I know this is not the most exciting topic, but I am looking to see if any residential architects are specifying “tankless” water heating units as the primary system. If so, any comments for or against would be appreciated.
We do lots of residential work, and always spec tankless water heaters. They're small and efficient and clients love 'em. You can get gas or electric, gas being a much cheaper option in LA. We usually spec Takagi, which has a wide range of sizes. In a larger house, you can have two or three smaller tankless heaters spread around so it doesn't take as long for the hot water to get through the pipes to your location. The only issue is something I've heard called a 'cold water sandwich' - it can take a minute for the gas to fire in the tank, so if you're using hot water, then turn it off for a minute and turn it back on, you'll get a blast of cold water (whatever was in the pipe while the heater was off) before you get hot again. not such a big deal.
some of those takagi's say they provide around like 4+ gpm.
most showerheads seem to be rated around 2.5 gpm. have you been able to find that you can run two showers simultaneously? (as you probably don't run 100% HW for the each shower...)
usually when there is a tankless water heater there is a contiuous loop where they are all attached so that each WH is not dedicated to only one bathroom, and every faucet has immdiate hot water.
we're using tankless on every residential project and forsee doing so for, um, pretty much forever.
we even have one project where a large tankless is going to drive the in-slab radiant heat system (all electric). i'm not a big fan of this idea - if the all electric fails, such as a power failure, you've got issues. plus, most of the radiant manuf. recommend using a 60 gal. tank. but, these are all second homes and are small (sub 1800sf), so the clients need the floors to heat up quickly more than being super efficient.
I wonder if multiple, point of use tankless heaters would still be more efficient than a single tank heater. I would suspect they are. Here in Bermuda, where my one bedroom cottage can see electricity bills as high as $350/month, I think that they are a logical choice.
As far as maintenence is concerned, someone will just have to learn to service them!
we've been choosing them for all our residential projects as well - just put one in for a house w/2 bathrooms & very picky clients, no complaints so far. we're going to switch ours out at home as well because we need the space.
we did specify them for a new 2-storey house w/3-1/2 baths. We would have needed 3 units according to the contractor, and the energy consultant calced it out and actually it is better to go with a standard system once you get more than 2 units... we go with takagi as well. they're about $2400 installed.
May 10, 06 8:03 pm ·
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Residential Specs
I know this is not the most exciting topic, but I am looking to see if any residential architects are specifying “tankless” water heating units as the primary system. If so, any comments for or against would be appreciated.
residential specs vs. commercial specs...
We do lots of residential work, and always spec tankless water heaters. They're small and efficient and clients love 'em. You can get gas or electric, gas being a much cheaper option in LA. We usually spec Takagi, which has a wide range of sizes. In a larger house, you can have two or three smaller tankless heaters spread around so it doesn't take as long for the hot water to get through the pipes to your location. The only issue is something I've heard called a 'cold water sandwich' - it can take a minute for the gas to fire in the tank, so if you're using hot water, then turn it off for a minute and turn it back on, you'll get a blast of cold water (whatever was in the pipe while the heater was off) before you get hot again. not such a big deal.
Yup - we're using them more and more. Check out Munchkin and Noritz...
any of the tankless companies do lunch-n-learns? i'm a believer but i don't think my bosses are...
We spec Chronomite, www.chronomite.com, 800-447-4962 for public and private use.
They recommend a heater at each use...
sink
dishwasher
shower/tub
some of those takagi's say they provide around like 4+ gpm.
most showerheads seem to be rated around 2.5 gpm. have you been able to find that you can run two showers simultaneously? (as you probably don't run 100% HW for the each shower...)
usually when there is a tankless water heater there is a contiuous loop where they are all attached so that each WH is not dedicated to only one bathroom, and every faucet has immdiate hot water.
i recommend one WH per shower.
we're using tankless on every residential project and forsee doing so for, um, pretty much forever.
we even have one project where a large tankless is going to drive the in-slab radiant heat system (all electric). i'm not a big fan of this idea - if the all electric fails, such as a power failure, you've got issues. plus, most of the radiant manuf. recommend using a 60 gal. tank. but, these are all second homes and are small (sub 1800sf), so the clients need the floors to heat up quickly more than being super efficient.
I wonder if multiple, point of use tankless heaters would still be more efficient than a single tank heater. I would suspect they are. Here in Bermuda, where my one bedroom cottage can see electricity bills as high as $350/month, I think that they are a logical choice.
As far as maintenence is concerned, someone will just have to learn to service them!
we've been choosing them for all our residential projects as well - just put one in for a house w/2 bathrooms & very picky clients, no complaints so far. we're going to switch ours out at home as well because we need the space.
we did specify them for a new 2-storey house w/3-1/2 baths. We would have needed 3 units according to the contractor, and the energy consultant calced it out and actually it is better to go with a standard system once you get more than 2 units... we go with takagi as well. they're about $2400 installed.
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