Best Way To Produce Domestic Hot Water?

I searched and didn’t see any recent posts…

Our 4-story brownstone had a hydronic heating system for heat and hot water, but we are going to be changing our heat production to another system.

With that in mind, what’s the best method of efficiently producing domestic hot water for our home?

There will be a tenant apartment on the garden level (1 full bathroom, 1 kitchen) and an owner’s triplex above (2 full bath, 2 water closets, 1 kitchen). Likely to be 5-6 occupants in the building during peak use.

All input welcome.

Guest User | 6 years and 7 months ago

6

Please log in, in order to post replies!

6 replies

Newest Oldest

Guest User | 6 years and 7 months ago

string(1) "3"
string(6) "199384"

@ashton13 – thank you!

smadargolan | 6 years and 7 months ago

string(1) "1"
object(WP_User)#4858 (8) {
  ["data"]=>
  object(stdClass)#4860 (12) {
    ["ID"]=>
    string(6) "193101"
    ["user_login"]=>
    string(11) "smadargolan"
    ["user_pass"]=>
    string(34) "$P$Bvlyvz3wGsuOm2N3WBgm81r0gInnBy0"
    ["user_nicename"]=>
    string(11) "smadargolan"
    ["user_email"]=>
    string(24) "locksmithfl.us@gmail.com"
    ["user_url"]=>
    string(0) ""
    ["user_registered"]=>
    string(19) "2024-02-23 10:37:06"
    ["user_activation_key"]=>
    string(0) ""
    ["user_status"]=>
    string(1) "0"
    ["display_name"]=>
    string(61) "Your first name Your last name Your first name Your last name"
    ["spam"]=>
    string(1) "0"
    ["deleted"]=>
    string(1) "0"
  }
  ["ID"]=>
  int(193101)
  ["caps"]=>
  array(1) {
    ["subscriber"]=>
    bool(true)
  }
  ["cap_key"]=>
  string(15) "wp_capabilities"
  ["roles"]=>
  array(1) {
    [0]=>
    string(10) "subscriber"
  }
  ["allcaps"]=>
  array(3) {
    ["read"]=>
    bool(true)
    ["level_0"]=>
    bool(true)
    ["subscriber"]=>
    bool(true)
  }
  ["filter"]=>
  NULL
  ["site_id":"WP_User":private]=>
  int(1)
}

There was a recent, relatively extensive discussion about on-demand units – search for “Tankless water heater”

Guest User | 6 years and 7 months ago

string(1) "3"
string(6) "199384"

Thanks all for the input. It sounds like whole house gas fed On Demand units are not a popular option. Are they simply too inefficient? Too expensive to maintain? Too expensive to run?

Augustiner | 6 years and 7 months ago

string(1) "1"
object(WP_User)#4895 (8) {
  ["data"]=>
  object(stdClass)#4894 (12) {
    ["ID"]=>
    string(5) "45573"
    ["user_login"]=>
    string(10) "Augustiner"
    ["user_pass"]=>
    string(34) "$P$B34SD8yEA6Hi8EPJJfH83mCf4GZmmP0"
    ["user_nicename"]=>
    string(10) "augustiner"
    ["user_email"]=>
    string(18) "flo@flat-peach.com"
    ["user_url"]=>
    string(32) "http:///forums/users/augustiner/"
    ["user_registered"]=>
    string(19) "2017-08-10 13:35:10"
    ["user_activation_key"]=>
    string(0) ""
    ["user_status"]=>
    string(1) "0"
    ["display_name"]=>
    string(6) "August"
    ["spam"]=>
    string(1) "0"
    ["deleted"]=>
    string(1) "0"
  }
  ["ID"]=>
  int(45573)
  ["caps"]=>
  array(2) {
    ["subscriber"]=>
    bool(true)
    ["bbp_participant"]=>
    bool(true)
  }
  ["cap_key"]=>
  string(15) "wp_capabilities"
  ["roles"]=>
  array(2) {
    [0]=>
    string(10) "subscriber"
    [1]=>
    string(15) "bbp_participant"
  }
  ["allcaps"]=>
  array(4) {
    ["read"]=>
    bool(true)
    ["level_0"]=>
    bool(true)
    ["subscriber"]=>
    bool(true)
    ["bbp_participant"]=>
    bool(true)
  }
  ["filter"]=>
  NULL
  ["site_id":"WP_User":private]=>
  int(1)
}

The most efficient way to produce hot water is a Solar Thermal System with a huge tank as John mentions. Probably with a gas backup system.

In a 4 story house, I would put in a recirculation loop so you don’t have to wait 5 minutes for water on the top floor. I’d use an on demand gas heater with an small extra storage tank for that.

Btw. Hydronic heating (water fed radiators or floor radiant) is best – there is no possible upgrade to that.

eman134 | 6 years and 7 months ago

string(1) "1"
object(WP_User)#4863 (8) {
  ["data"]=>
  object(stdClass)#4862 (12) {
    ["ID"]=>
    string(6) "177006"
    ["user_login"]=>
    string(7) "eman134"
    ["user_pass"]=>
    string(34) "$P$BaRrlDjFBcYAeDJ9.lwOTJ9pQC9nsT."
    ["user_nicename"]=>
    string(7) "eman134"
    ["user_email"]=>
    string(23) "errol832000@hotmail.com"
    ["user_url"]=>
    string(29) "http:///forums/users/eman134/"
    ["user_registered"]=>
    string(19) "2017-08-10 14:25:55"
    ["user_activation_key"]=>
    string(0) ""
    ["user_status"]=>
    string(1) "0"
    ["display_name"]=>
    string(7) "eman134"
    ["spam"]=>
    string(1) "0"
    ["deleted"]=>
    string(1) "0"
  }
  ["ID"]=>
  int(177006)
  ["caps"]=>
  array(2) {
    ["subscriber"]=>
    bool(true)
    ["bbp_participant"]=>
    bool(true)
  }
  ["cap_key"]=>
  string(15) "wp_capabilities"
  ["roles"]=>
  array(2) {
    [0]=>
    string(10) "subscriber"
    [1]=>
    string(15) "bbp_participant"
  }
  ["allcaps"]=>
  array(4) {
    ["read"]=>
    bool(true)
    ["level_0"]=>
    bool(true)
    ["subscriber"]=>
    bool(true)
    ["bbp_participant"]=>
    bool(true)
  }
  ["filter"]=>
  NULL
  ["site_id":"WP_User":private]=>
  int(1)
}

you might consider leaving the hydronic boiler in place and attaching an indirect hot water heater to it… pretty efficient when compared to a standard hw heater…my contact info is errol832000@hotmail.com

Master Plvmber | 6 years and 7 months ago

string(1) "1"
object(WP_User)#5114 (8) {
  ["data"]=>
  object(stdClass)#4893 (12) {
    ["ID"]=>
    string(4) "1447"
    ["user_login"]=>
    string(14) "Master Plvmber"
    ["user_pass"]=>
    string(34) "$P$BSHLZQSJWUzjnaSv9fyWJpNYjwcz.u."
    ["user_nicename"]=>
    string(14) "Master Plvmber"
    ["user_email"]=>
    string(24) "info@gatewayplumbing.com"
    ["user_url"]=>
    string(30) "http://www.GatewayPlumbing.com"
    ["user_registered"]=>
    string(19) "2007-08-10 20:40:53"
    ["user_activation_key"]=>
    string(0) ""
    ["user_status"]=>
    string(1) "0"
    ["display_name"]=>
    string(14) "Master Plvmber"
    ["spam"]=>
    string(1) "0"
    ["deleted"]=>
    string(1) "0"
  }
  ["ID"]=>
  int(1447)
  ["caps"]=>
  array(2) {
    ["subscriber"]=>
    bool(true)
    ["bbp_participant"]=>
    bool(true)
  }
  ["cap_key"]=>
  string(15) "wp_capabilities"
  ["roles"]=>
  array(2) {
    [0]=>
    string(10) "subscriber"
    [1]=>
    string(15) "bbp_participant"
  }
  ["allcaps"]=>
  array(4) {
    ["read"]=>
    bool(true)
    ["level_0"]=>
    bool(true)
    ["subscriber"]=>
    bool(true)
    ["bbp_participant"]=>
    bool(true)
  }
  ["filter"]=>
  NULL
  ["site_id":"WP_User":private]=>
  int(1)
}

I’m a huge fan of creating hot water efficiently and then storing it for use throughout the day. Nothing with a flue. The use of insulated storage tanks and indirect water heaters are the best ways to utilize the efficiency of a modern boiler to store energy in the form of hot water. This could be a long conversation, but look into those two options and select an installer who knows what he’s doing and why.
– John Cataneo