Replacing 90s Rads For Modern Rads Advice

Putting TRVs onto the rads and now thinking about replacing them with new rads if there is an efficiency difference.

Ive attached a photo of the rads in the house at present, they were put in during the late 90s.

What do you guys think, is there much of an efficiency difference in the 90s rads in comparisons to todays rads?

90s Radiator.jpg

The rads I would look to replace them with is in the below link, Single Panel Rads:

https://www.screwfix.ie/p/kudox-premium-type-11-single-panel-single-convector-radiator-600-x-1200mm-white-3882btu/94254

Wearb

To get a given energy output out of any radiator will require the same energy input no matter what efficiency claim is made.

For example if you have a room that needs 1kw per hour to heat, then it's going to be the same running cost no matter what type of rad you put in.

Now if you're changing them because they are all gunked up and can't be cleaned, then that's a different thing.

https://www.boards.ie/discussion/comment/118398727#Comment_118398727

The rads are all running perfect so no issues there.

I just thought that the newer rads might be better at getting heat out with same hot water input because of better material and design?

Wearb

No. Not for the same input.

https://www.boards.ie/discussion/comment/118398794#Comment_118398794

OK so less input to the newer rads making them more efficient?

Wearb

It depends on the rad design, size and material. Every manufacturer will have an output rating for each of their rad sizes. This output will be for a certain delta t ( you can look up what it means), which basically means, the radiator output at a given water temperature.

Radiators with fins on them give out more heat than ones without. But that heat has to be supplied to them in order to get more from them. They aren't creating any extra heat themselves.

Irish Steve

The underlying issue is that there has been a lot of discussion in various places about changing radiators, or using aluminium radiators on air to water heat pump systems, and the reason for this is because air to water operates at a much lower temperature differential in comparison to a traditional oil, gas or solid fuel heat source, so if you were looking at putting a heat pump in, the existing steel radiators might not be able to put sufficient heat into the rooms to get them to a comfortable temperature as a direct consequence of the lower core temperature of the radiator operating from the new heat source. Some of the newer aluminium radiators are lower capacity than the older steel radiators, so they get up to temperature more rapidly than the older styles, simply because there's less water to have to be heated to raise the temperature. The down side is that a lower content can mean having to push more water around the system to get the required heat transfer, so it's not a simple change

Looking at the Screwfix radiator you quoted, it looks like it's working with a similar temperature differential as your existing radiators, so unless there's a good reason to change them, like corrosion, or partial blocking that won't flush clear, I'd suggest leaving well alone, as changing radiators is not a quick or easy task, as it can mean draining the entire system, unless you have also got maintenance valves on the feed pipes, and they are rare on Irish heating systems. Maintenance valves can fail, and start weeping round the seal, I think I've changed 3 on a 19 radiator system over a 30 year period, but they have made life much easier when decorating,or doing other work that meant taking the radiator off the wall, and they've meant being able to continue to use the rest of the system with a radiator off the wall, but I've also had more than a few slightly barbed discussions in this forum about their use, so I'll say no more.

I will also mention that TRV valve units can and do stick during the summer months, in the closed position, and getting them moving again in the autumn can be a challenge, this can be partially avoided by either opening the thermostat unit to the highest setting at the end of the heating season, or simply unscrewing the unit from the valve, but that means storing it somewhere safe, so that it can be put back on again in the autumn. A small drop of silicon oil on the pin stem of the valve can also help to keep them moving.