When Should I Zone A Heating System? | Toolbox Talks
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- čas přidán 26. 01. 2022
- Want to know why we suggest not to zone? Watch this: • Why NOT to ZONE Heat P...
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Adam teaches a colleague when to zone a heating system - Věda a technologie
Great video this is the type of video that should be going out.
From your comment Adam. I started to think of an idea. Some timer that activates a relay if a heat pump is cycling. Then sends an SMS message to the installer / manufacturer there is an issue. Like it and love it. Rich
The way my system is connected a the moment is a bit of everything. 8 radiators are connected with the Honeywell wireless trvs and 3 radiators with normal trvs just run when the heating runs. There are 3 towel radiators will run with hot water or heating and underfloor heating zone in the conservatory. Two of the 3 trv rads are in the center of the house surrounded by rooms.
I originally re-piped it as an upstairs/downstairs zone after a large extension but after the Honeywell rep gave me a box of 4 wireless trvs i thought id give it a try.
What I'm missing out really is how you balance down radiators to get the desired temp when the HP is working away...I don't know enough really to deal with my own builders, so we will end up with a zone for upstairs, zone for downstairs and for a single story extension a zone for the living space (21) and a zone for the bedrooms (18).
Interesting, thanks... As someone who currently has a combi and a house with two parts (1980 and 2002), they have very different heating needs. I've gone for Tado TRVs, which has been great, but I know it's "microzoning" and, together with my 46° flow temp, will result in more boiler cycling since its lowest output is 5kw... BUT it's hard to give up the benefit of significantly lower gas bills due to better directed heat just to avoid extra wear on the system.
I guess the dream is for heat pumps to reach Viessmann boiler levels of modulation so they are less affected cycling in that "heat only the home office" example you gave... But in the meantime would a thermal store be a benefit to reduce cycling where only small areas need heat?
A little late to the party on this comment. But if you add a small buffer tank and ECM circulator to it, this will prevent short-cycling your boiler. You don't even need an expensive hydronic buffer tank. A DIY trick is to purchase a small, undercounter water heater and plumb it into your supply and return lines (and you simply never energize the element).
@@browncowvideo thanks. so this is just adding system volume to mitigate cycling caused by Tado running a small subset of the radiators?
@@TheBadoctopus yes on adding system volume, but it also allows low BTW (or kW) emitters and/or micro zones to serve the smaller loads, when your boiler is sized for a LOT more load.
It's not difficult to run a heat loss calculation for each room of your house based on some assumptions of your insulation value. Armed with these numbers it will make a lot more sense on how they all go together.
I am working on my second build of hydronics in my homes and I learned a lot along the way. I am becoming an "evangelist" of sorts for radiant heat. The human body finds it very comfortable.
As for resources, John "Siggy" Siegenthaler, a professor and professional engineer, has written several books on hydronics and you can also find him here on CZcams contributing to several channels, as well as Web searches.. He is THE man, in my book.
Caliefi also has an Idronics series of PDFs available for free inline that use a lot of John's work without having to buy one of his textbooks. It's all great, informative stuff.
Sorry, I went off on a tangent and didn't finish about the short cycling. Because the boiler can only modulate down so far (modern modcons are around 10% of the maximum BTU). And often boilers have been oversized, which will only exacerbate short cycling.
There are far too many HVAC pros that lean on the side of oversizing, for fear of a call back on the coldest day of the year, and there's far too many that don't even know how to run a Manual J calc., paying others do do them, and never learning the logic of why systems need to be designed around a load.
I've discovered this content trying to sort out my brand new system (boiler not heat pump). No thought about radiator size, no balancing, no zones, multiple drop legs, always seems to always have air in it no matter what I do, boiler commissioned at max output, flow temp set to 80c, pump speed left at max, some rads not getting hot. Wish I had someone who had been on your course install it.
How have you found yourself in that situation? What are the actual problems you're having? Surely any issues you have can be dealt with by the installer
@@silvergrim ghosted. Thanks to CZcams I've sorted most of it but I suppose a badly designed layout is a badly designed layout. No matter what I do the air keeps coming back.
@@TrickyTree84 argh... Any decent installer would be there for you. Crappy situation, there's so many variables, what type of system did you have installed?
@@silvergrim it's a combi sealed system. 2 zones (only a single rad on one of the zones). All the downstairs rads are dropped off upstairs as we have solid floors and it was a single pipe system we got replaced. I've sorted the balancing and I've sorted the boiler settings. Just the air that keeps coming back that's getting me now. I think possibly it could be down to one old towel radiator, the only original radiator that was left in the system. Problem is the air is getting stuck where the pipes drop
@@TrickyTree84 does the air effect the boilers operation? Or do you just hear it gurgling around the system? Personally on the face of it I'd get rid of the zones especially for one rad. Drops can be problematic with air but I've found once it's gone it's gone and there are no more circulation issues. I've seen badly laid plastic pipe that hoops up and down rather than being run flat that has caused issues with air. Also towel rads love to catch a bit of air imo but venting them a little only happens once a year
Ok. Does this mean in all other scenarios mentioned here, it is not necessary to have a thermostats controlling zones and will be much more efficient to just have a single thermostat sitting in the middle of the house?
Does this apply to gas boilers too? Our greenstar CDI will be powering both the new extension underfloor heating and the old part of the house rads. Plumber wants to put multiple zone valves in..
Can you use say a taco system with smart valves to effectively zone down bedrooms and keep up offices on the same floor?
Zoning upstairs and dowstairs in an average house using boilers, does work and saves a lot of energy.
It 'works' .. and cab save money with an on off type system. Not with an efficient weather compensated type system necessarily though
@@HeatGeek
I know of a 4 bed detached house that had an Intergas Xtreme weather compensated boiler that modulates down quite low so little to no cycling, operating for a few years. The way the piping was configured it was quick and easy to zone by fitting two zone valves. This was done. Notable difference in gas consumption. The upstairs is off most of the day.
I think what you are saying is that a boiler that does not modulate down low can give poor results as inefficient boiler cycling occurs. This is when the heating load is reduced because half the building's heating system is taken out of operation. In short the boiler cannot inject its heat at it lowest burner modulation into half the heating system - matters are made worse when the outside temperature rises reducing the amount of heat that can be injected into the building.
@@johnburns4017 cycling accounts for only 1% loss with gas boilers so not really the cycling but the higher temps needed. If weather compensation is basic so won't display the same way.. also every property is different.. how 1 property responds is not how all properties respond
@@HeatGeek
High temps needed in the on-off sawtooth graph? Needs high temp to get to setpoint after being switched off, then overshoot of setpoint, then cool down. Weather compensation is injecting _near enough_ the right amount of heat most of the time into the building -if the the slope is set properly.
In my weather compensated system I have an on-off room stat in the hall. This is used a timer and a _high limit_ not whole house temp control. The outside temp sensor pretty well does that.
I am on about an _average_ two floor house, which is most homes, not odd shaped buildings, etc, where a different approach of course has to be used.
@@johnburns4017 decent ec does not need an additional on/off stat.. watch this video.. the same applies for gas just slightly less..
czcams.com/video/zpTVIeUh04E/video.html
when you are designing the system on one zone, is it important the underfloor pipes to be separated by rooms, or single circle can be shared with multipke rooms. E.g my toiled has a little sqare metres, can I combine its pipes with the bedroom?
I can run my heat pump in cooling mode and want to fit an extra zone so that I can use the same heat pump to run a couple of wall mounted water cooling cassette with condensate on a separate zone.
What’s the best way of doing this please?
Don’t forget about the porch and any extension such as a conservatory, they by law have to be in sep zones in case of leaks
Can you explain - what leaks - how do zones help?
@@normanboyes4983 my law conservatory's and porch extensions have to be on a separate zone . Most people visually are on electric.in smaller property less than 12 ft conservatory's have 1or 2 electronic rads or none at all. Yet most orange extensions on bigger properties require a separate zone usually done with a system or regular boiler a heat exchanger and two zone electronic diverters one for the main loop of the house and one for the extension. Things get a little more complicated when a extra underfloor zone is needed normally we see up to three zones with diverters and tank beyond this or if ground or solarthermal are added it's more in line with a typical small industry commercial layouts
@@ram64man Are you in UK - is this underpinned by UK building Regs or CIBSE?
@@normanboyes4983 both usa and U.K. at the time due to family ill
What would you suggest in the home office scenario of just requiring one room heated during the day if not using central heating whether that be boiler or ASHP? Infrared panels?
That 1 option sure. 1 pannel though.. not multiple... if it needed multiple you'd go back to looking in to zoning...
@@HeatGeek The office is 12m² and the house is 280m² so I'm guessing I should keep to low ambient (16°c) for the house and panel for the room. We have a 16kw ASHP (hybrid config with existing gas boiler) going in next month so it's all going to be a learning curve. Getting loft insulation up to spec and some additional wall insulation to help keep the bills down. As a test we've been running flow temps between 40-50°C and the house seems to cope, I wish I'd know sooner, my condensing boiler has been set to 75°c for years! Although need to ensure water gets hot enough for legionaries. Finding your channel very informative and interesting source of information, keep up the good work 👍
Forgot to mention we also have EvoHome so we can also zone with ease. Still trying to work out how to use that with an ASHP though.
I did have another question... At what sort of temperatures do you find the COP drops off. I'm thinking of programming a switch to the gas boiler below a certain temperature when the ASHP becomes inefficient, but wondered when that would be. Currently electric rates are 4-5 times more expensive than gas but looking further into 2022 this may turn to be only 3-4 time more expensive. Essentially I don't want to running at ASHP at a COP of 1.5 when the gas boiler could take over for that period.
@@rob-stewart there's not really 1 point it's continuous..
Personally in my townhouse I prefer it cooler downstairs as that's the kitchen. Zoning is great and I am not giving up zoning. Not that it matters anyway a heat pump wouldn't fit in my house it would need a 30 metre run to get to the hot water tank. I am betting that's gonna hurt the flow and COP with heat loss
Why complicating and creating some zones when it's easy to add a thermostat in each room and you control it like that and have zones or am I not thinking correctly?
2:00 Why would you not zone upstairs and downstairs unless you intend to keep the downstairs heating on all night?
Please watch the why not to zone video
Hey Heat Geeks. New follower to the channel. Loving the content - you make these topic very accessible and I've shared with 4 mates already.
I have a question. If you were draw the following on your white board, how would you approach the zoning/rooming/control question:-
> 2016 build, 4 story town house, attached on both sides; B-grade energy raging, ASHP, UFH (basement, ground) & jaga DBE* rads (1 & loft) <
Basement & G are naturally cooler in summer; 1 & loft far too hot. In the Winter, 1 is very cold & the loft is freezing!
Also, an uncommon use because we AirBnB some of the rooms:
Basement (UFH) - master bedroom, dressing room & shower [8pm-7am use consistent]
G (UFH) - kitchen/diner w/ north-facing french doors, WC [7am - 10pm use most days]
1 - Guest room, office, bathroom [office 9-7 mon/fri & other rooms typically constant]
Loft - Guest room & ensuite [typically constant]
My partner and I run hot so can't blast the master-bedroom during sleep time and also the smart rads don't seem to work as well as the UFH so want to think about how those rooms have the potential to run a little hotter without relying on a 24/7 furnace from the lower floors rising up!
*considering upgrading to DBH for cooling as shifting to a pump that facilitates and that might help the loft in the Summer - d'ya reckon?
Thanks in advance :)
Install a 30kw boiler and 80C flow temp. What are zones?
If you have a heat pump you willcold anyway as it won't be working or you won't have the money to use it
Ah, but you’re just focusing on HPs Skaterboy, you don’t want to zone because HPs need High Flow Rates. Here on New Builds, we zone, FF & GF, both controlled by time/temperature.
Increasingly, with the Kung Floooo etc, more people are working from home - use a Bedroom as a Study.
So it’s very important that the property is Zoned. Why not come right out & say; for HPs you need limited controls & a High Flow Rate.
As for TRVs, they’re shite at controlling room temperatures.
aplicable to boilers too. will do a video for you.
All well and good until the customer puts their hand on the radiator and freaks out that it isn't burning them
That will, and is dieing out.
I've been explaining that for so long that it's part of the spec now, no problem with any of our customers.
Well i put TRVs in a house they complained the radiators were cutting out and not working properly since I put them on. I explained how they worked but they just didn't get it 🤬
Sorry I don't buy your advice for most UK houses with poor insulation. Even with a modern build you comments on a single office not being zones is absurd. I do the same and simply place the thermostat in the office. Once the office gets to temperature why would it 'cycle cycle cycle'? Also flow temp will drop once the room is being topped up. An alternative heat source would be an electric heater at 30p per KWhr. Also....take an example in the morning when houses are coldest. Why wouldn't you zone off a lounge that won't be used as people prep for work etc? The room will gain heat over day via solar gain. You're literally advising people to throw money away. .