The AFUE ratings indicated a higher efficiency for gas over oil. I am about to replace my boiler. Would switching to gas make sense: economically, environmentally?
Ric thanks for your message. You are asking a very common question and unfortunately it is not all that easy to answer. You are correct that many natural gas boilers have a higher AFUE rating then some oil boilers. However, it depends somewhat on what kind of oil boiler you are talking about. Some types of oil boilers, particularly condensing oil boilers, have AFUE ratings that are as high as for natural gas boilers. Therefore, in order to make a good decision you have to look at factors such as boiler maintenance and the price of fuel going forward. Most heating and cooling experts we have talked to feel that in general oil boilers require more frequent maintenance than natural gas boilers. We have found that for most homeowners it is very important to have good regular maintenance of their boiler for both efficiency and safety considerations. A properly maintained boiler is less costly in the long run. You might want to consider a boiler maintenance plan if your utility company provides this service, and most do. You can compare service plan costs from your utility company or companies for each type of fuel. If the maintenance costs are similar then this may not be a factor but we have found that in many cases natural gas maintenance plans are less costly.
Boilers last a long time so in our opinion we think the biggest economic difference over time is probably going to end up being the cost of fuel. Therefore in order to judge which is best you are left in the unfortunate position of having to prognosticate the difference in natural gas vs fuel oil prices for the next twenty years. If you were to look at it today the pendulum would swing strongly in favor of natural gas. Fuel oil prices shot up by 97% in 2007 as opposed to natural gas which rose about 11%. As we enter the era of post peak oil we think it is likely both natural gas and fuel oil will continue to increase in price. However, we believe the competition for oil resources will be greater than for natural gas and so it is likely that the proportional increase in fuel oil prices will be greater. This is however a best guess based on limited economic data so please take this observation with a large grain of salt.
From an environmental standpoint frankly both natural oil and fuel oil are bad for the environment. They both take trapped underground carbon and release it into the atmosphere which increases global warming. Both types of fuel add to air pollution and both disrupt the land when we drill for them. All in all when it comes to fuel oil versus natural gas it is a lose-lose proposition.
There are a couple of suggestions we would make since you are considering replacing your boiler. You did not specify whether or not your boiler was for water heating or home space heating. If it is the latter then we would also recommend that you put in a new thermostats at the same time you put in a new boiler. Modern digital thermostats can provide much greater control over how you use heating in your home and are very inexpensive considering the improvement they can make in your energy costs. If you are using the boiler only for hot water heating you might also want to consider going with a solar hot water heater. These types of water heaters have improved dramatically over the last twenty years and are an extremely effective way of reducing your energy costs. In addition they do absolutely no damage to the environment. Most systems cost between $4000 and $7000 and can pay for themselves in just a few years. In addition, many states now provide tax incentives and rebates for solar hot water heaters which can further reduce the cost.
That was our response to our reader's question. Let us know what you think!