/ News & Press / Video / How a boiler, fan coil unit, air handling unit and pump work together HVAC - Heating System 🔥🔥🔥
How a boiler, fan coil unit, air handling unit and pump work together HVAC - Heating System 🔥🔥🔥
WEBVTT Kind: captions Language: en
00:00:02.000 [Applause] 00:00:04.30000:00:04.310 hey guys Paul here from the engineering 00:00:06.95000:00:06.960 mindset calm in this video we are going 00:00:09.70900:00:09.719 to be looking at a typical modern 00:00:11.39000:00:11.400 heating system in a commercial building 00:00:13.57000:00:13.580 now there are many variations of how 00:00:16.93900:00:16.949 this can be configured and we'll make 00:00:19.37000:00:19.380 some videos to show you a few of these 00:00:21.41000:00:21.420 variations but this version is fairly 00:00:24.20000:00:24.210 typical of the newer construction 00:00:26.92000:00:26.930 commercial buildings now as you can see 00:00:30.41000:00:30.420 we've got two large boilers over here 00:00:33.35000:00:33.360 and they are piped in parallel and what 00:00:38.03000:00:38.040 that means is that both boilers can 00:00:40.67000:00:40.680 operate at the same time or individually 00:00:43.43000:00:43.440 so one could be isolated and cut off 00:00:46.79000:00:46.800 ready and opened up for maintenance 00:00:48.70900:00:48.719 while the other boiler here continues to 00:00:51.77000:00:51.780 run and provide heating to the building 00:00:54.43900:00:54.449 and this is the most common type of 00:00:57.63900:00:57.649 configuration for modern heating systems 00:01:01.02900:01:01.039 the other version would be series and 00:01:04.57900:01:04.589 for this type of building that's not 00:01:05.92900:01:05.939 really practical now just show you an 00:01:07.96900:01:07.979 example of what some of these large 00:01:09.88000:01:09.890 commercial boilers might look like so 00:01:12.64900:01:12.659 here's one I've done some work on 00:01:14.45000:01:14.460 previously and it's fairly difficult to 00:01:16.94000:01:16.950 the one I've shown in the 3d model so 00:01:19.96900:01:19.979 we've got the big gas burner at the 00:01:21.41000:01:21.420 front here and then the main boiler unit 00:01:23.69000:01:23.700 over here this is a very old boiler 00:01:26.06000:01:26.070 actually you're fairly unlikely to come 00:01:29.35900:01:29.369 across these in lava see newer builds 00:01:31.13000:01:31.140 newer heating systems may have some 00:01:34.19000:01:34.200 boilers like this where there's much 00:01:35.56900:01:35.579 smaller ones and they can change to the 00:01:37.70000:01:37.710 demand of the building but they may look 00:01:39.71000:01:39.720 something a bit like this I mean hovel 00:01:41.56900:01:41.579 are a fairly well-known brand for 00:01:44.66000:01:44.670 boilers in commercial buildings and 00:01:46.85000:01:46.860 these boilers are probably around 15 00:01:48.95000:01:48.960 years old as well so these boilers are 00:01:52.06900:01:52.079 the heat source for the heating system 00:01:53.89900:01:53.909 and that heat is then pushed into the 00:01:58.06900:01:58.079 hot water of the heating system and one 00:02:04.06900:02:04.079 of the terms you'll come across in these 00:02:06.10900:02:06.119 sorts of systems is the terms primary 00:02:09.16900:02:09.179 and secondary circuits so and as you can 00:02:12.53000:02:12.540 see here we've got the primary 00:02:13.69000:02:13.700 pump set so these two pumps here which 00:02:18.19000:02:18.200 in the real world may look something a 00:02:19.86900:02:19.879 bit like this and slightly larger system 00:02:22.99000:02:23.000 they may look a bit like this as well 00:02:25.29000:02:25.300 but these primary pumps they will push 00:02:28.86900:02:28.879 the water around the system so they'll 00:02:31.24000:02:31.250 push this around the primary side so 00:02:34.30000:02:34.310 that hot water leaves the boiler enters 00:02:37.83000:02:37.840 into this pipe back here is sucked by 00:02:40.66000:02:40.670 the pump and then pushed out into this 00:02:43.08900:02:43.099 the low loss header which we'll have a 00:02:44.71000:02:44.720 look at shortly and that water can then 00:02:47.65000:02:47.660 either exit through these pumps here up 00:02:51.46000:02:51.470 into the risers or some of it and it 00:02:54.55000:02:54.560 some of it will continue through into 00:02:56.77000:02:56.780 the other side of the head up so this is 00:02:58.24000:02:58.250 just one continuous pipe and that will 00:03:01.18000:03:01.190 then leave that water and return back to 00:03:04.12000:03:04.130 the boiler a lower temperature to pick 00:03:06.78900:03:06.799 up more heat and continue that cycle 00:03:08.62000:03:08.630 again I just show you an example of a 00:03:11.47000:03:11.480 low loss header so we've got the boiler 00:03:14.17000:03:14.180 feedwater coming into here and this is 00:03:17.05000:03:17.060 the header here come and head up and so 00:03:21.37000:03:21.380 that hot water is entering into here and 00:03:23.47000:03:23.480 that can either leave through this pipe 00:03:25.90000:03:25.910 or through this pipe or it can continue 00:03:29.28900:03:29.299 down and background into the boilers to 00:03:31.84000:03:31.850 pick up more heat now that water that 00:03:34.05900:03:34.069 leaves through these pipes can return 00:03:36.84900:03:36.859 back through these ones and then that 00:03:40.18000:03:40.190 water will then mix with the flow so the 00:03:43.24000:03:43.250 water's coming through from the boiler 00:03:45.09900:03:45.109 some of it will be sent down to return 00:03:48.55000:03:48.560 round and that will mix with this 00:03:50.11000:03:50.120 returned water here and that is known as 00:03:53.44000:03:53.450 the low loss header or the common header 00:03:55.39000:03:55.400 and coming off of the header from the 00:03:58.56900:03:58.579 the hot side is these which are risers 00:04:02.02000:04:02.030 and these go off and these make up the 00:04:03.90000:04:03.910 secondary circuits so in this example 00:04:07.62900:04:07.639 we've got four secondary circuits one 00:04:10.53900:04:10.549 two three and four and some of them have 00:04:13.90000:04:13.910 got the this dual pump and this one has 00:04:17.40900:04:17.419 got a single pump it may not need a pump 00:04:20.37900:04:20.389 if it's if it's close enough and the 00:04:22.63000:04:22.640 primary pumps can actually are actually 00:04:24.21900:04:24.229 powerful enough but in most cases you 00:04:26.46900:04:26.479 will have a pump on this in this 00:04:29.49000:04:29.500 configuration so I'll just show you a 00:04:32.86000:04:32.870 secondary pump there so you've got these 00:04:35.29000:04:35.300 grump runs four pumps so these will work 00:04:38.88000:04:38.890 to move that water up to wherever it's 00:04:41.68000:04:41.690 needed we'll have a look at that in a 00:04:43.12000:04:43.130 second as well and these are usually 00:04:44.92000:04:44.930 work in duty and standby same as the 00:04:48.19000:04:48.200 primary pumps they'll also work in duty 00:04:50.14000:04:50.150 and standby and that just means that one 00:04:53.83000:04:53.840 of the pumps is on duty so that's the 00:04:56.11000:04:56.120 working pump and the second pump is 00:04:59.33900:04:59.349 waiting for its turn to work usually 00:05:03.39900:05:03.409 they won't both run at the same time it 00:05:05.86000:05:05.870 is possible that they can in some 00:05:08.08000:05:08.090 configurations that is needed but then 00:05:10.89900:05:10.909 the pumps will cycle so for one week it 00:05:14.02000:05:14.030 might be pump one and then for the next 00:05:16.45000:05:16.460 week it might be pumped two which is the 00:05:18.52000:05:18.530 duty pump and the other pump won't run 00:05:20.58900:05:20.599 during that time unless the duty pump 00:05:24.18000:05:24.190 create at and receives a fault and it 00:05:27.73000:05:27.740 can no longer operate and in that case 00:05:29.64900:05:29.659 then the standby pump will then operate 00:05:32.20000:05:32.210 and take over so you get security built 00:05:34.69000:05:34.700 into the system in these configurations 00:05:37.45000:05:37.460 the same of the boilers that this can 00:05:38.92000:05:38.930 work exactly the same so both can run or 00:05:41.88000:05:41.890 individually or or neither 00:05:44.39900:05:44.409 so these secondary circuits they will 00:05:46.93000:05:46.940 take the water from this low loss head 00:05:49.33000:05:49.340 up and push that up to where it's needed 00:05:51.21900:05:51.229 and you can see in this first loop it's 00:05:53.35000:05:53.360 going off and feeding some radiators off 00:05:56.08000:05:56.090 on the first floor or the ground floor 00:05:58.77900:05:58.789 even and that water is then returning 00:06:02.92000:06:02.930 down for this one to the the other side 00:06:05.62000:06:05.630 of the low loss header and then the 00:06:09.01000:06:09.020 second secondary circuit you can see 00:06:11.92000:06:11.930 that riser there rising up the height of 00:06:14.44000:06:14.450 the building and that is supplying the 00:06:17.20000:06:17.210 hot water to all of the fan coil units 00:06:19.95900:06:19.969 so up here we've got Bank or units and 00:06:23.37000:06:23.380 the return is also coming back into a 00:06:26.08000:06:26.090 riser and net returns back back to that 00:06:28.75000:06:28.760 common low loss header so you can see 00:06:31.44900:06:31.459 there there so here we've got the riser 00:06:33.43000:06:33.440 coming up and we got 00:06:34.80000:06:34.810 action coming off and feeding into that 00:06:36.54000:06:36.550 fan coil unit you have to see you that 00:06:39.09000:06:39.100 then gives up its heat and then that 00:06:41.34000:06:41.350 water then returns cooler back to the 00:06:43.98000:06:43.990 return riser where it makes its way 00:06:47.36000:06:47.370 along here through the floor and then 00:06:50.01000:06:50.020 back into the low boss header the third 00:06:53.34000:06:53.350 secondary circuit you can see like 00:06:54.93000:06:54.940 feeding up and go off and feeding into 00:06:57.36000:06:57.370 the ahu is connected over here that 00:07:01.74000:07:01.750 water then obviously once it's cooler 00:07:03.69000:07:03.700 returns back to the header makes its way 00:07:06.87000:07:06.880 back to the low loss head up to make its 00:07:09.78000:07:09.790 way back to the boiler and pick up more 00:07:11.07000:07:11.080 heat now just show you an example here 00:07:13.23000:07:13.240 of the heating coil on Nhu so here we've 00:07:17.31000:07:17.320 got the flow the water coming in from 00:07:20.55000:07:20.560 that secondary system entering into this 00:07:22.83000:07:22.840 court heating coil where it gives up its 00:07:24.78000:07:24.790 heat to the air that heated air then 00:07:27.60000:07:27.610 goes off and is provided off into the 00:07:29.49000:07:29.500 office space and meanwhile that heating 00:07:33.87000:07:33.880 water returns at a cooler temperature 00:07:35.90900:07:35.919 and heads back to the boiler and the 00:07:39.45000:07:39.460 final circuit on the the set final 00:07:42.36000:07:42.370 secondary circuit is this one here so 00:07:44.82000:07:44.830 this is going off and feeding into a 00:07:46.46900:07:46.479 Collura fire 00:07:47.61000:07:47.620 now the glorify is where the domestic 00:07:51.12000:07:51.130 hot water is produced so this is the the 00:07:55.56000:07:55.570 hot water that comes out of the taps 00:07:57.89000:07:57.900 there's a lot of chemicals that go into 00:08:00.99000:08:01.000 this primary heating system or the LT HW 00:08:05.73000:08:05.740 system low temperature hot water system 00:08:07.46900:08:07.479 and you don't really want to drink that 00:08:09.75000:08:09.760 so what happens is the hot water is fed 00:08:12.24000:08:12.250 from here into the Colora fire and it 00:08:15.33000:08:15.340 passes into a heat exchanger where it 00:08:17.58000:08:17.590 just transfers its heat into some fresh 00:08:20.10000:08:20.110 water which is held inside the tank that 00:08:23.10000:08:23.110 fresh water was then heated up and that 00:08:24.90000:08:24.910 is supplied to the to the kitchens into 00:08:28.05000:08:28.060 the sinks etc meanwhile that cooler 00:08:33.17000:08:33.180 water is returned back to the logos head 00:08:36.20900:08:36.219 up all right mixes in with this and 00:08:38.88000:08:38.890 heads back to the boiler just show an 00:08:41.67000:08:41.680 example there so this is freaky Laura 00:08:44.21900:08:44.229 fire configuration and you can see here 00:08:47.04000:08:47.050 we got the heat exchanger 00:08:48.12000:08:48.130 just on the side there so that hot water 00:08:50.73000:08:50.740 is coming in exchanging its heat with 00:08:53.73000:08:53.740 the clean water on the other side and 00:08:56.28000:08:56.290 that then makes its way back to the 00:08:58.80000:08:58.810 boiler meanwhile the fresh drinkable 00:09:01.83000:09:01.840 water is take it off and send off around 00:09:05.07000:09:05.080 to the building now you can also notice 00:09:08.04000:09:08.050 here we've got the expansion vessel and 00:09:09.96000:09:09.970 the pressurization unit now the pressure 00:09:13.11000:09:13.120 in the system is going to change for 00:09:15.60000:09:15.610 example if this pump set here if that 00:09:18.33000:09:18.340 was off and it turns on then this 00:09:21.00000:09:21.010 primary pump set here is going to see a 00:09:23.61000:09:23.620 pressure decrease because this has 00:09:25.77000:09:25.780 opened up and so there's this flow there 00:09:29.19000:09:29.200 right so if these pumps then stopped 00:09:34.71000:09:34.720 working and they isolated this then 00:09:37.14000:09:37.150 these pumps will see a pressure increase 00:09:40.34000:09:40.350 because there is less room for that 00:09:43.92000:09:43.930 water it's pushing to go and so the 00:09:46.29000:09:46.300 friction inside is going to increase and 00:09:48.42000:09:48.430 the pressure will build up the same as 00:09:51.66000:09:51.670 if when when this the water in this loop 00:09:56.45000:09:56.460 increases temperature or decreases in 00:09:58.68000:09:58.690 temperature then it's going to change in 00:10:00.48000:10:00.490 density and that's also going to affect 00:10:02.91000:10:02.920 the temp the pressure as well so this 00:10:07.77000:10:07.780 expansion vessel and the pressurization 00:10:09.96000:10:09.970 unit is plugged into that usually into 00:10:13.05000:10:13.060 somewhere around the logos header it is 00:10:16.17000:10:16.180 a couple of places it could be but it's 00:10:17.43000:10:17.440 usually located here and that's just 00:10:20.16000:10:20.170 looking at the pressure there and it's 00:10:22.47000:10:22.480 going to react to that so if it gets too 00:10:25.29000:10:25.300 high then obviously the expansion vessel 00:10:28.29000:10:28.300 will take some of that and when it gets 00:10:29.52000:10:29.530 too low and the pressurization unit will 00:10:31.95000:10:31.960 force that back into the system to 00:10:34.17000:10:34.180 equalize it and the pressurization unit 00:10:37.56000:10:37.570 will probably look something like this 00:10:39.33000:10:39.340 where you've got the expansion tanks and 00:10:41.46000:10:41.470 the vessels over here and then the main 00:10:43.65000:10:43.660 pressurization unit just there as well 00:10:46.01000:10:46.020 now tucked away over here you can see 00:10:48.51000:10:48.520 we've got the dosing pot and that's 00:10:51.18000:10:51.190 usually located somewhere plugged across 00:10:54.42000:10:54.430 the low-loss header you can see an 00:10:56.67000:10:56.680 example there so we've got the main 00:10:58.95000:10:58.960 dosing pot and then 00:11:00.61000:11:00.620 you've got the two connections from the 00:11:02.94000:11:02.950 header just there and the doting pot 00:11:07.03000:11:07.040 this just allows chemical inhibitors to 00:11:09.76000:11:09.770 be poured into the into the system and 00:11:13.06000:11:13.070 to be pumped around and that just keeps 00:11:14.77000:11:14.780 it clean and bacteria free but we'll 00:11:18.49000:11:18.500 we'll look more into that in another 00:11:19.69000:11:19.700 video 00:11:20.58000:11:20.590 now the the pipes in this diagram have 00:11:24.25000:11:24.260 been color coded so you can see the red 00:11:26.74000:11:26.750 here that's indicating that the it's a 00:11:29.35000:11:29.360 high temperature so that's obviously 00:11:31.39000:11:31.400 leaving the boiler so that's leaving at 00:11:33.22000:11:33.230 around 80 degrees Celsius about 176 00:11:36.70000:11:36.710 degrees Fahrenheit and the yellow pipe 00:11:39.58000:11:39.590 here is indicating that it's a lower 00:11:41.65000:11:41.660 temperature that's the return but it's 00:11:43.90000:11:43.910 gone around the building and lost its 00:11:45.16000:11:45.170 heat and it's coming back and that's 00:11:47.47000:11:47.480 going to return about 70 degrees Celsius 00:11:49.60000:11:49.610 or 158 degrees Fahrenheit and I'll just 00:11:54.88000:11:54.890 show you the schematic representation of 00:11:56.77000:11:56.780 this so down here we've got the 00:11:58.48000:11:58.490 pressurization unit and the expansion 00:12:01.03000:12:01.040 vessels then we've got two boilers 00:12:03.16000:12:03.170 located just here and we've got the 00:12:05.77000:12:05.780 water coming through these and being 00:12:08.23000:12:08.240 pulled by the pump set there and that's 00:12:10.72000:12:10.730 pushing that water into this low loss 00:12:12.85000:12:12.860 common header and forming the primary 00:12:16.30000:12:16.310 circuit so that water then feeds around 00:12:18.94000:12:18.950 in the continuous loop there you've also 00:12:22.36000:12:22.370 then got these secondary loops so we've 00:12:24.55000:12:24.560 got a pump set here and that's taken off 00:12:26.53000:12:26.540 you can see the multiple valve 00:12:28.15000:12:28.160 configurations there as well and now 00:12:31.63000:12:31.640 that that's another secondary circuit 00:12:33.79000:12:33.800 coming off and then both of them are 00:12:36.16000:12:36.170 returning through this here down into 00:12:39.28000:12:39.290 the common header so that flow water 00:12:41.83000:12:41.840 will mix with this cooler return water 00:12:45.25000:12:45.260 and make its way back round to the 00:12:47.17000:12:47.180 boilers and over here we've got the 00:12:49.39000:12:49.400 dosing loop as well okay that's it for 00:12:52.63000:12:52.640 this video thank you very much for 00:12:54.16000:12:54.170 watching I hope this has helped hope you 00:12:56.26000:12:56.270 learn some of the system's if it has 00:12:59.05000:12:59.060 then please like and subscribe to us and 00:13:00.97000:13:00.980 share the video with anyone that you 00:13:03.55000:13:03.560 think might help alright thanks for 00:13:05.59000:13:05.600 watching
Office location
Engineering company LOTUS®
Russia, Ekaterinburg, Lunacharskogo street, 240/12