Gas water heaters are ideal for Canadian space heating
Hot water heating is getting more popular in this country and for good reason. I’ve never met anyone who didn’t like the quiet, even, fan-free heat delivered by hydronic in-floor heating or hot water radiators.
What fewer people realize is how well a gas-fired tank-style hot water heater works as a source of heat for hot water space heating.
You can either install one as part of a heating system upgrade, or tap into an existing water heater if it’s up to the job. I’m installing a tank-style water heater for backup space heating at my own place and what I’ve learned can help you choose wisely.
Hot water heating systems have been around since at least 1872 when the first cast iron radiator was invented. Typically fired by some kind of boiler, there are plenty of heating contractors who’ll tell you that tank-style heaters won’t work for heating. “You need a boiler,” they say.
But the fact is, a boiler is not essential for space heating applications. Tank-style water heaters offer simplicity, easier maintenance, year-round usefulness and they deliver a water temperature that’s ideal for space heating.
Any kind of alternative heat source such as solar or wood can also be easily connected to a tank-style heater to reduce or eliminate gas consumption. The trick comes down to choosing the right kind of tank-style heater, then having it installed correctly.
The most sensible configuration for a natural gas or propane water heater is to use it for both domestic hot water and for space heating.
Regardless of your situation and plans, begin by choosing a water heater that’s large enough to handle the maximum load of both space heating and domestic hot water combined. This works out to about 100,000 btus/ hour for an average house — more for bigger homes or older places that are less efficient. The tank-style propane heater I installed in my own place is rated at 150,000 btus/ hour input.
Today’s modulating heaters make the decision about heater size less critical than it used to be. Modulation is a heater’s ability to automatically dial in more or less heat output depending on the load demanded. This means you get just as great efficiency if you need just a little heat or all that the heater can put out. There is no efficiency penalty for a unit that’s larger than it needs to be for much of the heating season. Old-style non-modulating heaters and furnaces, by contrast, run either full blast or not at all, wasting energy when little heat is demanded.
Durability is another issue. Not all tank-style water heaters are up to the job of space heating because the continuous load is higher than heating just domestic hot water.
Check to see if a particular manufacturer warrants a heater for space heating applications before you buy it. The Polaris unit I chose for my own place is rated for space heating and domestic hot water production, it’s 95 per cent efficient and includes two sets of outlets, one for domestic hot water supply and return, and another pair for supply and return from infloor heating or radiators.
There are two different ways you can install a tank-style water heater for use heating spaces, and it’s important that your installer get things right. Visit baileylineroad.com/29222 for a design video and industry-verified downloadable schematic drawings that show how everything needs to fit together.
When it comes to home energy systems, simpler is usually better. Getting multiple, year-round uses from a single, gas-fired tank-style water heater makes sense. Just don’t let anyone tell you it can’t be done.