Intelligent heating controls

I have seen a heating control that had sensors inside and outside the building, unfortunately I was not able to get much information about it at that time. If the building was to be used at 7:00 then the heating time switch was set to 7:00 and the system calculated when to switch on based on inside and outside temperatures.
My two questions are:
1. Who makes this sort of system?
2.. Can it be fitted to an existing system?
I am thinking that it would be a real cost saving for a church as the heating needs to be on for 24 hours in mid winter to get the building form cold to comfortable.

Weather compensation.
Measures the outside and inside temperatures and decides how long it will take to heat the building to that desired temperature.
Don't really know all the technical details but there's plenty on here that do.

Your heat emmitters must be undersized. A compensator won't be any help in that case.

As said though might be an idea to have the current system sized correctly to see if that is where the problem lies.

Norcon said:

Your heat emmitters must be undersized. A compensator won't be any help in that case.

Click to expand...

this is why you have a heating curve... it enables you to set the optimum flow temp for your heat emitters...

UFH is low curves 0.2-0.8, rads 1.00 to 2.5, and convectors 2.5 plus

the curve number refers to the rate of change of the flow temp relative to the out door temp.

Norcon said:

Your heat emmitters must be undersized. A compensator won't be any help in that case.

Click to expand...

There is no problem with the system. It is just difficult to calculate when to set the heating to come on to make sure the church is warm in time. The way it is done now is to have the heating coming on in plenty of time and this wastes gas is the weather is warm. The timing is ok in mid winter but as the weather is getting warmer it needs to be on less, it would be good to have a system that calculated this automatically.

yes they can be retrofitted...ideally you the controller would look at the indoor temperature too, as well as the indoor one.

ALEC1 said:

Norcon said:

Your heat emmitters must be undersized. A compensator won't be any help in that case.

Click to expand...

this is why you have a heating curve... it enables you to set the optimum flow temp for your heat emitters...

UFH is low curves 0.2-0.8, rads 1.00 to 2.5, and convectors 2.5 plus

the curve number refers to the rate of change of the flow temp relative to the out door temp.

Click to expand...

So when you set this heating curve for the OP how much time will you be able to knock off the 24 hour period?

Should have mentioned boiler undersized too.

john4703 said:

Norcon said:

Your heat emmitters must be undersized. A compensator won't be any help in that case.

Click to expand...

There is no problem with the system. It is just difficult to calculate when to set the heating to come on to make sure the church is warm in time. The way it is done now is to have the heating coming on in plenty of time and this wastes gas is the weather is warm. The timing is ok in mid winter but as the weather is getting warmer it needs to be on less, it would be good to have a system that calculated this automatically.

Click to expand...

Hi John. Most Churches are notorious for being poorly insulated, with a resulting high heat loss. Another thing they're notorious for is limited funds.
With a high heat loss, limited occupation or use, the best thing to do is try to achieve overall target temperatures at specific times. If you are on the Fabric commitee or solely take to do with the building, PM me & I try to help further. I can't be a million miles from you & I'm happy to help.

john4703 said:

I have seen a heating control that had sensors inside and outside the building, unfortunately I was not able to get much information about it at that time. If the building was to be used at 7:00 then the heating time switch was set to 7:00 and the system calculated when to switch on based on inside and outside temperatures.

Click to expand...

Optimum Start/Stop (OSS) .

Weather compensation is a different feature whereby the heating flow temperature is adjusted according to the outside air temperature (which is proportional to the steady-state heat losses).

OSS is common on commercial BMS heating/cooling controllers. There was someone on this forum asking about it on Honeywell (I think it was ) domestic controllers, although they called it something else.*

OSS systems learn the response times of the buildings and alter the heating start time to achieve the occupied set-point temperature by the occupation start-time.

john4703 said:

I am thinking that it would be a real cost saving for a church as the heating needs to be on for 24 hours in mid winter to get the building form cold to comfortable.

Click to expand...

More a feature of the traditional construction of many churches, maybe yours as well ; masonry walls with a huge capacity to soak up a lot of heat before the wall surface temperature starts to rise. And very high spaces in which any warm air rises way up above the occupied space. They don't respond to heat inputs in the way that houses do. If you're hoping to find a heating contractor who understands mean radiant temperatures and the convective output of heat emitters, you'd best start praying.

* I Googled that; it was this thread;
//www.diynot.com/forums/plumbi...ponds-to-external-temperature.377219/#2894194

It was a Honeywell CM907 controller. According to the OP they only anticipate by 2 hours, which would be no use to you. Some Tekmar controllers also incorporate OSS.