Radiant Heat Efficiency Upgrade

[keenspoon]

I have a radiant heat system in a new house I just bought - given all the good things I have heard about it I was a bit surprised at the heating costs this past winter. I know that standard air furncaes have gotten a lot more efficient over the past 10-15 years - and as my system is about 15 years old was considering an upgrade. But given all that it is just a boiler (gas) it may be that upgrading to a new one won't make much difference - and it seems to work.

Anyoen know if the efficiency gains have been as great for radiat as forced air? Thoughts on how much more efficient?

Thanks

[johnsp]

Older gas boilers are usually in the low 80%'s efficency wise. Newer condensing gas boilers see big gains with in-floor radiant systems since most only require water temps under 120° No need to run the boiler up to over 160° to keep the boiler happy, then mix it down for in floor radiant. If you have rads or baseboard, most need higher water temps anyway. An expensive new boiler might save you some money, but will take forever to pay for itself.

Might be better to invest in insulation, new windows and doors unless the boiler was on its last leg. A boiler in good condition, should at least 20 years.

[keenspoon]

Do have an in floor system so that is good info. In terms of other bits I am going to drop another layer of insulation in the attic, the doors and windows are pretty new so unlikley they are big leakers. I did notice though that the crawl space underneath the floor/house has some open to outside portions. And even though the radiant heat pipes are above a bottom layer of insulation thought that might be something to look at as well.

Thanks for your input.

[cem-bsee]

seal your crawl -- but leave 4+ inch of masonry to look for termites -- pvc or pool linner on crawl floor --

storm windows protect main windows, add one more layer against robbers -- also, they insulate

[johnsp]

I agree. Seal the crawl. Your radiant floor is being robbed by the cold down there. It's very difficult to get air tight insulation up into the joists. If you have a dampness problem in the summer, maybe get vents that you can close off in the winter.