Radiator Covers

cgw

A church has low pressure steam radiators that are partially recessed in exterior walls with an exanded metal cover. To me this is a pretty inefficient installation. Any one have data or experience to back this up?

I'm looking for a way to provide a more efficient system for the space. Ugrade the steam system. Maybe replace with hot water (but if the radiators are converted, something would have to be added).

gerry gill

This should help you out

Its the best chart i've ever run across.

Steamhead

Upgrade the steam!

what type of steam system is it? Where is it located? 

nicholas bonham-carter

church steam system

is the system functioning well now? some insulation board between the radiators, and the outside wall might help. if you change to hot water heat unnecessarily, instead of making the steam work as well as it no doubt once did, it might be a shame, or at the very least a waste of money. many radiators have been recessed into walls [probably insulated with blankets in those days] and worked well as long as the airflow was not obstructed. new hot water radiators of the equivalent btu will be much larger, and the cost of new boiler, piping, and radiators, may take many sundays to pay for.

more important in the quest for greater economy of operation would be to keep things in good repair and adjustment.--nbc

Jamie Hall

Gerry's charts and sundry thoughts

Chances are you have, for all practical purposes, something like the two left bottom diagrams on Gerry's chart (lovely chart, by the way!).  So you aren't really losing much in efficiency from the enclosures themselves, assuming that someone hasn't cleverly blocked them with furniture or curtains or the like.  If the wall behind them is significantly thinner than the rest of the walls in the building, you may be losing some heat out the wall -- but that is curable if you can figure out a way to get some insulation in there.

As for overall efficiency and expense, it has been my experience that you will be much better off keeping the steam system and making sure that it is, itself, right -- all the usual suspects; traps, vents, valves, pipe pitch, etc. -- than you would be in trying to convert the thing to hot water.  The problem being that it will take a very long time to recover the capital cost of the changeover.  Even if in the process of getting the steam system up to speed you find you need a new boiler, you are still trying to recover the capital cost of the rest of the conversion with the savings in fuel with the hot water system.  Which savings may not exist at all, and at best might amount to say 5 % (assuming that you get a top end boiler in both cases).  Compare that with the cost of money (even in today's anaemic market!) and you just can't make a case for changing.