ᐅ Installing a Mechanical Ventilation System with Heat Recovery Yourself: Timeline and Costs?
Created on: 12 Jan 2016 12:57
A
andimann
Hi everyone,
We will be building in a few months. The building permit / planning permission was submitted last year to take advantage of the previous energy-saving regulations. So far, so good.
Originally, we planned to build without a mechanical ventilation system with heat recovery. Based on our experience in our current house, we considered such a system unnecessary.
However, for various reasons, we are now reconsidering. A mechanical ventilation system with heat recovery will never really pay for itself, but as a comfort upgrade and to improve marketability in case of a future sale, it might be worthwhile after all.
We are talking about a central system with heat recovery for nearly 180 sqm (approximately 1,940 sq ft) of living space over two floors plus basement.
The general contractor is quoting completely insane prices. I’m still waiting for the detailed offer, but initial estimates were between 15,000 and 18,000 Euros (around 10,000 to 12,000 USD, depending on exchange rate) for a system from Helios, and even more with the basement. So, a classic deterrent offer...
In a thread here, I came across a supplier who designs, plans, and assembles the materials for these systems, delivering everything ready for installation. The installation itself would then be done by us. According to the advisor, it’s truly no rocket science and for a house of this size, two people could easily do it in 4-5 working days (which equals 8-10 man-days).
It would also be a Helios system (specific model to be confirmed) with about 6-7 supply air and 6-7 exhaust air ducts. Installation is done within the impact sound insulation layer, that is, on top of the finished concrete ceiling. The supplier also provides plans for the necessary ceiling penetrations etc., so these can be incorporated directly during the concrete pour.
What caught my attention was his initial rough price estimate for the materials, which was about one-third of the general contractor’s price. So for around 10,000 Euros (about 11,000 USD), I might just take a week off work...!
But is it really that simple? This is a trade that happens right in the middle of construction, so our own work must be absolutely punctual, otherwise the overall schedule collapses...
My question is: How realistic is it to install such a system yourself within one week?
Has anyone done this before and could share some of their experiences?
Best regards,
Andreas
We will be building in a few months. The building permit / planning permission was submitted last year to take advantage of the previous energy-saving regulations. So far, so good.
Originally, we planned to build without a mechanical ventilation system with heat recovery. Based on our experience in our current house, we considered such a system unnecessary.
However, for various reasons, we are now reconsidering. A mechanical ventilation system with heat recovery will never really pay for itself, but as a comfort upgrade and to improve marketability in case of a future sale, it might be worthwhile after all.
We are talking about a central system with heat recovery for nearly 180 sqm (approximately 1,940 sq ft) of living space over two floors plus basement.
The general contractor is quoting completely insane prices. I’m still waiting for the detailed offer, but initial estimates were between 15,000 and 18,000 Euros (around 10,000 to 12,000 USD, depending on exchange rate) for a system from Helios, and even more with the basement. So, a classic deterrent offer...
In a thread here, I came across a supplier who designs, plans, and assembles the materials for these systems, delivering everything ready for installation. The installation itself would then be done by us. According to the advisor, it’s truly no rocket science and for a house of this size, two people could easily do it in 4-5 working days (which equals 8-10 man-days).
It would also be a Helios system (specific model to be confirmed) with about 6-7 supply air and 6-7 exhaust air ducts. Installation is done within the impact sound insulation layer, that is, on top of the finished concrete ceiling. The supplier also provides plans for the necessary ceiling penetrations etc., so these can be incorporated directly during the concrete pour.
What caught my attention was his initial rough price estimate for the materials, which was about one-third of the general contractor’s price. So for around 10,000 Euros (about 11,000 USD), I might just take a week off work...!
But is it really that simple? This is a trade that happens right in the middle of construction, so our own work must be absolutely punctual, otherwise the overall schedule collapses...
My question is: How realistic is it to install such a system yourself within one week?
Has anyone done this before and could share some of their experiences?
Best regards,
Andreas
Why should that be the case?
For the basement floor, sure, no question.
But for the ceiling between the ground floor and the upper floor? That’s all within the same thermal zone. The air temperature on the ground floor is 20°C (68°F), the air temperature on the upper floor is also 20°C (68°F), and the concrete ceiling temperature is also 20°C (68°F). The ceiling is heated one way or another—either from the underfloor heating above or from the room heat below (and thus from the underfloor heating on the ground floor).
Yes, with temperature changes and large temperature differences, insulation might have an effect. Insulation ensures that you can have a lower temperature on the upper floor compared to the ground floor at all. In reality, you won’t see differences greater than 2 to 3°C (4 to 5°F).
During heating up, insulation obviously helps heat move upward into the room faster, so the system responds more quickly. Okay, I accept that!
But in the medium term, a temperature equilibrium is established, and the concrete ceiling will warm up simply because it’s heated from the floor below. Since warm air rises, the concrete temperature might even be slightly higher than the room temperature beneath it.
I understood this better when underfloor heating used high supply temperatures in the past. But today, it mostly runs at around 30°C (86°F)—only about 10 degrees above room temperature.
Shouldn’t 30–50 mm (1 to 2 inches) of insulation be more than enough for that?
So why use 120 mm (5 inches) of insulation under the screed on the upper floor, as Oleda222 does? That’s even more than what was used a few years ago for external insulation! And there the temperature difference to cover is up to 40°C (72°F), not just 10°C (18°F).
There must be a reason, but right now, I don’t understand it…
Best regards,
Andreas
Masipulami schrieb:
Without insulation, the underfloor heating wouldn’t work effectively.
For the basement floor, sure, no question.
But for the ceiling between the ground floor and the upper floor? That’s all within the same thermal zone. The air temperature on the ground floor is 20°C (68°F), the air temperature on the upper floor is also 20°C (68°F), and the concrete ceiling temperature is also 20°C (68°F). The ceiling is heated one way or another—either from the underfloor heating above or from the room heat below (and thus from the underfloor heating on the ground floor).
Yes, with temperature changes and large temperature differences, insulation might have an effect. Insulation ensures that you can have a lower temperature on the upper floor compared to the ground floor at all. In reality, you won’t see differences greater than 2 to 3°C (4 to 5°F).
During heating up, insulation obviously helps heat move upward into the room faster, so the system responds more quickly. Okay, I accept that!
But in the medium term, a temperature equilibrium is established, and the concrete ceiling will warm up simply because it’s heated from the floor below. Since warm air rises, the concrete temperature might even be slightly higher than the room temperature beneath it.
I understood this better when underfloor heating used high supply temperatures in the past. But today, it mostly runs at around 30°C (86°F)—only about 10 degrees above room temperature.
Shouldn’t 30–50 mm (1 to 2 inches) of insulation be more than enough for that?
So why use 120 mm (5 inches) of insulation under the screed on the upper floor, as Oleda222 does? That’s even more than what was used a few years ago for external insulation! And there the temperature difference to cover is up to 40°C (72°F), not just 10°C (18°F).
There must be a reason, but right now, I don’t understand it…
Best regards,
Andreas
Reducing the two effects of sound transmission and the inertia of the underfloor heating (the ceilings have significantly more mass and steel) with an intermediate layer that is affordable and easy to install sounds reasonable to me. It also seems to be easier to achieve a smooth and even screed compared to concrete ceilings. Some companies offer alternative solutions with underfloor heating embedded directly in concrete ceilings. This topic can also be found here in the forum. However, this approach has not become widespread so far.
B
Bieber081513 Jan 2016 21:55andimann schrieb:
And their standard in the program is that if ventilation is installed, the floor construction height is immediately increased to 190 mm (7.5 inches). That would reduce the ceiling height in the upper floor to 245 cm (8 feet 0.5 inches) Can't you just "add a layer of blocks on top" to keep the desired ceiling height? That's how we do it...
Bieber0815 schrieb:
Can’t you just "add one layer of bricks" to maintain the desired room height? That’s how we did it... The building permit / planning permission has already been applied for, so an amendment would be necessary if the development plan allows it. That wasn’t the case for us, which is why on the ground floor we only have 2.43m (7 ft 11.6 in) up to the underside of the wooden beam ceiling.
B
Bieber081514 Jan 2016 06:26Hm, alright, that might be painful, but I would still do it (if there is a chance of success). After a few years, when you are still living in your house, you will have forgotten the hassle over the additional work, but the clear room height will remain.
I have also considered increasing the floor-to-ceiling height. However, since we are building with Poroton blocks, which only come in whole and half sizes, we would have to raise the height by at least 12.5 cm (5 inches). That’s already quite a lot on the upper floor. This would automatically require taller doors and windows, or else it would look very odd.
That would push the cost up by around 3500 €.
If quarter-sized blocks were available, I could simply raise everything by 6.25 cm (2.5 inches) all around and be done with it. That way, we wouldn’t need taller doors and windows.
I currently have a building permit (planning permission) in process where I’m already deviating from the building regulations by raising the house by 15 cm (6 inches).
The officials here are fairly relaxed about it, but I probably shouldn’t push my luck too much.
For now, I’ll try to pressure my general contractor to change the floor structure from
50 mm (2 inches) insulation
30 mm (1.2 inches) staple board
70 mm (2.8 inches) screed
10 mm (0.4 inches) tile/parquet
to
70 mm (2.8 inches) insulation
20 mm (0.8 inches) staple board
60 mm (2.4 inches) screed
10 mm (0.4 inches) tile/parquet
This is a cement screed, where 60 mm (2.4 inches) is apparently the standard thickness (with 40-45 mm (1.6-1.8 inches) coverage over the pipes).
Best regards,
Andreas
That would push the cost up by around 3500 €.
If quarter-sized blocks were available, I could simply raise everything by 6.25 cm (2.5 inches) all around and be done with it. That way, we wouldn’t need taller doors and windows.
I currently have a building permit (planning permission) in process where I’m already deviating from the building regulations by raising the house by 15 cm (6 inches).
The officials here are fairly relaxed about it, but I probably shouldn’t push my luck too much.
For now, I’ll try to pressure my general contractor to change the floor structure from
50 mm (2 inches) insulation
30 mm (1.2 inches) staple board
70 mm (2.8 inches) screed
10 mm (0.4 inches) tile/parquet
to
70 mm (2.8 inches) insulation
20 mm (0.8 inches) staple board
60 mm (2.4 inches) screed
10 mm (0.4 inches) tile/parquet
This is a cement screed, where 60 mm (2.4 inches) is apparently the standard thickness (with 40-45 mm (1.6-1.8 inches) coverage over the pipes).
Best regards,
Andreas
Similar topics