I currently have wet underfloor heating in a large conservatory. When it is cold outside like 2-4c, the temperature in the conservatory will not go any higher than 16c, even with the room stat set a 21c. I have got the UFH pump on the no.3 setting with the mixing valve on 50c. The question is would it be safe to turn the mixing valve up to 55c with a screed floor and ceramic tiles. Would appreciate any comments from any UFH experts.
Wet underfloor heating in conservatory not very hot
- Thread starter veto
- Start date
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Impossible to say from that info.
What is the screed thickness?
What are the pipe centers?
Is it an independent circuit or a slave to the rads?
What is the area of the conservatory in relation to the heatloss?
Is it full of furniture?
What is the screed thickness?
What are the pipe centers?
Is it an independent circuit or a slave to the rads?
What is the area of the conservatory in relation to the heatloss?
Is it full of furniture?
Hi Dan
I will try and answer your questions as best as possible.
Screed thickness - 65mm with 4" DPC.
Pipe centres - This i do not know but it is a single loop system.
Slave or independent circuit - independent from main CH system with its own pump and zone valve.
Area of conservatory - 24 square metres.
Heat loss - i do not know but the glass is Pilkington K argon filled.
Furniture - yes,three piece suite dining room table and chairs plus TV.
I also laid a thermometer on the floor which showed a temperature of 25c.
Hope this is enough for you to answer my question
I will try and answer your questions as best as possible.
Screed thickness - 65mm with 4" DPC.
Pipe centres - This i do not know but it is a single loop system.
Slave or independent circuit - independent from main CH system with its own pump and zone valve.
Area of conservatory - 24 square metres.
Heat loss - i do not know but the glass is Pilkington K argon filled.
Furniture - yes,three piece suite dining room table and chairs plus TV.
I also laid a thermometer on the floor which showed a temperature of 25c.
Hope this is enough for you to answer my question
A
ALEC1
you only get about 100watts per square meter from ufh in screed so multiply the floor area by that and that gives you the kilowatts.
for the place to maintain temperature you need to replace the heat loss from the conservatory...and this is usually calculated at -3c outside.
If the conservatory is old then the heat loss will be very high and the kw output from the floor will be insufficient.
If it is recent build you should have the heat loss to hand....so you can tell...
for the place to maintain temperature you need to replace the heat loss from the conservatory...and this is usually calculated at -3c outside.
If the conservatory is old then the heat loss will be very high and the kw output from the floor will be insufficient.
If it is recent build you should have the heat loss to hand....so you can tell...
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Typical pipe loop area coverage in conservatory using 100mm pipe centres to get 100w per sq metre = 12sq m
Your conservatory = 24sq m
Your heat output - probably not greatly over 50w per metre assuming 15mm pipe.
There's your answer.
You can only turn up the water temperature, this could cause expansion related issues, that is a difficult one to answer as there are too many variables.
Your conservatory = 24sq m
Your heat output - probably not greatly over 50w per metre assuming 15mm pipe.
There's your answer.
You can only turn up the water temperature, this could cause expansion related issues, that is a difficult one to answer as there are too many variables.
Alec/Simond
Thanks for the replies. I am still trying to break down your info into laymans language so i can understand it. I have got some more data if it will help.
the control system is a Polypipe zonal regulation unit which has got tees and spigot elbows fitted for a 2nd circuit.
The screed when it was put down was a Flexidry enhanced sand and cement with added fibres.
The thermal property of the Pilkington glass argon filled has a "u" value of 1.2 and a total solar radiant heat transmittance of 0.39. Not sure what all this means in relation to heat loss.
To make it simple so i can understand what you are both saying,is 50w per metre to low for the size of my conservatory,i.e i need extra heat to make up the loss whatever that is.
Also would i be silly and risk cracking the floor under the tiles if i turned the mixing valve up to 55c ?. I forgot to mention the conservatory is only 12 months old.
Thanks for the replies. I am still trying to break down your info into laymans language so i can understand it. I have got some more data if it will help.
the control system is a Polypipe zonal regulation unit which has got tees and spigot elbows fitted for a 2nd circuit.
The screed when it was put down was a Flexidry enhanced sand and cement with added fibres.
The thermal property of the Pilkington glass argon filled has a "u" value of 1.2 and a total solar radiant heat transmittance of 0.39. Not sure what all this means in relation to heat loss.
To make it simple so i can understand what you are both saying,is 50w per metre to low for the size of my conservatory,i.e i need extra heat to make up the loss whatever that is.
Also would i be silly and risk cracking the floor under the tiles if i turned the mixing valve up to 55c ?. I forgot to mention the conservatory is only 12 months old.
It seems that you dont really know whats in your floor! Neither the pipe length nor the spacing! Or apparently the depth of the UFH pipes in the screed!
It would be normal to have two loops in that size of conservatory.
What you can measure is the flow and return temperatures! Do that first and then we can then advise you what to do next.
Obviously this just shows how important it is to take professional advice on heating from a heating expert and NOT from a builder!
You seem to want to use the conservatory as a house room rather than what they are intended for which is for summer use in the daytime ONLY !
The heat losses from a conservatory are too high for UFH to provide enough heat even if the pipe spacing and number of loops are designed for the maximum output which usually means a floor surface temperature of 30 C.
For the moment if you want to sit at night in a goldfish bowl then use an electric fan heater to make it bearable! Expensive perhaps, but its your choice to sit there!
Tony Glazier
It would be normal to have two loops in that size of conservatory.
What you can measure is the flow and return temperatures! Do that first and then we can then advise you what to do next.
Obviously this just shows how important it is to take professional advice on heating from a heating expert and NOT from a builder!
You seem to want to use the conservatory as a house room rather than what they are intended for which is for summer use in the daytime ONLY !
The heat losses from a conservatory are too high for UFH to provide enough heat even if the pipe spacing and number of loops are designed for the maximum output which usually means a floor surface temperature of 30 C.
For the moment if you want to sit at night in a goldfish bowl then use an electric fan heater to make it bearable! Expensive perhaps, but its your choice to sit there!
Tony Glazier
All you can do is;
1. Go back to the person who installed the UFH
2. Or turn the mixing valve temp up. No one here is going to warrant that the thermal expansion won't crack a few tiles. The heating pipes can take it though.
3. Learn from the experience, get a proper installer next time.
1. Go back to the person who installed the UFH
2. Or turn the mixing valve temp up. No one here is going to warrant that the thermal expansion won't crack a few tiles. The heating pipes can take it though.
3. Learn from the experience, get a proper installer next time.
Tony
Not sure if you are having a go at me for not understanding the complexities of UFH. I am just a pensioner who likes to sit in his conservatory. First of all i do not know the technical detail that went into the floor. There could be 2 loops because of the tee elbows or spigots. I cannot measure the flow and return because there is no gauges on the system to check.Finally it was a heating company that fitted the UFH and not a builder.
If you go back to my original thread all i wanted to know if it was safe to turn the mixing valve up to 55c.
Not sure if you are having a go at me for not understanding the complexities of UFH. I am just a pensioner who likes to sit in his conservatory. First of all i do not know the technical detail that went into the floor. There could be 2 loops because of the tee elbows or spigots. I cannot measure the flow and return because there is no gauges on the system to check.Finally it was a heating company that fitted the UFH and not a builder.
If you go back to my original thread all i wanted to know if it was safe to turn the mixing valve up to 55c.
I am not having a go at you because I dont expect you to be a heating expert.
But I would expect you to take care with your hard earned money to ensure you get value for money.
You should put the problems to the installer! He should not have installed something which would not have provided what you need. Unfortunately due to the lack of work in a recession many will do an installation even if they know that its not going to do the job. He might not be an expert on UFH though and exactly what you said to him is very important.
It may be possible to increase the flow rate if the temperature drop is too high. But if you cannot or do not want to measure the temperatures or tell us how many loops you have then there is little we can do to help you.
The normal maximum flow temp into UFH is normally kept below 50 C and the surface temperature below 30 C. If you choose to increase the flow then you risk cracking the floor!
Tony Glazier
But I would expect you to take care with your hard earned money to ensure you get value for money.
You should put the problems to the installer! He should not have installed something which would not have provided what you need. Unfortunately due to the lack of work in a recession many will do an installation even if they know that its not going to do the job. He might not be an expert on UFH though and exactly what you said to him is very important.
It may be possible to increase the flow rate if the temperature drop is too high. But if you cannot or do not want to measure the temperatures or tell us how many loops you have then there is little we can do to help you.
The normal maximum flow temp into UFH is normally kept below 50 C and the surface temperature below 30 C. If you choose to increase the flow then you risk cracking the floor!
Tony Glazier
A
ALEC1
the fact that the floor gets up to 25c indicates that all is well with the floor. The maximum temperature permitted to avoid problems with circulations in the legs actually 27c. if the floor was say 18c or 20c that would be cause for concern.
In short it seems like the floor is giving out the right amount of heat.
Of course the other side of the equation is heat loss. This should have been indicated by the UFH designers as higher than normal...the big companies ask for the room usage, and high light where the output is defficient.
It sounds like if it is a kit then no design consultation was undertaken, but that does not make the UFH installer responsible, only the person who contracted him.
In short it seems like the floor is giving out the right amount of heat.
Of course the other side of the equation is heat loss. This should have been indicated by the UFH designers as higher than normal...the big companies ask for the room usage, and high light where the output is defficient.
It sounds like if it is a kit then no design consultation was undertaken, but that does not make the UFH installer responsible, only the person who contracted him.
Another disappointing underfloor heating install.
It may be fixable. Can't beat radiators. Heat on, bang the room is warm.
If all else fails add a radiator to the conservatory.
It may be fixable. Can't beat radiators. Heat on, bang the room is warm.
If all else fails add a radiator to the conservatory.
Tony/Alec
Many thanks for your helpfull comments. From the various responces that i have received now i fully understand the answer to my original question,and that is "no! do not turn up the mixing valve temperature as you may risk cracking some tiles".
Much appreciated Veto
Many thanks for your helpfull comments. From the various responces that i have received now i fully understand the answer to my original question,and that is "no! do not turn up the mixing valve temperature as you may risk cracking some tiles".
Much appreciated Veto
Vito, like all good examees, in the answers - at least when i was at school - we are trying to give you the extra information needed to come to an informed solution to the WHOLE problem.
The UFH kit you have is supplied by a company that although reputable, requires the installer to tahe responsibility of correctly designing the system tto tthe needs of the customer.
It appears one or both of you didnt research quite enough.
The ZRU you have can do two circuits if correctly plumbed ut is not going to be a primary heat source (from the info provided) for you kind of conservatory.
The UFH kit you have is supplied by a company that although reputable, requires the installer to tahe responsibility of correctly designing the system tto tthe needs of the customer.
It appears one or both of you didnt research quite enough.
The ZRU you have can do two circuits if correctly plumbed ut is not going to be a primary heat source (from the info provided) for you kind of conservatory.
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