Heating Up a Converted Garage
LESLIE: Mary in California is having a problem with an addition in her home. What can we help you with?
MARY: I have a home that we had to rebuild after a fire and it’s all insulated and we’re making the garage into a family room.
MARY: And there is no heat going into the family room.
TOM: How is the rest of the house heated?
MARY: Rest of the house is by gas.
TOM: Forced air, hot water? What kind of distribution …
MARY: Propane. Propane.
TOM: OK, that’s the fuel.
TOM: What I need to know is whether you have ducts or radiators.
TOM: So, with a forced air heating system you have ducts that deliver warm air and cool air to a conditioned space and then return ducts that take it back. The problem with converting a garage is typically they have at least one if not two and sometimes three exterior surfaces. If you – if it’s a one-story. And so, you have the roof above and you have the door and maybe you have another exterior wall because they’re almost in the corner of the house, you have a lot of exterior surfaces there and even though you insulate them they need a lot of heat to overcome that space.
So what you’re going to have to determine is, first, can I extend the duct system into the garage so I deliver enough heat to be comfortable in there. That’s the first question. And if you can do that then you have to figure out how to extend those ducts to do that. If you can’t, then you have to look into zoning that which means adding a second heating system. If you’re going to zone you’re going to want to probably divide up different sections of the house so that some are on one furnace and some are on another.
Now, if the family room is going to be a place that you don’t use frequently, you could consider a less expensive type of heat like electric baseboard or even a through-the-wall heat pump. But again, that depends on how much time you’re going to spend in there. If you want it to be comfortable all the time the best way to do that is to extend your existing central heating system.
MARY: So just extend it with a thing – heating going in and one going back out? Is that what you said?
TOM: Yes, but – that’s correct conceptually, but it’s a lot easier said than done because you have to make sure that the existing heating system is big enough to do that and that you’re moving enough air in and out to actually make it comfortable and warm.
My first step would be to get in touch with my HVAC contractor and find out if it’s possible to extend the existing heating system and if he or she thinks that you have BTUs in that system to do that because you want to maintain the value in your house and you want to create a family room. Let’s make sure that it’s just like any other space in your house that’s properly designed to heat all the time.
MARY: OK. So would it be best then for the guy that built the house, because it just go rebuilt from being burned…
TOM: Whoever is your HVAC contractor, that would be the person to talk to; not necessarily the builder, but whoever is servicing your systems. Because it’s a heat loss calculation. There’s a way to actually measure how much heat that you need in that space.
Mary, thanks so much for calling us at 888-MONEY-PIT.