust a backflow preventer. Do not make any connection between the boiler system and the potable water.
Do not put a pressure reducing valve on the system.
Fill the system with a hose connection and then disconnect the hose.
We did this on many systems and it worked fine regardless of the type of glycol used.
