Condensing heating systems
Thought I'd share in this conjunction how heating systems work over here. I'm back home on holiday right now, so this is a pretty decent example I think.
Some data.
Our house is - energetically - fron the late 80s, so some thin insulation.
Rated living space is about 2600sqft, though it's actually 4 floors with about 1000sqft each.
Unheated basement, 2 full floors and a 3rd floor under the roof.
This system was installed in 2015.
It was sized at 18kW (that's about 61500 BTUs) even though it is still somewhat oversized (especially after the new tripple glazed windows will be installed next week).
Rotex is a now defunct company as the heat pump specialist Daikin bought them up for their hot water tank technology and for other supplement technologies.
It's a fully condensing oil heating system.
The hot water tank is sized at 300l or close to 80gal.
The main burner unit does both hot water production and heating for the house via a 3 way valve.
One water circuit runs through the tank and burner as heating medium.
One runs through the underfloor heating and radiators.
You program the system with time programs for both hot water and heating as well as desired room and hot water temps.
The room temp together with the outside temperature sensor set the target heating circuit temp.
Currently it is in "Summer" mode which stops heating regardless of outside temperature.
The hot water system is set at 52°C / 126F but only is set to be active once in the morning for an hour.
It was about 2 in the afternoon when I took the picture and the water was still at anywhere between 45C and 50C depending on tank location.
The mechanical thermometer reas 50C/122F in the top quarter of the tank while the NTC for the heating system almost at the bottom of the tank read 46,5C/116F.
The plastic pipe is actually both exhaust and fresh air running concentrically, so the system runs completely independent of inside air.
I started a manual one time hot water demand to cycle the burner on. A turned on burner is indicated by the wavey line symbol in the top middle of the display.
After 5min exhaust temp only peaked at 55C/133F.
That's why plastic exhaust pipes are totally fine.
