Radiator TRV`s, worth it?

Gizmo247

lstar337 wrote: »

Exactly! :wall:

As the temperature required for restful sleep is lower than when just being in a room.e.g. Kids doing homework at 19C but sleeping at 17C, That is difficult to achieve by just turning down the hallway thermostat on a whole house setup. In my view manual TRVs are definitely worth it but once you have gone Evohome then there's no going back.

lstar337

Hengus wrote: »

This is probably not the best place to discuss the 'benefits' of smart controls but here goes. Forget about TRVs for the moment.

The basic hall thermostat fitted in most homes is nothing more than a bi-metallic switch with an ON/OFF function. TPI - enabled thermostats such as Nest, Danfoss and Honeywell (including the Evotouch controller) calculate boiler firing times based on the difference in temperature between the actual temperature and the target temperature. TPI-enabled thermostats will reduce boiler firing times and save money; however, like the simple ON/OFF thermostat, boiler modulation is left to the boiler to manage.

Opentherm devices such as Nest 3 and Evohome also control the gas valve to reduce boiler maximum output temperature based on TPI calculated demand. This results in a condensing boiler which spends a lot more time in the condensing mode. It also results in more accurate room temperature control as the radiators will often be warm rather than the classic hot then cold then hot routine.

The Opentherm protocol was developed at Glasgow University in 1996 and is in widespread use in The Netherlands and Germany but, as yet, not widely supported in the U.K.

Zoning adds to the above savings. Each electronic TRV has TPI and it is capable of optimised start and stop. For example, last week when the outside temperature was cold, my kitchen radiators came on about an hour before a target temperature of 20C was required. This morning, with a much higher outside temperature, the optimised start was about 35 minutes. The reverse happens when a reduced zone temperature is required. All these optimisations add to the savings.

TPI and Opentherm have also been shown to reduce boiler wear. Just one year of extra boiler life would go a long way towards covering the cost of smart controls.

All that said, finding a knowledgeable installer isn't easy in the UK.

All very good, but it is the saving compared to the cost of buying and installing such equipment that really matters. These devices cost a lot, and I can't see the cost being recovered in savings in any sensible amount of time. Result: False economy.

I have always said that they are cool gadgets and if I had the money to waste I would probably have one to play with, but they are really just a cool toy and nothing more.

lstar337

Gizmo247 wrote: »

As the temperature required for restful sleep is lower than when just being in a room.e.g. Kids doing homework at 19C but sleeping at 17C, That is difficult to achieve by just turning down the hallway thermostat on a whole house setup. In my view manual TRVs are definitely worth it but once you have gone Evohome then there's no going back.

TRV's are set and forget in my opinion.

I don't turn them down at night, I just have the rads upstairs permanently set lower. Of course I don't heat overnight either, but that is just a perk of a well insulated house. If I did need to heat overnight, I would just use a basic programmable stat to set a slightly lower temp at night.

It's all cost vs. benefit. Because my house is so well insulated and I pay so little for my heating bill, even the cost of a basic programmable stat isn't worth it for me. I have a crummy stat with a knob on it, but a programmer will cost me about £40 and that's about a third of my bill. The savings don't justify the cost.

Gizmo247

lstar337 wrote: »

All very good, but it is the saving compared to the cost of buying and installing such equipment that really matters. These devices cost a lot, and I can't see the cost being recovered in savings in any sensible amount of time. Result: False economy.

I have always said that they are cool gadgets and if I had the money to waste I would probably have one to play with, but they are really just a cool toy and nothing more.

It is never really about economy although I reckon I recouped the cost of my Evohome in the first 3 years. It is all about comfort and reliability, just like you'll never get your money back on a new boiler but you can pretty much guarantee you will be warm in the winter.

[Deleted User]

Maybe I'm suffering from age related Hypothermia, but I'm confused!

matelodave

I guess you need an OpenTherm compatible boiler to gain most benefit from a "smart" system. There's an advantage in remotely controlling all the individual rooms but at a cost.

We've got underfloor heating with a programmable thermostat in each room (8 zones) which controls the flow to each zone and enables the heating system at the same time, so it's nearly there. We don't have a need to keep tweaking once it was set up. I only need to change the stat clocks from GMT to BST in March & October.

The heating unit (ASHP) has weather compensation so regulates the flow temperature to suit the outside temperature and it just gets on with it.

FUNKYDADDIO

Thanks for a of your advice. I have an old 1950s house with 13 radiators in total. I spend roughly £1200 PA on gas heating. I have looked at evohome as probably the best option but to cover the new wifi controller and subsequent trvs it woud be almost £1000. This seems quite a lot even if I get a 20%pa saving that would be 5 years to pay it off. Really all I need is my house split into upstairs/downstairs as my biggest loss is keeping the heating on around 19.5/20 overnight via our wireless cm927 honeywell controller kept in our bedroom (we have 2 small children so need consistent heat level for them). This means the downstairs warms to this level also, bar some minor manual permanent tweaks on indivdual radiators such as dining room. I also feel it would be futile to have a routine 3 times daily to turn 13 radiators up and down. Is there a better option if i want to minimise zones and still have control, even over 2 different levels? Also is this difficult to install or could I do it myslef and what happens my combi boiler and water heating if I do go evohome?

Many thanks in advance..:)

System

FUNKYDADDIO wrote: »

and what happens my combi boiler and water heating if I do go evohome?

Evohome works well with combi boilers. If you have any specific questions about smart heating controls, then I would post them here:

http://www.automatedhome.co.uk/vbulletin/forumdisplay.php?13-Heating-Control

FUNKYDADDIO

Hengus wrote: »

Evohome works well with combi boilers. If you have any specific questions about smart heating controls, then I would post them here:

http://www.automatedhome.co.uk/vbulletin/forumdisplay.php?13-Heating-Control

Thanks, I'm just waiting on my registration being approved by moderators..