What is the most economical heat system for a 700 s.f. house with no furnace?
RightWing
| Posted in Energy Efficiency and Durability on
I have a relative who may have to give up her house due to illness/unemployment Her gas furnace went on the blink. To replace it would be $1800 +. What is the safest most economical method of heat to heat her 775 sf house. She closes off one room so actually 3 small rooms & a bath is what she would be heating. For now she is using an electric fireplace and two infrared heaters that are supposed to heat up to 1000 sf.
Thank you.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Ruby,
There are two ways to answer your question.
One answer would describe the least expensive equipment to purchase. She probably already has figured out the answer to that question: the cheapest equipment is an electric-resistance space heater.
The other way to answer the question concerns operating costs. These days, the lowest-cost fuel in most locations is natural gas. So before we can give advice on lowering her operating costs, we need to know whether natural gas is available at her location.
Of course, purchasing equipment to achieve a low operating cost still takes money.
One other point: most cold-weather states have a fuel-assistance program for low-income families called the Low Income Home Energy Assistance Program (LIHEAP). If you Google LIHEAP and the name of your state, you should be able to find the name of a local agency that can help with emergency fuel assistance.
What climate zone?
What is the approximate heat load?
The electric fireplace and infra-red space heaters are resistance heaters, with a coefficient of performance (COP) of 1.0. Any type of heat pump solution would cut the operating cost by half or more. From a fire-safety point of view the small finned radiator type space heaters are safer than anything that glows orange. Some space heaters with focused reflectors can start a fire on the other side of the room if left unattended.
It's cheaper to replace the gas furnace using a 5 year loan than heating with electric space heaters. It's also probably cheaper to install than a heat pump solution.
In zone 4 or lower there may be a PTHP (Point Terminal Heat Pump) solution of the type used for heating/cooling hotel rooms that might come in cheaper than $1800, installled.There are decent models for under $1000, but depending on how easy/difficult the installation would be you're looking at an installed cost between $1500-2500. Depending on the cost of electricity the upfront costs will be recouped in 1-3 years in lower heating bills.
In zones 5 or higher it takes a modulating heat pump like a mini-split to achieve the efficiency and heating capacity, at about $3-5K (installed).