HRV in radiants?

Ron Gillen

Mike, if you don't have a tight home you don't need an HRV, infiltration will probably meet your needs. If you do, they are the greatest. With radiant heat you don't get the statification that you would with forced air, but in my home the temperature is 70 from just above the floor to the 9 foot ceiling. The incoming air on a cold day is about 65 and is washed across the ceiling mixing with the room are before settling in the room. You are not moving air the way a furnace does, it's far more subtle than that and the result is clean fresh air and no drafts. It's something that you may need to experience to believe how well it works.

Mike.C

Do they work?

While I contemplate in my puny little mind how a HRV works I cannot see how it would help in a radiant system in a cold climate. Hear me out
Radiant systems without hot air rising up to the ceiling(where most HRV catch their heat) doesn't seem like the best way to do it. Say the room temp is 70 say the 12' ceiling is 60 say outdoor temp is 10. With the air exchanger in the HRV I can't see the temp coming back into the house any warmer than say 40.
So now I leave it to you to let me know your prior experiences and thoughts.
Thanks
Mike.

Weezbo

indoor air quality is an important part of the system...

in some climates environmental space conditioning can be accomplished with an erv.

controlled ventilation is the key.

energy recovery a side benefit.

while any atom excited moves more rapidly...radiant heat is not renowned for hot air poorly designed systems however may overshoot Bounce and droop...usually these systems are not much more than a proportional valve stuck in place of a 4 way motorised mixing valve with out door reset or an injection system or a three way or a modulating control or constant recirculation system ...HRV's are good things basically...they are not without operational costs however....

they have come a long way from the earlier conception ...

still i think that they ought to have some sensor to tell them the boiler is NOT running and Their services are not required,because evidently no one is home and the temps are falling....why drag in more outside air?

if someone IS home...i think that they dont need more cold air exchanges to satisfy their health requirements:)

Constantin

They do work...

... and have nothing to do with the heating system in your home, as far as I am concerned. The need for HRVs is a reflection of the better buildings that can be built today, buildings that can have very low infiltration figures. The HRV is simply there to keep the indoor air quality up. In our house, the HRVs exhaust the bathrooms and activate when someone steps into one (occupancy sensor).

As for the air temperature, there are a couple of approaches that may work. Some contractors will fit a heating coil to heat the fresh incoming air once it's past the HRV. Another thing to consider is the efficiency of your HRV, which depends on the air speed, the size of the heat exchangers, etc. The published data for the Lifebreath TRV units I used suggested 87% at the lowest speed.

So far, I am very happy with the results. The indoor air is always as fresh as the exterior. The only caveat with a well-ventilated house is that you'll probably need a good humidifier also. Otherwise, your indoor air RH will plummet in the winter time.

HTH.

Unknown

Radiant doesn't stratify AS MUCH as other heating systems.

It does, however, still stratify a little. Something like 30% of your output is heated air rising from the floor in a typical radiant floor; your ceiling temp will generally still be higher than room temp.

Weezbo

that is interesting information...

Today, i invited the manager of the local Wholesale company owned by Mr.Keller to take a look at the progress on the new Shop.....i purposely handed him a heat gun I.R. to check temps of the surfaces of the building as we went from each "Bay/shop" in the building....

Wow! he says...the ceiling is one degree warmer than the walls:)

i Must be doing something Wrong...Again.

next week when i get the temporary heat off line..I will drive the heat of the building up until the ceiling floor and walls is very close to 90 degrees....to get rid of the chemicals in the ; PVA, cement sealer, plastic finish materials, paint from a variety of electrical fixtures, garage doors ,man doors, trim, window vynil,door stain, carpeting & floor coverings ,counter tops,cabinets,OSB, Plywood...the HRV wont be my first choice to get rid of indoor air at that time...instead,i intend to open every one of the garage doors on both sides of the building..... Before i enter any of the spaces.....

The Reason for this is , i have noticed over the years , that there are more and more chemicals that are being introduced into our environment...i am ok at Chemistry...however, it would take me a long time to determine just which chemicals recombine into other chemical chains and just what these particular combinations just might do to human beings....i do Know this much however, that when i do this , the indoor air seems to turn a haze of light blue...one Sunday, when running up the stairs to open a window..i fell to my knees...i am fairly tough character...i Ran Up the Washington monument.....i am thinking that the HRV is removing these things slowly over time...i ain't got time for that right now though.... so i will continue to make sure i get rid of this stuff as quickly as possible. the first go around....

chris_86

HRV's,...

Hrvs equal moisture when and only when you have a superinsulated home with the airtight envelope. Consideering almost no-one builds this way in the states due the much increased cost, never mind the material cost for good poly films... hrvs are not manditory but are considered a good idea for fresh air... also a good way to add an air filter. They or a solution for mosture in envelope homes in Manatoba quickly became an issue when all of the windows and slime started to form on lots of inside surfaces. In this application air exchange became manditory and considering this defeated the envelope design by opening windows to let fresh air in the air to air was born about 20 years ago. An air to air always costs to install they are never perfect but the trade off is necessary to live in envelope structures...you only have to have the power fail to experience what it is like to live in a plastic bubble with one person in the shower and another cooking fish to realize the almost instantant effect of not having an air to air, this is applicible to much of the chemistry present in homes/ whatever, also. I think we are going to see more air to air exchangers as time goes on...they are here to stay.