Wirsbo vs. Blue Ridge

wpmgoblue

Hey all. Looking for advice and first hand experience with these two systems. Looking at adding a multi zone system on the 1st floor of our colonial. I have full joist access and will be running the pex myself. Have a plumber scheduled to hook up the manifold/mixing valve to existing boiler.

Plates are the real cost of this setup and I’m wondering if I will really see the benefit of a more than double cost of the Wirsbo plates. I have wider joist bays and like the idea of the wider blue ridge plate and of course... the budget help. But don’t want to skimp if there will be an appreciable difference when it comes to performance. Appreciate your thoughts on this. Kind regards.

Zman

What is you heat loss? What is your design water temp?
Are you considering the omega plates or extruded?

wpmgoblue

Our heat loss came in at around 65,000. Shooting for a water temp of 75-80. As for the plates - that's my original question. The Omega plates from Blue Ridge are more economical. The Wirsbo joint tracks are extruded and more than double $$$.

Alan (California Radiant) Forbes

The thicker the plates, the better the heat transfer. The better the heat transfer, the lower the water temperatures. The lower the water temperatures, the lower your gas bill.

Sorry, I don't have first hand experience. When we used plates, we went with another product.

hot_rod

the really thin plates had a history of "oil canning" that ticking sound of metal expanding when the heat is applied.

Use the lowest SWT and constant circulation or ODR to limit wide temperature swings, if you go that route.

Zman

How many square feet is the house? Is the heat loss per square foot pretty consistent?

wpmgoblue

First floor is roughly 1800’ hard to say on heat loss consistency because we are renovating. Adding wall insulation, replacing windows and reframing some areas. In addition, the goal is to remove 3 existing rads to allow for zoned heat on the first floor. The current issue is that the rads on 1 get very warm, but all the heat migrates up a large open stairway to the 2nd and 3rd floors. Making for a cold first floor and hot 2nd and 3rd. (Example, I removed the rad from the 3rd floor entirely and barely notice a difference.)

My hope is that radiant heat will be a better solution and will mitigate thermal rise.

But again. My specific question relates to the effectiveness of the 2 different style plates... do you really get the bang for the buck on the Wirsbo plates. They seem ridiculously over priced for a simple piece of extruded aluminum. Local advice I’ve gotten from pros actually walking the space say that regardless of which plates I choose, it will be way better than what it is now.

Thanks for the tip on circulation @hot_rod it’s a big old house, and I suspect the system will take a while to get to temp and will stay on pretty consistently to stay that way, so I’m hoping the tinking won’t be too present... but it’s also an old house, and a little bit of creaking is quite common (and certainly doesn’t bother us) anyway. 😉

hot_rod

Two important concerns is the tube to aluminum plate contact, and the plate to floor contact. Any air gap reduces conduction transfer.

No question the extruded cover these bases best.

https://radiantdesignandsupply.com/theheatexchanger/2013/3/4/comparative-infra-red-study-of-heat-transfer-plates

If, like Zman alludes to, the load is low then the less expensive, lower transfer may be adequate.

For best transfer, lowest SWT and noise free I always use the extruded.

Zman

hot_rod said:

Two important concerns is the tube to aluminum plate contact, and the plate to floor contact. Any air gap reduces conduction transfer.

No question the extruded cover these bases best.

https://radiantdesignandsupply.com/theheatexchanger/2013/3/4/comparative-infra-red-study-of-heat-transfer-plates

If, like Zman alludes to, the load is low then the less expensive, lower transfer may be adequate.

For best transfer, lowest SWT and noise free I always use the extruded.

That is exactly where I was heading....


What heat loss calculation method did you use? 36 btu/sq ft is likely double you actual heat loss.

wpmgoblue

I'm certainly no expert on doing a heat loss calc. Numbers I used and source (US Boiler) are attached. FYI - I measured the windows and there is roughly 275 sq ft of original leaded glass windows. 2/3'ds of those windows will stay (decorative and cool) the remaining 1/3rd will be swapped out with casement or double hungs. I've also included a layout of the 1st floor. We live in Western Pennsylvania.

I went back and read some of the conversations between competing brands/reps - and don't mean to relitigate the bad blood... but just want to know as a homeowner if the hype is worth the price in a real world scenario. I'll be doing the manual labor portion myself (with a helper) and will have access in perpetuity to check on sagging tubes/cold spots when and if they arise... But once the pipe goes up - as long as it's keeping the first floor comfortable - I won't much care which plates I used... But If I buy $2000 in plates and have to replace them with $5000 in plates because the $2000 dollar plates don't work... I'll be mad. Vice Versa - If I'm only paying for a name - and an energy savings that is going to take me 20 years to justify itself, then I'll just feel stupid.

I want to be practical and prudent... not flashy and cutting edge.

hot_rod

Like many things related to heat transfer, the more you spend, generally the better the product. Properly installed I doubt there is a huge difference in output between the plates you are considering, it's more about leveraging all the aluminum to it's best ability.

Keep in mind there are rooms and homes that cannot be heated by radiant floors alone. You may get some floor warming and require addition heat emitters.

1600 sq ft at a 70∆, I would guess around 40,000 or less load? I think your infiltration number is suspect?

wpmgoblue

Help me to understand those numbers a bit more @hot_rod I did the infiltration value at the highest (most drafty) value of the 3 options. Figuring any insulation I can get in as a bonus.

Thinking I might try the omega plates for our master bedroom, as I will soon be opening the ceiling in the Living Room below for electrical and the plaster is shot, so I can easily run pex/plates and see how it works as a test. If it works well enough on the 2nd floor I can have confidence in rolling out the 1st floor. Otherwise I’ll know I need to invest in the pricey plates. Sound about right?

Curious about your meaning on “some houses” can’t be heated by radiant alone.

I really appreciate you guys taking the time. I’ll keep you posted on my progress!

B

Zman

It would help if your heat loss was room by room rather than just the total. According what you are calculating, your house is not a great candidate for radiant in general. The highest I have seen in zone 7 has been 31 btu/ft and that was an absolute mansion with huge windows built on the side of a cliff @ 9,700 ft.

I would suggest trying a different heat loss program. The US boiler one gives you very few input options. Have you tried slant fin?

Back to your original question, the omega plates may get noisy, especially if you run them at higher water temps. I think I would be comfortable with the less expensive option if you have a heat loss off <20 btu/ft. That is a SWAG based on experience.

hot_rod

Try this calculator for a check on your numbers. Room by room is the best way to calculate.

https://www.slantfin.com/slantfin-heat-loss-calculator/

I would certainly do what you can to tighten up the home, a blower door test is really the only way to know that number. The more you insulate the more you save over the life of the building.

If the heat load for the room exceeds the amount a radiant floor can provide, it may not be a good radiant application.

Radiant ceilings and radiant walls are another option. Higher btu/ sq ft output and sometimes easier to retrofit. Thin plates work fine in ceilings and walls as they are encapsulated in the assembly, no movement.

PersonallyI feel radiant floors in a bedroom are a bit silly, much of the room is covered with the bed and furnishings. You probably don't spend enough time in there to appreciate the warm floors?

I'd do my next home with panel radiators, radiant floors in the kitchen and bathrooms only.

Panel rads with TRV give you room by room heat control, quick heat up, simple installation.

RetrosPex

The thicker plates do a better job of transferring heat to your floor. They are easier to keep tight to the floor, don't make noise, and do a much better job of reducing hot spots. One of the suppliers of thicker plates has case studies and videos on line that show you thermal proof and comparisons. Do a bit of searching.

HotRod pretty much gave you the bottom line. I used the thinner plates in my first couple jobs, and have switched to the newer, much thicker ones. You could get by with fewer of them that put more heat into the floor.

There are buildings and situations where it just isn't practical to use them for all your heating. When I built our latest addition I planned on all underfloor heat, with the thick plates. I've adapted my plans, bought Caleffi manifolds, and am going with less of the plates, but supplementing with wall mount, thin European radiators. And also using some of the smaller wall mount radiators underneath our towel bar racks, to heat the towels, and the nearby tub or tile shower. Less expensive than those dedicated towel bar warmers. This is just an example of different ways to accomplish the same purpose.

Good luck.