adding a radiator / radiant heat to a hydro-air system?

STEVE_17

My foyer is cold! I have 2 sets of doors leading outside from the foyer. Both are 100 year old solid oak with large single pane 1/4" glass panels. I weather-stripped and chalked but its still the coldest part of the house. I wouldn’t consider replacing them and im ok with the added cost of heating.

my heating system is a 2 year old hydro-air with 3 zones. I was hoping to tap into the zone that heats the foyer (and its surroundings) and add a radiator since the foyar air register is too far from the door and too small to overcome the large heat loss. im also thinking of installing staple up radiant tubes under the foyer from the basement.

Question: Can i connect an additional heat source "in series" (to use an electrical term since im no plumber) to the outlet of the radiator in my air handler in the basement (can do this myself = save $$) ? or should i make it a separate zone (hire plumber - and run new thermostat wiring = more $$)?

is one (radiant vs radiator) significantly better for my application then the other? my 100 year old pine t&g floor is nailed directly to the beams with no sub floor so a staple up application would heat the floor directly and wont need to overcome a sub floor...

Thanks!

Larry_10

Steve

if you put in a radiator you don't need another thermostat it may start short cycling your boiler

I would hire a heating guy to do a load test check out your boiler see if it can handle another radiator

then if all is good let him pick out a nice buderus rad
and put another pump off your manifold and run it as a new loop.

this way here when your tstat calls you will heat both the air handler and rad at the same time your boiler may run a tiny bit longer but that's good

with small load's you don't want to run them alone it will heat to fast and short cycle the boiler make it one big loop with 2 pumps and one t-stat

infloor heat would be nice but you have a air handler and that takes high temps and would not be good for infloor unless you use mixing valves and stuff it would be cheaper to put in a rad and it will work good with your high temp boiler

that's what I would do if I was you

STEVE_17

radiant tubbing (PEX?) cant handle the 180 degrees F that my boiler is set too?

the air handler is 10 feet away from the boiler and pump in my basement. the foyer radiator would be 8 feet further in a direct line and up 9 feet. cant the pump that feeds the air handler support both the air handler and the radiator? i have 3/4" copper pipes. (the same pump pushes hot water to my attic almost 40' stight up... so i assumed it could handle the air handler and the radiator/or radiant)

thanks for your reply.

Larry_10

steve im a Home Owner so

im not sure what you mean. the same pump is used for the air handler and to pump hotwater up in the attic to what?

another air handler?

if so it sounds like you are running 1 pump and 2 zone valves

if it were me id run another pump to the rad so you don't get cold return temp sent back to the boiler

also if you are serious about heating that area id call in a pro to look at the whole job he can look at your boiler and size your heat load and give you options

also 180deg is way to hot for under floor heating you need a mixing block or valve's. so a buderus rad would be a better solution

call a pro good luck

STEVE_17

again thanks for your post. sorry for not being clear.

I have 3 pumps - one pump per zone. one of these pumps to the attic and the same TYPE of pump pumps 10' away... the 3rd pumps to the 3nd floor.

i was hoping to piggyback on the pump that pumps to the basment since its not working hard and adding a radiator to that pumps loop.

it sounds from your post that returning cold water to the boiler is a bad thing - how so? isnt that what the boiler does - heat cold water back to 180 .. ?

thanks

Larry_10

I would get a HVAC contractor to come out and check your pump it may be to small to do this and if you do it with a small pump it could cause your boiler to condense and it wont last

if the temp comes back to the boiler to cold it wont last

pay a pro for his time to come and talk you through it all

you may have to up the pump to do this but if you up it to much it could cause velocity issues and then the copper wont last so let him do the load info for you to check delta t-s

good luck

Ted_9

Steve, do not tap into the existing hydro air lines. I should have been sized for the air handler and not for other heat loads. Please just spend the money the first time and do it right. Hire a hydronics pro and do it right.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

STEVE_17

can someone recommend a heating contracotor in/around brooklyn NY to do this type of work?

Al Corelli - Agix Associates

hPex can take 180 degrees and more.

I've been doing it in my house for years.

No problems. No leaks.

jerry scharf_2

a TRV would be ideal

Steve,

I would set up a separate zone with a small circulator that ran continuously during the heating season. Then I would install a nice low mass panel radiator with a thermostatic radiator valve (TRV.) The TRV adjusts the amount of hot water allowed into the rad based on the current temperature. With the low mass of the panel rad and the TRV, when a blast of cold air comes in, the rad will heat up quickly, warm up the area and drop back to the idle state with no external action.

I think you are fine running the rad with pex or pex-al-pex.

Normally I would recommend outdoor reset with the panel rad/TRV setup, but it would not mix that well with the fan coils. You may need to do some fudging of the control system to add the constant circ, but maybe not.

One warning: Once you do this, you may hate the heat in the rest of the house.

jerry

STEVE_17

sounds like a great idea. i wasnt aware of "low mass" and i do need something to supplement the heat upon the door opening...

i do have a question though: the boiler only keeps temp up @ 180 when at least one of the 3 zones calls for heat. so during the day it 'rests' due to the way my t-stats are set up. that means the circulator will be pumping unheated water through it... and when the TRV is 'closed' wouldnt that hurt the circulator in some way since it circulating water to a closed source...



im not a pro but im learning a lot here. thanks for your post

jerry scharf_2

reply to questions

Steve,

You can find nice panel rads from Runtal, Buderus and many others.

Remember I said you may need to change your controls to make sure heat is available from the boiler to the panel rad. If you set it up for a wide swing in water temps on the constant circ loop, the boiler shouldn't be too bad with short cycling. It depends alot on the type of controls and boiler you have now, and how much load the radiator needs to put out compared to the boiler size.

The TRV wouldn't close all the way, just most of the way. As long as there is some flow, the heat from the pump will be carried away and the risk of damage along with it.

I think you need someone on your site figuring out the details, I was just giving you an idea to play with.

jerry

STEVE_17

Thanks Jerry. I guess i need to start talking to pro's about this. Living in brooklyn, there are 100's of listed heating pros, the problem is finding one who know this stuff and not just going to slap a rad on (which i can do myslef)...

Thanks