You'll also need to be sure that your current system can handle the extra load on it without having to upgrade the boiler. Don't forget to include the structural costs included with installing the tubing. Then get a price for Zmesh and compare the running costs as well.

I'm going to here from the plumbers on this, as usual, but PLEASE! Stop taking the advice from plumbers on how much your electric radiant system will cost you. Ask how many electric radiant systems they've installed to give you this sound advice...as plumbers!! Then ask them how much an hydronic system will cost to run in your home, precisely. The answer is always "less then electric" with no definitive numbers. If they reply, it will be based on factory tests on a new boiler that is the most efficient they can quote from, not your boiler after using it for X number of years. Boilers start to loose efficiency from day one of use. Then take into account how many feet above sea level you're at, what form of fuel you use, the temperature of the water, the thermostat settings etc..

We have installed easily 50 low voltage electric radiant heating systems as primary heat in the past 4 years and NONE of our customers don't use it because it costs too much. On the contrary, it is more efficient, more even in it's distribution of the heat, a lot less costly to install, can be installed directly under the tile or hardwood and can be nailed through anywhere on the grid. You can certainly nail through pex tubing, but you won't approve of the result. Then there's the pumps, temperature settings, valves, boiler maintentance etc..let alone the possible leaks (that none of these installers ever have, I'm sure) Just look at this site alone for the problems that occur with hydronic systems. There is none of this with an electric radiant system.

You can easily find out how much the electric system will cost to run. Email me the type of system your electrciain is installing and I can tell you to the penny. Just have your electric bill handy at the time. And, it will probably remain consistant. I have been paying the same rate for my electrcity for the 8 years I've lived in my home. I bet if you happen to keep your old bills around, you'll find very little change in yours as well...unless you live in Alaska!

Yes, electric radiant, in the form of baseboard or wall panels and utilized in the wrong application, are what has hurt the electric radiant in-floor reputation. They're toasty to have but they are also known to be one of the worst forms of heat where efficiency is concerned. It doesn't surprise me that they were expensive to use.

Dana1

Quick question, are you experienced in installing systems or just design or both?

So, to stay on point of this thread, you're saying that the HO would be better served installing a single zone radiant system off her existing hot water radiator system with a separate control for a 130sf area (without cabinets) given her design requirements and it would be primary heat?

Also, I have never stated anywhere that generically using electricity to heat a home is cheaper or more efficient than hydronics. And, I have the utmost respect for real engineers in comparison to plumbers who think they're engineers through osmosis. I work with engineers almost every day in designing our layouts and requirements when being spec'd in on projects for primary heat, floor warming and snow melting. Only twice this week because I was out on jobsites all week. No time to play here.

In every design where we have been chosen to install a low voltage system as primary heat, (3 times this week) they have all doubted it's ability to 1) heat efficiently and 2) do it cost effectively, based on the same calculations you offered.

In every case, they are unable to explain why the system is actually running far less time then the calculations they ran said it would (trying to convince all that hydronics would be better) and could still keep the homes warm. I can't either. I can only say that it is. There are all kinds of 'maybe' explanations: maybe ZMesh is heating more effectively through the home so it doesn't need to be on for as much time; maybe our elements heat more evenly and faster so they don't need to run as long as expected; maybe it's all the drugs I took in the 60's! :) I only know we're doing it and I don't have a single unhappy client freaking out by their electric bill. Well, maybe the snow clients aren't so happy this year for all the snow we're having.

Further, and more importantly, look at this website alone under "Radiant Heating" or the RPA site where almost every entry is a problem a contractor or homeowner is having with their hydronic system. You're involved in trying to fix a lot of them here. You neglected to mention these costs in your analysis. Do you see even one issue with an in-floor electric radiant system on either site? NOT ONE!

You can go on all day about the calculations and I will agree with them...on paper. Complain all you want how generation to the source is cost inefficient. As I've mentioned before, all that matters to the homowners we supply is do I get $1.00 worth of heat for the dollar I pay. You do with electric in-floor radiant. You can't say that with hydronics and never will be able to.

You live in MA. We have a whole house (2800sf, paying 0.179 kWh) heating  system in Pittsfield using low voltage ZMesh through out the major portions of the house and a low voltage cable in the 3 bathrooms (8 zones in all). No other source of heat.  Last year their electric bill for January and February was 410.00 including their electrical appliances. No maintenance, no service calls, no contracts, no oil or propane bills. And, as you know, no rise in electricity this year when oil and propane went "through the roof", so to speak. Their propane for cooking only was $67.00.

So, to summarize, I agree with you...and I don't!