Posts

The darker side of energy efficiency

The dark side of energy efficiency

In the middle of the winter, it’s easy to find the drafts in your home. Sealing drafts can improve your energy efficiency, but there are some important considerations to think about. Building contractors talk about the “thermal envelope.” If you haven’t heard the term, it refers to the “tightness” of a building’s enclosure. The tighter the enclosure is, the less air travels between the building’s inside and its outside.

Energy efficiency requires ventilation improvements

Gaps can naturally occur between the foundation and the home’s structure. They also commonly occur in the attic, where the roof joins the walls. Windows, doors, vents and other openings degrade the thermal envelope. These hidden openings enable air to travel freely between the home’s exterior and interior. That means your warm air in the winter, and cool air in the summer will dissipate. This raises the cost of your heating and cooling bill, and admits unwanted moisture into your home.

Conventional wisdom said that these gaps helped to control the growth of mold and mildew. That is true. But it also means that older homes are draftier, leakier and cost more to heat and cool. If you decide to seal drafts in your home (which will decrease your energy usage), test your home’s ventilation! You may need to add supplemental ventilation to avoid moisture build-up and other problems.

Your water heater can’t go it alone

One of the big targets for energy efficiency is upgrading the furnace. Older furnaces aren’t energy efficient, so they consume a lot of fuel. Traditional furnace designs vented the by-products of combustion out the chimney. (“By-products of combustion” = carbon monoxide.) Newer heating equipment may instead vent flue gases out of the side wall of the home. This may have implications for your water heater and you!

A furnace is a big piece of equipment, and it can create a generate a big draft in the chimney. This air movement enables the flue gases to escape the chimney. If you have a gas water heater, it may also vent out the chimney. It probably leans on the furnace to create enough draft to expel its products of combustion safely. If you upgrade your furnace but leave your water heater standing, your water heater may not be able to generate enough draft to clear the chimney of noxious gases.

This can set up a dangerous situation known as back drafting. Back drafting allows the nasty, noxious gases to pool in the chimney, or worse, escape into the house. This can cause carbon monoxide to accumulate in the house. Major danger!

There are a few solutions for discouraging back drafting when your water heater is the last man standing. Your heating and cooling professionals will want to line your chimney when they upgrade your furnace. This reduces the inner size of the chimney and allows the water heater to create a better draft. You could also upgrade your water heater to a “power vent” model. A power-vented water heater mechanically creates draft in the chimney to avoid carbon monoxide buildup.

Heating and cooling professionals can help!

Air sealing, insulating and upgrading your heating and cooling equipment all save money, but they change your home’s environment. It’s very important to avoid the unintended consequences that can come about from tightening your thermal envelope.

At Boston Standard Plumbing and Heating, we can help you choose the most efficient heating and cooling options. We can also help you ensure that your home remains safe and comfortable, while also saving you money!

Call us at (617) 288-2911 to schedule an appointment today!

Photo Credit: David Singleton, via Flickr

Tank v Tankless: Water Heaters Come Full Circle

If you’re like most people, you only think about hot water when you want it and don’t have it. On-demand hot water has only been around for about 120 years. Before that, people didn’t shower much; they bathed – and they didn’t bathe often. When they did, they brought heated water to the tub and then added cold water to get the right temperature.

During the 20th century, domestic hot water became a standard, and that’s pretty much where we are. Today, debates about hot water ask the question, “Tank or tankless?” The vast majority of domestic hot water today comes from a tank storage system, but the earliest water heaters were invariably tankless. (In fact, some were even portable!) So we’ve come full-circle on domestic hot water, and we’re still asking, “Tank or tankless?”

Team Tank
Storage tank water heaters are relatively cheap, easy to find and relatively easy to install or fix. Compared to other water heating techniques (like electricity), gas water heaters are also reasonably efficient. The design of a water tank hasn’t changed much, but newer tanks have more insulation and safety features like pressure relief valves. Storage tank water heaters can discharge about 7-10 gallons per minute of hot water, so you can shower, launder and wash your dishes simultaneously.

On the minus side, water tank storage systems use a lot of energy, and their efficiency is limited by design. Once the tank is empty, you’ll need to wait as long as an hour for more hot water.

Worse, the tanks themselves are pretty much designed to fail every 6-10 years. Some early storage water heaters had replaceable tanks. Others were made of non-corroding alloys. (75 years later, a few of these tanks are still in service.) If you’re on Team Tank you’ll be buying a new one about once every decade.

Team Tankless
Tankless water heaters have more recently made their grand return to the market. They eliminate many of the storage water tank’s faults. Some gas models are up to 98% efficient, and they’re designed to last for about 25 years. You can take advantage of tax credits and rebates that storage tank water systems don’t qualify for, and a tankless hot water system may even help sell your home!

As long as you are scrupulously honest with yourself about your hot water needs, you can have “endless” hot water. Good tankless water heaters can crank out about 4-5 gallons per minute of hot water. That’s enough for a shower, but you won’t also be able to do the dishes and the laundry at the same time. You may have to choose how and when you use hot water. (The prospect of a cold shower should make the choice easy.)

On Team Tankless, your hot water can be “endless” as long as the electricity stays on. The cold truth about tankless hot water systems is that even the gas-fired ones use some electricity. When your power goes out, your hot water goes out with it. You’ll also pay more up front for a tankless system.

So again, which is it – tank or tankless? If you need an instant solution because your tank is broken, Team Tank is calling. They’re fast, relatively cheap and you can have them in a couple of hours.

If you can replace your hot water system on your schedule and you can afford to get a system that’s large enough to accommodate your hot water demands, you should at least consider a tankless system. They’re more energy-efficient, last 2-3 times longer than a tank, take up less room, and cost less to operate over their lifetimes. In the long run, the additional money you spend up front on a tankless system (and then some) will come back to you in the form of lower energy bills.

If you’d like more information about water heaters or tankless hot water systems, give us a call at Boston Standard Plumbing & Heating at (617) 288-2911. We can help you figure out which option is best for you!

Photo Credit: Svilen Milev, via FreeImages.com

Will A Tankless Water Heater Fit In Your Boston Home? (Part 1)

Many homeowners are looking for ways to conserve energy and reduce their “carbon footprint.” One idea that has been gaining traction is the tankless water heater. Boston homeowners who are considering the move to a tankless hot water system should consider the move carefully before they make the decision to throw out the old hot water tank.

The first question most homeowners have about tankless systems is the cost. A tankless system does cost more than a conventional hot water heater, but the tradeoff is that the system lasts longer. A conventional residential hot water heating system will last between 6 and 12 years. Tankless hot water systems last about twice as long. Even so, the up-front cost of a tankless water heating system may leave you with a case of sticker shock! Generally, the system (with installation) will run between about $2,000 and $5,000, depending upon the system you choose.

If you have natural gas or propane in your home already, you’re in good shape for a tankless water heating system. If you need to bring gas or propane in, you’ll need to factor this additional cost into your calculations.

You can find electric tankless water heating systems. They’re generally less expensive to purchase and install, and their efficiency is higher, too. The problem is one of cost. Natural gas costs less per BTU than electricity does. In areas where both energy sources are readily available, you’ll spend 10%-15% less on a gas-fired tankless water system.

Here’s another consideration for electric tankless water systems; your house will likely require a 200-amp, 220V electrical service. Some electric tankless systems operate on smaller services, but you may incur additional expense if you have to upgrade your household electrical system to accommodate a tankless electric water heater.

With a conventional system, you’ll pay your equipment costs over time, in the form of tank replacement and tank maintenance, whereas with a tankless system, you’ll pay all system costs up front. The big question for most homeowners is (and will continue to be): “Can I recover the cost of the system?” Depending upon your hot water usage, you may not be able to recover the cost through normal operation, but your house may command a better price on the market if you have a tankless system installed.

Don’t fall for the myth that the tankless hot water system provides an infinite supply of hot water. Depending upon the size of the system you buy, a tankless system may be able to handle 1-2 showers simultaneously or a combination of a shower and a hot-water appliance, like a dishwasher or washing machine. Also, don’t plan on having “instant” hot water. The system will still require a little time to heat the water and deliver it to your tap.

Finally, if you use a significant amount of hot water (in other words, you have a 60-80 gallon tank), you may come out ahead on a tankless water heating system. I’ll show you why next week. If you get by just fine with a 40- or 50-gallon tank, I’ll show you why going the tankless route may come down to a coin toss.

If you have questions about water heaters, Boston Standard Plumbing has the answers. We offer 24-hour emergency service for all plumbing, heating and cooling systems. Contact us at (617) 288-2911.