Which heating system is best for my use?

**rick.a** · 07-10-2010, 10:51 AM

I have a 930 SF house in Massachusetts that has been a Summer only place, but now we need to convert it to a year round home. We are insulating it to the max but need to add a heating system. Propane and electric are my only fuel options. We are getting quotes on central heat systems but I want more info to be able to decide. Which do you think is better and more affordable... Propane fired boiler with baseboard HW or Propane fired furnace with forced air? The heating contractors say that the furnace is cheaper than a boiler but the air ducting is much more expensive than water baseboard plumbing. We also have a clearance issue, with only about 3 feet of headroom in the crawlspace where the heater needs to go. Putting heater inside the house is NOT an option. Floorspace is critical to us and it must go under....any thoughts on this? I don't want to rely entirely on what the contractors propose as each has an obvious self interest with the systems that they like to install.

Also, any guesses on the approximate payback time period of a Propane fired central heat system as opposed to simple electric baseboard heat, which is very cheap to install but costly to run. I have no idea how to compute electric costs vs Propane costs. Can this be done?

thanks, Rick.

**jadnashua** · 07-10-2010, 12:18 PM

One BTU = 0.2930711 watt-hour, so if you know how many BTU's you need, you can calculate how many watts that equates to, and then use your local energy costs to figure out the impact. Electric is essentially 100% efficient, a burner won't be, but could be closer to 100% than you think, depending on the one chosen.

With such a small space, wall space for the baseboards might be a big problem, and adding ductwork under the floor means it may not be very efficient if you wish to add central air later. The least expensive way to run the ducts would be to have registers in the floor.

A boiler could serve two purposes, heat and domestic hot water by use of an indirect WH. Those can be had in both vertical and horizontal formats that you'd probably be able to fit underneath. A boiler would also give you the option of staple-up radiant heat, which wouldn't restrict furniture placement or the search for a place you could put a radiator in a small room like a bathroom or the kitchen without getting in the way. A small, mod-con (modulating/condensing) boiler can often run at as little as 20% of full output under light load conditions, and this also aids comfort and economy where you can match the output to the need. The most comfortable heating system is one where it is perfectly matched to the output and is running alll the time so the heat remains constant. Forced air is probably the worst in that area, and will dry the air out in the winter. It does have the advantage that since you are running the air through the filter, you take out more dust, but hydronic doesn't stir up any that is there. 3' feet is an issue. But, you may be able to dig a well or area big enough to support that. If you already have a WH in the living space, that could be moved underneath with an indirect, and the boiler would easily fit in that space. The smaller mod-con's are wall hung, and are so quiet, you normally can't hear them run from a few feet away. I have a Buderus unit in my townhouse. The US distributor is in Londonderry, NH, so parts and expertise are close by.

**rick.a** · 07-10-2010, 01:40 PM

Thanks Jim, This gives me more to think about. But did you say that a mod-com boiler can be small enough to be wall hung? That is pretty small. Is it similar to a tankless WH?

Rick.