[nonhuman]

We just purchased a home in the Takoma neighborhood of Washington, DC (contract signed and ratified, home inspection on Monday), and so I'm starting to look into HVAC updates. The house is about 80 years old, brick exterior, and currently has an ancient boiler attached to several radiators throughout the house.

What I would like, is to replace the existing system with central heating and air of some variety. We have a lot of options in this regard as the house has a semi-finished basement and an unfinished attic either of which would be suitable for running ductwork to install a ducted system; the concern there being that we would like to finish the attic and possibly turn it into a master suite in the future which complicates the issue of using it to run ductwork. So it seems that both ducted and ductless systems are on the table.

The other question is what sort of heating/cooling system we use. I know that a lot of people around here use heat-pumps (and intend to ask my home-owning coworkers about their systems), but I really have no idea what is ideal for this climate (I grew up in the Bay Area...). I love the idea of using geothermal, but I really don't know if it's the best option.

Does anyone have any pointers, or ideas of things I should look into?

[The Godfather]

Glad to know you are getting ahead the monstrous energy prices of 2011.
Cooling: heat pump
Heating: floor radiating
Insulate like hell, while those contractors are still desperate for jobs.

[cjrivera]

You can get a 30% tax credit on the install of a geothermal system. Several of my neighbors have it and they love it. Their bills (heating and cooling) are ridiculously low.

WaterFurnace : Geothermal Tax Credits

[Cold Warrior]

I've always hated heat pumps in cold areas. They just don't seem to heat when the temps drop lower than 20 degrees F. It's probably ok for the A/C and in the fall and spring to warm when cool, but you'll want a real heating solution for the DC winters.

[nonhuman]

Originally Posted by Cold Warrior 

I've always hated heat pumps in cold areas. They just don't seem to heat when the temps drop lower than 20 degrees F. It's probably ok for the A/C and in the fall and spring to warm when cool, but you'll want a real heating solution for the DC winters.

What kind of heat pump are you talking about? Exposed coil ones suck when it's cold, but geothermal heat pumps, from what I've heard an experienced myself, work quite well.

[Cold Warrior]

Exposed.

[nonhuman]

Originally Posted by Cold Warrior 

Exposed.

Yeah, definitely wouldn't even consider one of those. It's either geothermal, or a traditional natural gas furnace (unless there's some other awesome option I'm not aware of).

[Cold Warrior]

what kind of temps high and low have you seen geothermal do well in? That's where it's buried x feet into the ground, right?

[lexapro]

What is geothermal heating and cooling?

[nonhuman]

Originally Posted by Cold Warrior 

what kind of temps high and low have you seen geothermal do well in? That's where it's buried x feet into the ground, right?

Yeah, geothermal is where the coils are buried to use the ground as a heat source/sink. It's vastly more efficient than air exchange systems because the ground temperature is much more stable and much closer to the desired temperature (warmer than the air in the winter, colder than the air in the summer). Typically the coils will be sunk into ~200 ft. shafts to reach a depth where the ambient temperature is nearly constant, though there are also 'trench' system that bury the loops horizontally in shallow trenches which are much cheaper but less efficient.

There are a number of success stories for heat pump systems around here, one of my coworkers actually has an air exchange system up in Frederick, MD which he says did a perfectly adequate job this winter, which was more severe than usual for the area. After talking to him about it I'm starting to wonder if perhaps the exposed coil heat pumps might not be sufficient here (according to wikipedia they're effective at heating even with low temperatures, but suffer in efficiency approaching the dismal performace of electric baseboard heating as the temperatures approach 0° F). One of my uncles, who lives in Bethesda, MD, also has a heat pump system that is perfectly adequate that I had assumed was geothermal, but am now wondering if it might not be (and will be sending an email about that momentarily).

[Laminar]

Originally Posted by lexapro 

What is geothermal heating and cooling?

Read all about it at this link.

[nonhuman]

Well, the research I've been doing has suggested two things thus far:
1) ground-source heat pumps (otherwise knows as geothermal heat pumps) are efficient, but very expensive to the point that it might not be worth it (though I've seen reported costs of installation ranging from $6000—acceptable—to $30,000—less so—and pretty much everyone claims that they tend to pay for themselves within 5 years which makes very little sense at the $30,000 end of the spectrum);
2) air-source heat pumps (what I'd been referring to as 'exposed coil') are less efficient, but newer models are getting good enough that they may well be worth consideration and apparently work quite effectively all the way down to 0°F, which is well below the norm here.

Heat pumps in general, it seems, are better at cooling than at heating and so are probably not well suited to most parts of the country where really only heating is necessary in a properly insulated home. Personally, however, I feel that the DC area is generally in more need of cooling than heating; the summers here are, in my opinion, oppressive while the winters are mild. Hopefully my coworker who lives a little ways north of here and has an air-source heat pump system has collected some info on what he has so I can take a look at work today.

[Big Mac]

Congratulations on the home purchase, nonhuman! Unfortunately, I have little to contribute to the subject of HVAC upgrades. Not my area of expertise.

[sek929]

Stay far far away from any forced air heating, it's ancient technology and should be avoided at all costs. I'd rather have an ancient radiator system than forced air. Forced air systems are filthy dust magnets and incredibly inefficient, no matter what the installer tells you. With ductwork you end up heating the areas the ductwork travels through more than the living spaces.

Radiant floor heating is the best, and the most expensive. People scoff until they are barefoot on their kitchen tile in the winter, it's amazing. I've installed both electric and water-based radiant floor systems. If you have the space for the needed equipment then water base tubing is my recommendation.

Barring the expensive radiant system I'd run regular baseboard heat in lieu of forced air (did I mention I hate forced air?) As far as geothermal or heat pumps it's not my area of expertise, but have you thought about a solar system (not PV) to compliment a smaller main boiler?

[Eug]

I'm installing electric radiant for the floor in my basement bathroom, but I shudder to think what it would cost to heat my whole house that way electrically.

[nonhuman]

Originally Posted by Big Mac 

Congratulations on the home purchase, nonhuman! Unfortunately, I have little to contribute to the subject of HVAC upgrades. Not my area of expertise.

Thanks! Just now got into the office after our home inspection; came back spotless!

[nonhuman]

Originally Posted by sek929 

Stay far far away from any forced air heating, it's ancient technology and should be avoided at all costs. I'd rather have an ancient radiator system than forced air. Forced air systems are filthy dust magnets and incredibly inefficient, no matter what the installer tells you. With ductwork you end up heating the areas the ductwork travels through more than the living spaces.

Yeah, after going over the whole house and particularly the boiler with our inspector, I think we're actually going to just keep the radiators we've got and install central air separately. Our inspector suggested that we could run the ductwork for forced-air air conditioning in the attic which makes it easy to install vents in every room without having to do any major work.

Is there an alternative to forced air for cooling other than the mini-split systems with the giant, ugly wall units (which I think could probably look good in a modern home with a contemporary design, but would look like shit in our little '20s bungalow)?

Radiant floor heating is the best, and the most expensive. People scoff until they are barefoot on their kitchen tile in the winter, it's amazing. I've installed both electric and water-based radiant floor systems. If you have the space for the needed equipment then water base tubing is my recommendation.

Yeah, I love radiant floor heating. My mom has it in her house in New Mexico, and it's awesome. The only complaint I've found about it is that you need to wear lightweight slippers or your feet get sweaty!

Barring the expensive radiant system I'd run regular baseboard heat in lieu of forced air (did I mention I hate forced air?) As far as geothermal or heat pumps it's not my area of expertise, but have you thought about a solar system (not PV) to compliment a smaller main boiler?

As far as the water heater, it's currently got a standard 40 gal. tank that will probably need to be replaced in about a year. I'm thinking we'll probably put in a tankless water heater. Other than that, I'd love to do solar for the water, though I'm hesitant to put anything on the roof just yet as we're hoping to turn the attic into a master suite which would require some changes to the roofline.

[sek929]

Originally Posted by nonhuman 

Is there an alternative to forced air for cooling other than the mini-split systems with the giant, ugly wall units (which I think could probably look good in a modern home with a contemporary design, but would look like shit in our little '20s bungalow)?

Not that I'm aware of, but then again I'm really not that informed about cooling systems besides opening a window.

Originally Posted by nonhuman 

As far as the water heater, it's currently got a standard 40 gal. tank that will probably need to be replaced in about a year. I'm thinking we'll probably put in a tankless water heater. Other than that, I'd love to do solar for the water, though I'm hesitant to put anything on the roof just yet as we're hoping to turn the attic into a master suite which would require some changes to the roofline.

Tankless water heaters are the new 'in' thing for houses and they really do rock. Extremely efficient since there is no need to keep 40 gal. heated all the time. If you are thinking of some upstairs renovations that would change the roofline then I'd imagine that would also be the perfect time to get solar installed, if that was feasible. We aided in the installation of a PV and hot water solar system a few years back and it was quite the complicated process. Course on a summers day they are feeding out into the grid and all the hot water is made with sun. This was on a totally furnished home with a slate roof (ugh), if you are going to tear a hole in your roof I'd think about every possible project that could involve the roof (reflashing the chimney, gutters, etc.) and try and do as many of them at once.

Congrats on your new house! You should post a few pictures if you get the chance.

[sek929]

Originally Posted by Eug 

I'm installing electric radiant for the floor in my basement bathroom, but I shudder to think what it would cost to heat my whole house that way electrically.

Depends on what you are used to paying for. Electric radiant will be cheaper than electric baseboards to heat a whole house. Electric radiant would be cheaper than forced hot air and radiators. Being in a basement means that the heat will eventually travel down through your foundation and the foundation itself becomes a thermal mass.

Really the best way to go if you are building a new home is a slab foundation with radiant throughout. Once the slab is heated it presents a huge thermal mass to warm the house with, and takes very little energy to maintain that temp. Or in your case radiant in the whole basement (water radiant) set off of a furnace that runs a small amount of baseboard heat in the rest of the house. Heat rises from the basement and warms evenly, while the upstairs baseboards allow heat on demand.

Our latest customer (who got electric radiant) had difficulty understanding that radiant systems are in no way similar to anything you are used to. She was turning the thermostat up at night and down during the day. We had to explain that radiant is extremely efficient because it simply stays one temp. In fact, you'd be surprised at the lower overall house temperature you find comfortable when the floor surface produces warmth.

[The Final Dakar]

I could heat my house for a month with all the hot air sek is spewing forth here.

wink

[nonhuman]

Originally Posted by sek929 

Not that I'm aware of, but then again I'm really not that informed about cooling systems besides opening a window.

I did a little searching and it looks like Sanyo makes some recessed ceiling units, but they're way more expensive. I would much prefer just opening the windows, but sadly I don't live on Cape Cod.

Tankless water heaters are the new 'in' thing for houses and they really do rock. Extremely efficient since there is no need to keep 40 gal. heated all the time. If you are thinking of some upstairs renovations that would change the roofline then I'd imagine that would also be the perfect time to get solar installed, if that was feasible. We aided in the installation of a PV and hot water solar system a few years back and it was quite the complicated process. Course on a summers day they are feeding out into the grid and all the hot water is made with sun. This was on a totally furnished home with a slate roof (ugh), if you are going to tear a hole in your roof I'd think about every possible project that could involve the roof (reflashing the chimney, gutters, etc.) and try and do as many of them at once.

Yeah, I'll have to look into the cost-effectiveness of solar here. We actually had solar (water heating) when I was a kid in South Jersey only about 3 hours from here, and that was with significantly older technology, so I assume it will work pretty well (I'll have to ask my parents about that). PV, however, I suspect isn't worth it money-wise right now; we'd see a much more significant impact from simply reducing our usage as much as possible, but perhaps the numbers have changed enough since I last looked at it to make it worth considering. Fortunately we probably won't be doing any of that stuff for another couple years.

Congrats on your new house! You should post a few pictures if you get the chance.

Thanks! My wife's actually already got some pictures up on her MobileMe account: MobileMe Gallery (The pictures with the dinosaur are for our niece who left it in my wife's purse when we were visiting this weekend; whenever she does that we take pictures of whatever dinosaur around town for her, they're her favorite toy. The BMW is our realtor's.)

[sek929]

Love the floors, looks like native yellow pine.

[nonhuman]

Originally Posted by sek929 

Love the floors, looks like native yellow pine.

Yeah, the floors are pretty awesome. Even better than the original 1908 pine floors in our condo in Boston!

[nonhuman]

Also, heavy kitchen renovations are definitely on deck!

[BadKosh]

Does your house have duct work? Usually, the boiler/radiant heat systems don't. If you do have airflow through your house, look into Pellet stoves. Cleaner than traditional wood stoves or fireplaces. Stoves are tax free, as well as the pellet fuel. You get a tax credit for buying one. I used to have $400-500 bucks a month electric bills until I fired up the Pellet stove. $220 a month is far better than last years $641 bucks.

[nonhuman]

Originally Posted by BadKosh 

Does your house have duct work? Usually, the boiler/radiant heat systems don't. If you do have airflow through your house, look into Pellet stoves. Cleaner than traditional wood stoves or fireplaces. Stoves are tax free, as well as the pellet fuel. You get a tax credit for buying one. I used to have $400-500 bucks a month electric bills until I fired up the Pellet stove. $220 a month is far better than last years $641 bucks.

No ductwork, but I think we've decided that we're going to stick with the radiator system for heat at least until the boiler needs to be replaced (which our inspector said will probably not be for another 10 years). Though unless I can find a good ductless solution, we'll probably install ductwork in the attic for central air before it gets too hot this summer.

I would absolutely love to have a wood or pellet stove, but with our limited square footage I just don't think it's going to happen.

[finboy]

Originally Posted by nonhuman 

We just purchased a home in the Takoma neighborhood of Washington, DC (contract signed and ratified, home inspection on Monday), and so I'm starting to look into HVAC updates. The house is about 80 years old, brick exterior, and currently has an ancient boiler attached to several radiators throughout the house.

Just read through and looked a pics. What a beauty.

Keep the boiler system for heat if you can. That means you have to have access to someone who can fix it (in DC that shouldn't be hard to find), but it's far superior to any of the newer systems in a lot of ways. My parent's HVAC guy maintained theirs as long as it was feasible, and it changed the whole house when they went to central heat and air. The chief difference as I see it is that the boiler system doesn't dry out the air in the house, and there are no ducts to keep clean of dust & allergens. With an older house that may not mean much, but I can tell a tremendous difference in the air quality when I visit. Their system lasted nearly 50 years. Can't say that about any of the other systems. I never appreciated it as much when I lived in the house as I do now.

For central air, Trane is a good brand. Better to get a commercial-grade system when you can. Have someone figure out your needed BTUs and then multiply that number by 1.5. Also, see if you can find someone to keep ductwork to a minimum. Either that or check into the air piping systems that are available, because they're much easier to keep clean.

If/when you get ducting, the flow analysis is the most important thing. Anyone can just throw something in, but that doesn't mean it will work worth a damn. Get someone with lots of references and call a few to make sure they know what they're doing. And get someone used to putting flow systems in older houses.

[nonhuman]

Originally Posted by finboy 

Haven't taken the time to read through the thread, so sorry if I repeat.

Keep the boiler system for heat if you can. That means you have to have access to someone who can fix it, but it's far superior to any of the newer systems in a lot of ways. My parent's HVAC guy maintained theirs as long as it was feasible, and it changed the whole house when they went to central heat and air. The chief difference as I see it is that the boiler system doesn't dry out the air in the house, and there are no ducts to keep clean of dust & allergens. With an older house that may not mean much, but I can tell a tremendous difference in the air quality when I visit. Their system lasted nearly 50 years. Can't say that about any of the other systems.

For central air, Trane is a good brand. Better to get a commercial-grade system when you can. Have someone figure out your needed BTUs and then multiply that number by 1.5. Also, see if you can find someone to keep ductwork to a minimum. Either that or check into the air piping systems that are available, because they're much easier to keep clean.

Yep, that's pretty much the plan now. From what I'm hearing keeping the radiators is definitely the way to go, at least until the boiler needs to be replaced. So I'm just looking at cooling options now. I'd like to avoid having to run ductwork for all the reasons that both you and Sek stated, but the only real ductless option for cooling seems to be a mini-split system. I really like those, and have used them extensively (mostly when living in Southern China and in Jamaica), but neither I nor my wife is interested in having those giant wall units uglying up our house. I'm going to look into the possibility of getting either less unattractive ones or incorporating some sort of architectural detail to hide them, but at the moment a traditional ducted system, or a high-velocity, small duct system seems like the best option.

[finboy]

Originally Posted by nonhuman 

a high-velocity, small duct system seems like the best option.

That's what I was thinking of as "air piping". Used to be the rage about 20 years ago.

Man that house is something else. Congrats!

[nonhuman]

Originally Posted by finboy 

That's what I was thinking of as "air piping". Used to be the rage about 20 years ago.

Man that house is something else. Congrats!

Thanks!

The price was so ridiculously low that we kept waiting for the other shoe to drop, but then our inspector basically told us that there was absolutely nothing wrong with it. The only thing to worry about is regular maintenance! Total steal; really couldn't be happier and can't wait for closing!

[the_glassman]

Forget Geo. The payback time isn't worth it. You would be better of investing that kind of money into insulation. Forced hot air is gross. I'd keep your current heat setup and replace the boiler with a modulating condensing boiler that falls into your Btu requirements. For AC the mini splits work pretty nice. You can also do a lot with having proper overhangs and cross ventilation.

[Cold Warrior]

The unfinished basement looks like fun. You'll have a blast figuring out what to do with it, then doing it.

[nonhuman]

Originally Posted by Cold Warrior 

The unfinished basement looks like fun. You'll have a blast figuring out what to do with it, then doing it.

Oh, I've already got some plans, and they definitely involve wood paneling and a wet bar. I've even got preliminary spousal permission!

[Arty50]

Another cooling solution would be a swamp cooler. There huge however. Also, I'm guessing DC is humid in the summer and a swamp cooler adds humidity as opposed to traditional forced air A/C which removes it. Swamp coolers are awesome in dry climates for that reason.