heating system recommendation

T

thepool700

Guest
Hi

House is currently set up as follows:
downstairs - ufh
upstairs - rads with thermostats
all systems been heated by oil burner
Solar tubes on rough for hot water cyclinder

Am looking for feedback on best possible efficent way to run above system
am thinking 3 zones on time clocks, 1- ufh 2 - upstairs 3 - hot water in tank
Does this make sense?

Also anyone recommend best way for working ufh? constantly on? set for few hours?

Any feedback would be appreciated as still trying to get to grips with most efficent way to run system as current system is running all(ufh, rads and hotwater) of same feed and I feel am just burning money

Thanks
 
I have underfloor heating downstairs and upstairs. I also have solar thermal for domestic hot water and backed up with a high efficiency condensing boiler. Each room is thermostatically controlled by a room stat opening the circuit for the room when their is a heat demand.
Originally, the manufacturer recomended a set back system, leaving the system on 24/7 but with a setback mode, reading 4c less on the stats, i.e. if stat was set to 20C, it would think it is reading 16C when in setback mode.
I am a heating engineer and this system sucked and drank oil. I employ an electrician, who I got to take their system apart and rewired to remove this. I then zoned each manifold with motorized valves and the hot water circuit with one. Fitted a 7 day electronic timeclock. Still used each stat and the original control box. Now using half the oil I was and heat is directed to where I want when I want. Also got a grant for the works too.
 
Shane 007, you say that you are a heating engineer. I am interested to find out where you can train to be a heating engineer in this country. Have you a background in plumbing/heating or building services?
 
Hi Villa1, I am not sure about courses in this country. All my studies were in the UK which began nearly 24 years ago, apart from my OFTEC oil boiler technician course. I done this with Metac in Co. Laois. This really does not cover heating systems but the oil boiler itself, only touching on the system itself.
I have found that a wide variety of courses, such as thermal insulation courses, will give you a better and more complete understanding of heating systems or on the building fabric that they are trying to heat. I suppose when you understand where and how heat is lost in a dwelling, we can more easily determine a counter-action to solve the issue of the loss. This gained with experience and opened ears is my best advice. Even on sites like this, I am ever learning.
 
hey 007, the ufh systems do drink the kero, you say you zoned the manifolds in the end how many valves did ya put in? what make of ufh did you put in?
 
I put one valve per manifold, i.e. one Myson zone valve for downstairs, one for upstairs and a third for the domestic hot water. I have a Heatlink system with an outdoor weather compensator. The Heatlink system is a mixture of 220V and 24V, so my electrician had to put in a few relays and completely remove the setback system. It used to drink it alright, but I changed to a condensing oil (Grant Vortex) also and along with zone work, I am even surprised myself with the outcome. I have a 3,000sqft house with underfloor in both upstairs and downstairs (no rads) and I filled the oil tank in April and did not fill again until middle of December.
Done a similar job for a client with a Heatlink system in the summer and he tells me he is getting the same results.
Just be careful of the wiring into their system. On mine anyway, I heard a good few "f" words coming from the electrician but only a couple on the next job.
I have solar too (domestic hot water only), and that eases the burden on the boiler too.
 
hey the pool,
have you ever heard of an interlocked system, in effect it is a way of wiring your cheating system (talk to your electrician) basically your thermostats run your boiler, lets say you have the three channel time clock 1hot water 2rads 3u.f. heating, when you clock calls for hot water it sends power to your cylinder stat which in turn send power to the motorised valve which opens and then and only then will send power to the boiler which will fire, so if you cylinder has hot full hot water from solar, the stat, even when power is sent from time clock wont open the motorised (zone) valve and the boiler wont fire up saving you oil. same goes for the upstairs rads run off the room stat. the underfloor heathing is a different matter, alot depends on type of system whether you've been supplied with a set back controller, the reaction/ heat-up period of the floor and how long you are at home. IMO the set back mode on the ufh WILL reduce your bills if set correctly the manufacturers have spent alot of time and capital in developing these products to run the most comfortable and efficient as possible so if you follow there installation manufracturers instructions there shouldnt be any bother.

btw.. ufh has a slightly higher running cost than rad but much greater comfort.
 
oh bother, I've been asked to look at some of the heat-link where the system been fond of the kero, but these heatlink systems are probably all bout 10 years and older the set back in some of the latest models IE rahue (spell) much improved. I'd sooner take on a mine field than heatlink did ya see the way they plumb in the flow and return all over the shop works though.
 
BTW, shouldn't all systems have boiler interlock. It's part of the regs since 1st April 2008.
You are completely correct. I think this is where I am getting the big saving of oil.
 
Sounds like you may have a good solution, based on fuel usage alone.

Did any warranty or compliance issues arise when you altered the set up?

ONQ.
 
No, as my system is 2003 and well outside warranty. If your system is within warranty, you will have to check with the manufacturer. I did incidently check with Heatlink and they said it would not cause any damage to their system and understood why I was doing it!!
 
Also as I got a SEAI grant for the upgrade, I also got an audit from them after works complete. They use an independent company called EAGA to audit systems and that engineer passed the system, in that it complied with current building regulations and met all SEAI guidelines.
 
hi shane

Thanks for taking the time for detailed reponses i will have to look into it more.
The system I have is from heatlink as far as i can see from delivery docket of the ufh. No i have been onto the plumber for documentation on how the systems run. after ages waiting he just sends me a copy of wiring the manifold.
Would ya know where i could source documentation on this?

Also you appear to have some experience in running ufh What would you recommend in running ie. what temp should boiler be at? what temp on manifold? should it be left 24/7?

Sorry for all the question would love to get my head around this year and not have same issues again.

thepool700
 
Shane, you ever had a systemlink that always calls the pumps in, but hit and miss on calling to the boiler (240v call on boiler, no volt free)
 
Hi thepool,
Here's a link to Heatlink's download page of all their technical data & brochures.
[broken link removed] or try their american parent company website.
Boiler temperature will be independent of ufh as this temperature will be cooled or allowed to cool before it enters circuits, otherwise you could crack the concrete floor. Generally, 70C is a good temp with a return of 50C. Return temp will depend on whether your boiler is a condensing one or not. Boilers should never have returns of less than 40C. Ufh differential temps are generally 10C temp diff. You can guarantee return temp by fitting a loop between the flow and return with a three port thermostatic mixing valve set to required return temp. If you look at Grant's website and download one of their condensing boiler manuals, it will have a circuit diagram for this.
Another efficient and effective way of balancing a system is to install a small well insulated buffer tank (say 100 litres or less) between the boiler and the circuits. The boiler heats the buffer tank to maintain its temp and the heating circuit takes the heat from the buffer tank when required. I know that Firebird is currently working on a new boiler that encorporates this. This dramatically increases efficiency. The temp on the manifold will be determined by the design room temp, outside design temp, heat loss factors and length of pipe runs. If you give Heatlink a call in Tullamore, I find their tech guys fairly helpful.

With regard to 24/7, I might have to duck from an incoming attack on this one, but in my opinion, I do not like having them on 24/7. I am personally getting better results with less oil when system is on part-time. I do realise that manufacturers say this and that about leaving them on, but I did that and it drank oil. When I changed it, I get better heat where and when I want it. Also zoning the hot water cylinder plays a big part. If you think about it, if you calculate the volume of water within the heating circuit, it probably averages at about 150 litres. HW cylinders can be more than this, so in effect, it's nearly like heating 2 houses. I know this is not exactly true and more factors come into play, but you know what I mean. Remove this element and you are heating a vastly smaller volume of water. If you have a balancing valve on your flow or return for the cylinder, try it and turn it off but count the turns it takes to turn off. You will see that your heating will heat up much quicker. Don't forget to open it the same amount of turns to re-set it to the balanced position it was originally set to.

DGOBS, when you say systemlink, I take it that you are talking about SystemLink Zoned controllers. If so, sounds like a problem with the system controller. Has the problem just started or was it there from installation? I have not dealt much with them. Perhaps give their tech dept a call.
By the way, I got that condensate drain and it's perfect. €28 + VAT. Just ordered another 4.
 
Any of the cylinder manufacturers will make whatever size you wish, such as Lycris Byrne in Wicklow. Any Heat Merchants or Chadwicks can order for you. They will make in copper or stainless steel and factory insulate to whatever specification you require. The cylinder can also be direct or indirect.

Just make sure the guage of the material is suitable for the installation, i.e. pressurized or vented system.
 
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thanks

thanks again shane appreciated the time and effort.

Area I am covering is appox 1200 foot. I burned approx €300 in a month so it is fairly guzzling it I think.

Now the guy who installed the ufh for me has the following set for me(I did query things but he is not helpful and talks as if I was a qualified in ufh plus has the attidute of i installed the ufh the rest is yours and blah blah blah .....So to me its like talking to a wall)

I have a firebird condensing boiler alright. on the manifold ufh was temp set at 35c and we have a return on 6c difference. Is this an ok temp to be set at?

When you say you dont use it 24/7 what hours to you have it on for? What temps would you be achieving in room?

Once again apoligies for all the questions but so far you have been the only person who can speak in laymans terms about it.

thepool700
 
€300 per month for 1,200sqft is a huge cost. I have 3,000sqft and I am doing less than that.

It sounds like the average flow rate through the manifold is set too high. Basically, what is happening, the heat from the boiler is flowing through the circuit too fast and not getting a chance to transfer into the floor, so you are heating the circuit for nothing. I would also imagine that your boiler is "short cycling". This is when the water temperature within the boiler has reached it's required temp and the boiler switches on and off maintaining it. The return temperature is too close to the flow temp. This uses a lot of oil "stop starting" all the time. Boilers prefer and are more efficient when chasing heat. This is why it is better to undersize a condensing boiler rather than over-sizing it. (If your boiler is over-sized, you can have the power output downsized by changing the oil pump pressure and installing a smaller nozzle. This should be carried out by an OFTEC engineer as the boiler should be re-analysized to ensure optimum efficiency at that setting.
On your manifold you will have a number of pipes flowing out to each room/pipe run. These will have actuators that opens and closes to allow flow to that circuit when called by the room thermostat. On the return manifold, you should have a head on each circuit with a dial numbered 0 to 12. 12 is fully open and 0 is closed. This determines the flow rate. Each will be set differently as it will depend on the length of pipe run that it covers.
You should have a flow temperature of approx 50C with a return of approx 40C. Mine is 50C flow and 38C return. You will need to test the flow and return temperatures of EACH PIPE RUN and adjust to give the above temps. The overall manifold flow and return temps will then average at the required no matter how many circuits are open.
 
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